Issue: Octob1r 20, 2001

Sawdust in firewood

I was stacking pinon firewood the other day and noticed a lot of sawdust and small insects. Is this something to be concerned about?

The sawdust may indicate the presence of pine bark beetles. It may also indicate borers. The insects you saw may or may not indicate a problem because there are many insects that will inhabit firewood piles. Many of the insects in the firewood are benign. The bark beetles are the greatest concern.

If you peel the bark from the wood and find "engravings", the tunneling patterns left by bark beetles as they feed on the layer just under the bark, you have a concern. Borers will also leave engraving marks, but they are usually broader tunnels. You may also find the adults of these insects. Your County Extension Agent can help you identify what insects you have found and if they will be a problem. It is the bark beetle that is the greater threat to your landscape trees.

To be safe, stack firewood away from pine trees in a sunny location. Cover the firewood with clear plastic and seal the edges with soil if the firewood is showing signs of recent insect activity (fresh sawdust). This covering with clear plastic in a sunny location will allow the heat from sunlight to kill the beetles, and it will also contain the beetles keeping them from infesting your nearby landscape trees.

Covering the firewood with plastic will interfere with the curing of the firewood, so after a month or two uncover the firewood to allow it to cure before burning. Cured firewood may have borers but will not have active bark beetles and will not need to be covered. When possible buy aged, cured firewood.

Keeping flowering fruit trees from fruiting

For the past several years I have wondered if there is a way to keep my ornamental (flowering) fruit trees from making fruit. The fruit is not edible but makes a mess. Is there something I can spray to eliminate the fruit problem?

There is a product called a fruit eliminator which is labeled to prevent or at least reduce fruit production on a large number of ornamental trees. It functions by producing ethylene gas, a naturally occurring plant hormone that can cause immature fruit to drop if applied when the fruit are very small (just following flowering). It will not be effective if applied later.

I have seen it promoted by some horticultural supply retailers in New Mexico, so I suspect you can find this product in the state. Be sure to read the label to determine if it is labeled for your types of fruit trees. Then be certain to follow the directions when using the fruit eliminator.

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, email: desertblooms@nmsu.edu, office: 505-865-7340, ext. 113.

For more gardening information, visit the NMSU Extension Horticulture page at Desert Blooms and the NMSU Horticulture Publications page.

Send gardening questions to Southwest Yard and Garden - Attn: Dr. Marisa Thompson at desertblooms@nmsu.edu, or at the Desert Blooms Facebook.

Please copy your County Extension Agent and indicate your county of residence when you submit your question!