November 26, 2016

1 - The delayed onset of cold weather has not harmed trees and shrubs, but now that winter has arrived you can begin pruning and doing other winter garden chores.

Q.

I have finally had a frost in my garden. This is the latest I have ever seen frost in the fall, will that hurt my trees? Can I prune my trees now? What else should I be doing in my garden now that the frost finally came?

- Tom G.

Albuquerque

A.

This year the warm weather has lasted longer than usual, but there have been other warm autumns in the past. Plants are usually capable of surviving such variations in the weather. Drought and lack of irrigation is usually much more harmful to plants. Some temperate zone plants may exhibit problems if there would be no winter. When I was young, I lived in Southeast Texas where winter was relatively warm and brief. In that location we could grow lilacs, but they would rarely produce flowers because a longer period of cold temperatures was necessary for them to flower. In Albuquerque, even with a delay in the onset of cold weather, trees and shrubs should exhibit no injury.

We usually recommend waiting until after deciduous trees and shrubs have entered dormancy before conducting major pruning as this allows the plants to store nutrients necessary for good growth next year. However, dormancy may be controlled by both day length and temperature. Some trees and shrubs may have already entered dormancy under the influence of diminished day length, but others may have delayed dormancy because of the warm autumn. The falling of leaves from deciduous plants is a good indicator that these plants have entered dormancy (unless they dropped their leaves under the influence of drought or disease). Yes, it should be safe to begin pruning your trees now, or in the near future. You may safely continue pruning until it is too cold to comfortably work outdoors or until the trees and shrubs produce their leaves and flowers and begin growing in the spring. Pruning outside these time limits may not harm your plants, but pruning during dormancy is a way to minimize any potential negative impacts on your trees and shrubs.

As far as other things to do in your garden, there are numerous things you can be doing. If you have not finished planting spring flowering bulbs, do that now. Now that frost has killed many vegetable and flowering plants, it is time to clean them from the garden. Pull up dead plants and trim the tops from perennials that have frozen to the ground (peonies and such plants). Place the garden wastes into your compost to decompose and produce useful soil amendments for your garden. You can also be putting kitchen wastes into your compost now and through the winter. There are many other garden chores such as disconnecting and draining irrigation systems to protect them from freezing. Disconnect hoses from outside faucets to protect your house plumbing. Clean and oil garden tools now. The list of chores is longer than the space allowed for this column, but remember to enjoy the chance to rest from gardening for a little while.


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.

Links:

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

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

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