My Ultimate Guide
Here is a guide on when to plant, how to plant, and when to harvest.
There are so many variables and ways….hopefully this will help the beginner. This is a guide for starting and growing in Denver. Other areas you might have to adjust the dates.
When planting seeds or transplants, I always recommend using a root stimulator. Whether it be a liquid or granular, a synthetic or organic. Root stimulators will help heal the roots when transplanting and create more feeder roots which will get the plant off to a great start. Root stimulators are not mentioned in any of the how to grow but I strongly recommend them. I also recommend amending the soil before you plant. With our heavy clay soil or sandy soil, the roots need the tools to expand and be healthy. The roots are the foundation of a plant. The healthier the roots the healthier the plant.
Artichoke
Grown for its tropical look and for its edible flower bud.
Sow inside 3-4 months before the last frost. January is a good month. Plant the seeds in a light weight seed starting mix ½ inch below the soil using a heating seed mat. The seeds need 70-degree soil temperature to germinate.
Plant outdoors around the middle of May after they have been hardened off. Plant them in compost rich, well drained soil. Careful when transplanting so not to disturb the tap root.
Grow in a sunny hot location with consistent water. Drought will promote premature flowering and soggy roots will encourage root rot.
Artichokes are heavy feeders so fertilize once a month with a organic fertilizer so as not to promote stress.
Harvest the flower bud just as it is starting to open. But the bud a couple of inches down the stem and fertilize to encourage side bud shoots.
If you let the artichoke bud flower, it will have a huge beautiful purple flower that encourages bees, pollinators and can be used in a cut flower arrangement.
Flower buds are best if eaten the day of harvest but can be stored for 1-2 weeks in the fridge. The unopened bud is the only edible part of the plant.
Companion plants; peas, cabbage, sunflowers and tarragon.
Arugula
A leafy early or late season green. Grown to add to salads for its peppery kick.
Directly sow out side 4-6 weeks before the last frost. Usually the first of April.
Not recommended to start inside because most varieties like cool temperatures and need a lot of sunshine or they will bolt faster.
Grow with at least 6 hours of sunshine.
Fertilize with a organic fertilizer to prevent a quick growth which will lead to it going to seed faster.
Start to harvest when the plant is young pulling or cutting away a few leaves off of each plant letting the other leaves grow.
Seed a fall crop the first to the middle of August.
Harvested leaves will last a week in the fridge.
Companion plants; lettuce, beets, onions celery, spinach, beans, dill, garlic, kale, radishes, cucumbers, cabbage and carrots.
Do not plant next to any night shade like tomatoes, potatoes, peppers, and eggplant.
Beans
Green beans and string beans are one in the same. When picked young or the variety that you have chosen will not have strings. The trait has been carefully been bred out, however some heirloom varieties still have the trait. Beans come in bush form or pole varieties. Bush beans provide a 3–4-week bumper crop so in Colorado should be planted in two different planting times to take advantage of the season. Pole varieties produce a steady crop all season.
Directly sow seeds the middle of May or the first of June. Beans won’t germinate until the soil is warm.
Starting inside trying to get ahead start is not recommended because they won’t transplant well and perform better when directly sown. When the soil temperature is warm, they germinate and grow rather quickly.
Direct sowing the seed outside, plant them a couple seeds per hole and 4-5 inches apart in a compost emended soil. Using a inoculant is not necessary, but the bacteria works with the roots to create nitrogen helping the overall health of the plant.
Plant them in a area that gets at least 6 hours of sun.
Fertilizing isn’t necessary because beans being part of the legume family will create their own nitrogen. Adding additional fertilizer will not increase production but increase leaves instead of flowers and beans.
Harvest the beans when they are around 4 inches in length, just as the beans start to form in the pod.
Once they start to produce, check and pick 3-4 times a week. Beans grow rather quickly and picking them on a regular basis will encourage the plant to reproduce, flower and produce more beans.
Beans flavor is highest at harvest but can be stored up to a week in the fridge. If wanting to store for longer periods, you can or blanch and freeze for later consumption.
Plant with broccoli, Brussel sprouts, cabbage, carrots, cauliflower, celery, peas, corn, kale, tomatoes, eggplant, radish and squash.
Do not plant with beets, onions, peppers, leeks, chives and sunflowers.
Beets
Beets are used for their leaves and roots. The leaves and stems can be cooked or eaten raw. The roots can be pickled, cooked, and used in salads. They come in different colors and are rich in vitamins.
Starting inside is not recommended because root crops do not transplant well.
Direct sowing outside in a compost amended soil ¼ inch below the surface that has been worked deep so when the root starts to develop it will have room to grow. Sowing the seeds the end of March to the beginning of April.
The seeds sown are small and will need to be thinned unless you are just using the tops.
If wanting to do a fall crop sow the seeds the first of September. The seeds that are planted will be planted shallow so you want to make sure that they never dry out and a crust does not form on the top.
Fertilize a couple times a season using a organic fertilizer with the last two numbers high. They are for root development and disease resistance.
Harvest the leaves when they are a couple of inches and you can take half of the leaves without hurting the plant. The youngest leaves are better tasting.
The roots you can start to harvest when they get to be 3 inches in diameter depending on the variety. Don’t let them get too big or they will become woody tasting.
Beet tops should be eaten fresh or store for up to a week in the fridge.
Beets can be canned, pickled or stored in the freezer for up to a year.
Plant with bush beans, onions lettuce arugula, garlic, chives, marigolds, carrots, cucumbers, cabbage, radish, peas, broccoli, cauliflower, kohlrabi and kale.
Do not plant with pole beans and tomatoes.
Broccoli
Broccoli when harvested is a flower bud that hasn’t opened. A plant that is rich in vitamins, it prefers the cool over hot and should be planted early and can be planted for a fall crop.
Starting them inside for a head start should be done in February, hardened off and planted in April carefully so not to stress the plant and be prepared to cover in case of extreme cold.
Direct sowing should be done the middle of March through mid-April. Direct sowing takes more patience but will give the plant less stress and the plant will respond better.
Seeds should be planted ¼ to ½ inch below the soil and not dry out.
The soil should be amended with a good compost.
Fertilize the plants with a good organic fertilizer with even numbers. Once or twice is all they need.
Being stressed whether it be from cold, drought or heat will lower production.
Harvesting can be done when the main flower bud starts to swell but before the flowers start to open. The side shoots will then grow and can be harvested the same way.
Eat them fresh or blanch and freeze for later.
Plant with onions, dill, cucumbers, beets, potatoes, radish, beans, carrots, spinach, rosemary, basil and summer squash.
Do not plant with nightshades like tomatoes, peppers, and eggplants. Also do not plant other brassicas because of the competition for nutrients.
Cabbage
Cabbage is a biennial that comes in all shapes, colors and sizes. Since it is a biennial, to harvest the seed you will have to wait until the second year. It is recommended to stagger your crops since you harvest the whole plant at one time.
Starting them inside is recommended and is usually done the middle of January to the middle of March with the help of a seed starting mat.
Planting 2-3 seeds ¼ - ½ inch below the surface using a good lightweight sterile seed starting mix.
Transplant them after hardening them off starting the middle of April.
Direct sowing can be done in March and will come up naturally with less stress but you have to have patience and you don’t get as many crops. Direct sow seeds the first of August for a fall crop.
Cabbage should be planted in a soil that has been amended well with a good compost. Their roots are very shallow and shouldn’t dry out. Cabbage heads are 90% water so it needs to be watered frequently to produce nice heads.
They do not like temperatures over 80 degrees. They also like at least 6-8 hours of sunshine. That is why cabbage grows so well in Alaska because of the temperature, moisture and the amount of sunshine.
Cabbage are high feeders and should be fertilized a few times throughout the growing season using a balance organic fertilizer like 1-1-1, 2-2-2, 5-5-5…you get the idea.
Harvest the heads when they are firm all the way through (usually 80-85 days after planting). If you are unsure, wait a few more days.
They store well when stored in a cool place. Put them in the crisper or in a plastic bag in a cellar type situation. Too warm and in a plastic bag will encourage fermentation.
Your fall crop will have smaller heads.
Plant with onions, garlic, lettuce, arugula.
Do not plant with tomatoes, potatoes, peppers, eggplant and other brassicas because of the competition for nutrients.
Carrots
Carrots come in different colors and like cabbage, if you want to harvest seeds you have to wait until the second year. They are also a biennial.
Starting carrot seeds inside is not recommended because transplanting them could hurt the roots.
Direct sowing out side is best in a well tilled soil for better root development in soil that has been well amended with a good compost.
Sow the first part of April ¼ inch below the surface should never dry out and the top should never crust over.
Fertilizing should be done prior to seeding with a ratio of 1-2-2, 5-10-10…you get the idea. You want roots not tops. It likes to be planted in raised beds away from the hard clay soils.
Giving it 6 hours of sun, 8 hours is better.
Harvesting could be done after a couple of months.
Harvest some as you need them letting the rest grow and let Mother Nature keep the rest fresh even into the winter.
When harvesting make sure the soil is damp to make it easier to dig around and gently lift the carrots.
Carrots keep very well and for a long time. You can keep them in the crisper, the freezer, or leave them in the ground with a good deal of mulch on top so you can harvest in the winter.
Plant with beans, broccoli, chives, lettuce, arugula, peas, peppers, pole beans, and tomatoes.
Do not plant next to dill, parsnips, potatoes and space between other root crops because of the competition for root development nutrients.
Cauliflower
Cauliflower is a cool season veggie that is known to be low in carbs and grown in the early spring or as a fall crop. It can tolerate light frosts. Cauliflower is very similar to growing broccoli and is similar in the fact that you harvest the unopened plump flower bud.
Starting them inside for a head start should be done in February, hardened off and planted in April carefully so not to stress the plant and be prepared to cover in case of extreme cold.
Direct sowing should be done the middle of March through mid-April. Direct sowing takes more patience but will give the plant less stress and the plant will respond better.
Seeds should be planted ¼ to ½ inch below the soil and not dry out. The soil should be amended with a good compost.
Fertilize the plants with a good organic fertilizer with even numbers. Once or twice is all they need.
Being stressed whether it be from cold, drought or heat will lower production.
Harvesting can be done when the main flower bud starts to swell but before the flower opens up.
Each plant will produce one head which makes it easy when you want to freeze a bunch.
Plant with lettuce, arugula, dill, potato, thyme, onions, and garlic.
Do not plant with corn, cucumber, tomato, peppers, strawberries and squash. I also wouldn’t plant any other braccics next to them unless you fertilize heavily.
Celery
Celery is another biennial vegetable that if left to grow the second year you could harvest the seeds. It is a easy to grow as long as it doesn’t get too hot or cold and the stalks are shaded from the sun by something like a paper milk carton with both ends cut off and slid over the plant with the top sticking out.
Starting inside with a seed starting mat under it is recommended.
Sowing the seed ¼ inch below the lightweight seed starting mix in January or February works best.
Direct sowing outside isn’t recommended unless you have patience and the weather cooperates.
Transplant starts outside the middle of May to June after the soil has warmed up. The soil should have been amended with a good compost and the plants should be fertilized a few times over the course of the growing season with a ratio of 1-2-2.
Celery is 90% water so never be stingy if you want a good crop.
Use something to protect the stalks from the sun keeping them white, crisp and not green tasting.
Harvest should be ready late August.
Cut the celery right below where the stalks come together and store in the fridge crisper. Wrap the stalks with aluminum foil for best results and use within 4-6 weeks.
Plant with beans, tomatoes, radishes, lettuce, arugula, spinach, peppers, kale and others that need more than usual water.
Do not plant with parsnips, parsley, carrots and turnips because they will compete for nutrients.
Chard
Swiss chard and rhubarb chard is a easy leafy vegetable that is closely related to beets and used like spinach. Chard is an easy to grow cool weather salad leaf that will sometimes come back the following year. Chard will produce all summer.
Sowing and starting indoors is not recommended because the roots are sensitive to transplant shock when moved outdoors.
When sowing outside the first crop should be planted in full sun for good germination. The second crop to be planted in part sun for good germination.
Sow the seed ½ below the well compost emended soil.
Fertilizing with a fish emulsion is recommended every few weeks.
Chard is 95% water and has shallow roots and should be watered frequently to prevent the soil to dry out.
Harvesting can be done multiple times picking the outside leaves and adding to or making a salad.
Cut the outside leaves and do not let the leaves get too big that will have a green taste instead of a crisp taste. When used as salad fresh leaves work best or kept in a fridge crisper. Chard can be blanched and frozen then be used in soups.
Plant with tomatoes, peppers, cucumbers, basil, squashes, pumpkins, beets, onions, lettuce and broccoli.
Do not plant with potatoes or corn. The two will compete for the same nutrients
Corn
Corn is as much American as apple pie, but it takes a lot of room and it if your neighbor plants corn it is hard to eat the variety that you planted because corn is wind pollinated and should be planted a ways away from your neighbors. Some people say 250 feet away. Sweet corn and Flint corn (Indian and popcorn) are the most popular varieties grown in backyards.
Sowing corn inside isn’t necessary but you can get more satisfaction when you transplant the seedlings outside.
To stagger your crops, start one crop inside the middle of April with 2 seeds per container then the middle of May direct sow another crop following another direct sow crop the middle of June.
When planting outside the seeds should be 1 ½ - 2 inches below the soil, plant 12 inches apart, and plant your crops in blocks for better pollination so that your ear of corn will be full.
When the ear starts it will have the silk which is attached to a potential kernel of corn if pollinated.
Fertilizing corn with a 2-1-1 balance using a slow-release fertilizer and following another shot of fertilizer 6 weeks later will help the plant grow, tassel and set seed.
Corn is a shallow rooted crop that is a heavy feeder and needs a lot of water.
Corn is a member of the grass family and will require the same requirements.
Harvest sweet corn starting about 3 weeks after the silks appear. The silks will be brown, the foliage still green and the feel of the ear will be plump. To test to see if they are ready to pick, gently pull back the husk and test a kernel. If the kernel is popped and the liquid is white, you can pick. If the liquid is clear wait a few more weeks.
If you are growing popcorn or Indian corn, let the ears dry on the stem. When the kernels are hard pull the ear from the stalk, peel away the husk and dry for 4-6 weeks.
Sweet corn can be frozen and stored in the freezer and the popcorn stored in a dry place out of the sun.
Corn has shallow roots and can get quite tall so when growing you might think of staking before they get too tall.
Plant with cucumbers, squash, beans, pumpkins, tomatoes, peas and melons.
Do not plant with brassicas like cabbage, brussels sprouts, broccoli and cauliflower. The corn will shade and there will be too much competition for nutrients and water.
Cucumbers
Cucs are easy to grow in Colorado at elevations of 5500 and below. A vine that will need support to keep it contained and keep it off the ground.
Cucumbers and other vining vegetable are usually sensitive to transplanting and should be direct sowed outside where they will do better and grow quicker than transplanted because of the stress.
If wanting to start inside start them the middle of May in a lightweight sterile seed starting mix, planted ½ deep and 2 seeds per pot, planning on planting the seedlings when they have their first 2 leaves the beginning of June when the soil temp is starting to rise.
If transplanted too early the seedling will struggle and be stunted.
Direct sow cucumber seeds the first of June. The seeds will need warm soil to germinate and June is the time that the soil will be warm enough.
Remember that cucumbers are fast growers and do not like the cold soils. Don’t push it because you will get discouraged. Take your time and enjoy, don’t rush it and fail.
The soil that they are planted in should be rich in compost and well-draining. They would rather be planted in raised beds away from the compact clay soil.
Plant them in a area that gets 6-8 hours of sun.
Fertilize cucumbers with a 5-10-10 or a 10-10-10.
Cucumbers have a shallow extensive root system so careful with fertilizing too much around the plant.
They are sensitive to burn. Water is important at any stage of life with a cucumber. The fruit is 95% water. Not enough water will result in bitter fruit.
Maybe consider mulching around the plant for moisture retention.
Harvest the fruit at any size by cutting the stem instead of pulling at the fruit. Harvesting on a regular basis not letting the fruit get too big will result in the plant keep trying to set seed and produce more fruit.
Cucumbers will produce male flowers first before the female flowers resulting flowers but no fruit.
As the plant gets older, they will have both flowers and start to produce fruit.
Plant with corn, onions, garlic, squash, chives, peas and radishes.
Don’t plant with potatoes, tomatoes, broccoli, cauliflower, and peppers because of the competition for nutrients and the attraction of some diseases.
Eggplant
Eggplant is a frost sensitive vegetable that is also grown in beds next to other flowers because of the large star shaped lavender flowers the plant produces or grown in containers on the patio.
Starting eggplant in Colorado is recommended the months of February and March.
Direct sowing is not recommended because the seeds need warmth to germinate and the growing season is long.
Sowing them inside using a heat seedling mat. Use a lightweight, sterile seed starting mix planting the seeds ½ below the soil.
Eggplant does not like the cold or cold soil so transplant them outside the first part of June using the last part of May as a hardening off period.
Transplant them in a area that gets at least 5-6 hours of sun.
Planting them in pots will warm the soil quicker and can be moved around the yard.
Fertilize a couple of times a growing season using a balance fertilizer 1-1-1, 10-10-10, 20-20-20.
Eggplant needs lots of water. The fruit contains 90% water and if not watered or fertilize often the plant will not produce or the production won’t be as good.
Harvest eggplant the month of August. Harvest when the skin is glossy before the skin dulls. The younger smaller fruit is the best tasting. Harvesting often will get the plant to keep trying to set seed producing more flowers and fruit.
When harvesting cut the stem a inch above the fruit and not pull from the plant.
Plant with tomatoes, onions, garlic, spinach, arugula, lettuce, peppers, and potatoes.
Do not plant next to squash, broccoli, brussel sprouts, and cauliflower because of the competition for nutrients.
Garlic
Garlic is a edible bulb that is usually separated into two categories being soft neck and hard neck. Garlic is easy to grow and it doesn’t take up much space. It is easy to store. You don’t have to can it or freeze it, you just keep it in a shaded cool area like a root cellar or the garage. You can plant it between other plants to keep away rodents and insects and in a lot of instances it can increase yields of other veggies you are growing. Growing your own garlic will beat any garlic that you can buy at a super market. Once you taste the difference you won’t turn back.
Plant garlic cloves in the fall in the months of October and November.
Water well so they will set down roots before the ground freezes it.
Garlic needs a period of cold to produce a garlic bulb.
If planted in the spring you will get all tops and no bottoms.
Soft neck garlic can be planted in the spring if planted early enough like February or March.
Garlic cloves should be planted 2-5 inches below the soil remembering how much water it takes to soak 5 inches into the soil.
Garlic needs a 2-1-1, 10-5-5, 20-10-10 organic fertilizer a couple of times throughout the season. The soil should be amended with a good compost at least 6 inches to give the bulb room to grow.
Planted in areas that get 6-8 hours of sunshine it is recommended to be planted near other plants to repel insects.
As the garlic flowers forming scrapes that should be cut so the energy goes into the bulb.
The scrapes can be used in producing garlic salt, other herbal salts or in pesto.
Harvest is done in July when the tops start to die down.
Gently lift the bulb without pulling. Shake off the dirt off cure by putting in a dry dark area and store in a netted bag.
Plant next to almost everything except peas, beans, asparagus, sage and strawberries because garlic will reduce production and stunting the growth.
Kale
Kale is one of the easiest leaf greens you can grow and is full of nutrients and vitamins. You can start it inside and transplant outside or direct sow outside. Kale is a cabbage that doesn’t actually form a head and can be used as a substitute for cabbage in things like cole-slaw. Kale is another biennial vegetable that flowers and sets its seed the second year if you are collecting your own seeds.
Start kale inside using a sterile, lightweight seed starting mix, planting the seeds 2-3 seeds per cell ¼ inch below the surface.
Most seeds you will use a heat seed starting mat for quicker germination that warms the soil.
Starting leafy greens like kale or lettuce it is not recommended to use because too warm of soil will reduce germination of things like kale and lettuce.
Starting a few crops a few weeks apart starting the beginning of March will space your harvest.
Leafy greens like kale and lettuce like the cool but not cold weather and can be transplanted outside in April.
Direct sowing can be done in March into a well tilled bed amended with a good compost.
When the soil warms the seeds will come up with less stress and less work than transplanting starts but only if you have patience.
You can grow them in the ground or in pots that are at least 12 inches in diameter.
The planted pots can take direct full sun in the early spring and can be moved to a cooler shaded spot when the temperature gets hot.
Kale is part of the brassica family along with broccoli, cabbage and cauliflower and are heavy feeders.
Fertilize with a organic slow release fertilizer with a 2-1-1 ratio. The first number represents nitrogen which will give you leaf growth which is what you harvest.
Kale needs a lot of water to keep their leaves tasting good.
Harvest when the leaves get to be 3-4 inches long. The young leaves are the best.
Start a fall crop by direct sowing the first of August.
Plant with tomatoes, beans, hot peppers, onions, garlic, chives and leeks.
Do not plant with other brassicas like broccoli, cauliflower and cabbage. All of these will attract the same certain pests and will compete for the same nutrients.
Lettuce
Lettuce is a leafy green that some varieties will form a head and others leaves. They can come in different colors and textures. Greens are easy to grow with the right lighting, fertilizer, and temperature. Most lettuce likes to grown at a cooler temperature and struggle causing it to go to seed when the temperature gets warm.
Start lettuce inside using a sterile, lightweight seed starting mix, planting the seeds 2-3 seeds per cell ¼ inch below the surface. Most seeds you will use a heat seed starting mat for quicker germination that warms the soil.
Starting leafy greens like kale or lettuce it is not recommended to use because too warm of soil will reduce germination of things like kale and lettuce. Starting a few crops a few weeks apart starting the beginning of March will space your harvest.
Leafy greens like kale and lettuce like the cool but not cold weather and can be transplanted outside in April.
Direct sowing can be done in March into a well tilled bed amended with a good compost.
When the soil warms the seeds will come up with less stress and less work than transplanting starts but only if you have patience.
You can grow them in the ground or in pots that are at least 12 inches in diameter.
The planted pots can take direct full sun in the early spring and can be moved to a cooler shaded spot when the temperature gets hot.
Fertilize with a organic slow release fertilizer with a 2-1-1 ratio. The first number represents nitrogen which will give you leaf growth which is what you harvest. Lettuce needs a lot of water to keep their leaves tasting good.
Harvest when the leaves get to be 3-4 inches long.
Using the cut and come again method of harvesting can get you a crop of greens every week to ten days. This method is used by giving the tops a haircut, leaving 2 inches and letting the bottom regrow getting new growth after each haircut.
The young leaves are the best.
Start a fall crop by direct sowing the first of August.
Lettuce is best to use fresh and can be stored in a crisper and kept for up to a week.
Lettuce is a great companion plant for everything except the brassicas like cabbage, broccoli, cauliflower and kohlrabi. These plants will not only outcompete for nutrients but will also prevent germination in lettuce.
Melons
People think that it is difficult to grow cantaloupe or honeydew melons in Colorado. It isn’t that difficult when done right but it is the space that it takes up for the produce that you get. Some of the best areas to grow melons is in the southern part of the state. Growing melons on a trellis is a great space saver with a little bit of training of the plant.
Melons need a long growing season and also do not transplant well because of the disturbance to their roots. Keeping that in mind when starting inside use a pot that will decompose like a peat pot. Use a lightweight sterile seed starting mix, plant 2-3 seeds per pot ½ inch into the soil with a warm seed starting mat underneath the seed tray.
Start your melons the first part of May on the intent of transplanting outside the middle to the end of May once the soil warms up and you have hardened off the seedlings.
If direct sowing outside use something like a wall-o-water that will warm the soil, and protect the seedling as it starts to grow outside without any transplant shock and still get a long growing season.
Set the wall-o-water up the middle of April and plant your seeds ½ inch below the soil the first of May. The wall-o-water works like a mini greenhouse heating and trapping the heat, warming the soil which protects the plants even if it freezes for a couple nights in a row. It does not water the plant.
Melons should be planted in light well drained soil that is rich in organic material. Raised beds work well.
Melons need 8-10 hours of sunshine a day to keep the soil warm.
Melons are high feeders and should be fertilized in the beginning with a 2-1-1, 10-5-5 etc. ratio for growth then a 1-2-2. 5-10-10 etc. ratio to form the flowers and fruit.
Melons like a lot of water and as the fruit starts to ripen, lighten up on the water to prevent splitting.
Strong healthy leaves and vine will help the fruit with a good sugar content leading to a great tasting melon and not bitter. Watering and fertilizing is important for this.
Leaving the fruit on the vine until harvest is best. Look for the tendril attached to the fruit to tell when to pick. When it starts to turn brown and the melon has a hollow thump sound it is time.
Fruit should last in the fridge for 2-3 weeks after harvest.
Plant with onions, garlic, lettuce, arugula, basil, carrots, chives, beans, broccoli and cabbage with melons.
Do not plant with cucumbers, squash, tomatoes, peppers, potatoes and pumpkin.
Onions
Onions are cool-season crops that prefer colder temperatures. Most often, onions will be planted in early spring and harvested in late fall.
Sowing seeds inside should be done in January to be put out in April.
Start seeds in a lightweight, sterile seed starting mix ¼ inch below the soil.
Direct sow seeds outside the first of March ¼ inch below the soil.
Most beginners will use starts or bulbs to get started. The starts or bulbs will give you a head start and make it easy for the first-time gardener.
After amending the soil with a good compost 6 inches down, the bulbs and starts are planted 3-4 inches below the surface to give the bulb room to grow.
Use a well-balanced fertilizer, 1-1-1, 5-5-5. 10-10-10 etc. to start then a 1-2-1, 5- 10-5 later not needing fertilizer late in the season.
You can harvest onions at any time. There is no perfect size, just pull when they are big enough to suit you.
For a full-sized bulb, let onions grow and mature. They are ready to harvest when the bulbs are big and the tops begin to turn yellow and fall over. Pull them up shake off the soil, and lay them out to cure with the tops still attached.
You can harvest onions at any time the bulb reaches a useable size, but for storage, you want them fully mature.
Curing the onions is as simple as leaving them out to dry after you dig them out of the ground. After you have shook off the dirt, spread them out on a dry surface out of the sun for a couple of weeks until the necks are dry and the skin is papery.
After they are cured, store the onions by cutting of the top and storing them in a net bag so air can get to them.
Hang them out of the light and out of any extreme heat or cold.
If there are any soft ones use them up first. Keep them separated from the others so if there is a bacteria on it it won’t spread to the others. They are still ok to eat.
Plant with arugula, lettuce, tomatoes, squash, pumpkin, peppers, cucumbers and others. Onions will help repel insects.
Do not plant with beans, peas or other legumes. Onions can kill the helpful bacteria that grows on legume roots stunting their growth.
Peas
Snap peas have both sweet, edible pods and tender peas when the pea is fully developed. Shelling peas are grown for the large, sweet peas that form in the pod and are shelled. The pod is not eaten. Snow peas have a sweet, edible pod with small peas inside that are used in salads and stir-fries.
Sowing peas inside for transplant outside is not recommended because the vine does not transplant easily and peas like it on the cooler side.
Sowing peas outside in a compost rich fertile soil in mid-March.
Plant the seed an inch into the soil in a bed that has 6-8 hours of sun and you should set up some kind of support that the peas can grow on.
Pea vines grow so fast that it is best to set it up beforehand.
Soaking the peas in water for 6 hours before you sow is not necessary but speeds up the germination process by softening the outside shell.
When planting peas it is recommended to use a inoculant. The bacteria will help the plant produce its own nitrogen and fertilizing isn’t necessary as long as the bed is rich in good compost to begin with.
Peas like a lot of water but do not like their feet soggy.
Harvest snow peas when the seeds start to form, shelling peas and snap peas when the pod is full and plump using a scissors to cut the pod off the vine.
Checking and harvesting often will keep the vine producing longer as the plant will continue to try and reproduce.
Peas can either be eaten fresh or after they have been blanched, frozen for later use.
Plant with tomatoes, peppers, cucumbers, squash, beets, and carrots.
Do not plant with onions, garlic, or leeks because these plants will interfere with the legume growth.
Peppers
You can write a book on peppers so lets keep it simple to start. Peppers are classified as sweet and hot. Peppers take a long time to grow, flower and set fruit so direct sowing outside in Colorado is not recommended.
Sowing and starting peppers is usually done in January.
Sow the seeds ½ below the soil using a sterile, light weight soil. Using a seed starting heat mat is also recommended to get a quicker germination.
Peppers like a warm soil.
Because you are growing the pepper so long inside you will need to fertilize. The seed itself contains enough food for the seedling until it reaches the second set of leaves then use a even balanced fertilizer like a 1-1-1 or 10-10-10 in a water soluble type fertilizer that is mixed with water.
Because peppers like warm soil, transplant the seedlings outside the first part of June. Planting too early could stunt the plants growth.
Peppers are high feeders so use a balance fertilizer after they have been transplanted outside.
Once the plants are at the size you want, I would change fertilizers to a 1-2-2 or 5-10-10 for flowering.
The plants will start to flower at a young stage. I like to get growth from the plant first before I let the plant flower and fruit. If it sets fruit when it is small the plant will put a lot of energy into the fruit.
I pick the flowers and encourage growth until it gets to the size I want and then let it flower and set fruit. In the end you will get more fruit.
Peppers will change color when the fruit ripens. Picking some of the fruit early will send a message to the plant that it needs to continue to flower to reproduce and your result will be more fruit.
If you are growing hot peppers, stressing the plant by watering less creating a drought situation. Not letting the plants wilt but giving it less water will create a hotter pepper.
Plant with tomatoes, carrots, onions, garlic, squash, pumpkins, lettuce, arugula and cucumbers.
Do not plant with broccoli, cauliflower, brussel sprouts and kale. These plants will compete for nutrients.
Pumpkins
Pumpkins are a type of winter squash that is grown and harvested the same. Pumpkins come in different sizes and shapes. They can be used in breads, casseroles, soups, deserts or just for decoration.
Sowing inside is not recommended because they do not transplant very well.
If you still want to try, start them inside ½ inch below the soil with three seeds. Use a sterile, lightweight seed starting mix. You do not want them to get too big inside so I would start them mid-May and transplant them outside the first of June after they have been hardened off for a couple days. The seedlings should only have their first set of leaves.
Another way to start them early is to use a protection like the wall-o-water and directly sow in the ground with the wall-o-water over the top. You can use this method the first of May.
Pumpkins grow fast. I like to recommend direct sowing without protection the beginning of May. As the soil warms up the seeds will sprout and grow fast. So fast that it usually will grow, catch up to and surpass the transplanted seedlings.
Pumpkins are heavy feeders and should be fed with a well-balanced slow-release fertilizer early like a 1-1-1 or 10-10-10 and fed mid-season with a 1-2-2 or 5-10-10 for flowering and fruit setting.
Pumpkins are 90% water so watering on a regular basis is important all the way until harvest. Watering should be done from underneath and not from overhead. Water on the leaves, high humidity and temperature with no breeze is a good combination to create a fungal problem.
Harvest before the first frost or when the leaves and stems start to turn brown.
When harvesting cut the stems leaving a couple of inches looking like a handle but never use the handle to carry a pumpkin. Breaking the handle or bruising of the pumpkin can prevent a long shelf life.
Plant with other squash, tomatoes, peppers, corn, beets, lettuce, arugula, potatoes, mint, onions and garlic.
Do not plant with cabbage, broccoli, kale, brussel sprouts, or cauliflower. Both are high feeders and will compete for nutrients.
Radishes
Radishes are a very fast-growing crops that can be planted every two weeks, be planted in between other crops and harvested quickly so as not to disturb those crops. They prefer a cooler temperature to grow verses warm weather where they get all top and little bottom. Spring/summer radishes like cherry belle take only a few weeks to grow and harvest but fall/winter radishes like watermelon and daikon take up to 10 weeks in the fall to produce a edible root that are larger and can be stored for the winter.
Because radishes are a root crop that doesn’t transplant well and since they grow fast, they are not recommended to start indoors.
Sowing outside is done the middle of March and crops are planted every couple of weeks. Direct sow radish seeds ½ inch below the soil and thin to allow the bulb to develop.
Winter radish is planted at the same depth but planted the first of August.
Early crops should be planted in full sun and later crops can be planted more in the shade where it is cooler.
Fertilizing isn’t as important in Colorado as long as they are planted in a well compost amended soil. Radishes do not need a lot of nitrogen to grow and Colorado soils are naturally heavy in phosphate which they need to produce a nice root.
Keeping the soil moist is all they need.
Harvest can be done at any size but do not let them get too big because they will have a woody taste.
Radishes can be eaten fresh, stored for a couple of weeks in the fridge, pickled, fermented or frozen.
The tops and seeds can be harvested anytime and used for salads or sandwiches.
Winter radishes can be harvested at anytime and can get large without tasting woody.
Winter radishes can be left in the soil letting Mother Nature store them for you.
Be careful when harvesting when the ground is frozen so the tops don’t break.
Plant with tomatoes, peppers, beets lettuce, arugula, onions and garlic.
Do not plant with broccoli, cauliflower, kale and cabbage.
Radishes will sometimes attract bugs to these certain crops that are affected by bugs that eat their leaves.
Spinach
Spinach is a easy to grow cool weather salad leaf that will sometimes come back the following year. Spinach will produce all summer.
Sowing and starting indoors is not recommended because the roots are sensitive to transplant shock when moved outdoors. Starting inside will also be poor because of the warmth will prevent a good germination.
When sowing outside the first crop should be planted in full sun for good germination.
The second crop to be planted in part sun for good germination.
Sow the seed ½ below the well compost emended soil.
Fertilizing with a fish emulsion is recommended every few weeks.
Spinach is 95% water and has shallow roots and should be watered frequently to prevent the soil to dry out.
Harvesting can be done multiple times picking the outside leaves and adding to or making a salad.
Cut the outside leaves and do not let the leaves get too big that will have a green taste instead of a crisp taste.
When used as salad fresh leaves work best or kept in a fridge crisper.
Spinach can be blanched and frozen then be used in soups.
Plant with tomatoes, peppers, cucumbers, basil, squashes, pumpkins, beets, onions, lettuce and broccoli.
Do not plant with potatoes. The two will compete for the same nutrients.
Squash
Squash are usually classified into two groups. Summer squash (zucchini, straight neck) and Winter squash (acorn, buttercup, butternut, spaghetti, hubbard) which also include pumpkins. They can be used in breads, salads, casseroles, soups, deserts or just for decoration.
Sowing inside is not recommended because they do not transplant very well. If you still want to try, start them inside ½ inch below the soil with three seeds. Use a sterile, lightweight seed starting mix.
You do not want them to get too big inside so I would start them mid-May and transplant them outside the first of June after they have been hardened off for a couple days. The seedlings should only have their first set of leaves.
Another way to start them early is to use a protection like the wall-o-water and directly sow in the ground with the wall-o-water over the top. You can use this method the first of May.
Squash grows fast. I like to recommend direct sowing without protection the beginning of May. As the soil warms up the seeds will sprout and grow fast. So fast that it usually will grow, catch up to and surpass the transplanted seedlings.
Squash are heavy feeders and should be fed with a well-balanced slow-release fertilizer early like a 1-1-1 or 10-10-10 and fed mid-season with a 1-2-2 or 5-10-10 for flowering and fruit setting.
Squash is 90% water so watering on a regular basis is important all the way until harvest. Watering should be done from underneath and not from overhead. Water on the leaves, high humidity and temperature with no breeze is a good combination to create a fungal problem.
Harvest summer squash on a regular basis to keep the plant flowering and producing fruit.
Once the plant starts to flower and set fruit, check on a daily or bi-daily basis. You will be surprised what a day makes and the fruit will double in size over night.
Harvest winter squash before the first frost or when the leaves and stems start to turn brown.
When harvesting cut the stems leaving a couple of inches looking like a handle but never use the handle to carry a squash. Breaking the handle or bruising of the winter squash can prevent a long shelf life.
Curing winter squash is important by putting the harvested squash in the sun for a couple of weeks, without frost, will sweeten up the flavor and help preserve the squash.
Summer squash can be eaten fresh or frozen for later use.
Winter squash can be stored on the floor in a cool basement. Do not stack.
Plant with other squash, tomatoes, peppers, corn, beets, lettuce, arugula, potatoes, mint, onions and garlic.
Do not plant with cabbage, broccoli, kale, brussel sprouts, or cauliflower. Both are high feeders and will compete for nutrients.
Tomato
Tomatoes are usually classified as Determinant (bush varieties that ripen all at the same time) and indeterminant (tall vining varieties that that ripen produce and ripen all season long). In Colorado for me all of them are determinant. I never get an 8 foot tall plant. Our climate is too short to get tall season long producers.
Because our climate is so short, sowing inside is better than direct sowing, unless you use a wall-o-water.
Sowing inside using a lightweight sterile seed starting soil with a heating seed mat gets quicker, better germination. Plant the seed any time in the months of March or April ½ inch below the soil.
Direct sowing in April using a wall-o-water that had been set up a couple of weeks prior to sowing. The wall-o-water will heat the soil and the tomatoes will germinate and be protected by the wall-o-water. It doesn’t water the plant but acts like a mini greenhouse protecting the plant even if it freezes.
While the seedlings are young, they do not need to be fertilized. The seed has enough fertilizer for the plant until it gets to the second or third stage of leaves.
Use a good water-soluble fertilizer at half strength until it is hardened off and transplanted outside the middle of May into June.
Tomatoes grow fast so don’t be scared to wait until June to put out your tomatoes. Tomatoes do not like cold soil. It will stunt or slow them down.
It is easier to put up the supports when the plants are young than to wait.
Tomatoes are high feeders and should be fertilized often starting out with a good balanced fertilizer like 1- 1-1, 5-5-5, you get the idea. As the plant gets to the size you want let it bloom and fertilize with a 1-2-2 ratio. Colorado soils usually have enough phosphate for blooming but still need nitrogen which is the first number. Pick a fertilizer that has also calcium.
In Colorado with our temperature swings from daytime temps and night time temps and with the soil being wet and then dry, tomato fruit will develop blossom end rot. Especially in pots.
When watering tomatoes after they have been transplanted outside, I start by checking and watering every day while the plant is small. The soils usually dry out fast and the root system of a seedling isn’t extensive. As the plants grow, I water less times but deeper waterings.
Harvesting the fruit as it is changing colors is ok. Picking fruit often will get the plant to want to continue to reproduce and put out more flowers which turns into more fruit.
Plant with peppers, onions, garlic, lettuce, squash, radishes, beets and beans.
Do not plant with anything in the brassica family like cabbage, kohlrabi, cauliflower, kale and rutabaga. These plants will compete for the same nutrients and stunt the growth of the tomatoes. Do not plant with potatoes or corn. They both attract the same insects and fungal issues.
Watermelon
Watermelon is easy to grow but the downside is that it does take a long time and a lot of space. The smaller melons will generally ripen a couple of weeks earlier than the larger. As the melons start to ripen in August and September the nights start to cool down dramatically and slows up the process.
Melons need a long growing season and also do not transplant well because of the disturbance to their roots. Keeping that in mind when starting inside use a pot that will decompose like a peat pot. Use a lightweight sterile seed starting mix, plant 2-3 seeds per pot ½ inch into the soil with a warm seed starting mat underneath the seed tray.
Start your melons the first part of May on the intent of transplanting outside the middle to the end of May once the soil warms up and you have hardened off the seedlings.
If direct sowing outside use something like a wall-o-water that will warm the soil, and protect the seedling as it starts to grow outside without any transplant shock and still get a long growing season. Set the wall-o-water up the middle of April and plant your seeds ½ inch below the soil the first of May. The wall-o-water works like a mini greenhouse heating and trapping the heat, warming the soil which protects the plants even if it freezes for a couple nights in a row. It does not water the plant.
Melons should be planted in light well drained soil that is rich in organic material. Raised beds work well.
Melons need 8-10 hours of sunshine a day to keep the soil warm.
Melons are high feeders and should be fertilized in the beginning with a 2-1-1, 10-5-5 etc. ratio for growth then a 1-2-2. 5-10-10 etc. ratio to form the flowers and fruit.
Melons like a lot of water and as the fruit starts to ripen, lighten up on the water to prevent splitting.
Strong healthy leaves and vine will help the fruit with a good sugar content leading to a great tasting melon and not bitter. Watering and fertilizing is important for this.
Leaving the fruit on the vine until harvest is best. Look for the tendril attached to the fruit to tell when to pick. When it starts to turn brown and the melon has a hollow thump sound it is time.
Fruit should last in the fridge for 2-3 weeks after harvest.
Plant with onions, garlic, lettuce, arugula, basil, carrots, chives, beans, broccoli and cabbage with melons.
Do not plant with cucumbers, squash, tomatoes, peppers, potatoes and pumpkin.