Gardening with Gary

Gardening Advice from an Expert

Houseplants

Houseplants may be the best kind of houseguests. They bring life and beauty into your home, require little more than a bit of nutrients and water, and best of all, they do the cleaning for you! How is that?

Indoor pollution can be significantly reduced by houseplants. The EPA has said that it may be a more serious health risk for some people than outdoor pollution, but that plants have the ability to remove contaminants from the indoor air, as well as outside.

Q. Isn't it better to water my house plants just a little bit at a time, so that the roots do not rot?

A. Water should not stay in the soil mix so much that it shuts off air pockets and the roots rot. That is why the lightening additive perlite or some sort of small gravel is so necessary. It is also the #1 reason I feel that people suffer dying plants, since they buy those prepackaged soil mixes and use them straight. The producers love that, as you go through it so much faster without additives. But, the mixes tend to be way too compact and heavy for normal house plants.

The big difference I have seen is the cacti mix, which has been appropriately lightened and can be used as soil.

If you are watering your house plants, letting the water run through, drain and be discarded, and the plants are rotting, then the soil mix is to blame. You will be leaving behind in the pot the byproducts of the roots, the salts made from the fertilizers, and any growths of fungi which can all be controlled by thorough drenching. I picture it as taking a shower with the drain shut. Keep washing and washing and your feet are still standing in dirt and all those extra things you do not want on your body! The same is true for the plants. If you water 'just a little', then the residues stay in the bottom third of the soil mix forever and ever. And guess what happens when the roots grow down into that ugly mess.

Member Cora writes~
I live in an apartment with just northwest windows, and I love house Plants, but I was wondering will you tell me a good house plant that grows well without much direct sunlight that isn't a vine? I'd like a plant that stays in the pot maybe that bushes out, but not a long vine. I'd like one that blooms with fragrance, but I know most of the fragrant plants seem to need more direct sun. I need one that I can at least lightly touch since I am blind. I remember my Mom telling me I shouldn't touch African violets, but I have two of them, and I love them, and I lightly touch the leaves and they live and bloom. I don't rub the leaves or anything like that, but I do touch the leaves a bit.

A. African violets can be touched. Just be sure not to press on them, as they are indeed tender, but they like attention, too! Grow them in a filtered window, east or north.

I recommend several plants that grow well in partial sun. Try philodendron [there are species which are upright, not vines], Dieffenbachia [many kinds], Dracaena [many kinds] and sanseveria [snake plant]. There is the Cast Iron Plant which would be well-suited for your desires!

have you considered spider plants? They grow nicely in hanging baskets or on pedestals. They hang, but are not actually vines. Very easy to grow and need little attention.

These plants also do not require a great amount of water. If you are gone for a week, I would have someone tend to them and give them some water. They also do not need much in the way of fertilizer, but monthly applications of a house plant food will spur growth.

I hope this will start you off in the right direction.

Suzanne writes~
I have a wonderful room that plants love. The only problem is that the plants (philodendron, etc.) always get too big and get pot bound. I don't have room to keep repotting into larger and larger pots. Is there anything I can do (short of dividing them) to make the plants smaller--trim their roots, etc.?

A. I wish everyone had such problems who writes me! You can allow the plants to dry out, but not to wilting, in order to make the potting mix light and flaky. Lay pot on its side on newspaper and gently shake loose some of the old mix. Using very sharp and clean clippers or a knife, cut the roots uniformly around the ball, but remove only about 2-4". Do not send the plants into shock. Repot into a clean pot the same size as before using new potting mix emended with some perlite and peat moss.

Then, cut off an equal amount of foliage to even it with the root ball. Cut back any dead, weak or yellow growth and interior growth which may be shading the good inside young growth.

If you perform this root and top pruning every 9 to 12 months, a bit at a time, the plants will stay rather dwarfed but happy. Remember to continue to feed the plants regularly, because you do not want to starve them or deprive of water in order to stunt them. This will lead to poor weak growth and unruly plants.

Q. I have these dracaenas and philos in the house. They're kinda large, and it means that when I walk past them, I usually brush against their leaves. I was wondering if this might be adverse for the plants, to be brushed up against a couple of times a day. Also, can I clean the leaves safely...they get so dusty!

A. Most definitely. Plants do not like to be disturbed in this sense. It can lead to cell bruising and browning on the edges and tips, even curling to cover a spot which got bumped and hurt. They can get distorted and then turn yellow and die.

Try to move them back a bit out of your walk area. Turning the plants to the light source every couple days helps to push the leaves and stems away from your area. I find that the sticking out can be helped also by twining the vines and even hooking a particular stem with another on the plant.

Even so, you can use green 'twistem's and tie them gently out of the way. The color blends in and the stem is protected.

Also, a little gentle brushing of the foliage with a damp cloth takes off dirt and dust which clog the air pores of the leaves. Yes, like on our faces, they get clogged and this slows down photosynthesis and therefore the growth of the plant. Plus, it makes the natural polish shine through where they were once dull. This brings more light into the cells.

Use warm water and even a drop or two of Ivory liquid soap, rinse well, but carefully. There is also a product on the market for leaf polish. Use as directed and not too often, as you do not want to wax the foliage since this, too, will cut down on food production via light.

Karen writes~ I live in Mississippi. Our low temps have been in the low to mid 50's. Would it be safe to go ahead and put my house plants outside now or should I wait? I'm going to repot them first. What is the lowest temperature they can withstand? I have corn plants, aloes, peace plants, philodendron, and a few tropicals.

A. The key word here which you wrote is tropical. These plants have been introduced into our homes since they like temps around 70F give or take and really like good humidity and strong filtered light [picture a foliage umbrella above them allowing light to drift down to their leaves.] They abhor lower temps, so those 50F temps are way too low for them to be happy. Sure, they probably will not die, but you will see suffering effects later down the road, even up to 2 months later. Then, you will regret placing them outside.

Wait a while longer. They will love the late spring and summer, provided that they are cared for well, as to water, shelter and fertilizer. Treat them as any other growing plant.

Keep yellow and dead leaves and stem trimmed off as they play host to harbor insects and diseases. Turn the plants so that all sides get equal light and keep a saucer under the pots [which have drainage holes!] and allow to absorb excess water for an hour or so and then empty.

Do not rush things. Let them enjoy the warm house conditions for a while longer.

Judy writes~
I want to buy a large houseplant, like a Ficus Benjamina or a Schefflera size. But it will be in my apartment with almost no light. What should I buy that is not easily killable?

A. Definitely do not get the Ficus. They are ornery, temperamental and need good indirect light and humidity. They drop leaves all the time and most do not survive the change from a shop to a home unless conditions are very good.

I recommend for your spot to choose:

Philodendron:
Heart-shaped climber, crawler, up a totem pole, extremely easy to grow. Mine is over 27 years old! ***
Medium-sized round or oval large upright
Large, split-leaf bushy and upright ***

Dieffenbachia:
Various sizes, types, mainly upright with large foliage, ranging into the yellows and creams, spotted, silver

Cast Iron Plant:
As the name suggests, it can take a lot of abuse and is readily adaptable to most indoor conditions. Watch the watering, as they like it dry and will rot if kept wet. ***

Avoid anything that loves light, as cacti and succulents. In low light, less water is used by the plants, so watering must be watched very carefully to avoid disaster.

Let me know what you get and I can give you Full Care for it!

Q. I have a couple house plants with weak, long, stretched leaves. What am I doing wrong?

A. If your plant has leaves that are weak, long and stretched the plant is screaming for more light. It is stretching and reaching for any available light it can get. If possible, move the plant closer to the light source or add fluorescent lights, even screw-in GroLux bulbs.

When plants are growing in the nursery they are getting light from all directions. But when they move indoors, the light source usually is from only one direction. It is natural for the plant to grow towards the light. If the plants are severely ben ding then it may just not have enough light.

Try rotating the plant on a regular basis a quarter of a turn every week. If not, you may end up with a flat or one-sided plant. Plants are great communicators. We just need to listen to them.

Assistance from plant-care.com

Ladydebayou writes~
My indoor plants seem to thrive then get the weirdest odor to them. I have noticed that when I water them it is more noticeable than at other times. Also there is a white residue on the top of the soil. What could this possibly be? I never seem to have very good luck. When I used my well water, I never had this problem. I have changed the soil but it seems I would have to change it monthly to do any good. I try to take care of them but it seems nothing helps. I have ivy and a few other green plants. I am truly surprised they are still alive. I have never had this much trouble growing plants. I use Miracle-Gro on them. Maybe it is the water?

A. It sounds that there is a fungus growing in the soil and another the white growth on top of the soil. They will probably not cause death, but do give off a foul odor. The water can be contributing to the problem. Allow containers of water to sit overnight Sterilize your potting mix and add perlite to aerate it. Place moistened new mix in preheated 170 degree F oven for 25-30 minutes. Do not reuse old mix...toss away. Reduce the frequency of watering so that the top inch of mix feels dry to a finger and then water well so to drain out the bottom into a saucer which is emptied immediately. A slow water drench of all pots into a sink will flush out old material including salts from past fertilizing and many dead cells of organic matter and fungi. The odor will diminish after several leachings.

Crissy writes~
I have a couple of indoor houseplants that I keep on my desk at work. I have noticed one of the potted plants has very tiny little white bugs moving around on the surface of the dirt. What could these be and how do I get rid of them?

A. Since they are moving, they are not foliar mealybugs I would say that they are springtails. They are a nuisance in and around homes, seen as small creatures, measuring only up to 1/3", but because they emerge in such great numbers they can be annoying but not harmful to people. They thrive where there is a lot of moisture, can live under mulch, and readily live in all types of soil when wet, damp conditions are available. They eat mold, mildew, fungus and decaying organic matter which is usually present in moist areas. Springtails will develop into many sizes and move in short runs, then rest, and then move again. Use granules, dust or liquid sprays to break the cycle of springtails. You may need to use a combination of the products feature above. Two or three treatments will usually resolve any level of infestation along with moisture reduction and you should be able to knock them out once and for all.