August 24, 2003|By Dennis Bishop | Dennis Bishop,Special to the Sun
A local garden center recently recommended that I spray aphids with horticultural oil rather than an insecticide. I thought that horticultural oil was only for fruit trees and was only sprayed in the dormant season. Is that true?
What was once called dormant oil spray is now generally referred to as horticultural oil. Dormant oil was primarily used during late winter and early spring to control insect pests before they became active. It is still used for that purpose; however, it can be sprayed in all seasons as long as the temperature is above 40 degrees and below 90 degrees. When sprayed in very cold or very hot weather, it can be toxic to plants.
Horticultural oil will control soft-bodied insects like aphids and white flies, and it will control the nymph and larva stage of a number of other insects. It is considered less toxic than most chemical insecticides and can be used by certified organic growers for pest control. I recommend horticultural oil and insecticidal soap as one of the first lines of defense in pest control.
We are holding a wedding reception at our home in early October, but our lawn is in terrible condition. If we reseed now, will it look good by that time or should we lay sod?
I would plant seed, but you could do either. It takes about six weeks to get a lawn established from seed, so you will need to plant seed immediately to get a nice lawn by early October.
Should you choose to plant seed, be sure to prepare the area well before planting. The areas to be seeded should be lightly tilled to a depth of 1-4 inches (the deeper the better) and then raked smooth. After you spread the new seed, you must commit to watering everyday. Seed that is not watered will not germinate, and once it germinates, the young seedlings can die quickly without adequate moisture. We recommend planting turf type tall fescue seed in most conditions. Tall fescue seed germinates and establishes itself fairly quickly, and it grows well in our climate.
Sod might be the safer bet at this late date, but it will be quite a bit more expensive, and it also needs a lot of care to get established. Like seed, sod must be watered every day.
Checklist
1. The soil in many gardens has remained moist throughout the summer, but newly planted trees may still need supplemental water. Be sure to water them once a week.
2. Has your mulch begun to wear thin? Adding a fresh one-inch layer now will keep your plants through the fall.
3. Many gardeners planted vegetables late and their plants are behind schedule. Don't give up on them yet; they should still produce an abundance of fruit.
Dennis Bishop is an urban horticulture educator for the Baltimore office of the Maryland Cooperative Extension Services. If you have a gardening or pest problem, you can call the Home and Garden Information Center hot line (Monday through Friday, 8 a.m. to 1 p.m.) at 800-342-2507. You can also e-mail questions, order publications and diagnose plant problems by visiting the Web site www.hgic. umd.edu.
