Stinkhorn mushrooms earn their name

Q: All summer we have had an infestation of nasty stinkhorn mushrooms in our mulch beds. We see the little mushroom balls that eventually bloom into odorous glory. These are not great for entertaining guests on the patio. My understanding is the only remedy is to remove all the mulch and scrape the topsoil … and then start over with a different kind of mulch. — Mark Testerman, Canton

A: I think the recommendation to scrape the mulch and topsoil is excessive. You don’t have to replace the mulch unless the stinkhorn balls are found throughout. The way to eliminate stinkhorns and have a more pleasant patio environment is to keep the mulch dry. A good way to dry out mulch is to rake it a few times with a leaf rake. If it’s being irrigated, stop until we have a freeze and it gets too cold for the mushrooms to develop.

Q: Our 20-plus year-old Japanese Maple has shown signs of Asian ambrosia beetle infestation since last year. On inspection, I removed sawdust and decayed wood and found white, living insects inside the trunk, along with occasional small black/brown beetles. I have not observed the characteristic “toothpick” frass typically associated with the Asian ambrosia beetle. — Dan Goldsmith, Santiago, Chile

A: You don’t see Asian ambrosia beetles because you’re looking at a different boring beetle. According to the pictures you sent, they are working in a wound in the tree trunk. Different beetles specialize in the damage they do to unprotected wood. I suspect these are another kind of ambrosia beetle that bores deeply in sapwood and kicks out lots of sawdust. These beetles can be controlled by soaking the wood where you see the holes with insecticide. This has to be done at least twice a year. The reason your Japanese maple has continued to thrive is that there is still some unharmed bark next to the wound. Moisture and nutrients travel under healthy bark.

Q: I have old azalea bushes that have leafless, dying branches. What could cause this? — Ron Laflamme, email

A: You will have to get on your hands and knees and inspect each of the limbs of your azalea. Particularly inspect the dead or dying limbs to see if you can find a starting point for the damage. Many times, you can simply prune back the dead part, and either the stub will sprout new leaves, or the limbs on either side of the gap will send branches into it.