Trichocereus hybrids grow well in large pots or in the ground in the desert Southwest. Some growers can adapt them to full sun, but to avoid sunburn it’s safer to grow them in light shade, as under an unirrigated mesquite or palo verde tree. They respond dramatically to generous water and fertilizer. With weekly watering and monthly feeding, the best cultivars will flush massive blooms every two weeks or so for three months or even longer. With water restriction, bloom will be much reduced in number. (Some clones will flower for only one or two days a year; there is a great deal of genetic as well as cultural variability.) The authors obtain superb results using a water soluble ‘Bloom’ formula fertilizer, one with low nitrogen and high phosphate. Deadheading (cutting off the spent blooms) close to the stem will result in greater flowering potential since the plants may often abort new flower buds in favor of producing fruit from pollinated flowers. Trichocereus flowers may be enjoyed as cut flowers indoors in water.
If you live in the desert, you’ll need to protect your trichos from javelinas, rabbits, squirrels, or even deer; they will eat your flowers. Additionally, insect pests may include, the giant cactus beetle, Moneilema gigas, the cactus weevil, Cactophagus species, thrips, and cactus moth (blue cactus borer), Cactobrosis fernaldialis. These can easily be treated with regular applications of systemic insecticides.
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