How do you know what to spray and when to spray it?
Proper identification of insect pests and diseases is an important step before attempting to control the pest. Not all plant problems are caused by pests; some are caused by cultural, nutritional or environmental conditions.
Spraying dormant oil is a great way to protect your trees. Dormant oil is a horticultural oil (mineral oil) applied when a plant is dormant read on to identify when your tree is dormant. This low-impact pesticide is used to treat trees and shrubs vulnerable to attack by insects (particularly scale insects) and mites.
Lime sulphur is mainly used on trees and shrubs as a fungicide (e.g. against apple and pear scab). This low-impact pesticide also affects insects and mites.
In the dormant period, horticultural oil may be sprayed before the buds open and when there is no chance of rain or frost in the 24 hours following application. For the most effective results, it is preferable to wait until the daytime temperature reaches 12-15 oC three to four days in a row. Applying too soon will not produce satisfactory results. However, applying too late (when the buds have started opening or are already open) may cause damage.
Being able to understand what these insects and diseases are, and knowing how to help your trees withstand the onslaught, is really important. Doing nothing is not an option in our climate today. But by the same token, a spray schedule doesn’t have to be super intensive. As long as we’re choosing the right sprays for the right time of the, it really can help grow a healthy tree and healthy fruit.
Here are the most common types for spraying fruit trees and the best time for spraying trees to prevent future issues.
The easiest way to take care of all possible pests and problems with your fruit trees is by using a general-purpose spray mixture. You won’t need to identify every pest and disease that is bothering your tree, and it will cover those you might even miss. Check the label and use a mix that is labeled for fruit tree use only.
To take care of scale insects, apply a substance called dormant oil. Dormant oils should be used early in the spring before the leaf buds begin to open. They can cause damage to trees if you use them when the temperature drops below 40 degrees F. (4 C), so check the weather for the next week before using these oils. Most fruit trees only need dormant oils applied about every five years unless there is a large infestation problem in the area.
Use a fungicidal spray early in the season to eliminate scab disease, such as with peaches. You can wait a bit longer in the spring to use this spray but do so before the leaves have opened. These general-purpose fungicides should always be used when the daytime temperatures are steadily around 60 degrees F. (15 C).
Use insecticidal spray when the flower petals fall to take care of most fruit tree pests. The only exception to this rule for home use is probably the codling moth. To take care of this common insect, spray the trees again two weeks after the petals fall, and one final time in the middle of summer to take care of the second generation of moths that often arrives. No matter what type of spray you’re using on your fruit trees, take care to never use them just when the blooms are opening. This will avoid damaging the bees that are so important for pollination and fruit development.
The timing for the end of dormancy can vary from year to year. I’ve seen it here in Nanaimo where we’ve had the dormant season end in or appear to end in early February only to have more winter set in. And other years it can stay relatively cool through March and the trees may not look like they’re waking up until early to the middle of April.
A reminder about when to Prune.
Prune: When completely dormant in December or January, remove about 20% of the current season’s growth. Apple and pear trees produce flowers and fruit on short stubby stems called spurs. The spurs develop on two or more year-old lateral branches and will continue to produce flowers and fruit for 10 or more years. They must be preserved when pruning. Competing or crossing branches that interfere with the spurs should be removed. Long water sprout types of current growth should be removed at their origin.
If you are unsure when to spray and prune then book a garden consultation.
February 2nd, 2022