Garden School:


Garden School:
Teaching this week: Nepeta pruning, how to rake leaves, and how to retrieve Yew topiary.

Wednesday, 11 April 2018

Frost does strange things....

We've had the coldest, most miserable March for years, and four episodes of snow - four!! - over this past winter,  so it's no wonder that a few of the plants in the garden are suffering. We've also had many frosty nights .....

Last week a Client dolefully showed me a large pot of tulips which looked as though someone had held a blowtorch over them: the tips of all the leaves were brown, and the flowering stems were just a line of mush across the surface of the pot.

Frost is responsible for the damage: it causes the water inside the tissues of the plant to freeze and swell up, thus breaking the cell walls. Once they are ruptured, there is no going back, and those cells die.

New leaves are particularly susceptible to this damage, and can be completely ruined, which sometimes means the death of the bulb, as it relies on the spring leaves to build up nutrients to see it through the winter.

Here's a sad example from my own front garden: these are some pots of bulbs, which were too small to plant out and be useful this year, but which I'm growing on in the hopes that next year they will be of flowering size.

The ones on the right are my miniature Red Riding Hood tulip: those on the left (the nice, lush, green ones) are Queen of Night.

As you can see, the Red Riding Hood have all turned brown and mushy, and are definitely not going to survive the experience. The leaves were too small to survive the frost, they are not going to be able to build up their bulbs at all, so they are probably going to die (*sobs quietly*)

The Queen of Night tulips on the left, however, were much larger, and are completely  unscathed.

As a general rule, older leaves can survive snow and frost unharmed, although sometimes a sharp frost will cause them to temporarily wilt:

These daffodils, after a sharp frost a couple of weeks ago, were fine....
...but these ones - right - which were growing less than a yard away from the ones above, were rather less than happy!

Next day, though, they were standing upright again, quite unharmed by the experience.

The buds are a different story: if they are not yet fully formed, frost (and snow, for that matter) won't harm them at all. They seem to have an in-built protection.

However, if the buds are about to open, they will be ruined: turned to mush, brown and nasty, and no chance of recovery. Or of growing a replacement, sadly, and this is what happened for my Client: unfortunately her tulips were just about to flower, and the frost has spoiled them completely.

Even the daffodils are having a tough time of it this year: here are a couple of pots of spare Tete a tete (my second favourite daffodil of all time) which, although known to be a miniature, are not normally quite THIS small:

This phenomenon is caused by frost at the wrong time: a heavy chilling as the flowering stem has just broken the surface of the soil doesn't damage the bud itself, but it causes them to go into a period of dormancy.

Then when it warms up again, they seem to have had their clocks re-set, rather like the way a power cut causes my central heating to come on at odd times of the middle of the night (memo to self, really should remember to check it after a power cut).

With bulbs, it's the other way round - instead of being "late", they think that they have already done all the growing that they need to do, and go straight on to opening the flowers.

And you can see that several of the leaf tips are very pale greeny-yellow, indicating the frost damage.

Is there anything we can do? Well, not really: I'll give these daffodils a good liquid feed every couple of weeks, and hopefully next year they'll come up at the normal size.

As for those Red Riding Hood tulips.. well, both my Client and I will probably have to resign ourselves to losing them.




2 comments:

  1. Not noticed any fatalities despite the snow and frost and miserable weather so far this month. What I was surprised to see was "slug" damaged tulip leaves so early in the year! I think I have isolated the true culprits - mice. A sprinkling of chilli powder around the plants seems to have deterred them.

    ReplyDelete
  2. Mice eh? And now you're serving them gourmet chilli flavourings for starters!!

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