CORVALLIS, Ore. – Searching the internet for gardening information is quick but often frustrating and accuracy can be an issue. Asking a professional via the expediency and ease of an email provides answers you need backed by research you can trust. 

Ask an Expert, a free online question-and-answer service of Oregon State University’s Extension Service, has a cadre of specialists who will answer your questions on average within 48 hours.

Since 2011, OSU experts have answered 26,056 questions, according to Sandy Reichhuber, the program’s administrative program assistant. In 2018 so far, the number of questions logged is about to break 5,000. The subject matter is far ranging, but questions about insects, sustainable gardening, plant identification, lawn care, and tree and shrub issues are especially common.

“Oregonians are finding research-based answers directly from our experts,” Reichhuber said. “More people are using us every year. Ask an Expert really makes a difference.”

Here’s a sampling of some recent questions. Get on board with yours.

Q: Why exactly does fireweed thrive so well in disturbed landscapes, such as after the 1980 volcanic eruption at Mount St. Helens and after a fire?

A: There are typically two answers to this question, depending on the type of plant: "opportunity" and "genes." As to the first, when terrain is covered with tall trees and shrubs that use up a lot of the soil's moisture and nutrients and keep sunlight from hitting leaves of shorter, smaller plants, the canopy restricts the smaller ones from growing. As to the second, some plants' seeds or pods or cones do not germinate until and unless they have been subjected to very high temperatures created only by an intense fire.

As to fireweed, the answer appears to be opportunity – "let the sun shine in." Here's a link to a Forest Service article about this plant, how it colonizes and reproduces, and its benefits to its environment. – Kris LaMar, OSU Extension Master Gardener

Q: This tree is growing in Cedar Canyon near Banks and has this weird growth on it. Mistletoe? Witch's broom? Something else?

A: This is an uncommon, but routinely observed, phenomena sometimes called stimulation broom. No one knows what causes this, but some type of stimulation must be involved. Brooming is a general term for branches that become abnormally clustered, or lose apical dominance and sprout lots of branches from one area.

Douglas-fir dwarf mistletoe does not occur west of the Cascade Mountain crest in central and northern Oregon, so it’s likely not that.

The classic pocket guide: "Common Tree Diseases of British Columbia" by R.E. Foster and G.W. Wallis from 1974. (Canadian Forestry Service) has a picture of this exact brooming. The photo is titled, "large stimulation broom in the crown of Douglas-fir, cause unknown."

That sums it up. These occur throughout the Northwest, but no one knows what causes it.

A mystery! – Dave Shaw, OSU Extension forestry specialist

Q: I grew up in Benton County and had an intense interest in insects as a child. I still live in Benton County and keep an eye out for those insects I knew. I have noticed a definite decrease in the numbers of insects over the past years – no cicadas that buzzed regularly on warm summer days, no giant katidids with their single shhhht call, and few mantis. I could go on with a long list of the missing. What do you think is going on?

A: You are very perceptive to notice the decline in insect abundance. This is a worldwide phenomenon, with potentially dire consequences for the Earth's ecosystems. It has been much in the news lately: Hyperalarming study shows massive insect loss and Bye-bye bugs? Scientists fear non-pest insects are declining.

Habitat preservation and restoration on a large scale is the only real answer. If enough people and communities make insect-friendly habitat a priority in their gardening and landscaping, it is possible this trend can be reversed. However, a piecemeal approach is only moderately helpful, as I can personally testify. I have an abundant, diverse, insect-friendly garden, but it is surrounded by lawn-dominated suburban lots and mowed fields, so the variety of insects I see in my garden is not very large. Butterflies, in particular, are very scarce –  they need larval host plants to thrive, and one garden can't really supply enough.

If you want to see and hear the insects of your youth again, be an insect evangelist. Encourage everyone you know to plant a diverse, pesticide-free landscape, to leave unmowed natural areas and hedgerows, to plant native plants, to leave dead plants standing in the winter, and in general to allow more room in our lives and landscapes for the world's smallest, but in many ways most important, creatures.

The Oregon Bee Project is one resource with lots of good information. It is focused on bees, but good for all insects as well. – Signe Danler, OSU Extension Master Gardener

Q: This year, our two old laurel trees produced a large number of berries. What is the most effective way of reducing the number of berries?

A: You can reduce the number of berries by pruning off the flowers. This can be done by shaping the plant (shearing) prior to bloom, which is often done to prune the plants into a formal hedge. This will usually cut off most, or all of the flower buds, depending on how deeply into the canopy you cut, because flower buds will be concentrated near the tips of the previous season shoots. Or if you prefer to enjoy the blooms, which do smell nice, prune the plant as the blooms fade, which will eliminate the berries as well. – Neil Bell, OSU Extension horticulturist


Extension Service

About the OSU Extension Service: The Oregon State University Extension Service shares research-based knowledge with people and communities in Oregon’s 36 counties. OSU Extension addresses issues that matter to urban and rural Oregonians. OSU Extension’s partnerships and programs contribute to a healthy, prosperous and sustainable future for Oregon.

Story By: 

Kym Pokorny, 541-737-3380, [email protected]


Sandy Reichhuber, 541-737-0799, [email protected]



Click photos to see a full-size version. Right click and save image to download.