By Laura Pottorff, Colorado State University Cooperative Extension agent and plant pathologist
Pity our poor houseplants. Most of us water them, fertilize them and forget them.
If we really love our plants, however, we'll also groom them. This means cleaning leaves and trimming out brown spots and dead leaves. And what better time than winter to do just that?
A clean houseplant is a healthier plant. Dust and dirt that collects on plant leaves acts as a filter to the sun's rays. A clean plant not only looks good; it uses energy from the sun more efficiently for photosynthesis, the process by which the plant uses the sun's energy to produce its own food.
Use a feather duster for leaves that aren't too dusty. Dampen paper towels, cloths or sponges with water to wipe dirty leaves. Carefully wipe both upper and lower surfaces of the leaf at the same time. Using a wiping motion, start at the point of attachment of the leaf and end at the leaf tip. Apply enough pressure to remove the dirt, but not enough to pull the leaf off the stalk. Don't, however, try this on leaves with prominent leaf hairs.
You might want to add a small amount of insecticidal soap or dish soap to the water. Test the water-and-soap mixture on a small part of the plant first, to be sure there will be no damage to leaves.
Leaf shine products aren't highly recommended. These products tend to inhibit leaf transpiration (the loss of water from leaves). They can work against your attempts to preserve plant health by cleaning leaves in the first place. Healthy leaves do not need to shine to look attractive.
Plant leaves can become spotted or blemished from a variety of factors including heat, dryness and physical damage from kids or pets. Remove leaves that are yellow or dead. If more than half the leaf is affected, remove the entire leaf. You can remove some leaves by hand; others, you'll need to cut off. If only a small portion of the leaf is discolored, you can trim that portion to the natural shape of the leaf. Use sharp scissors for best results. To prevent wounding of healthy tissue, leave a small margin of yellow tissue as you trim. Leaves of some plants that you trim, such as Draceanas and Yuccas, may continue to grow at the leaf base. Once you trim the leaf tip, however, it will not grow back.
Remove flowers as soon as they become old and fade. Remove both the flower and the stalk. Make cuts at the base of the flower stalk.
In addition to creating a healthier more attractive product, cleaning also keeps leaves free of insects and diseases. When you wipe leaves, you often wipe away unwanted pests, as well. With close-up attention, you'll notice problems sooner and will be able to control them easier.
There's one more benefit to houseplant grooming: Outdoor gardening enthusiasts can still garden throughout the winter. They just have to do it indoors.
Photograph courtesy of Judy Sedbrook.
© CSU/Denver County Extension Master Gardener 2010
888 E. Iliff Avenue, Denver, CO 80210
Date last revised: 01/05/2010