Saguaro buckling caused by overwatering

Question: I saw your blog and was wondering if you would help us with a saguaro problem. We bought a healthy saguaro in December and transplanted it. We have noticed that the base is buckling. I admit I watered it several times right after transplanting and about twice a week since then. It did not rain here this winter, and I normally have green thumbs but am afraid something bad is happening to the cactus. It does not show rot or darkening at the base.

It is unusual to get arms starting that low already. The two biggest problems or mistakes that people make with establishing a saguaro are watering too often after transplanting or not having good water drainage in the soil.

Watering no more than once a week (I like every two weeks) in the summer and once a month in the winter is plenty. You need to cut back, or you will probably lose the plant. It looks like it started to lean after transplanting.

Cactuses such as these have all the water they need for rooting inside the trunk. I know you know this intellectually, but as a good gardener, this is counterintuitive. You have to force yourself not to water too often and get used to it.

With that size cactus, I would water with about 10 to 15 gallons at each watering. I would put a shallow basin, about three to four feet from the trunk, around the plant and fill the basin at each watering.

This growing season, I would apply infrequent shallow irrigations four or five feet away from the trunk to help grow its root system farther from the trunk.

Bob Morris is a professor emeritus in horticulture with the University of Nevada and can be reached at extremehort@aol.com. Visit his blog at
xtremehorticulture.blogspot.com. For more advice, check the Home section of the Las Vegas Review-Journal.