Home on the range
|This opuntia was completely undamaged by 18 degrees centigrade of frost for three weeks in 2010|
You might think growing cacti outside all the year round was nye on impossible in York! You might be right!
For several years now I have had a degree of success with growing cactus outside. Cactus were my childhood passion!
My first plant ever was a cereus barrel cactus. It was quickly followed by the succulent Sedum rubro-tinctum, a rather insignificant plant but one that fascinated me because the globular succulent leaves would root and then grow. It is easy to forget the thrill of rooting ones first cutting. I subsequently grew a dozen or so cactus for several years in my parents barely heated conservatory. When I went to horticultural college I put such childhood things behind me. Marilyn my sister took over my collection and it's remnants survive in her house to this day!
Now in my dotage I have been growing cacti outside for several years.Today, I am being rather self indulgent. Hardly anyone shares my interest and nobody read my previous post. What is the point of having a blog if I cannot write for myself?
|All these have proved to be hardy and have been completely outside for several winters now|
Just occasionally a visitor shows an interest. Cactus growers are very peculiar and dedicated people. I love them all, they are fascinating folk!
Allan in Orkney used to grow magnificent cactus at Askham Bryan College. He is my editor in chief and I regularly receive an e-mail missile with my latest spelling mistake which I immediately change. I had better watch what I say today!
About my indulgence
I originally researched on the net about hardy cacti and discovered there were several sources such as the Cactus Shop. I mean true cacti and although I also grow other succulents they are not my subject for today.
Unfortunately the Cactus Shop lumps cacti and succulents together.
Cacti are all members of the family cactaceae and include the very different desert and epiphyte species.
I discovered that certain cacti are very cold hardy indeed, coming from very cold places such as high in the Andes. Such habitats are either very dry in Winter or are under a blanket of snow. The difficulty of growing cactus in the UK is winter rainfall and high humidity. Worse the fluctuating conditions of moisture and temperature. If cacti don't like their Winter conditions they soon turn to mush!
The site that I chose was at the foot of the south wall of the house. Desert cacti must have lots of sunshine. I judged that the slight overhang of the roof would to a small degree shelter them from the worst of the winter rain. No matter that the site was a hardcore path! This was my most successful site but with hindsight had the soil had been a little richer but still very well drained, my cacti would have developed more quickly. Desert conditions although dry can be surprisingly fertile.
|This really is quite deep hardcore covered with gravel. I do infiltrate a little soil when I plant|
I have perhaps a dozen different cacti that have successfully over wintered outside in my garden. Some for several years now. Opuntias, the prickly pears have been the most reliable bankers. I emphasise that they need to be carefully selected. Those from the garden centre are unlikely to survive outside. I did however recently increase my stock of Notocactus leninghausii at Aldi!
|Both the notocactus and the echinopsis are lifted into my cold greenhouse for the worst three months of the winter|
Although I continue to grow many varieties completely outside, for others I have changed my technique. I bring them into my unheated greenhouse from mid December until the end of March. They love their nine months outside and grow better than any left in the greenhouse but by giving them this mid Winter protection I can grow a wider range of varieties that thrive.
I just dig them out in mid December using a hand fork or spade. Indeed because of their nasty spines anything other than my hands! I no longer plunge them in pots when I plant them and it is a very speedy operation to deposit them loosely in pots or plastic seed trays and to prop them vertical with extra soil when I bring them inside.
|They will remain like this unwatered for three months. This notocactus is said to only survive four degrees centigrade of frost but it has survived two winters now|
When lifted their roots will usually be wet. They will receive no more water until a week or so before they are planted outside in March. The time of planting varies a little with variety, nature of the season and whim. All I give them in Winter is an open unshaded position in my unheated greenhouse.
Unheated greenhouses in the UK are described as cold greenhouses. They will usually be several degrees above outdoor temperatures especially when the cold outside lasts for a short period such as a cold night.
Where there is continuous severe cold over long periods in Winter (unusual in these parts) then the cold does penetrate and the inside of the greenhouse will be similar to outside. In the exceptional Winter of 2010 my greenhouse temperature was – 15 degrees C for several days. The benefits at such times are wind protection and dry conditions. As there is no internal heat source in such circunstances bubble insulation is useless. Some of the truly hardy cacti withstand down to -20 degrees C.
Cacti have simple requirements providing they have plenty of light. Good drainage is essential but ordinary well drained soil is absolutely fine. Don't waste money with cactus compost when any gritty mix will amend a heavy soil. Because yanking out once a year rather restricts their roots I do sometimes water them in dry spells in Spring. I also water the ones permanently planted under the roof overhang. I also feed them by top dressing with my usual NPK fertiliser - especially those growing in my hardcore!
Readers will know of my admiration for hybrids! The fragile pads sometimes become detached and will root to rapidly increase clump size
The flowers of echinopsis are only open for a couple of days A huge range of colours are available
|Brenda criticizes me when I let nigella seed everywhere! In this case she is right as it is important that cacti receive the maximum light. Any volunteers for weeding? Try a trowel|
|This opuntia permanently thrives well in full sun in ordinary garden soil.|
|New plants are easily propagated from pieces merely popped in! Most of my cacti are propagated inside in pots of my ordinary sandy garden soil|
|I later pulled the competing delosperma away|
|Rooted Maihuenia poeppigii cuttings planted to make a ground cover. It is the hardiest cactus that I know|
|This picture is for Po Simpson (the moonshot man). The name might suit him!|
Mistakes I have made
I originally bought about sixty different hardy cacti from a range of suppliers. All small plants. Cacti on the net are really quite cheap and I spent no more than £200. Some were no more than unrooted cuttings and as a Yorkshireman I only buy one plant of each!
I attempted to remember their names and failed.
I now regret leaving several outside for the first Winter when they were still very small. Most turned to mush. Larger plants seem to do better and before risking them I should have propagated spares in my cold greenhouse.
Although echinopsis need to be brought into the unheated greenhouse in Winter many fine varieties are available and I should have tried more. It’s not too late!
I did push the barriers with regard to sunshine and lost some to poor light. Only the maximum will do.
Although it was not necessary to amend my own sandy soil, I do recommend that gardeners with heavier soil amend it with grit and coarse sand. It is often beneficial to create a raised bed and plant on the plateau. I think had I planted in my sandy soil rather than retain my hardcore at the base of the house my plants would have faired better.
My only wall with the root overhang actually faces south/south west. A significant difference from south. We get superb morning light – a south/south east aspect would be excellent. Unfortunately it often clouds over by lunchtime. Worse a few of my shrubs cast a little shade when the sun is low in the sky. It is really important that cacti are in full sun.
|I really feel at home on the range|
More about my hardcore