The North Surrey Branch
	Of the British Cactus and Succulent Society

Guidelines to growing Cacti and Succulents

Sulcorebutias and Rebutias in my cactus greenhouse

(High light levels, and low temperatures (5C) in winter promote flowering in these plants)                                                    

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Some guidelines to growing healthy Succulents

The right plant

To start with, you must have a healthy plant. When buying a plant, look for signs of damage. Rotting of the stem, particularly at the base, signs of insect damage, would all cause me to leave the plant alone. If you identify any area of the plant where the colour appears different from an obviously similar part of the plant, be suspicious. Test this area to see if it is much softer that a similar area of the plant. After all, if the plant is healthy, you should not be able to damage it by gently pressing against the suspect area. If this area is softer, then the plant is most likely to have some kind of fungal infection and will have a very poor chance of survival. If you know what you are doing, and you absolutely must have this specimen, then the infected area must be cut out with a sterilised knife so there is no trace of the infection left. You must weight up your chances of success depending on where the infection is, how much of the plant has to be cut away, and whether you can get the plant growing again. Bear in mind also that the rest of the plants in your collection could suffer from being in the vicinity of an unhealthy plant. 

There is a considerable difference between the types of establishment where you can buy plants. Some beginners may not realise that there a number specialist suppliers of Cacti and Succulent plants even in the U.K. There are at least 7 in the southeast of the U.K. 

If you buy a plant from a normal garden centre chances are that it is an easy to grow plant. I rarely see the more difficult to grow plants in local nurseries, and unfortunately, they are often those that don't flower easily. Even if the plant is from a local nursery, it may need winter heat, so the best position to ensure it's survival would be a south facing window in a centrally heated house. If you give a plant these conditions they are unlikely to die. It may not flower profusely, or may not grow as it would naturally, but you won't loose it. The combination of warmth, moisture and a high light level is good for almost all succulents including cacti. Cold, damp, dull conditions will soon lead to a sticky end. 

If you can't supply high light levels in the U.K winter, then reduce the watering to a minimum. The aim will be to stop the plant from shrivelling too much, but not to promote unsightly out of character growth. Of course if you live in more conducive conditions it is possible to keep succulents growing all year round so long as you take precautions against them being burnt by strong sunshine or damaged by very high temperatures. Above 45C and there is a chance of damage.

If you go to a specialist grower or seller, then he/she should be able to tell you how to look after the plant. Some need high light levels to flower or to keep their natural shape. Some need cold, bright conditions in the winter to flower. Some grow in the U.K.'s winter period so you have to be careful when watering them.

Just to give you some idea of the real complexity of giving the right plant the right conditions to grow I try to give all my plants the correct macro conditions to grow well. After nearly 30 years of experience I have learned to place plants in the right places of the greenhouse. Some plants like a lot, a little, or no shade so I place some under the shade of others. Some like top shelf treatment or being placed in full sun outside in the U.K summer. Ferocactus species obviously like this treatment as I have had two flowering sessions from a large Ferocactus Glaucescens in 2001 in spite of the rain. Some do not like a lot of moisture, so I have adopted all sorts of ways to ensure the moisture I give them does not hang around for long. Clay pots are useful so long as you give plenty of space around the plants for their roots to grow. I treat some so called difficult plants with total abandon when in clay pots, watering for example Ariocarpi even in the winter at times to keep them growing. They don't like loosing their fine roots in the U.K. winter through being totally dry. Different soil structures within the pot, pure grit in the top level for example, will protect the stem from getting anywhere near damp soil. Temperatures are different in different parts of the green house so I keep the temperature sensitive plants near to the centre or on heated pads. Other plants are placed in different places in the greenhouse depending on what temperature I think they will need. Some positions in my greenhouse stay around 11 to 12C, others may go as low as 4C.

If you really want to know how a particular plant can be successfully grown, go to a specialist grower seller and ask about the specific plant you want to grow. If he has been growing it successfully for more than around ten years, he/she will know how to grow it.    

Dealing with an infected or damaged plant

More often that not, fungal infections start from the base of the plant. If you must have the plant, or it would be a rare acquisition, cut the base of the plant off with a sterile knife until all signs of infection are removed. You can determine this by looking at the cross section of the stem for a brown or yellow ring. If the cross section is a light green colour all over then the infection has not proceeded beyond this point. If there is a brown or yellow ring (Usually where the xylem is (water carrying ring) then you must cut back further.

At this point, you must decide if you are going to re-root the plant or graft it. Whatever you decide, the ideal conditions are those of summertime in the U.K. Damp, cold conditions for either method are likely to lead to problems. 

Re-rooting should be carried out after thoroughly drying out the cut stem. (Two to three weeks in dry conditions, longer if the atmosphere is damp) You then place the stem on moist sand  and leave it for approximately 6 weeks. (Depends on the type of stem you are trying to re-root. Very woody stems are usually a waste of time) When you are certain the plant has rooted, re-pot as normal. You can add a systemic fungicide when re-potting, but if you have not lost the plant so far, there seems little point in taking any more precautions other than ensuring the compost used is properly sterilised and the growing conditions are correct for the plant.

If you want to graft the plant, choose a stock plant ( An easy to grow plant that is closely related (Cactus to Cactus) to the plant you want to save) that has a stem almost the same size. (Obviously you can re-root the stem cut off the stock plant for further emergencies). Cut the the stem of the stock plant and secure the plant to be saved on the base of the stock. Some people use diagonal cuts, others use simple horizontal cuts. Make sure that the zylem (Water carrying ring) of the two pieces to be joined meet each other. I often use elastic bands to hold the pieces together, but any method that will exert slight pressure between the two pieces will be satisfactory. 

Insect Pests

Mealy bugs and Sciara flies are the most common insect pests found on succulents. Look for tiny white sticky cotton wool type encrustations on the body of a plant for Mealy bugs. Sometimes you will find Mealy bugs in between a plant stem and a leaf. 

Look for fast moving tiny flies, Sciara flies, above a plant. I blow hard over a suspect plant and the flies quickly become visible above the plant. It is not the flies that damage plants however, but their small white eel like larvae. The damage is very serious for seedlings, almost always leading to heavy losses, for large plants however, they damage the roots allowing fungi to penetrate the plant. Large plants have been known to collapse because of their activity.

I have found that pinguicula's, insect eating plants with sticky leaves, are the most effective natural method of eliminating sciara flies in greenhouses containing succulent plants. They are comparatively hardy, will tolerate occasional drying out, and grow vigorously. The best way of eliminating sciara flies is however to reduce the amount of peat in your compost to the absolute minimum. Failing all else, and if you have to use peat, a new systemic insecticide sold in the U.K. PROVADO, seems to last for at least 6 months, and is effective against both Mealy bugs and Sciara flies.

Other pests are Cats (And I have a well loved one) , Molluscs, Eelworm, etc. Do not frighten a cat in a greenhouse as it may frantically try to climb over the plants with disastrous results to the Cat and your plants, I know, I have seen it happen. You all know how to deal with molluscs, but eelworm and other pests require treatments that would be specific to the country you are living in. Ask a specialist grower.

Composts

A lot of succulents need a slightly acid soil. This is by no means a golden rule, but it does mean in a lot of cases, succulents do not enjoy a standard compost. I make this slightly acid compost from 3 parts Loam,  1 part of ericaceous compost (No peat) , and 1 part grit. The grit must be coarse to allow excess water to drain. I also use a product called Miracid, from a U.K. company called Miracle Garden Care, to fertilise the plants I think need a slightly acid compost. Watering plants with tap water in Croydon, U.K. tends to turn compost Alkaline over a period of time. 

There are however a considerable number of cacti that like slightly alkaline conditions, Ariocarpi and some Ferocacti are among some common ones. For these I use a PH meter to ensure the Acid/Alkaline balance for the type of plant is correct. It again pays to research the needs of a particular species. A particular book that has information in this area for most genera of Succulents is that by Gunter Andersohn and is called "CACTI AND SUCCULENTS" ISBN number 0 7136 2599 6.  

In general however, often all that matters is the free draining nature of the compost, particularly if you have not had much experience of looking after Succulents. Most succulents are succulents because there is not a lot of moisture where they grow, an obvious statement, but one some people ignore.

Light

Some succulents like full sun, some prefer deep shade, and others every light level between. You will have to find out where your plant comes from and under what conditions it grows. Those in the picture above are mostly species of Cacti coming from mountain areas where there are high light levels, and cold conditions in the winter. They get those kind of conditions in the greenhouse pictured above.

As a very rough guide, blue-grey bodies tend to like high light levels, light green bodies less. The more material that covers the body, i.e. spines, hair, farina, bark etc, the more light as a rule the plant can take. If your plant's new growth is a lighter colour than the rest of the body, or the new growth is considerably narrower that the rest, the plant is not getting enough light. Conversely, if the new growth is a lot darker than the original, the plant may be getting too much light . Remove to lower light levels in this case. Succulents, even those whose natural habitat involves high light levels, can burn easily if moved from a low light level to a high light level. Nurseries, flower shops often keep plants in much lower light levels than they should. Moving a plant to full sun could be a total disaster.

Watering

For beginners the simple rule is not to water until the compost is dry, and water then only if temperatures are not low.(Less than 15C during daytime as a very rough guide) All the experienced growers in temperate zones know when to ignore the advice, but they often use extra grit, or they use clay pots to ensure the plant does not get too wet. If you live in a more suitable climate than the UK where temperatures do not go below 15C, then for most plants, damp soil is not likely to cause root rot. The trouble is that some succulents like very arid conditions with consequent low levels of fungi present in the atmosphere, and others live in steamy jungles. To complicate matters further, a lot of succulents have certain times of the year when they prefer to be dormant. The plant pictured below in spite of being in flower is in it's dormant state. It has lost all of it's large leaves, and only has a few small ones. 

Water them at this time, and you may have a disaster on your hands. Some prefer to be dormant in the Summer, others in the Winter, Spring and or Autumn It pays to find out about your plants.

The plant above is Jatropha Podacrica, commonly available in U.K. nurseries. It is a prime example of a plant selected for growth in domestic conditions. Give it warm, low moisture conditions, as would be experienced in a centrally heated house with well insulated windows, and it will grow without trouble. Give it cold damp conditions and it will readily turn into just a memory. 

Feeding

If you are careful watering your plants, and you ensure they are potted in good quality compost, you can feed your plants every other time you water them. This is a simple generalisation, but I find it works with the majority of plants. Use a low in Nitrogen feed (See what is said about the product Miracid above) at the recommended rates for houseplants. For a long time, every grower thought that succulents, and in particular Cacti, were better grown in the most unfertile soil, and in the driest of conditions. I would suggest you investigate what happens if you grow the plants in an unrestricted rooting medium with as much food as they could want, and with the correct light and warmth. They grow fast. This is not true of some particularly sensitive plants, those that are generally only available at specialist nurseries.