I got a chance for some time in the garden yesterday, although it is still cool (8-10°C; 46-50F). With the extreme cold this winter I was sure we’d lost a lot of plants. You see, with a relatively large garden (30ft x 200ft) we were given a generous wedding present of gift vouchers for a specialist nursery. We set about landscaping what had been a mature but undeveloped space, and used the vouchers for some unusual shrubs to dot around the edges of the lawn and vegetable patch. That was many years ago now.
With December 2010 daytime temperatures down to -5°C, and as low as -13.7°C recorded one night I did wonder how much I could trust our outdoor sensor. How many of the more sensitive plants have survived and what does this say about temperature?
“UK winters tend to be relatively mild: extreme subzero temperatures of -12°C to -18°C over large parts of the country only happen occasionally. Recent extreme winters were those of 1940, 1947, 1963, 1979 and 2009–10 [now also 2010-11]. Every 20–30 years seems to be the pattern, global warming notwithstanding. I am not sure how useful such winters are in assessing hardiness, as they only come along once in a generation. If a plant survives 29 years out of 30, should it be considered hardy?”
Dead as a doornail
Pictured here in its prime in 2006, this one was a risk. We managed to grow it to about 12ft, and it used to put on a spectacular display in May which I could see from the kitchen window. In the last three years it did not like the cool wet summers and colder winters, despite being in a sheltered spot. Now dead!
Hardiness: the book says “hardy to -5°C” but likes well-drained soils (our’s isn’t).
I loved this for its penetrating blue colour flowers in Spring. It survived Winter 09/10 (-8°C) with a lot of damage, but there is no hope this year – brown leaves, brittle stems. We’ve already cut it down; now we just need to dig out the stump.
Hardiness: the book says “hardy to -5°C”. Mostly hardy in the UK, but can be damaged by frost and wind in exposed situations. Yeah!
I wish I could remember the name of this shrub. I only remember it was Lebanese (or perhaps Syrian). I didn’t think it would survive the wet but it thrived and grew to about 7ft in a sheltered spot, even surviving last year. It had the sparse look of a plant suited to dry soils – tiny leaves covered with silver down on the underside and small flowers. Now it is brown and crispy, with no sign of green life under the bark.
A slight cheat – this is in my parent’s garden, not far from the coast. This was fully mature when we moved there 30 years ago and lost perhaps the odd trunk in the coldest winters. This year skeletons of mature trees are a common sight. Mature plants are common as ornamental plants in coastal regions in milder parts of the UK; common names include Torquay/Torbay palm, or Cornish Palm.” Hardiness: the book says “hardy to -5°C” but from previous years I’d say more than that.
Looking very sad
This spurge has been cut back more than I’ve ever seen it. One plant does have some life at the base but the one in a more exposed location looks decidedly ill. Hardiness: Book says “hardy to -5°C”
There may be hope
This had formed a huge clump 6ft x 6ft and each summer sent up 3-4 flower spikes. It is now a thigh-high heap of dead leaves. The photo shows some colour on a still-fleshy leaf near the middle of the clump. Here’s hoping. Hardiness: the book says “May tolerate temperatures of -12°C if given a deep dry mulch”. We didn’t, but I guess there’d be some protection from the outer leaves – and the snow itself.
This is the strangest plant in some ways. In some years it will try to flower in January; in fact I have seen it trying to flower in many different times of the year. It is spiky and unruly and tries to invade our preferred patch for sitting in the sun, but I do hope it survives. Now every single needle-like leaf is scorched, but it nestles in a ‘cove’ formed by dense foliage and perhaps will regrow from the base.
Hardiness: the book says “some will survive to -7°C if wood is well-ripened in the summer.” Fingers crossed.
Cosmetic Damage Only
I’d never heard of Eucryphias until we planted one. They are handsome evergreen trees, tall and columnar in shape; in late summer the blooms are covered in bees. They’re from Chile I think. I’m glad to say ours is now 17ft and has only suffered some scorching to lower leaves. Hardiness: one book says intermediate between (UK) H3 (= FH) and H4 (= H); another says “*** (Borderline)” where *** is “Hardy to -15°C”.
A Tasmanian plant, which I just found out is called the Mountain Pepper, this is such a handsome plant with red stems and dark evergreen leaves. It has the most wonderful, aromatic properties; apparently the berries can substitute for pepper or allspice. This plant has aways tended to be damaged by frost, but usually only the outermost leaves. Given previous years’ experience we really didn’t think it would survive this year, but we were wrong. Both the upper and lower parts of the plant have suffered damage, but the core of the bush is still healthy. Hardiness: the book says “frost hardy to -5°C”; from the placement of the temperature sensor, and the other plants which died (or survived) this plant has survived at least -10°C.
It had taken us ages to establish a Chilean Flame Tree – apparently they can’t tolerate soils rich in phosphorus. Our young tree is now about 12 years old and flowers spectacularly every May.
Hardiness: according to Wikipedia “The leaves are evergreen, occasionally deciduous in cold areas…” I found a website specialist in Patagonian plants that says hardy to -10°C. We’ve certainly never seen such a great loss of leaves before as compared to this year. It still looks alive, just a bit pathetic. I guess I’d be fairly confident this one will recover.
I guess this all says more about the plants than anything certain about the temperature. Yes, a few surprises and some where the jury is still out. Now if we were to have a run of cold winters it would be interesting to see what survives. I got used to gardening in recent warmer times and was able to grow tomatoes (although cold tolerant varieties) outside for a few years, but the last two last summers were a disaster – green tomato chutney was about the height of it.