Issue: November 18, 2000

• Remov1ng paper wasp nest
• Coffee grounds in flower pots
• Grubs in compost

Removing paper wasp nest

Is there a humane way of removing hornet nests from eaves? I would rather not shoot the nests with those chemical sprays that are available, but the nests are accumulating around the eaves of the house.

You are probably describing the paper wasps which often build their flattened, dish-shaped nest under the eaves of our homes. According to Dr. Carol Sutherland, NMSU Extension Entomologist, the weather has been cold enough in most of the state to drive the wasps from their nests. They have taken winter refuge in various hiding places (attics, cracks and crevices in your house and surrounding structures, as well as under rocks and mulch materials). They will return to the nests in the spring, but now in their absence you may remove the nests with little worry about the wasps stinging you. Dr. Sutherland stated emphatically that this is not true of honey bees. They persist in the nest all winter, so don't apply this advice to bee removal.

Next spring the wasps will emerge from their winter hiding places and return to the nests or to the sites where the nests once existed. At that time, you may need to take some action to discourage nest reconstruction.

Coffee grounds in flower pots

Is it safe to put old coffee grounds on my houseplants?

It is okay as long as you don't overdo it. In fact, there may be some benefits. However, if you put too many into the pot, there may also be some detriment.

There will be some nutrients released as the coffee grounds decompose. This is good, but the decomposition process can cause some problems. As the coffee decomposes, various fungi (which are necessary to decompose the coffee grounds) may increase resulting in disease in the houseplants. The process of decomposition produces heat which may be sufficient to damage or kill the houseplant if there is a thick layer of coffee grounds. In a thick layer, the coffee grounds may become soggy. This sogginess may create an environment conducive to the growth of damaging fungi and bacteria, which may then kill your houseplant. Various organic acids may also be released into the soil creating an unfavorable environment for some plants.

Use the coffee grounds sparingly, and be careful with water after application of coffee grounds to the soil. Concerns about increasing acidity will also be eliminated by sparing use of coffee grounds around the plants.

Grubs in compost

I have a composter and it is working well. However, there are many, many grubs in the pile. I am afraid to put the compost in my garden or around the yard. Do I need to kill them or will they be okay? I am assuming they are grubs. They are small white/brown worms. Jeff Gruda

Grubs are common in composting material. They are fat, white, larvae of beetles. They have a brown head capsule and legs and a dark gray area at the end opposite their head. There are other "worms" that inhabit compost, so be certain yours are really grubs.

Grubs may actually participate in the composting process. There are many types of grubs, so yours may not be a problem. However, it is possible that they are a problem. You should consult with your local Cooperative Extension Service agent for information about the grubs common in your area.

If you have a problem, you may use various insecticides labeled for use in the location (vegetable garden, flower garden, etc.) where you will apply the compost. It is also possible to kill the grubs by heating the compost in a plastic bag placed in the sunlight for several hours or days prior to applying the compost to the garden. However, treatment will probably not be necessary.

Send gardening questions to Southwest Yard and Garden, Attn: Dr. Marisa Thompson at desertblooms@nmsu.edu or at https://www.facebook.com/DesertBloomsNM/. Please include your county Extension Agent (aces.nmsu.edu/county) and your county of residence with your question!

For more gardening information, visit the NMSU Extension Horticulture page: desertblooms@nmsu.edu.

Marisa Y. Thompson, PhD, is the Extension Horticulture Specialist, in the Department of Extension Plant Sciences at the New Mexico State University Los Lunas Agricultural Science Center, office: 505-865-7340, ext. 113.