Cacti and succulents are plants that I have always liked and as our water use has become a huge problem in certain areas of the world we need to adapt our gardens to a more conservative model. Some people seem to be put off by the tough and spiky exterior of the cacti but if you do it right they will reward you with some of the loveliest flowers that nature has to offer. Here's how to grow cacti in a foolproof way to get flowers.
Although most people probably have a cactus in some shape or form they rarely get to see it flower. It takes a few simple steps to make sure that you also see the splendid display that they offer me each year. Please note that this post is about the desert cacti and succulent types, not leaf cactus or tropical types.
The biggest cactus killer out there is too much water combined with too little drainage. When I re-pot my cacti I add at least 50% grit to the soil to ensure that they get ample drainage for any longer spell of wet weather. I also add a layer of about 2-5 cm of gravel in the bottom of any pot to ensure that water does not get trapped in the bottom of the pot. Cacti and succulents will rot readily if their soil remains wet for too long. I also always use terracotta pots as they breathe and let excess water out through their pores.
As for temperature and sun conditions you want full sun although some shade is okay for parts of the day. Temperature wise cacti and succulents are quite hardy. As long as they are dry they can handle temperatures down to freezing and there is really no max temperature that they cannot handle unless you live in Death Valley.
How to get flowers?
This is a question I get a lot. To make this simple I'll say exactly what I do with my succulents and cacti to force them into flowering. I find that plants will want their natural habitat to be perfectly happy, and since most cacti and succulents come from warmer, dry areas this is what you want to duplicate. However it is not the warmer temperatures that will make your cactus flower - it is the opposite. To properly get a cactus to flower you need to make sure they go into a winter rest period. This is usually a period of 2-4 months of temperatures under 15c with very little water. Think of a desert in winter - cold, crisp air with pounding sunshine and maybe one or two showers.
I take most of my cacti in around the end of October as the chance of frost starts increasing, they go in various locations like the shed, guest room windows and anywhere we are not heating. Please note that you do not need to store them over winter in light if you ensure that the temperatures are below the range where a cactus would grow. In fact most of my cactus stay in a totally dark shack for most of the winter, I then gradually introduce them to the light when the temperatures outside are warmer again. I do this by leaving them in the shadow for about 1-2 weeks with a few hours in the sun here and there. I water my cacti on Christmas Eve, once in the end of January and then I gradually water more and more as the weather heats up. Please note that you should not water any cactus without light in winter more than a few drops here and there to make sure that the roots survive.
From May on I give my cacti and succulents a seaweed plant food once every two weeks. I also sowed a smaller type of clover in the bigger pots to give them a small, steady amount of nitrogen which is called nitrogen fixation. The clovers also ensure that the pots dry up quicker.
In short, the three keywords to having a display like me is drainage, hibernation and sun. Good luck and do share any pictures of your cacti and succulents with me! I will be posting about how to divide your cacti soon for a smart way of creating more plants out of the ones you have.
In case you do not have a cactus or have never seen one blossom you'll be surprised by how big the flowers actually are. Here is a picture of a flower with the hands of a grown up as comparison. Depending on the type of cactus the flowers can get as large as a dinner plate! There you have it, my guide on how to grow cacti.
I have also written a guide on how you can grow succulents from seed, you can grow cacti the same way by following these steps.