Much like most succulents, kanna is very easy to grow. It is possible to grow from both seed and cuttings, and can be grown in both the ground or in a pot. All it needs is a place with good light and warm conditions. Kanna is very intolerant to frost, so make sure that if you have it outside, you bring it in for wintry conditions.
Kanna will need pots with large drainage holes. Clay pots are preferable as the porous nature of them allows water to escape. Clay pots will also stay cooler than plastic pots in hot, summer conditions.
Kanna - Tommi Nummelin
Kanna does best on fairly porous soil, with a similar constancy to the arid and dry climates that plants like this can normally be found growing wild in. This will allow any excess water to drain through fast and efficiently, stopping kanna plants from rotting. The soil kanna is in should be allowed to fully dry out between each watering, ensuring that the roots can be fully aerated. Resist the temptation to over water kanna plants, the only time you should consider watering them more is when they start going a bit wrinkly, indicating they are losing water.
As mentioned, watering too much will cause rot, whereas watering too little will cause stunted growth. Kanna plants should be watered with moderation until shoots and roots have been given time to establish fully; also, once established, kanna will need little care during its 9 months of inactivity. It is when you begin to see blooms or new growth that you know that your kanna has become active again. You can also consider using a liquid plant feed during these periods to really enhance growth.
As mentioned, kanna has very little resistance to frost, so make sure it is never in a condition where it has to suffer it. Generally speaking, for kanna to really thrive, it needs to be kept in conditions that only ever reach 16 degrees Celsius as a minimum. So consider putting it in a greenhouse or on an indoor table that gets lots of light.
Sceletium tortuosum - H. Brisse
Kanna seeds don‘t preserve well, so if you gain seeds from your kana plant, then they should be immediately potted, no matter the time of year. Use general purpose cactus soil and place them in a warm, well lit, frost free place – such as a greenhouse. Keep the soil damp at all times until it begins to grow.
Common pests that will attack kanna are slugs and snail, spider mites, and aphids. Problems are more likely to occur with these pests when grown outdoors. Slug pellets and various other shop bought methods can be used to deal with slugs and snail, who will target the leaves of your kanna plants. Soapy insecticides can be used to deal with aphids and spider mites, who suck the plant dry.
The most common disease your kanna plants might face is kanna virus. It can be identified by the pale color dots and streaks it creates on the leaves of the kanna plant. There is no cure for this and you will have to remove and destroy the plant before it spreads.