Gardening season is underway, and you may have questions. 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: Something is pulling my Ailsa Craig onions from underground and eating the entire thing. There are no mounds of dirt nearby. I just realized this creature has eaten probably 20 onions or more. Any advice on stopping this fat critter? – Linn County
A: I looked up your onions and as suspected they are sweet onions. Rodents love sweet bulbs. There are a few culprits that could be doing this – gophers, voles or mice. The holes look to be small, so I am thinking voles or mice. Voles look like mice with shorter tails and are also called field mice. You may not see tunnels as they can tunnel long distances. Sometimes there are indentations in the ground.
The only way to save the onions that you have now is to carefully dig them up, not damaging the roots, and put them in pots.
Then, when you have the time, you need to empty your raised bed and put a fine metal mesh cloth on the bottom and nail it every few inches so they cannot get in from the ground. Fine means 1/4 inch or less holes. However, they will crawl over the raised bed so you might consider a protective covering for the top as well. Or plant them in pots.
Another less suggested treatment are mouse traps set in the garden. They like peanut butter and cheese. However, you must keep your pets and children away from the traps.
There are some organic treatments, such as repellents that will dissuade rodents in general. My experience is that it works sometimes.
You can also plant various flowers that rodents do not like, such as marigolds and lavenders. They do not like but may tolerate essential oils of cloves, cinnamon, rosemary and eucalyptus. However, they are expensive and need to be sprayed often. – Sheryl Casteen
Q: I have a large pile of wood chips from two spruces that had to be taken down last year. The pile sat for one year. At this point, would the chips/mulch still be too acidic to use as ground covering under a Japanese maple tree, around perennials (flowers and grasses) and under rhododendrons? – Lane County
A: No problem using the chips for mulch. Chips break down very slowly and unless turned underground have no adverse effect on the tree. – Pat Patterson, OSU Extension horticulturist, retired
Corkscrew or curly willows love plenty of water. OSU Extension Service
Q: I live in Linn County and have a curly willow with dying branches, bark splitting and sucker shoots. I’m not sure if the emerald ash borer can infect this tree or maybe another pest. Any suggestions on how to help my tree? – Linn County
A: There is no way to diagnose a disease or insect from your photo, but I will say that curly willows are very prone to having random branchlets and branches die back. It does seem a bit excessive on this one, though.
No, they would not get emerald ash borer since that only attacks ash and is not (yet) widespread here anyway. You can inspect the dead branches for signs of canker, rot, damage or insect boring – any of those would give you a clue as to the problem.
The problem could well be cultural. Is it getting enough water? Willows are very thirsty. Planted in the middle of a lawn, it may not be getting enough, especially if you water frequently and shallowly for the lawn. The grass may take most of the shallow water, and as the deeper soil that the willow can access dries out, there is not enough water for it.
I also see something at the base of the trunk that could be a girdling root. If it is, there could be others – this is common if trees are pot-bound when planted and the roots aren’t effectively loosened and spread out. Eventually girdling roots can cut off the circulation of parts of the tree and the top growth above the root will die. Something else to check out. – Signe Danler, OSU Extension online horticulture instructor
Are these newly hatched stink bugs?OSU Extension Service
Q: I found an egg cluster on the underside of a petal from a flower I brought in as a floral bouquet. I thought they might be butterfly eggs so I followed directions to allow them to morph. Clearly, they are not caterpillars. What are they and are they harmful? – Lane County
A: It’s often summer pruning that turns up brown marmorated stink bug (Halomorpha halys) eggs and nymphs, but cut flowers can harbor them, too. The brown marmorated stink bug (BMSB) has piercing-sucking mouthparts with a straw-like stylet that sucks plant juices. They feed on leaves and stems but prefer reproductive structures like fruits, pods and seeds. BSMB is also a homeowner nuisance pest because it has overwintering habits to seek shelter in residents’ homes, similar to boxelder bugs and lady beetles. BMSB first showed up in Oregon in 2004, and feeds on more than 100 plants, particularly vegetables, pears, apples and hazelnuts, but also ornamentals. You can find more information about these pests here and report a sighting in the OSU tracker. BMSB is now present in counties throughout Oregon, but is most prevalent in the Willamette Valley, where it can be found in urban, rural and natural areas.
Oregon has offered BMSB a comfortable environment with abundant habitat and fewer natural enemies than it has in its native range of China, Korea and Japan. However, that may be changing as the Samurai Wasp (Trissolcus japonicus) was discovered in 2015 along the Oregon border in Vancouver, Wash., and in 2016 in Portland. This minute wasp (1-2 mm) is BSMBs chief natural enemy in Asia and has recently been found in Salem and Beaverton, and we expect that it will continue to spread.
Female Trissolcus wasps seek out the egg masses of BMSB, and they lay their own eggs inside. Instead of the BMSB eggs hatching with BMSB nymphs, they instead produce a new set of wasps. The wasps don’t sting people and a clear sign of their activity is BMSB egg masses that darken to a black color.
OSU scientists are tracking the Samurai Wasp and redistributing to selected sites in Oregon. – Stephen Oldfield, OSU Extension Master Gardener
