Issue: December 9, 2000

• Chile houseplant freeze injury
• Pet rabbit injury to young tree

Chile houseplant freeze injury

We have a chile as a houseplant. The top 3/4's of it got frost-bitten when we briefly placed it outside. Should we prune these apparently dead branches now or wait so see if the leaves will come back? Thanks! Steve Lekson

The chile plant may be able to regrow after this injury. It depends on how much damage was done by the cold weather. Since it was outside briefly, and if the temperature was not too cold, there is an excellent chance that only the ends of the branches or perhaps only the leaves were injured. It would be a good idea to wait and see if regrowth occurs.

During this time, reduce watering. The fewer leaves the plant has remaining, the less water it will use. If you continue to water normally, there is a chance of causing root rot. As new leaves are formed, begin increasing irrigation frequency.

It is good to know that someone else likes to grow chile as a houseplant. Many people think that it is an annual and only lives for the summer. The fact is that it functions as an annual because it freezes outside. In warm climates, or when it is grown indoors, it can live for several years.

Pet rabbit injury to young tree

Our children's pet rabbit chewed off all the bark down to the white under-wood of a 1-1/2 inch diameter new dwarf pear tree planted last spring. It is damaged from about the 2nd inch off the ground for about 12 inches. Is this the end for this tree? Can we save it? Also, is rabbit manure a good soil conditioner? OR, should we have rabbit stew some evening? Thanks. E. Baca

The vertical extent of the injury that you described is not as critical as the extent of the damage to the circumference of the tree. If the bark was removed from 1/3 or more of the trunk of this young tree, the wisest approach is to replace the tree. At 1/3 girdling, it might survive, but it will be significantly injured and slow to recover. A new tree will do a better job. Even with extensive girdling injury, bridge grafting can be used to repair the injury. In this type of grafting, a twig from the same tree is grafted into the healthy bark below and also above the injury. There are several considerations, such as polarity of the twig (up must remain up) that must be considered. If you wish to try bridge grafting, go to the library or book store and look for a book on grafting that discusses repair grafting.

If the injury was to less than 1/3 of the circumference of the trunk, the tree should be able to close the wound and grow fairly normally. It will be important for you to provide adequate moisture (not too much) during the growing season to allow wound closure. Now, an interesting fact about trees: wounds do not heal, they close. The damage will remain through the life of the tree. The cambium and bark will close over the wounded portion of the trunk and the tree will attempt to "wall-off" or partition the injury. If the tree succeeds in partitioning the wound, the tree should be able to grow fairly normally. If the partitioning of the wounded area fails, rot organisms will spread through the trunk. This may result in death or delayed failure of the trunk. In the case of delayed trunk failure, the tree may blow over many years after it appeared that the wound had "healed."

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.