When to spray your fruit trees this spring
There’s no doubt it’s been a wild winter for many parts of the country. Some days we basked in lovely above average warm temps, just to turn around to throw a polar vortex our way the next day. For us, this “cold snap” lasted all of February with 32 inches of snow and actual temperatures diving to -32 without the added bonus of the windchill. But now it is officially spring, and even though there is still a foot of snow on the ground, it’s time to get those fruit trees sprayed.
Timing is critical when spraying your fruit trees, whether your focus is disease or pests. If you spray at the incorrect time period, not only are you being ineffective, you are potentially damaging the tree or your fruit crop. If nothing else, you’re wasting your time and money, particularly when there are so many other projects screaming for attention at this time of the year.
What to spray when the tree is dormant
Before there are signs of life in the branches, spray the trees with a horticultural oil spray to smother scale and other overwintering insects (like aphids and mites) that snuggle down in the bark for the cold season. This is easily found as an organic product and is one of the easiest and most effective means of improving your fruit quality.
To cover additional problems, such as fungus or fire blight, add additional products to the regime. If you have issues with apple and pear scab, a fungal disease, add lime sulfur to the dormant oil spraying. This is a natural fungicide, and thankfully is fairly mild.
For fire blight, which is a continual battle in many parts of the country, the former protocol was applying streptomycin when it was blooming, but with the increased – and well founded – concern over bacterial resistance researchers looked for another remedy. Copper products are effective killing the fire blight bacteria that it is on the surface of the tree, so by spraying now, you can help prevent the spread. (If the tree is already infected and it’s within the bark, the copper can’t reach it, but it still has been shown to make a difference in the overall infection rates.)
When the tips are just greening
If the spring is getting away from you and your trees are already starting to green up a little bit, you still have time to spray copper or the horticultural oil. Just keep in mind that horticultural oil can burn green parts of trees so use prudent judgement if the trees are ahead of schedule.
You can also apply a fungicide like Captan at this time to further control scale in the trees, although do not spray it at the same time you are spraying the tree with the horticultural oil. Give it a few days in between.
When the pink of the blossoms are showing
You have to think more about insects, along with disease, at this point. You can still spray Captan, but if you typically have insect issues, stay ahead of them by adding a pesticide at this time. There are heavy duty sprays that can be used, or if you’d rather go a less toxic route, utilize Neem oil, Bt (Bacillus thuringiensis) spray. This can help take care of caterpillars early on in the season.
It’s good to think about the harvest now, and tending our fruit trees is one of those spring projects many of us enjoy. Just be sure to follow the labels on whatever you use, try the less harsh products whenever possible, and time it right to make the best use of it.