Editor’s note: Kelly R. Jackson’s Garden Corner column has a different format. He takes questions called into his phone recently at the Christian County Extension Office and answers them in the column.
Question. What’s causing my houseplant to have brown edges?
Answer. There can be several reasons leaf tips and margins of houseplants turn brown, but two are especially common.
Fertilizer, although needed by plants for growth, also contains salts. Over-fertilizing will increase fertilizer salts, causing injury to plant roots, which is exhibited as leaf burn. Leach the soil to wash out the excess fertilizer by watering the soil until the excess runs out the bottom of the container four times in one hour. Then water the plant as needed and wait one to two weeks to see if further browning of the leaves occurs. Leaching washes out excess fertilizer and reduces damage. To help prevent a buildup of salts, avoid over-fertilizing and water the plant thoroughly each time by letting water run out the bottom of the container. In general, fertilize plants every one to three months with a water-soluble fertilizer.
Pot-bound houseplants are also more susceptible to brown leaf edges. The soil in a pot-bound houseplant is filled with roots. This reduces the amount of water the soil can hold. The solution is to increase the watering frequency or repot the plant into a container 1 or 2 inches larger in diameter. A larger container and new soil mix will reduce the frequency of water.
Q. Should I remove the dried-up fruit on my apple (peach, pear) trees from last year?
A. The remaining dried-up fruit found in backyard fruit trees are called mummified fruit. Many disease-causing fungi and bacteria survive in these leftover fruit. Managing tree fruit diseases begins with cultural practices like pruning out and destroying diseased and dying twigs and branches, raking up infected fallen leaves and removing mummified fruit. The dormant season is a good time for sanitation efforts. The following are some selected fruit diseases with specific sanitation procedures useful in disease control.
n Apple scab. The fungus overwinters on old leaves on the ground. Destroy all of last year’s leaves by raking them up and destroying them.
n Apple fruit diseases. Fruit rot pathogens can be found on mummified fruit. Most of the pathogens are also capable of residing in dead twigs and branches in the tree. Remove fruit mummies from the tree and destroy them and prune out and destroy dead wood and cankers.
n Apple and pear fire blight. The bacteria survive in branch and limb cankers in the tree. The dead wood associated with the cankers also harbors fruit rot fungi. Prune out and destroy fire blight cankers.
n Peach and plum brown rot. The decay fungus survives in mummified fruit. They should be removed and destroyed.
n Peach and plum cankers. The fungi survive in dead and cankered twigs and branches. Prune out and destroy cankers and dead wood.
n Plum and cherry black knot. The fungus survives in the swellings. Remove and destroy all knots before bud break. Prune a few inches below the swelling.
n Cherry leaf spot. Rake up and destroy last year’s fallen leaves because they harbor the fungus.
Kelly R. Jackson is the Christian County Extension Agent for horticulture. He can be reached at 270-886-6328 or visit Christian County Horticulture online at www.christiancountyextension.com.