Houseplant care — As winter stretches on, take a quick check of your houseplants:
• Have you dusted the leaves? They gather dust just as our furniture does. Give them a swipe occasionally with a damp cloth to be sure they’re taking in light.
• Have you seen any insects flying around, or damage they may be causing? Fungus gnats, for example, look like mosquitoes and are common in soil that is kept moist and that is high in organic matter, Ward Upham of K-State says. The adults don’t bother humans or pets, he said, but in the larval state they can harm plants by feeding on the roots. Signs of this are sudden wilting, loss of vigor, poor growth or yellowing leaves. Bacillus thuringiensis v. israelensis (Gnatrol) can be used to control an infestation. Planting in a sterile medium and not overwatering can help prevent the gnats, Upham says.
• Salt levels can build up in potted plants and eventually scorch leaves. To wash out excess salts, place the pot in a bathtub or sink (or outside when the weather is nice), and slowly add twice as much water as the volume of the pot, Upham says. You don’t want the water to overflow the rim of the pot.
If there is a salty crust on the surface of the soil, remove it without taking more than 1/4 inch of the underlying media, Upham says. “This may also be a good time to repot the plant,” he writes in the Horticulture 2014 newsletter.
Because apple trees are tougher, the application can be delayed up to the green-tip stage, he says. Temperatures must be at least 40 degrees so the spray has a chance to dry before freezing, and spraying in the morning also helps ensure proper drying. If the spray does freeze before it dries, it can injure the plant.
Limbs, branches and twigs must be covered thoroughly for good control, and that is more easily done if the tree is pruned first, Upham says.