Saguaro cacti

On television I saw a show about transplanting saguaro cacti. I think it was your show, "Southwest Yard and Garden". Why did they cut the roots on the cactus before replanting it? Isn't it bad to replant it deeper than it was growing before? Can I grow saguaro in Socorro? Jason L.

The "Southwest Yard and Garden" show did tape a segment on transplanting saguaro cacti in Tucson. I suspect that is the show to which you are referring. Your questions are good questions.

Any time you move plants, minimizing damage to roots is important. When transplanting large plants like a saguaro cactus and trees, it is an unavoidable fact that you will damage roots and cut off a large part of the root system.

Any torn or ripped roots should be cleanly pruned back before replanting. This will minimize rotting and allow for more successful development of new roots. Pruning damaged roots before planting is recommended for trees, shrubs and cacti, but it is especially important with the cacti because they are succulents. The nature of the cactus root system seems to allow removal of much of the root system because their roots are smaller in diameter and more likely to regenerate new roots than the larger roots found at the base of a tree. The succulent nature of the cactus also provides food and water reserves to help in the redevelopment of lost roots, but it does increase the risk of rotting if the soil is too wet and the ragged cut remains.

Planting it deeper than it was growing in nature is something to avoid. The root system needs oxygen, and deeper in the soil, less oxygen is available. The nursery transplanting the cacti on the show explained that they were planting it deeper to keep the cacti from falling over. That is the reason I asked them to show some plants that had survived their method of transplanting. Their method was shown to be successful by the saguaro surviving many years following their transplanting.

Finally, saguaro are very unlikely to survive in Socorro. It is too cold. The saguaro are native to the low Sonoran desert. You are at the northern limits of the high Chihuahuan desert. The temperatures are not the only differences between these deserts. Patterns of precipitation also differ and will create a difficult environment for the saguaro in Socorro.

Storing seed until spring

Why is it necessary to rototill or dig my garden with a shovel? In nature, plants grow without the soil being rototilled.

There are several reasons related to developing a soil that plant roots can penetrate. The fact that we usually garden near a building means the soil in the area has been compacted by vehicles and procedures involved with the construction. These soils are often as dense as brick.

Another consideration is that we often grow plants not native to soil in the area. For best growth, these plants need amended soil. Organic matter, fertilizer, and other materials are the most common amendments. These are best "incorporated" into the soil (mixed into the soil) rather than being spread on the surface. This requires digging.

You may observe that once the garden has been prepared, plants may "volunteer" by sprouting from seeds that fall to the ground and grow well on the site. In this case, further preparation of the soil may not be necessary.

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.

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