Growing euphorbia’s successfully
Rikus van Veldhuisen
Growing euphorbias successfully. Euphorbia World 9(3)2013, page 5 – 6.
Over the years I have been asked to write something about the cultivation of euphorbia’s quite frequently. However I played with the thought several times, I have always, until now, refused to do this. The main reason was in fact that there are so many exceptions to any general advice. The thought there are only guidelines instead of rules put me at work at last.
Another drawback to write down any sensible thing about how to grow euphorbia’s is the fact that a person doing so must be a skilled grower of euphorbia’s indeed. Speaking for myself I must admit that I collect lethal casualties of my growing skills in my collection on a daily basis. Another thing is that I could only answer to the question ‘How do you grow for instead Euphorbia guillaminiana?’ was that you must have at least five nice growing plants in autumn, when you’re lucky some survive in winter and in spring you must try to get seeds in order to compensate the losses. And then there is of course the fact that for quite a few species, seen in other collections or offered by some nurseries, the only words I can say are; ‘How on earth can you grow this thing?’
I guess the reader now understands why I was so reluctant to write an article, or a series of articles, about a successful growing of euphorbia’s. However I have reached the point that I think it is worthwhile to the readers of Euphorbia World that I show and explain how and why I do the things I do.
Rule number one: There are no rules.
The Genus Euphorbia is a very heterogeneous Genus, which means the diversity of growing forms is enormous. There are species which make a tree of 30 meter high, miniatures of only a few centimeters, tuberous species, stem succulents of nearly all sizes, etc. On top of that succulent euphorbia’s grow on every continent, except Antarctica, from sea level to high up in the mountains, as long there is no frost, at least for the succulent ones, in several different vegetation zones and climates. Needless to say that these wide variation yields species with very variable demands regarding their growing conditions. Yet their skills of adaptability must In fact exceed our skills of cultivation by far as it is still possible to grow so many species of euphorbia in one and the same hothouse.
Another troublesome thing is the fact that I have seen and explained how to grow a particular species of euphorbia by somebody and obviously the plant is flourishing, it is not working for me (or vice versa). Not all systems of cultivation can be duplicated. One of the best things in order to become a skilled grower is to have a mentor. I was lucky enough to have such a mentor in the person of Jaap Keijzer. He was already growing euphorbia’s for over 20 years as I first visited him. I remember how stunned I was when looking at a seriously sized Euphorbia samburuensis. Jaap’s knife swiftly cut off a 30 centimeter long branch while adding: “Now you try.’ Since then 30 years have passed and even up to today I gather valuable information every time I pay Jaap and Corrie a visit. By the way, have you seen his film on Youtube about grafting euphorbia’s?
What I want to point out to you is that when you start to visit fellow growers of euphorbia’s you are on the highway to success. You must take home what you see there and the answers you get. And then you have to try it yourself and find out what works for you. You proceed with the things which work for you and stop what doesn’t work. You have to find it out all by yourself. I found out that for me Euphorbia candelabrum is a much longer lasting grafting stock with higher success rates that Euphorbia canariensis. This despite the fact that Jaap prefers Euphorbia canariensis and hates using Euphorbia candelabrum. Euphorbia ingens is a look-a-like of Euphorbia candelabrum, but a bad grafting stock for us. I have seen people using Euphorbia resinifera very successfully, but I don’t like it. The fact remains, what works for you. There are no rules, only guidelines.
Trial and error.
I want to conclude this first article with an example that growing euphorbia’s successfully starts by trying to do something. On the picture going with this article are two plants of Euphorbia nivulia, north of Salem, Tamil Nadu District, India. The plant on the right was given to me by a collector of stapeliads and, as euphorbia’s from India with good locality data are hard to get, I was very happy with it. I repotted it, as I always do with new additions, and gave it a nice place. After a year it was still looking poor and had only made a few small leaves on the little side shoots. I decided to cut off such a little side branch, despite it was only a few centimeters in length and less than a centimeter in diameter. I always put cigarette paper on the cutting edges of small plants or when the cutting edge is quite large and/or soft. This prevents the cutting a bit from drying out or get infected. Also the forming of a layer of callus is much quicker. After having the cutting let to dry for a week or so in a dry, warm and shaded place, it was potted and put in the ‘intensive care’ area. It started growing quickly enough and also in a pace and size I was amazed about. The picture was taken two years after the cutting was taken and is another example how vigorous growers our euphorbia’s are when they are having fun.
We can learn two things here. One is that when you don’t multiply you plants, you just are waiting for them to die. The other thing is that both plants were kept under the same conditions, potting mix, etcetera, but one plant grows like crazy and the other one is struggling. Sometimes the grower is not to blame.