Several of you have us spray your Hawthorns for Scab and Quince Rust. This year you may be noticing that the little round balls of fruit on Hawthorns have orange spikes and may be dropping some orange dust on the leaves and on your sidewalks, patios and driveways.
Our main goal is to keep the leaves from turning black and dropping too early and our sprays are accomplishing that. However, the Quince Rust on the little fruiting balls are not responding as well to the spray applications. Why is this?
Those little fruiting balls have a waxy, slippery outer coating making it more difficult for our sprays to adhere to the fruit. The leaves, stems and branches, however, are more porous allowing them to better absorb the product, yielding much better results.
There are all types of funguses out there and the wetter the Spring, the worse fungal issues are, some years worse than others. We can’t control every single fungus that might occur as we can’t predict which strains of fungus might be an issue from year to year. As a comparison, different strains of human flu also vary from year to year. Doctors do their best to determine which strains to vaccinate against when we get our yearly flu shot. As we all know and may have experienced, that doesn’t mean that we won’t get the flu that year. All we can do is control the worst funguses that do the most leaf damage to your Crabs and Hawthorns.
It is important to note that the Quince Rust dust on or from the fruit will not weaken or kill the tree.
You can simply hose off your patios, sidewalks, etc. if you are noticing orange dust.