Early-Season Landscape Tasks

By Cynthia Bee, Conservation Garden Park

Whew! The harshest days of winter are now happily behind us and spring will arrive in just a few short weeks. If you complete a few tasks now, you can avoid landscape problems later in the season and protect your landscape investment for years to come. However, they are time-limited opportunities, and once trees and plants break dormancy, the window of opportunity closes.

Dormant Oil Spray

Some trees, and especially fruit trees, are susceptible to borers, pests or diseases that overwinter on the wood. In late winter, these pests are in an early life stage such as egg or larva and are easier to treat.

Dormant oil sprays, also called horticultural oil, can be purchased at your local nursery or farming supply store. These sprays are generally used on fruit and ornamental trees. Some are petroleum based, and others vegetable oil based, and they come in both chemical and organic versions. They work by coating the soft egg or larva to prevent oxygen exchange, smothering the pest. Once pests reach later life stages, the oils have no effect on their tough outer shells.

In the case of diseases such as Fire Blight, prevention with dormant oils is much easier than trying to save a diseased tree. The application rates and technique vary by product, so read all instructions carefully and follow them exactly when applying.

Pre-Emergent Herbicides

As soon as temperatures hint at warming, weed seed will begin to germinate. Like desirable plants, there are both perennial and annual weeds. Annual weed seeds begin to grow in early spring, whereas perennial weeds, such as field bindweed, won’t appear until later in the season. Annual weeds sprout from seed while perennial weeds emerge from overwintering roots (though new perennial weeds will also come from seed).

You can dramatically reduce weed numbers by applying a pre-emergent BEFORE seeds germinate—which means right now. Pre-emergents do not impact existing plants but will keep even desirable seed from sprouting, so keep that in mind, especially when applying to your vegetable garden (you’ll be fine if you start your garden with 4-inch plants, but don’t use pre-emergents if you’re starting veggies from seed). Pre-emergents can be chemical or organic and they work by creating a thin chemical barrier on the soil surface that inhibits seed germination. It also means that as soon as you dig in the soil or if you till it, the benefit may be lost. For this reason, pre-emergents should be applied AFTER you’ve cleaned the planting beds and applied seasonal mulch. They also require about one half-inch of water to activate, so apply before a rainfall or use your sprinklers to get them started.

We all want to enjoy maximum benefit from our landscapes for the least amount of maintenance. Completing these early season tasks can preserve your landscape investment and dramatically reduce work later in the season. For more information, visit ConservationGardenPark.org.