Watering in the UK climate

[gerald]

Or should I say weather, because the UK doesn't really have a climate as such.

This question has perplexed me for years, I don't know why I have only just got round to asking it, because it's always at the back of my mind. It's much easier to grow cacti when the weather is warm and sunny day after day, you just water them and they grow, just as they would in their natural habitat. I'm jealous of the continental and US growers for this reason. But what about in the UK, when one day it's sunny, the next is cold and rainy, the next is cloudy, then warm and rainy, then sunny - and sometimes cold, warm, rainy, cloudy and sunny in one day, or over several days. Et cetera et cetera.

This to me is the big question of successfully growing cacti in the UK, and I know there's no easy answer. 'When to water' is probably the greatest skill the Anglophile cactophile can possess, especially when considering rot-prone species. What's the secret?

[iann]

I'm psychic. I know exactly when it is going to be sunny for three days in a row. I also go flying with my pigs on the weekend

[BrianMc]

This question has perplexed me for years, I don't know why I have only just got round to asking it, because it's always at the back of my mind.

Thats what makes it fun


As long as the temperature is above 50/55 F most cacti will assimilate water, so therefore at temperatures above this the action of watering is safe.
The higher the temperature above this the quicker the plants will use the water and growth rate will be better. The most important thing is to use a growing medium suitable for the worst part of our unpredictable weather. eg. a medium that will drain well and not remain too wet if we have a week of miserable dull weather. If we are lucky enough to get an extended spell of sunny weather we just have to water more frequently.

In the Mediterranean cacti are very often grown in more peaty mixes that will be more water retentive in the predictable sunny weather. Using the same mix there that I have to use would probably necessitate a daily deluge!

While you may be jealous of the the Mediterranean and US climates, spare a little thought for those of us even worse off than you, who don't even get a summer! Now that is frustrating!

But it just goes to show how accepting and tough cacti and succulents are

[cactuspip]

I carried out an impromptu test over the winter.

When I put my plants back in my new greenhouse there were a number that I didn't think in good enough condition. I left these on the patio all winter.
They were completely exposed to all the rain and weather we experienced. We had quite a mild winter here, with only a couple of light frosts.

Some of the plants succumbed or marked up really badly. You can see from the photographs that a number continue to grow and are going to flower. I note they are all Gymnos, apart from one Thelocactus.

[DaveW]

Cacti grow in a range of climates and altitudes so no conditions are right for all. Many of us have problems with Melocactus or tropical cacti, particularly over winter, but do fairly well with plants from cooler climates or higher altitudes. Those in permanently warm countries usually cannot flower Sulcorebutia's very well since they don't get a cold enough rest period.

As has already been said by others, the requirement for our unpredictable climate is a compost that drains freely and dries out quickly, particularly in dull periods since you can always increase the frequency of watering in hot weather, but it is hard to dry out water retaining mixes in dull periods.

Occasionally putting cacti out in a rainstorm Pip is usually of benefit since it washes all the dust off them and perks them up, because after all rain falls from above and wets the plant body in habitat, therefore it is bottom watering or only into the top of the pot that is unnatural for them rather than top watering, meaning the plant body never getting a proper wash! However only do it with clean water since that containing fertilizer may dirty or stain them. Just imagine what state human bodies would be in if they only ever washed their feet!

[gerald]

Iann - I'll have what you're smoking

BrainMc - thanks for reassurance, how you manage in Scotland I will never know but I take my hat off to you!

Cactuspip - I think that deserves a thread in it's own right. Shows how hardy they some cacti (not all!) can be!

DaveW - I wish I had a greenhouse with a flip top lid rather than the 1ft window, it does get hot and dusty at times, but actually that's the way I like it

[CactusFanDan]

If your plants are thirsty enough then they don't seem to mind if they just get a day or two of dull weather.

[Agavegeoff]

Don't look outside, what's the weather doing in the glasshouse, hot and dry I bet.

[iann]

Don't look outside, what's the weather doing in the glasshouse, hot and dry I bet.

That's half the problem. 100 degrees one day, then freezing cold the next because the sun didn't come out. I've lost plants in May because it suddenly changed from desert-like to cold and damp for many days in a row. There are some that hate to be wet when that happens, others that cope OK.

[Agavegeoff]

Keep the air moving on the hot days.

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