Fall is on the horizon, but the gardening season isn’t over yet, and you may have questions. To ask a question, simply go to the OSU Extension website, type it in and list the county where you live. The picture is very useful.
Q: I need some help and wisdom with a big problem. I have these insects on the bottom of my raspberries and last year I removed the entire crop to rid myself of them because they were covering the plants. I discovered they were all over the big tree behind my fence, which in the fall sheds leaves covered in insects. what are they? How can I get rid of them? I like to eat berries, not insects. Any thoughts? -Washington County
A: It sounds like you have the lace bug. I can’t find any reference to lace bugs on raspberries, but they have become more of a pest on other plants and I believe they are coming from one of the trees in your neighbor’s yard. Controlling them involves six steps that may not get rid of them completely but will hopefully reduce the population:
- Monitor plants for early infection. Small clusters of oval-shaped eggs are laid on the undersides of plants.
- Prune and dispose of infected leaves from your plants and any leaves that fall into your yard from neighbors’ trees.
- Spraying high-pressure water under the leaves may help when wingless nymphs are spotted or when leaf discoloration begins to flush them out.
- Make sure your plants have water and nutrients to help them resist lace bug damage.
- Insecticidal soap or horticultural oils can be applied to the undersides of leaves before flowering or after harvest.
- Beetles, lacewings and other predatory insects can be released or encouraged to enter on their own. Planting dill, cilantro, or fennel will help attract these insects to your area.
Harvesting the berries immediately when they are ripe will help you have a crop to eat and beat those miscreants. – Rhonda Frick-Wright, Master Gardener at The Ohio State University
Why did the radish become long and narrow?
Q: I grow radishes in the greenhouse year-round. I live in Yachats with mild winter temperatures, which rarely freeze. I noticed that about 25% of the radishes grow long and narrow instead of in a round ball shape. These are also usually tough and rubbery. What am I doing wrong? The variety is ‘Cherry Bell’. Plant the seeds 1/4-1/2 inch deep. -Lincoln County
A: When radishes grow long and narrow, it usually means they’re crowded in the soil, causing competition for water and nutrients. It causes the plant to send its roots farther into the soil. It’s always a good idea to plant seeds 2 inches apart or thin out seedlings to this distance to ensure they don’t get too crowded. Another cause of long, narrow roots may be too high temperatures and/or insufficient water. Growing radishes in the 50-65 degree range and hotter temperatures may cause the roots to grow downward and not form the round ball we want. A firm, rubbery radish likely indicates that the radish has been left in the ground for a long time. They are ready to harvest when the top of the red root is about one inch in diameter and begins to push up through the soil. They are fast growers so it is best to harvest sooner rather than later. -Bill Hutmacher, Master Gardener at Ohio State University
What is the best way to prune a dogwood?
Q: I have two large red-twig dogwood trees that I planted about six years ago. I’ve done some light pruning in the past, but now it’s completely overgrown. I have read various methods of pruning from cutting them to the ground to removing only a third of the old branches. What is the best way to prune a larger plant? Is it also necessary to wait until early spring as mentioned in some articles I found? – Multnomah County
A: There are many ways to manage red twig dogwood. Once established, you can make a mistake for a year and the plant will likely recover, so I hope you’re willing to experiment.
In some spaces, cutting them almost to the ground each winter and enjoying full regrowth on the branches is what the gardener wants, while other gardeners want consistently large, bold shrubs. If you want red bark branches every winter, wait until the leaves start to appear on those red branches before cutting the shrubs (February or so).
However, if you want the shrubs to be the size they are now, cut off a third of the branches every year. This means that two-thirds will flower and make berries but lack the bright bark color.
I have a dogwood bush in a mixed hedge that I forgot to prune last winter. They are huge. I know from experience that I can cut them back significantly at this time of year and they will recover in the spring. However, the color of the fall leaves is stunning, so I plan to cut them down to ankle height once the leaves fall. This sacrifices the red branches of January, but I can’t afford to miss the heavy March pruning window again. My answer seems like a big shrug of the shoulder, but in many situations these plants are really that resilient. – Jackie Duggan, Master Gardener at Ohio State University
Can dahlia tubers overwinter?
Q: I still have dahlia tubers that I didn’t plant. Can they overwinter again without being planted? Tillamook County
A: It may have dried out by now depending on how you stored it. They need some moisture inside to keep the fetus alive. However, there is no harm in trying to winter them again. Store them again in a cool, dry place in a container with sand or dry compost and make sure the roots do not touch each other. During the winter, check for rot and discard any rotting tubers. Then replant them in the spring and hopefully they will provide some pretty flowers. – Bill Hotmacher, principal gardener at The Ohio State University