May 3rd Pest Alert

May

May 3, 2022

Apricots & forsythia are blooming.  Apples are at tight cluster to first pink tip stage but It is TOO EARLY to spray fruit trees for pests. We used to spray fruit trees just after apple bloom, but now we know that it is better to time fruit tree sprays to target the vulnerable stages of specific fruit tree pests. If you want to monitor for Codling moth, the insect that causes wormy apples, you can put up Codling Moth pheromone traps soon when apples are starting to bloom. These traps will NOT control the pest, but will show you how high a population you have.

Apricots and cherries are oozing from cracks and wounds on trunks and lower branches. This is probably from cold stress or wounds and not disease-related, but keep an eye on oozing and if it becomes dark colored like honey, it could be the start of canker disease. You can also cut into the bark, if you find brown streaking instead of whitish wood that is also a sign of fungal canker, pruning is the only solution.   

It is still a good time to spray for Ash leaf curl aphids. The least-toxic option is neem oil or a mixture of insecticidal soap and pyrethrum. Aphids are hatching now on Dogwood, ornamental and fruiting plums, and other aphid-prone shrubs and trees. If aphids were a problem last year, you can spray with insecticidal soap. The woolly-aphid stage of the spruce gall adelgid is present and laying eggs now. If you had pine-cone like galls on spruce last year, you can spray these cottony, white aphids on alberta and blue spruce and on Doug fir now with insecticidal soap or permethrin.

Mountain Ash leaves have emerged and flower clusters are getting ready to bloom. If you had problems with blister mites causing yellow, puckered blisters on Mountain Ash leaves, now is the time to spray for blister mites. You can use insecticidal soap or add pyrethrum to the insecticidal soap spray if you had a serious blister mite infestation last year. But, remember that even least-toxic options like pyrethrum can kill beneficial insects like ladybugs, who are present in gardens and landscapes now. 

Soil temperatures are averaging 47 F. It’s time to mow lawns and apply fertilizer. Compost is a good option for plant nutrients and increase soil water-holding capacity. If you have not done so already, aerate your lawn ASAP; Dandelions are blooming now and if you aerate lawns when dandelions are seeding, you provide great dandelion seed germination sites.

Annual weeds are germinating now. It is a good time to treat them with vinegar sprays. White and cider vinegar can be used on tender succulent annuals; but newly sprouting perennial weeds, such as quackgrass and knapweed are not affected by these low acetic acid concentrations of vinegar. For sprouting perennials, purchase weed-killing formulations with acetic acid-oil combo’s and plan on several repeat applications. Tillage can also be used to kill newly germinating annual weeds. Till on a warm, dry day so weeds dry out and die. It is too early to put out frost-sensitive vegetables  such as tomatoes and peppers unless you are putting them in wall of waters or covering them. Our last average frost date is the 18th of May.