Question: I called your office this spring to see if you thought I could successfully grow a garden in the soil where an old spruce tree and old grass clippings had been.
Should I dig out and replace the soil to build grow boxes above the soil? Could I just go ahead and use the soil? The person I talked to said I should give it a try. My neighbor tilled that spot, and I was amazed to see that the soil was soft, crumbly and black.
I planted directly in the ground instead of building grow boxes. Here is a picture of my garden; it’s been one of my best gardens. Thanks for encouraging me!
Answer: Thank you for the wonderful feedback! We’re here to help people with their landscape and garden problems and questions, but we also love to hear about garden successes.
Your experience is a great example of what good soil care can do for a garden. All that nice, decomposed organic matter made your soil rich, loose and well-drained — just what a vegetable or flower garden needs.
Don’t be afraid to add an inch or so of composted organic matter over the top of your garden every year to help keep your soil nice and crumbly.
Happy gardening, and thanks for the fun picture!
Question: I’m worried about my maple tree. There was no way to water most of the root zone for about a year. Now, it has at least 50 perfectly round borer holes in the trunk.
A medium-sized branch broke off, and the top is dying. I saw reddish-brown, wasp-type bugs flying around. Then I saw a giant ichneumon wasp. I want to know if I should cut the tree down soon for safety or can it be saved?
Answer: The insect in your photo with the ruler is a Pigeon tremex horntail, a non-stinging wasp. The “stinger” that you see is actually an ovipositor — the egg-laying structure used to insert eggs under the bark.
You can blame this insect for the holes in your tree, but not for the tree’s decline. The tremex attacks severely stressed or recently killed hardwood trees, like your maple, so the declining health of your tree attracted the borers, not the other way around.
The larvae of the Pigeon tremex tunnel and overwinter in the wood of the tree, reducing its structural strength. Snow and wind can cause weakened branches to fail.
The insect in your other photo is an ichneumon wasp. These wasps are beneficial. Females use sound and scent to locate tremex larvae in trees, then use the extra-long ovipositors to lay an egg on or near a tremex larva. Once the egg hatches the ichneumon larva will find and feed on the tremex larva.
These two wasps are commonly found together; where you find the tremex, you’ll usually find the ichneumon.
Insecticidal treatments aren’t recommended because the affected trees are already either dead or dying, and any spray treatment would harm the beneficial wasps.
You can avoid problems like this with your new trees by choosing trees that do well in our area; planting them properly; watering them deeply, but not more than once a week in the summer after they’re established and less often in the spring and fall; and taking time to give them a quick “exam” about once a month.
All of this is interesting for entomologists, but the real issue here is — does this tree present a hazard to you, your home or your neighbors?
The branch that broke off tells you the tree isn’t stable, and you mentioned there are some “targets” at risk if the tree fails. Your maple tree is close to a sidewalk where a branch or tree failure could injure a pedestrian or damage a parked car. Your home is also close enough to the tree to be damaged if the tree fails.
This tree is in decline, in very poor condition and can’t be saved. The borer damage looks extensive, so there are probably other branches ready to fail.The tree should be removed to protect your home and your neighbors.
If you aren’t sure, you can confirm this by consulting a certified arborist who is experienced and qualified to do a Tree Risk Assessment.