Diggin’ in the Dirt: The First Frost

Regional events of note:

All About Fruit Show. Clackamas County Fairgrounds, Canby  10/18-19  from 10am-4pm both days.  $6 entrance fee.  http://www.homeorchardsociety.org/events/all-about-fruit-show/


A great opportunity to taste hundreds of apples, pears, kiwi and grapes. You can order a custom-grafted tree, made just for you, to be delivered in the spring. Excellent speakers, experts available to answer all your questions, pie baking contest, exotic fruit sorbet to taste. The Apple ID Team will try to identify your mystery apples.


Fall Mushroom Show. Miller Hall, Western Forestry Center, Portland  10/19  12pm-5pm


Admission: Adults $5; Seniors and students $3; Children under 12 free. Free to OMS Members.

Beautifully arranged tables display wild, locally foraged mushrooms of the Pacific Northwest, carefully picked, identified and arranged to educate the public about fungi. The number and type of mushrooms vary with fruiting conditions. This colorful event also features special interest tables, including mushroom cookery and preservation, toxic mushroom information, dyeing with mushrooms, a truffle exhibit, mushroom themed art, a “Kids Corner”, mushroom cultivation, as well as books, posters, and “grow-your-own-at-home” kits for sale, and much more!! And there are plenty of knowledgeable OMS members on hand to answer questions, identify mushrooms that you bring in, and chat with about fungi.

When will the frost arrive?

By the time you read this, the first fall frost will probably have come to Vernonia, Chapman, and other locations that tend to be colder in the winter. The average first fall frost date for Vernonia is September 28th. This is true for other high elevation or frost prone low areas around the county.

The St. Helens and Scappoose area have an average first fall frost date around Halloween. Are there any guarantees here? Certainly not.  These dates are only averages. Predictors, perhaps, but not perfect. If I could infallibly pick frost dates, I would be playing the ponies. For those in the north end of the county, the best information I have puts Rainier at a date similar to St. Helens and Clatskanie about one week later at the end of the first week in November, before the first frost.

Some other frost facts:

• When skies are clear, heat from the soil rises which allows cooler air to settle near the plants. Cool air is heavier than warm air.

• When it is windy, the warm and cool night air is mixed, generally keeping temperatures above freezing if it has been a reasonably warm day.

• Plants are less tender in the autumn than the spring, so light frosts do less damage. Woody plants are less affected the herbaceous plants. Plants already exposed to cool temperatures may be somewhat acclimated and more resistant to cold temperatures.

• Plants can be covered to give protection in light frosts.

Since meteorologists can’t decide whether we are going into an El Nino event, a hint of that pattern, or a big forecaster’s puzzle, it is hard to see where this fall and winter is headed.

Whitewash saves trees

Trees can be injured by sun in either the summer or winter. Reflected sunlight off of snow onto dormant bark can cause sunburn even when air temperatures are quite low.

The ten degree temperatures last December caused damage to young trees that is showing up now as vertical cracks and open wounds.

Hot days and the direct rays of sun in the late afternoon also cause sunburn. It is more pronounced on the southwest side of a tree or bush and is especially an issue on trees with a modest leaf cover.

Farmers have painted tree trunks and lower scaffold limbs for years with a calcium mixture called whitewash. There are lots of formulas. A modern solution is to mix exterior white latex paint 50-50 with water and paint it on the trunk. This treatment will help protect your trees from both winter and summer sunburns. It is particularly useful on young trees.

DigginFruitFly-webFruit flies

Where did they come from? Why won’t they leave?!!  Fruit flies cause an otherwise rational person to believe in spontaneous generation. They appear overnight and then take over in the kitchen. With the great spring weather, our kitchens are full of fruit of all types waiting to be preserved, eaten or stored. This is fruit fly heaven.

Fruit flies are attracted to fresh and fermenting fruit and vegetables (they are also called vinegar flies). They can pass through standard door and window screens, attracted to the smells inside. They can also be brought in on tomatoes or other fruit from the outside.

They are fast breeders. Eggs hatch and the tiny maggots eat their way to fly adulthood in 8-10 days. The females then mate and produce 500 eggs in two days. They have very large genes and a well-studied inheritance pattern so they are the “lab rat” of the insect world on all sorts of molecular genetic research under the genus name Drosophila.

To regain control of your interior airspace, remove rotten fruit and vegetables promptly. Take compost trimmings out daily and scrub the containers. Wash cracks in the kitchen that may have accumulated fruit or tomato juices.

The flies can be trapped in vinegar, wine or fruit juice by adding a little liquid soap to the mixture.

Donate extra produce to the food bank, senior center, or community meals programs. Cash donations to buy food are also greatly appreciated.

The Extension Service offers its programs and materials equally to all people.

Free newsletter

The Oregon State University Extension office in Columbia County publishes a monthly newsletter on gardening and farming topics (called County Living) written/edited by yours truly. All you need to do is ask for it and it will be mailed to you. Call 503 397-3462 to be put on the list. Alternatively, you can find it on the web at http://extension.oregonstate.edu/columbia/ and click on newsletters. You can also be sent an email when the newsletter is posted.

Contact information for the Extension office

Oregon State University Extension Service – Columbia County

505 N. Columbia River Highway (across from the Legacy clinic)

St. Helens, OR 97051


Email: chip.bubl@oregonstate.edu