<body><div><figure><img src="https://img.particlenews.com/image.php?type=thumbnail_580x000&amp;url=1c2UlS_0kNRcFRm00" alt="https://img.particlenews.com/image.php?url=1c2UlS_0kNRcFRm00" width="1280" height="720" ></figure>Gardening season is in the rearview mirror, but you may have questions as you plan for next year. To ask one, simply go to the <a href="https://extension.oregonstate.edu/ask-expert">OSU Extension website</a>, type it in and include the county where you live. A photo is very helpful.Q: Late last spring we took out an area in front of the house that had gravel paths bounded by boxwood hedges. We removed all the gravel to bare dirt, tilled the areas down about 6-8 inches, brought in new garden soil as an amendment, tilled that in, raked it all out and seeded per Extension Service publications.We used a perennial rye seed developed here in Oregon. We had automatic sprinklers set up, so the watering was controlled closely all summer long. The grass generally came in well except for the three areas I noted with red arrows in the attached pictures.The areas that didn’t come in well are where the boxwood hedges were removed. When we removed them, we dug them out completely making sure we got all the roots. Could the boxwoods have left some kind of toxic substance behind that is making the grass struggle? If so, how do I get rid of it? If they did not leave a toxic substance, do you have any other ideas for why the grass is struggling in these areas? – Clackamas CountyA: My guess is that a pre-emergent herbicide (possibly Casaron) was put in the beds where the boxwoods were growing to prevent grass and broadleaf weeds from germinating. Does this ring a bell? Did you or a landscape maintenance service apply a pre-emergent herbicide? I have never heard of boxwoods leaving behind growth-suppressing chemicals although some plants do indeed do that to reduce competition. The chemical should break down over time. I would try to re-seed again in mid-April. If the lawn dies again in these areas, remove the soil down to about 4 inches and then replant. – Brian McDonald, OSU Extension turf expert<figure><img src="https://img.particlenews.com/image.php?type=thumbnail_580x000&amp;url=2Jc1J3_0kNRcFRm00" alt="https://img.particlenews.com/image.php?url=2Jc1J3_0kNRcFRm00" width="1280" height="1025" ></figure><h2>What sort of trees attract emerald ash borers? </h2>Q: Is the golden desert ash, Fraxinus oxycarpa aurealfolia, susceptible to getting the emerald ash borer? We have two of them as street trees in Forest Grove.Also, my next-door neighbor has two summit ash street trees. I googled summit ash and learned that it has the scientific name of Fraxinus pennsylvianica and that the emerald ash borer has attacked it. Is this true?I looked for D-shaped openings in my two golden ash trees and his two fairly large summit ash trees and did not see any D shaped openings. Not sure whether I knew what I was looking for, however. – Washington CountyA: Yes, Fraxinus oxycarpa is definitely susceptible to EAB. As well as Fraxinus pennsylvianica. This <a href="https://www.oregon.gov/odf/Documents/forestbenefits/fact-sheet-emerald-ash-borer.pdf">guide</a> notes susceptibility. Here is a <a href="https://extension.oregonstate.edu/forests/cutting-selling/what-do-about-emerald-ash-borer-recommendations-tree-protection-eab">guide</a> about “What to do”. It contains suggestions for protecting trees with insecticides if that is an option you would consider. – Dave Shaw, OSU Extension forester<h2>Is it ok to disturb insects by adding mulch in winter?</h2>Q: I am in the process of removing my front lawn and need to rake up some wood chips. I was impatient and spread the chips around my new plantings last spring without sheet mulching with cardboard first, and now the grass is starting to peek back through.I have also read about the importance of not disturbing yard debris during the winter so as to allow overwintering insects a chance to finish doing their thing and emerge in the spring. At what point in the spring would it be least disruptive for me to rake back the wood chips and sheet mulch?Alternately, would it be advisable for me to just add more wood chips on top of the existing ones, or would that also be problematic for overwintering insects?I’m not particularly concerned about the grass coming through as an aesthetic thing, more about it competing for moisture. I guess my priorities here are:<ul><li>Mulching to conserve soil moisture during the dry months</li><li>Not disrupting my local bugs</li><li>Trying to get the grass covered before it really starts growing in the spring.</li></ul>– Multnomah CountyA: Thanks for your question about the complex issues of trying to mulch for weed control and help the insects you are harboring.Here is my best take on your situation. I would go ahead and rake up the chips into a pile now and put your cardboard down. Most of the insects are in a dormant stage and if you spread the chips out soon (don’t let them sit in a big pile that heats up,) your insects should be fine to hatch out when the weather warms up. If it would be easier to just add more chips now, that is also an option. There might not be as many insects in the chips as you think since most of them need to burrow down to a warmer layer to overwinter. Also, they are very persistent in being able to work their way through layers to hatch in the spring. More insects will move in when you have the right chips to keep your grass under control. Thanks for helping our arthropod communities! – Rhonda Frick-Wright, OSU Extension Master Gardener<figure><img src="https://img.particlenews.com/image.php?type=thumbnail_580x000&amp;url=1K7T0z_0kNRcFRm00" alt="https://img.particlenews.com/image.php?url=1K7T0z_0kNRcFRm00" width="1280" height="847" ></figure><h2>How much water is too much for manzanitas?</h2>Q: I recently planted two madrones and one manzanita in sunny, well-drained areas of our yard. I understand that these plants do not like water during the summer, and that they perform best when planted in late fall/early winter so they can get established while it’s raining.However, I have read some accounts where a gardener noticed their recently planted madrones or manzanitas were “wilting” during the hot summer and gave them “a little drink”.My question is - what constitutes “a little drink?”I’m guessing it’s not the long, deep watering I give my other recently planted trees, but I also don’t want to give too little water either. I’ve already killed one manzanita with summer watering and do not want to make the same mistake with these guys. Anything a little more specific would be appreciated. – Multnomah CountyA: During the first year (or two) extra water to the roots during summer is generally recommended. You’re right though to avoid constant deep soaks. I can’t be more specific because so much depends on your soil drainage and the root size of your plant. Watch the leaves for signs of severe drought stress. Before actual wilting, leaves will often change texture or glossiness.<a href="https://landscapeplants.oregonstate.edu/plants/arctostaphylos-andersonii">Here</a> on the Oregon State Landscape Plants page for Anderson’s manzanita, you’ll see 29 others listed to the right. Check out growing conditions for the one you have. Also, the write-up on specialty nursery pages for your plant can be helpful. This article about growing manzanitas from <a href="https://xeraplants.com/arctostaphylos/">Xera Plants</a>, for instance. The nursery is located near Portland which makes advice regionally appropriate. <a href="https://pacifichorticulture.org/articles/arctostaphylos-for-pacific-northwest-gardens/">This Pacific Horticulture</a> article is another I’ve also found helpful. Knowing about the specific type you have is important as the best growing conditions are not all the same for each type of manzanita.Madrone trees require the correct location, soil and care also. Check out <a href="https://extension.oregonstate.edu/news/native-madrones-are-special-northwest">this OSU Extension</a> article to better understand growing these trees. – Jacki Dougan, OSU Extension Master Gardener</div></body>

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What’s killing the grass we planted where a boxwood hedge once stood? Ask Extension

Gardening season is in the rearview mirror, but you may have questions as you plan for next year. To ask one, simply go to the OSU Extension website, type it in and include the county where you live. A photo is very helpful. Q: Late last spring we took out...