Blooming Annuals for Indoors

Bringing the outdoors in.

I recently had a question about bringing in and preserving a outdoor blooming plant for the winter. Most of the plants that you buy at a garden center have been growing inside, so why do they not work well when I bring them in?

First lets get the definition of a indoor plant.

This will give us a guideline. A houseplant is any outdoor plant that we bring into our house and grow. Most of the houseplants that are popular are tropical plants that can’t survive our winters and are easy to grow. Most are low humidity plants. Because humidity is low in our houses, plants that are chosen to bring inside have to be able to take the low humidity for long periods of time. The perfect humidity for a tropical houseplant is between 50-80%. Can you imagine how that would happen in your house and the implications if that were to be possible? You would have to hose off your plants every other day. A high humidity for long periods of time will eventually form wet stains on your walls, musty smells will hang in the air, molds will start to grow, and moisture loving insects will start to show up in numbers. Too little humidity will cause the plants to show signs of leaf curl, brown patches, drying up flower buds that won’t open. Plants could have smaller leaves and drop leaves prematurely and plants may not look as healthy as they would outside. Spider mites will usually attack the plant because a plant is suffering from the lack of humidity giving the backside of a leaf a dirty look but when under a microscope you can see the little buggers moving around sucking the life out of the leaf.

Popular houseplants are also picked out for lower light requirements. Light is one of the most important factors for growing houseplants. All plants require light for photosynthesis. This is the process within a plant that converts light, oxygen and water into energy in order to grow, bloom and produce seed. Light through a window is not direct sunlight as the light will be filtered as it comes through the glass, which impacts its intensity. This means that this light can be at least 50% less intense than direct outdoor sunlight, although sunlight through a south facing window can be close to direct light.

Temperature is a third factor. Not just air temperature but soil temperature. We often assume soil temperatures mirror the air temperature but they don’t because of things like soil moisture and soil density. Most tropical plants do not like their feet cold. This will restrict the plants growth and overall health. Sun is not heat. The sun is light. The sun can provide heat but in the case of houseplants inside, being defused, the sun can heat the soil and pot for a shorter amount of time than if it were outside.

The popular plants that are usually picked are usually poisonous. The reason is when you have a plant inside there are no natural predators for the insects that the plants attracted. Being poisonous, the plants naturally repelled insects. Most of the poisonous plants are mildly poisonous or are skin irritants, but others are extremely toxic. Animals will usually leave them alone however, small kittens or puppies haven’t learned the difference yet and should be kept away.

Here is a list of annuals that I have tried in the past with somewhat success. The bugs were probably my biggest enemy when trying to grow them through the winter.

• Geraniums

• Peppers

• Begonias

• Impatience

• New Guinea Impatience

• Coleus

• Diamond Frost Euphorbia

• Rosemary.

I plan on trying more as time and space allows next year. This year my new ones are Mecardonia and my Amazel Basil.

Of course I bring in my traditional tropicals that come in and out every year. Every plant can be brought in and wintered over, however how much time and effort is it going to take?