Tuesday, 17 May 2011
Walking the Territory - Climate and Micro-climates
This is a photograph of the territory of rain in January, when we actually had some, and what there was, was augmented by snowmelt after the hard winter. Normally there is an awful lot of rain, especially in May, which has heavy showers and sunny intervals, so that you dash in and out with the washing and there are spectacular rainbows spanning the river, or across the face of the hill, or with their feet in the orchard opposite. Often this happens at the end of a cold dry spell with an easterly airdrift (too sullen and reserved to be called a wind) which doesn't bring frosts here, but keeps the gardens hanging dryly between daffodil and roses, and is hellish depressing. Then you get the winds from the south-west, and the air softens and brightens and all the green bulks up, and the gardens are full of nestlings fledging and harassed adult birds stuffing their bills with all the invertebrates that have ventured onto the soil surface.
Last week we had that rain, earlier than usual and now the wind is in the south and the sky is grey from Dumyat to Grangemouth - which fortunately I can't see from here, being too low down.
The village is just about at sea level, deep in the Forth Valley, and this has consequences for the weather we get. It is (mostly) marginally warmer than other places - Dunblane can have snow when we have rain - and sheltered from the worst of the winds. It isn't all good. when Falkirk had sun and wind and a thaw at Christmas we had mist and ice, and as the water pipe coming into our house had frozen solid, this was particularly disappointing. People who have hay fever and asthma often have more problems here than in other places too, because pollens and pollutants don't disperse so well. We have more rain than Edinburgh, but less than Glasgow, and tend to be a degree or so cooler than the BBC forecast in summer and a degree or so warmer than it in winter.
But even within the village there are differences in the climate. Sometimes we can see our neighbour's garden white wth frost when ours isn't. Ours is narrower and enclosed by a tall hedge on two sides, is more densely lanted and includes two good-sized trees and a pond which acts as a heat sink, just raising the temperature enough to keep above freezing point.
We have cooler areas to the north side of the herb patch and warmer ones, like the patio which gets all the late afternoon sun, and the south-facing wall of the house which is painted white. This only works in summer, though, when the sun is high enough to compensate for the fact that its lower than the rest of the garden which creates a frost pocket.
Winds behave differently in our garden too. The prevailing wind is from the south-west, but the one that does the damage is from the east, because the fence on that side creates turbulence.
All of this is going to help me get the best out of my garden. I'll be able to work out which plaants are going to need most watering. Pots of beans tomatoes and pumpkins can be moved to get the best of the sun, and plants which need staking can be placed where the wind won't be so fierce. Mints and parsley go in the shade of the herb patch, and strawberry plants will go at the top to catch the heat rising off the yard. I'll know where plants need to be brought into the greenhouse, and where I can take a chance.
Posted by Forthvalley scribe at 11:25