Tuesday, 15 December 2015

GRAPES FOR SCOTTISH GARDENS



GRAPES FOR SCOTTISH GARDENS

As an apprentice gardener way back in the mists of time we were trained in propagation of grape vines, and told how to grow them, but I don’t recall ever seeing one actually grown. To own a grape vine then, you had to be very clever or wealthy. It was another twenty years later before I got my first grape vine. However it was essential to have a greenhouse, as no-one ever considered growing them outdoors. Black Hamburg was the only one around for unheated greenhouses, but if you had heat you could grow Muscat of Alexandria. Today we have moved on and the choice of vines for both indoor and outdoor is quite extensive. Both Black Hamburg and Muscat of Alexandria are excellent grapes for the greenhouse, but they both have pips and today nobody wants grapes with pips. However if you grow them for the health benefits, I am told it is the pips that are the healthy part. Supermarkets demand seedless grapes, so now we buy vines with grapes that have no pips. This brings in another wee problem as we discover our seedless grapes are smaller than normal. It is the pips, or seeds that produce the growth hormones to make the grapes swell up. Commercial growers get round this problem by spraying the growing vines with several sprays of the growth promoting hormone gibberellic acid. We amateur gardeners do not have access to this chemical so we grow smaller grapes, but so much more healthy without covering the skins with chemicals. Thompson Seedless grapes are very popular in USA, but the markets demand really big grapes so the vines get large doses of this hormone.

In Scotland I have tried the white seedless grape Perlette and red seedless Flame, both needing the protection and warmth of a greenhouse. After several very successful years the weather changed resulting in very poor ripening of growth in autumn so the following year the vines produced very few bunches. I am now trying Seigerrebe which has a Muscat flavour and a few pips, so time will tell how it performs in my cold greenhouse.

We all love to experiment so I have planted a few outdoor grapes to see if there is any merit in hoping that global warming could be on our side way up north. We do know that to be successful, sun and warmth are needed to ripen up growth in autumn to help initiate fruiting buds the following year and also to ripen up the grapes. The sugar content of the grapes at harvest is totally dependant on getting plenty sun in summer and autumn. This year our Scottish summer was not at its best, but we had plenty of rain to encourage growth. I have been trying out several grapes with varying degrees of success. Both Rondo and Regent produced a few bunches of decent grapes, but Phoenix was outstanding giving me about thirty bunches. If the autumn had been better this would have been my success story. Solaris has a good reputation as the grape for the north, but I have not been impressed so far.
The ornamental variety Brant produces over a hundred bunches, which always ripen up, but they are very small. This year I put all my indoor and outdoor grapes together for a batch of home brew wine, but the low sugar content (specific gravity of 64) was only going to give 8% alcohol strength so it was necessary to add some grape concentrate, and a bit of sugar.
All my outdoor grapes have the benefit of a south slope and south facing walls and fences, so I will continue with a few more varieties, (Polo Muscat and Muscat Bleu both show a lot of promise) in the hope that one decent summer will give me a vintage year.

Wee jobs to do this week

Now that lawns have had their last cut this is a good time to carry out any renovation work. Spiking to aerate the lawn and scarifying to remove moss and thatch is usually done in late autumn followed by top dressing with sterilised soil and slow release fertiliser, but worn patches and broken edges can be repaired now. It is too late to oversow with seed but fresh turf can be used to repair damaged edges. Remove old turf and soil to same depth as thickness of new turf and lay and firm in carefully to maintain the same levels.

 End


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