I've always thought that alpines were fairly drought resistant. I have 4
of these growing in a container, in a 50/60 mixture of sand and
uni-compost. But despite being exposed to rain, I've noticed after a few
dry days that a couple of them begin to wilt notably a Helianthemum and
a Mazus Rwptans. The other 2 alpines are unaffected. I've watered since
and the 2 wilted plants soon perked up. But I'm surprised they wilted so
easily.

On 16/05/2012 20:10, Frank wrote:
I've always thought that alpines were fairly drought resistant. I have 4
of these growing in a container, in a 50/60 mixture of sand and
uni-compost. But despite being exposed to rain, I've noticed after a few
dry days that a couple of them begin to wilt notably a Helianthemum and
a Mazus Rwptans. The other 2 alpines are unaffected. I've watered since
and the 2 wilted plants soon perked up. But I'm surprised they wilted so
easily.

Many alpines appear to grow in dry areas, simply because it looks dry.
Even if you take those growing in scree - which may be several or even
tens of cm deep , it's what's beneath that scree which is important.
The soil may be quite damp from continuous snowmelt from above, thus
keeping the plant well-watered.

It's quite strange, but dryness at the roots and extreme cold in winter
are two things which alpines often can't tolerate. In the latter case
they are often protected by a couple of metres of insulating snow
throughout the coldest time of the year. That also protects them from
the very dry dehydrating winds at altitude, of course.

--

Jeff

If you think of alpines in the terms of plants growing in mountainous regions, I would have thought that they would be used to high levels of rainfall (as rainfall is high at high altitude), in other words, they require good drainage, but need a frequent water supply.

Equally, plants that *do* grow in dry regions and have fleshy leaves to store water also often supplement this by deep roots, so you can't assume that something that grows in dry areas copes with a shortage of water - it may merely be that it grows its roots to where there is water, and if you have it in a shallow pot or trough where it can't do this, you have to make sure that
the trough always has enough water.

Jeff Layman wrote:
On 16/05/2012 20:10, Frank wrote:
I've always thought that alpines were fairly drought resistant. I have 4
of these growing in a container, in a 50/60 mixture of sand and
uni-compost. But despite being exposed to rain, I've noticed after a few
dry days that a couple of them begin to wilt notably a Helianthemum and
a Mazus Rwptans. The other 2 alpines are unaffected. I've watered since
and the 2 wilted plants soon perked up. But I'm surprised they wilted so
easily.

Many alpines appear to grow in dry areas, simply because it looks dry.
Even if you take those growing in scree - which may be several or even
tens of cm deep , it's what's beneath that scree which is important. The
soil may be quite damp from continuous snowmelt from above, thus keeping
the plant well-watered.

It's quite strange, but dryness at the roots and extreme cold in winter
are two things which alpines often can't tolerate. In the latter case
they are often protected by a couple of metres of insulating snow
throughout the coldest time of the year. That also protects them from
the very dry dehydrating winds at altitude, of course.

You make some good points. It's become obvious as has been proven by my
experience now that growing alpines in a container will still require a
certain degree of watering. Of course if one grows a few of these in a
confined space the uptake of water over a week or so is not going to be
negligible. Yet it's surprising that some books and gardening programmes
continue to give the misleading impressions regarding growing conditions
for alpines, like you can plant them in sand/scree and forget about
them. Not so.