Bees, yellowjackets, wasps, and hornets, oh my!

We had a warm and somewhat dry April this spring. Honeybees loved that month, and most fruit trees are loaded (or overloaded) with fruit. Bumble bee colonies, which start anew each year, are abundant. They are all over our open-faced dahlias and other summer flowering plants. Mason bees also seemed to fare quite well; however, there is a developing story of yellowjackets, hornets, and wasps. My experience has been that a dry spring leads to lots of yellowjackets and wasps.

While April was dry, May was wet and cool. The result? I think we are on the edge of lots of yellowjackets and wasps for the rest of the summer and into fall. In the last several weeks, their numbers have ramped up fast. Ground-nesting yellowjackets are the big pain! You don’t know they are there until you walk near or on them. They don’t appreciate that, and their disposition isn’t friendly.

Ground-nesting yellowjackets make a version of the paper nests that you see on trees and buildings made by other species of yellowjackets, hornets, and wasps. They are complex and beautiful. The queen knows what she is doing with all the heavy early lifting until her brood starts to hatch and take over the architectural work.

If you can locate the hole in the ground to their nest, the aerosol insecticide sprays (which are accurate to five to nine feet), can do a pretty good job, assuming that there is no bend in the tunnel for the spray to get to the nest. I have found that if you locate the opening and wait to spray until you can just barely see the opening in the evening, you are less likely to be stung. Spray for 5-10 seconds and then get the heck out of there. You will know in a day or two if you were successful.

If the nest location is in a place you can avoid, there is some value in the yellowjackets. They consume a good number of caterpillars and other damaging insects in your garden. They clean up the carcasses from the parts of the vole (field mouse) that your cat doesn’t eat. Their nests will be gone by mid to late fall. The queens look for places to get through the winter. Wood piles seem to be favorites here. All the rest of them die.

It is not unusual to find a nest that has been ripped out of the ground. Portions of the papery nest are scattered everywhere. Generally, it is the work of either a bear or raccoon looking for the juicy morsels of the developing larva. This is yummy if you are a bear.

The large paper nests you see in trees or under the roof peak of homes and outbuildings are the work of bald-faced hornets. They are not generally aggressive except when competing for BBQ meat. These colonies live for about 125 days and are then abandoned. Do not get on high ladders to treat them. They will disappear in good time.

Very hot weather coming?

As this is being written, there is a forecast for an extended period of temperatures near mid-90 degrees or above for two weeks starting this coming Sunday. Locations close to the coast may get some reprieve but, right now, it’s hard to predict. What will be some of the impacts in your food garden besides needing lots more irrigation? Green beans and tomatoes will not set fruit, and the flowers will fall off during 92-degree-plus weather. They will recover flowering and fruiting after the extreme heat is done. Peppers are usually not affected the same way. Squash family plants are a mix. Lettuce turns bitter. Small vegetable seedlings are stressed since their roots are not well-developed. If you have any newly planted woody trees or shrubs, start watering them. Fruit trees generally do not need much water if well-established, but this weather pattern might be an exception. Expect sunburn on fruit facing west where it will get direct sun at the hottest time of day.

Keep vegetables producing

Most “fruiting” vegetables like summer squash, green beans, tomatoes, peppers, and eggplants need regular harvests, or they slow or stop producing flowers to make more fruit. This is especially true of zucchini, cukes, and bush beans. Winter squash can be harvested if the skin can’t be dented with a fingernail. If you can’t use the large zucchini or cucumber (they are generally still good to eat), compost them.

Final notes

Take excess produce to the food banks, senior centers, or community meals programs. Cash donations to buy food for the food banks are also greatly appreciated.

Very helpful information sources are your local Extension offices. The Columbia County Extension is 503-397-3462 and the Wahkiakum County Extension is 360-795-3278. The Extension Service offices offer their programs and materials equally to all people. They will all know where you can get your pressure gauge tested.

Advice on future garden topics is always welcome, Email me at chip.bubl@oregonstate.edu.