WATERING SCHEDULES AND CHRISTMAS CACTI

by Curtis Smith, Ph.D.  

Q. A friend asked me to look on the computer for any information regarding what to do for a fig tree in the winter. We live in zone 6. I'm not sure if this tree is in the ground or potted. Any information would be appreciated.

A. I assume you are asking about edible figs, not ornamental figs and will provide an answer appropriate for the edible figs. While figs will grow in New Mexico as far north as Albuquerque, that is pushing their limits. Albuquerque is in hardiness zone 7 as determined from the U.S. Department of Agriculture's hardiness zone map. I am not aware of figs growing further north in New Mexico. However, in a protected courtyard, it is possible that they will grow in colder climates. In zone 6 a protected location shielding the tree from the coldest weather and where the soil doesn't freeze would increase the chances of the tree's survival. It may freeze to the ground many winters, but if it is a variety that bears on the current season's growth, it will still produce figs. There are other varieties that produce on older growth. These will not produce figs if they freeze to the ground. It is possible to wrap the tree with insulating material after the weather has turned cold and the fig tree has lost its leaves. This must be done with special care. If it warms inside the protection, the tree may begin growing and suffer severe damage in the next cold spell. This protective material must be removed while it is still cold to avoid the situation described above. The tree will begin to lose dormancy when the weather warms and be very subject to damage once the material is removed if the timing is not good. You must also be prepared to replace the covering quickly if late, extremely cold weather is expected. A potted tree may be easier to grow. Once it is dormant, it can tolerate some freezing and doesn't need light. What must be avoided is extreme swings in temperature and excessive warming. The tree may be stored in a cold garage in which the temperatures range from below freezing to a little above freezing. It will need to be watered as the soil dries but will need little additional care until the weather warms.

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Q. Are snails and slugs a problem throughout the U.S.A.? Alden

A. The answer depends on the context of your question. Snails and slugs are a problem in landscapes and gardens in much of the U.S. In the natural environment, they are not as great a problem. Here in New Mexico, they cause problems only where we irrigate and have imported them in the soil of our landscape and garden plants. I don't remember any problems with snails and slugs when I lived in Montana. Perhaps that was due to the cold winters, but the lack of any problems may have been because fewer imported plants from snail- and slug-infested areas were used in landscapes. So, I can answer from the context of New Mexico. They are a problem in our irrigated landscapes and gardens. In the desert, they are not a problem. Perhaps Extension Service people in other states could answer for their states.

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

A. 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.

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Q. 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?

A. 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.

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Q. Our pinon tree is dripping sap in large amounts. The tree grows over our flagstone patio, and the patio is covered with a fine spray of sap or pitch. Is there anything we can or should do to prevent this? via internet Santa Fe

A. I suspect that the problem is pine aphids because you described the problem as a fine spray. The aphids that would be on your pinon look like clusters of small spiders on the branches (they have longer legs than most aphids and look like spiders). They feed on the sap from the tree and excrete a sugary substance called "honey dew." The honey dew is the fine spray that you are seeing on the patio. The answer to this problem is to reduce the number of aphids on the branches. You can use insecticides, but in many cases washing the branches of the pinon with a strong jet of water will knock the aphids out of the tree. The aphids will try to climb back into the tree, but many will not succeed. If you wash the branches frequently (once a week or so), you can reduce the population of aphids enough to control the problem. By the way, the reduced number of aphids will do little damage to the tree, so washing should be sufficient to solve the problem.

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Q. What will happen to leaves I put into my compost this fall? Will they wait until spring when it gets warmer to decompose?

A. If you add green grass clippings, manure, or some other source of nitrogen to the leaves, they will decompose through the winter. The heat in the compost is generated by the composting organisms; it does not come from the air. Of course, the air may cool the compost and slow the decomposition process around the edges of the compost, but the center should generate enough heat to continue composting through the winter.

This depends on the balance of materials in the compost. A source of nitrogen, such as green grass clippings or manure, should be mixed with a source of carbon such as brown leaves or shredding branch trimmings. The nitrogen and carbon are the foods needed by the composting organisms such as fungi and bacteria. They will generate heat and decompose the landscape debris so that in the spring you will have a supply of compost to add to your garden as a soil conditioner.

Just remember that you will need to supply moisture to the compost and to turn the compost materials through the winter.

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Send your gardening questions to:
Yard and Garden, ATTN: Dr. Curtis Smith
NMSU Cooperative Extension Service
9301 Indian School Road, NE, Suite 112
Albuquerque, NM 87112

Curtis W. Smith, Ph.D., is a an Extension Horticulture Specialist with New Mexico State University's Cooperative Extension Service. Dr. Smith and Dr. George Dickerson host Southwest Yard & Garden, a weekly program for gardeners in the Southwest. It airs on KRWG in Las Cruces Saturdays at 11:30 a.m., repeating Thursdays at 1 p.m.; on KENW in Portales on Saturdays at 10 a.m.; and on KNME in Albuquerque on Saturdays at 9:30 a.m.

Questions or Comments? Email editor@nmjournal.com