Question: I have recently acquired this 48″ tall Saguaro cactus from family. It is a legally purchased plant. Is there a better way to keep it healthy in the Magnolia climate? It has been in Colorado for the last 20 years. Would it survive if planted outdoors? Magnolia, Texas
Answer: You are going to have to make a special area just to grow this. You might consider large containers to give you more control. The problem is our rainfall. We average about 49 inches of rain per year while in the Sonoran Desert where the Saguaro cactus (Carnegiea gigantea) lives receives 10 – 12 inches per year.
I have seen a garden in Dallas where they put a large slant clear fiberglass roof over the whole cactus bed, just to keep the water out and slopped the bed in such a way to prevent water coming into the bed when it rained. The only time the bed received any water was when the owner turned on the irrigation system.
Plant in well-drained soil. To build up a bed, add a layer of rocks and cover with rocky, loose grained (mineral) soil. Avoid organic soil (peat moss, bark, anything organic). Cacti look nice mixed in among larger rocks.
For an outdoor garden, first decide an area. Make sure there is ample sunlight available there. Choose a location which is sloped that will allow proper drainage. The beds of the plant should be at least 18-24 inches high. First add a layer of gravels at the bottom of the bed. Then add soil that is specially prepared for cactus. Mix two sandy loam soil, one part gravel and two parts coarse sand. If your cactus grows in limestone area, you may add one-fourth part of limestone gravel to the mixture. For that desert look you may add rocks of your choice. You can create different patterns by adding various varieties of cactus.
Give cacti some shade until established. Shade cloth works best as it allows the plant to adjust to the sun. During the growing season, (April through August) water your cactus garden when there is limited natural rainfall (every two weeks or less).
Yucca Do Nursery in Magnolia has a beautiful area built to grow cactus. They may be able to help you with some tips on the construction of a desert bed.
See links for additional information:
http://txmg.org/elpaso/files/2010/08/Create-Cactus-Garden-Haupt.pdf
