Applying Dormant Oil Spray

Gardeners are not the only ones who enjoy fruit trees. Pests — such as scales, aphids and mites — feast on the tender plant parts and overwinter on the fruit trees. Dormant oils control these annoying pests and are safe for use on fruit trees.Aphids scale on apple tree

Dormant oils once contained heavy oils that had to be applied when the fruit tree was in its dormant stage to prevent damage to buds and foliage. Nowadays newer dormant oils are lighter, allowing them to be applied at anytime during the year without harming buds. Because you can apply newer dormant oils throughout the season, the term “dormant” typically refers to the time at which the oil is applied. Dormant oil consists of refined petroleum oil that — when applied to trees — will smother overwintering insects — such as aphids, scales and mites — and their eggs or will dissolve their protective waxing coating. It is applied in the winter months when fruit trees are in their inactive period. For dormant oil to provide proper control, the oil must come in contact with the pests.

Dormant Oil Recipes

Several dormant oil recipes are available and help control pests on fruit trees. A dormant oil formula developed by scientists at Cornell University controls overwintering pests and foliar diseases. It contains 2 tablespoons of ultrafine canola oil and 1 tablespoon of baking soda mixed with a gallon of water. Cornell University scientists also developed a nourishing formula containing 2 tablespoons of horticultural oil, 1 tablespoon of baking soda, 1 tablespoon of kelp and 1 tablespoon of mild dish soap mixed with 1 gallon of water. Another dormant oil recipe contains 2 tablespoons of baking soda, 5 tablespoons of hydrogen peroxide, 2 tablespoons of castile soap — which is made from an olive oil base — and 1 gallon of water. If you are not one who likes to do DYI, you can buy it premade at the store.

Application

No matter which recipe you use, the application for the homemade dormant oil is the same. During the fruit tree’s dormant stage — which is typically between November and early spring before bud break — fill a pump sprayer with the homemade dormant spray and thoroughly coat the fruit trees — stems and both sides of the leaves — with the oil. Never apply dormant oil when the temperature is below freezing or when fruit trees are stressed. Stressed trees are more likely to become damaged when treated with dormant oil. Furthermore, only apply the oil spray when the fruit tree is dry. Moisture or high levels of humidity lower the effectiveness of dormant oil sprays.

Considerations

Dormant oils generally won’t harm beneficial insects since they are applied at a time when beneficial insects aren’t present on fruit trees and have a low toxicity level to humans and mammals. Furthermore, dormant oils won’t leave harsh residue behind. It loses its ability to control pests once dried, however, and can harm plants susceptible to oil sprays. Cedars, maples, spruce and junipers are a few susceptible tree species that dormant oil should not be used on.

Some of the first plants to spring up after winter are weeds. Here’s how to get control.

weeds

Bright flashes of green in the garden in spring can be a welcome sight. Or not.

Some of the first plants to green up after the winter are weeds, such as creeping Charlie, common chickweed, deadnettle and shepherd’s purse.

Early spring is a good time to tackle them because you can spot them easily.

It’s also a good time to control aggressive ground covers that may be sprawling or taking over. Evergreen or semi-evergreen ground covers such as English ivy, vinca, euonymous and pachysandra have an advantage over other garden plants, including trees and shrubs. Because they stay green through the winter, they still have chlorophyll and can continue to photosynthesize and grow while the rest of the garden is dormant. They have time to conquer more territory before the other plants wake up.

Tackling them early makes it easier to avoid damaging other plants, which are mostly still small and compact.

Why control weeds and aggressive ground covers?

They are battling your other plants. Their roots are competing for water and nutrients with the roots of your trees, and shrubs and their leaves can shade out your perennials.”

Work carefully to avoid damaging plants you want to keep.

Trim ground covers back to the edge of a path or sidewalk. Pull up woody stems or vines that have crept into areas where they are not wanted, but be sure to dig up the roots too. If you leave the roots, they’ll just resprout.

Some aggressive ground covers, such as spotted deadnettle and bishop’s weed, spread by sending out stems to creep along the ground or just below the soil that can root and send up plants in new spots. Several rosettes of leaves may sprout from a single stem.

“Be sure you trace that stem all the way to the end and dig up all those new plants, along with their roots.

Creeping Charlie spreads the same way. This shade-loving perennial plant is easiest to remove in spring when it has just one compact rosette of leaves, before its slender stems snake out between grass blades and among other plants.

Dandelions are another perennial weed, sprouting from a deep taproot in early spring. Other early weeds, such as common chickweed, are annuals growing from seeds that germinated over the winter.

The important thing is to weed early and often. Focus on one area at a time. That way, you can be methodical about digging up the roots, not just the leaves. You can be careful about not pulling or stepping on desirable young plants. And as you clear each patch, you can savor a small early victory.

Conquering these weeds now will save you a lot of work so that you can sit back and enjoy your landscaping over the summer, rather than fighting with it.