Issue: January 4, 2003

Pollarded trees

I toured several cities in Europe this fall and noticed that many of the street trees in those cities have been topped. I thought that was not good for the trees. Why do they do this?

The trees you saw were probably "pollarded", which looks like topping but differs in some significant ways. This procedure is done to allow the growing of trees in smaller streetscape settings and also as a matter of tradition. Pollarding of trees began hundreds of years ago as a way of producing annually renewed stove wood and weaving wood for baskets. The look of pollarded trees became accepted as a normal appearance of trees, so pollarding continues, especially when a formal garden appearance is desired. I hope by now you are wondering about the difference between topping and pollarding. In the case of proper pollarding, the branches that are cut are never more than one- to-two years old. In topping, much older and larger branches are cut. Only a few varieties of trees tolerate pollarding as a management method. The pollarding process does not severely circumvent the natural protective mechanism that protects the tree from disease and insects. Topping, on the other hand, totally defeats the protective mechanism of the tree. During the dormant season, you can see that all the new growth on a pollarded tree is small (one-to-two years old) and originates from the same area of the branches. Every one-to-two years, the sprouts are cut back to the same area of the branch stump where they originated. This results in knobby ends to the major branches from which the new sprouts grow each year. Topping is indeed not a recommended manner of pruning trees. Pollarding is okay as long as you are willing to assume the responsibility and expense to assure that it is done every one-to-two years for the life of the tree.

Houseplant winter fertilization

Should I fertilize my houseplants during the winter?

If your plants are receiving sufficient light and the location will allow for growth, you can fertilize your houseplants. Choose the type of fertilizer based on the type of plant. Plants grown for their foliage need fertilizer higher in nitrogen while flowering plants need more phosphorus. Read the label on the fertilizer container to determine which nutrients are available and their relative proportions. If your plants are becoming leggy because of low light and high temperatures, fertilization may increase the problem. If the space is limited, encouraging growth by fertilization will definitely add to the problem. Based on the type and needs of the plant, and also the growing conditions, you can determine whether fertilization is right for your houseplants.

Also, please join us on Southwest Yard & Garden, a weekly program made for gardeners in the Southwest. It airs on KRWG in Las Cruces Saturdays at 11:30 a.m., repeating Thursdays at 1:00 p.m.; on KENW in Portales on Saturdays at 10:00 a.m.; and on KNME in Albuquerque on Saturdays at 9:30 a.m.

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 an Extension Horticulture Specialist with New Mexico State University's Cooperative Extension Service. New Mexico State University is an equal opportunity/affirmative action employer and educator.

Please join us on Southwest Yard & Garden, a weekly garden program made for gardeners in the Southwest on: KNME-TV Albuquerque at 9:30 p.m. Saturdays, KENW-TV Portales at 10 a.m. Saturdays, and KRWG-TV Las Cruces at 11:30 a.m. Saturdays (repeated at 1 p.m. Thursdays.)