Remember back in the 1970s when houseplants suddenly became must-have items? I’m identifying my age group here, obviously. In Doonesbury, Zonker talked to his plants and they answered him back. As college freshmen we went to cute little plant stores and filled our tiny dorm rooms with little plants that dripped all over our homework and term papers. Most were destined for brief, though well-loved existences. As time went on most of us got tired of taking care of indoor plants and dropped them from our lives. Now researchers are discovering that plants have the ability to absorb toxins from the air, which is especially important in newly-constructed buildings; also they’re finding that we have a greater sense of well-being when there are plants in our homes and workplaces. Indoor plants are a much better fashion to revive than platform soles.
Basic discoveries I have made through the years:
Move indoor plants outside to a shady place for the summer and they will thrive.
Have fewer plants so it’s easier to care properly for them without feeling burdened.
Larger plants are easier to display well, and often easier to care for. Just don’t have a plant that’s too big for you to move.
If it isn’t attractive, throw it away.
Find what works and stay with it.
Indoor plants are all outdoor plants somewhere in the world. What makes them work as indoor plants is their ability to survive in the low light and still air of the indoor environment. In most cases these are plants from tropical regions, where the temperatures rarely go below 60 degrees. Many of them would be native to the jungle floor where very little light filters down.
The three most important factors in any plant’s growth, indoors or out, are light, water and a survivable temperature.
Light
Plants make food out of light. We talk about fertilizers as “plant food”, but that’s really not accurate. Fertilizers are like vitamin pills for plants, substances that help our health and vigor, but not what we actually live on.
Your house has varying degrees of light – more near windows, most near south windows, less near north windows. If you’re lucky enough to have a sun porch or an enclosed patio you have a wonderful range of plants available to you. If you have a shaded house with the largest windows facing north, you’ll probably lose a few plants before you find the survivors and the best spots in the house.
If a plant seems pale colored and soft, and you don’t find any evidence of insect problems, try moving it to a sunnier location and see if it looks better after a couple of weeks. Remember, furniture does not need light to live, but plants do. You may have to rearrange the room to favor the plant’s needs. There’s a brief list of plants and their light requirements at the end of this hand-out.
Water
Overwatering problems are more common than underwatering problems, though there are people who consistently forget to water their plants. Most plants want to get moderately dry before watering. No plants want to wilt before watering. This is one of the main ways in which larger plants are easier to care for. Bigger pots hold more water, bigger plants use more water, so there’s more of a buffer zone, a fudge factor, if you’re erring one way or the other. Remember plants need less water in winter and more in the summer. Judge soil moisture by looking at it, then by feeling the top 1/2 inch with your finger, then by lifting the pot to see if it seems heavy or light.
If your plant is wilted, but the soil looks wet and the pot feels heavy, the roots are sick and rotting and aren’t able to take water up into the plant. It’s difficult to revive a root-rotted plant. Throw it away unless it has great personal meaning.
If you’ve let a plant dry out to wilting, you’ll want to resoak the soil by immersing it in a bucket, if it fits. Dunk the pot until air bubbles stop rising out of the soil, then let it drain before putting it back in place. If the pot’s too big for a bucket, fill your bathtub with several inches of water, set the plant in, and scoop up water and pour it into the top of the pot until it stays without draining away rapidly. You might use this opportunity to turn the shower on it gently with slightly warm water and give the leaves a good washing.
Now, if you’ve made a watering mistake, get yourself in tune with what your plant wants, don’t keep making the same mistakes. Remember, we are adults, we have awareness and self-control, right? That’s what we didn’t have when we were 19 year-olds killing plants in our little apartments. That’s why we can do this better now.
Temperature
This is the easy part. Most plants like what we consider comfortable room temperature. When you move your plants out for the summer, wait until late May- early June, and move them back inside in late September.
Now that we have the basics understood, here are the extras that really keep the plants nice:
Fertilizer
Indoor foliage plants will do fine with a time-release feed like Proven Winners brand (yes, the same stuff I recommend for outdoor flowering plants) One sprinkle when you move them back inside in fall will go all winter for most plants. Another sprinkle when they go outside, and one in mid-summer, or else fertilize them when you do your flowering baskets and planters, just not as often. You can play around with more and different stuff, just watch out for overfertilizing and the root-burning salts accumulation that can result. Don’t use the fertilizer spikes you poke into the soil; the feed works better when it’s spread around evenly.
Insect and mite control
The stand-bys for indoor plant care are :
Safer “soap” spray, Neem oil extract, imidicloprid – the stuff that’s in the Bayer products, rubbing alcohol, and water.
The main pest problems are:
Aphids – Easy to pick up while outside in summer. Squish or spray off with water (outside, obviously), then spray with soap spray, unless your plant is damaged by soap. Spray one leaf of any new plant to test it before spraying the whole thing. If damaged by the soap, try neem extract on a leaf next. If that also damages, use Bayer products.
Fungus gnats – The tiny gnats flying around your plant aren’t the problem, it’s their nasty little baby worms in the soil eating the roots that are doing the damage. Hard to control with chemicals of any kind. Let the soil get drier than it has been. Buy or make yellow sticky cards to trap adults. Trap larvae (worms) with slices of raw potato pressed onto the soil surface, throwing away and replacing the pieces every other day until you see no adults flying around.
Mealybugs – They look like fuzzy white blobs in the crevices and axiles of the leaves and stems. Dot them with rubbing alcohol on a Q-tip; check once a week for new ones and re-treat until no more appear.
Scale – They look like flat little brown shells attached to the undersides of stems and leaves. The alcohol treatment works well on them, too.
Mites – So tiny they look like powder on the undersides of the leaves. Safer soap spray works well, but you’ll need to treat more than once to get subsequent generations as they hatch from the unkillable eggs.
Disease prevention
The only common disease in indoor plants is root rot, which can actually be caused by a number of different fungi. Avoid overwatering and they won’t have it.
Most other symptoms that look like disease will usually be environment and care problems, or insect problems. For example, dry leaf tips are usuallycaused by dry air and/or dry soil. Brown, dead patches in leaves can be caused by mite damage. An unusually cold summer night can leave brown edges on cold-sensitive plants outdoors.
Cleaning
Misting or gentle spraying or showering is good for both plant appearance and health. They don’t like have dust build up on their leaves. Leaf-shine products are not necessary, but do make plants look nice.
Different plants have different light requirements. Here’s a short, approximate list:
Able to tolerate lower light
Chinese Evergreen Aglaonema
Cast Iron Plant Aspidistra
Dieffenbachia
Philodendron
Prayer Plant – Maranta
Peace Lily – Spathiphyllum
Likes more light
Norfolk Island Pine Auracaria
Calathea
Spider Plant – Chlorophytum
Ti Plant – Cordyline
Dracaena
Figs – Benjamina, Fiddle-leaf, and Rubber Plant
Palms, except Lady Palm – Rhaphis