CONOPHYTUM, CRASSULA & ADROMISCHUS
GROWING CONOPHYTUM, a beginner’s guide.
What are they?
Conophytum is Latin for cone plant and pronounced konnofytum. It is often abbreviated to “cono” (singular) and “conos” (plural). They only grow in the winter rainfall areas of South Africa and southern Namibia. Summers are hot and dry. In nature, even in winter they can endure periods of drought, so also survive on moisture from fog, mist and morning dew. They grow on open, stoney plains, in cracks in rocks, in grit pans and on mountain tops.
Conophytums basically consist of a fused pair of leaves (known as heads or bodies) which in most cases will divide and increase to produce clusters or clumps in time. Most of them will produce their flowers in autumn but a few will flower in winter and late spring or early summer. They are extremely variable in size, shape and markings. There are more than a hundred separate species and almost two hundred different ones when subspecies and varieties are included.
How do I grow them?
Conophytums are easy and rewarding to grow if you take the time to learn and understand their needs. Due to their origins, they have a specific growth cycle which is really important to follow and to appreciate why they do what they do.
In the short, darker days of autumn and winter they are actively and visibly growing. During the longer days of spring and summer they need a “resting” or dry period. This is how they have adapted to survive in their natural habitat and how they grow best in cultivation. So they need water while growing but little or none when resting. When resting, the old leaf pair slowly dries up, forming a sheath to protect the new leaves that are growing inside.
A common mistake beginners make is watering the plants too soon in summer. Some species will sheath earlier than others but that doesn't mean they can be watered sooner. Neither does it mean you can peel off the dry sheath, as doing that will expose the next leaves too early and they may burn in the summer sun. The new leaves will be quite happy inside the dry sheath until the days get shorter and cooler and they will often break out by themselves when they are ready to accept water again.
When growing they need just enough water to keep them turgid. Too much water and the leaves can split or push out the immature leaves too soon. So really, resting is not an accurate description as they are, in fact, continuously active : it's simply that you can't really see what's going on inside the old drying leaves. If you water them in the summer, before the old leaves are completely dry, you will usually end up with unsightly, multiple (“stacked”) leaf pairs. Some species have tougher skins than others so they don't all sheath at the same time.
Be patient. Growing conos is not really a hobby for those who are not.
Where should I grow them?
Conophytums are quite tolerant and will grow in a greenhouse, on a windowsill or under artificial lighting. They will grow in whatever country you live in, be it in the Northern or Southern Hemisphere, as long as you stick to the summer-winter growing regime. Depending on where you are and your individual conditions, there will be local differences in the timing of growth and resting periods as well as in flowering times. Even within the same country and believe it or not, between locations just a few dozen kilometres apart, timings can vary by several weeks. So you really can't say conos grow from one specific date until another because it depends on your seasons and individual growing conditions. Fortunately, the plants sense what to do and if you are observant, their state of growth will tell you what they need and when.
Regardless of where they are grown they still need the same annual cycle.
Conophytums need good light, especially when growing in autumn and winter. If they are grown in natural light some sort of shading is often beneficial in summer. They can be killed by scorch in a just a couple of hours if they get too hot, so air movement with a fan can help with cooling. In habitat they can tolerate freezing conditions for short periods in winter, but there it invariably warms up during the day. Elsewhere in cultivation, winters can remain cold for long periods so less water will be needed by the plants then. A minimum winter temperature of 3C will suffice. Anything over 35C in summer can cause serious damage.
If you have no natural daylight and want to grow them, LED lighting is the way to go, but that's a whole different game of which I have no experience. However, in theory, it should be very successful as both light and temperature can be controlled to provide the necessary conditions.
What do I grow them in?
Growing medium, soil, compost, substrate......all terms for what Conophytums can be grown in. What they grow in best is often the topic of much opinion and debate. Some growers will only use a mineral blend, others prefer a soil and grit mixture. It really depends on what you can find and buy locally or get delivered. Essentially the growing medium just needs to hold water for a short period before drying out, so needs to drain well and not stay wet for days. It's interesting to experiment and see what works best for you and your individual growing conditions.
Most people find standard plastic pots are fine but others prefer ceramic or even fancy ornamental ones. Again it doesn't really matter as long as the container drains freely and the basic growing principles are followed. Whatever type of pot you choose need not be large. I grow my plants in 5cm (2 inch) plastic pots to start with, then only pot on to something larger as required. In nature Conophytums often grow in very shallow depressions which flood when it rains then dry out quickly. They really can't use and have no need for large or deep pots. It's getting the drainage right that matters most.
Conophytums are not heavy feeders. Feeding depends on what growing medium you use. If it's inert like pumice then they will appreciate occasional weak low nitrogen liquid fertiliser. If grown in a grit-soil mix or a commercial compost, they really need very little additional feed because it's already present in the mix. Some growers advocate a half strength feed at the beginning and end of of the growing season, to give them an early boost and then to help them recover from flowering and to produce seeds.
Where can I get them?
Most people buy their Conophytum plants online these days. This can be risky, as due to their ever-increasing popularity, prices have increased, supply is limited and many sellers are only in it for a quick profit, selling poor quality and often wrongly-named plants. So do some research before buying. Find recommended sellers. Perhaps join one or two Facebook `groups` to see what others are doing and ask for advice.
You should only buy conos when they are growing, so be sure they are actually in growth in the country you are buying from. If purchased when they are resting they have insufficient vigour to re-establish and if watered, may not accept it, or if they do, will start to grow too early. This results in the afore-mentioned “stacked” leaves, where the old leaf pair has not dried away before the new leaves start to grow.
Please beware of buying plants taken (poached) from their wild habitat. It's often not easy to tell the difference between nursery-grown and ex-habitat plants and unscrupulous sellers may tell you they are not poached when in fact they are. Poaching is a huge problem reaching epidemic proportions and many habitat conophytums are now endangered and potentially at risk of extinction due to human greed. Be especially cautious if purchasing plants from China and Korea as many poached conophytums are sent there.
Can I grow them from seed?
Certainly. Growing from seed is interesting and rewarding but perhaps not easy for the inexperienced. Again, seeds are in great demand and it can be disappointing to order some from eBay or Etsy and end up with a pot full of grass. Do your research (which is often half the fun) and find reliable sources.
Assuming you have obtained good seeds, you need to understand a few basics for success. Once again there are many opinions and methods of how best to proceed. Some growers sow in autumn but others have success sowing in spring, so both will work.
The seeds are tiny, so treat them carefully. The same growing medium you use for plants can be used to sow seeds, although some growers prefer to sieve out the mix of larger particles. Some advocate sterilizing soil before sowing but others consider it detrimental. I know many successful growers who microwave the sowing medium on high for 5-10 minutes and letting it cool before sowing.
A variable temperature range of 15-20C (60-70F) during the day to 5-10C (40-50F) at night works well for germination as it mimics what they experience in habitat. Small pots or trays may be used. Sow the seeds evenly and gently water them from above or let the pots or trays stand in water until the surface is wet. Some growers sow onto a shallow top layer of fine grit. Fine sand is not recommended as it can harden or “cake” when it dries out. If sown onto fine grit, the seeds should be carefully washed down between the particles. This is my preferred method as the grit supports the seedlings as they grow and also inhibits any growth of moss or algae on the surface. The pots and trays will benefit from being covered by either clear plastic or glass, to maintain the humidity. They can also be put inside plastic bags. Whatever is used should then be shaded from the sun. Under the right conditions healthy seeds will usually germinate within a week to ten days. Any cover should then be removed otherwise the tiny green seedlings can rot. They appreciate air moving over them with a small fan and should be kept out of direct sunlight for the first few months.
It's all about experimenting and seeing what works best for you in your conditions.
Keep them growing by lightly watering all the way through their first year. They should be kept moist (but never wet for long periods) and as they increase in size can dry out for a day or so between watering. After this they should be large enough to be treated as adults, with a dry summer period in the second year.
Taking and rooting cuttings....
…. is a good way to get new plants faster than growing from seed. Conophytums often lose vigour and look less attractive as they get older so some growers like to break them up and start afresh from cuttings. Breaking up a large, old cluster into individual heads or pieces of 2-4 heads can give you spare plants to sell or trade with other growers, which is often a great way to increase your collection and make new friends. Even if you like large, older plants, you can still carefully remove heads from the lower edges or sides of a plant to make cuttings.
Cut below the heads to leave ideally 2-3mm of hard stem, never cutting into the soft leaf tissue which invariably leads to failure, as does taking them in the resting season. They can be planted immediately into your standard growing mix and kept constantly moist until firm in the pot and obviously rooted. Cuttings root best taken early in the growing season, when they often produce new roots within a couple of weeks. If cuttings are taken later, then some bottom heat will help to speed up the process but rooting takes longer.
What about bugs and other nasties?
Cultivated conos can suffer from mealy bugs both above and below soil level, but most generally available pesticides will control them. A more persistent pest is Western Flower Thrips. They will feed inside flowers and also on new leaf growth and are not at all easy to kill. Acephate is a good systemic pesticide which controls thrips but is not available in many countries due to its extreme toxicity.
Seedlings may be attacked by Sciara flies, also known as mushroom flies or fungus gnats. They lay their eggs in the soil and the larvae eat the seedlings. A general systemic insecticide, especially Imidacloprid, will usually control them. Another problem for very young seedlings is damping off. This is a fungal disease that usually occurs when the soil is too wet and there is not enough air moving over the seedlings which first turn white, then opaque, then die. It can be controlled by using a solution of copper sulphate.
Other pests and animals which can cause serious damage are slugs, snails, caterpillars, crickets, birds and mice. All of them can appear suddenly and unexpectedly, so need to be considered and kept away at all costs.
I'm ready to give them a go. Any last words of advice?
Help them maintain their cycle, watch them and be patient. Remember that all this advice is guidance. Every grower has a different environment and conditions and this will affect how their plants grow, so it's a process, a learning curve. Everyone has successes and failures along the way, but every success is a joy and assuming you discover why, every failure should help to understand more about these plants and how you can grow them better.
You may consider joining the MSG - Mesemb Study Group. Based in the UK they produce a quarterly printed bulletin and an annual seedlist.
This guide was produced and edited with thanks to my friends, Catherine Arthur, Trudy Marsden and Andy Young, who, between us, have over a hundred years of experience growing conophytums.