The Gardening Season has started, and you may be asked questions. Use Ask an Expert, an online question-and-answer tool from the Oregon State University Extension Service. When answering a question, simply enter the address, and enter the county where you live. Here are a few questions asked by other gardeners. What's your favourite?
Q: I have a few clumps of Spanish bluebells infesting various parts of my yard, and I find them to be expensive and quite difficult to remove.
Some people claim to dig up the bulbs, but this is because there are a lot of baby bulbs that get away. Another advice is to remove the leaves and flowers out to starve the bulb. I even read advice that said to trample the leaves. Do you have any suggestions for how to get rid of these plants? Multnomah County
A: I am wearing your shoes. I have a large patch of bluebells.
One year I bet my husband that his technique of burning them would not be as effective as my method of often wearing hoes. It was a tie. Both methods took about the same amount of time, although I think I'm a little more thorough, so my "plot" has a few less than his...after three years of this.
As you said, digging them out is the most appropriate technique, as herbicides do not touch them. The problem with this is that the bulblets are small, and the bulbs themselves can be so thick.
If you cut the tops off every one to two weeks, they will then starve, but you have to be very diligent and it's difficult to keep it up until a whole season. I'll keep it up this year with a screen to sift out the smaller bulbs.
One year ago, I received a lot of success by instructing my grandchildren that they were hidden treasures, allowing them to dig with gusto. Yet that only worked once. I'm on my own again. Persistence is the key for any method you choose. Thank you so much for being willing to recognize a highly invasive plant and begin the process of eliminating it.
Hang in there after four years I'm down to plants I can manage. Rhonda Frick-Wright, OSU Extension Master Gardener
This rhododendron might need a darker spot.OSU Extension Service
Q: I have three rhododendrons, one is a bit stable, but it has yellow on the leaves, and the other two are very sparse. How can I get rid of the yellow issue on the leaves of the healthy one? Washington County
A: All are seriously stressed, including the leafiest one. (I don't really know why that one appears to be in much better condition than the others. Perhaps it has a larger root system.) In any event, it will take an extended effort to help the rhodies restore their health, an effort that should focus on regular regular regular supplemental irrigation, especially during the dry months.
The only way to get rid of both the brown spots and/or the yellow tissues is to grow new, healthy leaves. The most obvious signs of long-term stress are:
The bulk of the damage can be attributed to a lack of water supply coupled with a full-sun exposure. The single drip hose should be increased by at least two additional drip lines, each one closer to the shrub. After all, the soil should be thoroughly moistened for three weeks during the dry months. It may take one to 1.5 hours to complete the process.
Add a 3-inch-deep mulch of bark chips to the rhododendron soil to help preserve soil moisture, whether natural or supplemental. A particularly beneficial side effect of the organic mulch is that it will slowly degrade, thus providing an extended supply of fertilizer components for the shrubs.
Other options are to replace the rhodies by shrubs that are better suited to a sunny location and potentially a less water-thrifty diet. You may consider visiting several local garden centers to see, and ask about, several spring-flowering shrubs that will be a better fit to your site. Jean Natter, OSU Extension Master Gardener diagnostician
Why does this tomato blossom?OSU Extension Service
Q: I am curious if you can help me identify what is going on with my heirloom tomato starts. Germination seemed to be normal until the leaves were turned purple. Finally, the purple color spread to the first true leaves right above the cotyledons, and little bumps appeared on the underside of the purple leaves. It almost looked calcified, but it wasn't particularly textured.
The leaves formed a curl, and at this point we realized it was all of the 'Vernazza' variety. It then started spreading to the other solanaceous varieties, so we separated all tomatoes away from the other crops. I looked at the roots, and I don't see anything unusual, however I also don't see any pests.
I was wondering if you have seen this issue before, however, I intend to reseed any 'Vernazza' with fear that the seed is infected. I reached out to the seed company, hoping that they had heard or seen it happen. Multnomah County
First the good news: This is not an infectious illness condition, but a physiological response by the plants due to poor light conditions and increased water absorption. Low transpiration rates along with a decrease in water absorption due to wet soils increase cell pressure, causing the eruption of epidermal cells so that inner cells enlarge and protrude. Leaves may also exhibit curling and distortions, although certain varieties are genetically predisposed to develop symptoms early or to a greater extent when multiple varieties are sown alongside
This problem can be reduced by providing better lighting and/or decreasing the watering amounts or schedules, especially in cold or overcast conditions. In addition to this, the coloration of tomatoes is common for tomatoes, but it may also be a sign of a nutritional deficiency, such as a phosphorous deficiency. However, since your seedlings have oedema, I think this is because because your wet soil is also humid.
Good luck. I hope you have a fantastic tomato harvest this season. Cynthia Ocamb, OSU Extension plant pathologist