Do you sometimes forget to water your houseplants? A cactus, by definition, is a plant that is designed to withstand long periods of drought. And, contrary to popular belief, cacti grow in a variety of climates. For instance, the species Coryphantha vivipara var. vivipara reportedly can withstand temperatures down to -20ºF!
Did You Know that Cacti Bloom?
Some individual cacti are known to be hundreds of years old. While it may take a cactus years to produce its first flowers, the wait is well worth it. The passionate colors which spring forth from their sometimes dull and spiny bodies have the same other-worldly effect as an urchin blooming from a seafloor rock. Some of them, like the flower of the albispina variety of Oroya cactus, resemble the exotic dragon fruit, while others resemble more familiar flowers like the passionflower and the daisy. The Opuntia bergeriana flower, for instance, resembles hibiscus.
Where to Place Your Cactus Garden
The most important thing to do before starting any cactus garden is to determine where you will locate it, and then find cacti that are adapted to the conditions in that location. These days, cacti are available for purchase from many garden centers and other distributors, where there should be salespeople able to help you choose cacti appropriate for your climate and living situation. But here are some general tips for growing and maintaining a cactus collection.
If growing indoors, place cacti on a windowsill where they will receive maximum light. A south-facing window is best. Give windowsill cacti a nice turn every every couple weeks so they don't grow lopsided. Some easy-to-grow indoor cacti are Epiphyllum species and cultivars, and Myrtillocactus geometrizans.
If you live in an area that is dry throughout the year, then you can grow cacti in a range of soil types. If you live somewhere that is more moist throughout the year, a higher gravel and sand content is better since it allows for better drainage. For growing medium, a simple mixture of one part garden soil, one part coarse sand, and one part compost will suffice. Of course, your local garden center should have brand-name products which you can use to build your soil. Talk to your local gardening professional to find out what's best for your cacti.
The Right Temperature for Cacti
In order to flower properly, most cacti need to experience some coolness during the winter nights. This would only be a problem if you keep your cacti in a heated apartment or greenhouse during the winter. However, some cacti can tolerate the year-round warmth. A couple examples are the species Astrophytum capricorne and Notocactus magnificus.
Drainage and Fertilizers
Cacti need good drainage. If growing cacti in containers, make sure you have a minimum of 3-4 inches of soil and holes on the bottom for drainage. Use any type of container you like, plastic or ceramic or whatever else you wish. Each type of material has its own pros and cons.
There are various types of cacti fertilizers or “feeds” such as liquid feed and slow-release granular fertilizer. Some cactus gardeners avoid the pellet fertilizers since, because of their slow-release, they may cause cacti to continue to grow into their otherwise dormant season, which will cause subsequent growth problems.
When to Water Cacti
How much you need to water your cacti will depend on the season, humidity, even the type of pot you use. But generally, during the summer, only water when the sun is out and allow soil to dry completely and water about every 8-15 days. In winter, keep your cacti dry and don't water them more than once a month. As for spring and fall, if it's cool, keep them dry, if it's hot, then water them.
As for pests, you shouldn't have any problems as long as you remove spent plant material from your growing area.
This general advice should help you manage your first few cacti, whether they're on a dorm room windowsill or whether you're dedicating a space in your front yard to cacti. Either way, like any gardening adventure, you will find that growing cacti has many rewards