Some Barrel cactus can grow as tall as 9 - 10 feet. They are ribbed and covered in dense prickly spine clusters. In spring they develop a flowering crown, colors vary from yellows to reds. The flowering crowns develop into small oval fruits with a pinkish yellow exterior. Their edible interior flesh is a seed cavity that contains small black seed that look like those tiny black seeds found on rolls and bagels - poppy seeds. The gem of this desert vegetation is its fruit which is tangy sweet, some have likened it to pineapple others to guava.
The Barrel cactus fruit is high in vitamins A and C and its pulp is sometimes used as a topical pain reliever.
There are over a dozen species of Barrel Cactus that produce edible fruits.Some of the small fruits are a tiny facsimile of a pineapple. They are not commonly cultivated, although they can be, and are usually acquired via foraging. Some species are considered endangered. It is indigenous to the south west US desert regions and parts of Mexico.
The fruit of the Barrel cactus can be eaten fresh and is also used to make preserves and in baking. Its natural sugar content lends itself well to these applications. The seeds can be ground into a flour or used as a spice.
Although the fruit is delicious and the seeds are edible, the cactus itself should never be used as a water source in survival situations as it induces diarrhea, nausea and cramping which leads to further dehydration.
Caring for barrel cactus is a snap. getting them started can be a little tricky at times, but not overly difficult.
For optimal results, seeds should be aged a year before trying to germinate them. They should be dried and preferably pulp free before planting. They require very little water.
You can start seeds outdoors is in the spring, but it is best to start them in flats. Be sure to use cactus soil.
Cactus soil is a potting soil with a coarse material added for drainage. Commercial blends are usually peat or shredded bark, however too much peat will clump up into soggy balls when watered. These clumps once solidified are difficult to re-hydrate, water runs right off them.
The best cactus soil is a sandy loam blended with perlite, I prefer to blend in some coco coir as well. Some people use sphagnum moss. A thin top layer of fine gravel is also advisable as it retains moisture and helps to prevent clumping.
Using a flat or seed tray, fill it with commercial cactus soil and sow the seeds directly on the soils surface and gently add a fine layer of sand on top of them.
The next step is to mist the soils surface with a fine spray of water. Covering the tray with a plastic lid or dome his advantageous only until they germinate. Be certain that if you do use a lid to allow for aeration / ventilation by cutting a holes in the plastic.
Place the pots in a sun drenched area or window sill. If you have suitable artifical lighting or grow lights that will work well also. Soil temperatures should be at least 70 F. Mild temperature fluctuations are acceptable. Remember in the desert to which they are indigenous, night time temperatures are chilly while day temperatures are oppressively hot.
With cactus there is a thin line between watering and over watering. You should never allow the soil to become saturated - never. A fine mist over the soils surface is all it takes, a very fine mist. Water your barrel cactus weakly weekly in the summer. In the winter cut back to about every once monthly, as the barrel cactus doesn't require much water during its winter dormancy.
You might notice condensation building up on the inside of the plastic lid if you chose to use one. That condensation can also be deadly, it creates an overly moist environment for the cactus and promotes fungus, mold, bacteria. Remove the lid periodically to allow for better air circulation.
Fertilizer is also low on the Barrel Cactus regimen, once a year in the spring is sufficient. A low nitrogen fertilizer is best.