Potato Growing in Polythene Pots and Bags
10th Sep 1997
What a good season it has turned out to be for the show vegetables, particularly after such a miserable June, with the potatoes grown in polythene pots doing really well as did the celery. If you recall earlier on in the year I said that I would grow my potatoes this season following the same method exactly as Allister Gray grew them last year, and excellent results I had as well.
Because of my heavy commitment to the Chelsea collection of vegetables I was unable to get them in to the bags during the first week of May and in fact they were planted by my father during the Chelsea week having already had the bags filled up with the compost before hand. As I have very little room for potatoes in my own garden the bags were then transported in my trailer down to my friend Jim's garden where they were laid in rows to half the depth of the pots.
The bottom of the rows were loosened up and some potato fertiliser was added as well as plenty of slug pellets. Three varieties were planted, Kestrel, Mona Lisa and Winston and they grew away almost immediately with very strong haulms. As soon as they were growing away strongly, four foot canes were pushed into the soil behind every bag and attached to a wire running the length of the row. Every haulm was then tied individually and loosely to the canes and they really made an impressive sight when at their full growth.
I have to admit that I am particularly lucky living in Anglesey as I have only ever sprayed once for blight a few years ago and have never been bothered with it since and have never sprayed, even though my friend George Armstrong had blight up in Cheshire which forced him to cut off the haulms early. It must be the effect of living on a comparatively small island measuring some 23 miles by 20 miles and the constant sea breeze must be preventing the spores from attacking the foliage.
During the last weekend in July one of the pots with average growth was selected and the haulms cut, the pot was then emptied and from that single pot I had exactly 3 lbs of potatoes. The variety was Winston and there were 15 in total from which I had 6 large but misshapen ones, 3 that were showable and 6 that were good for eating but smaller.
The haulms were cut off on the remainder on the 5th of August and the pots brought back into my own garden where they were left covered over with black and white polythene to prevent them getting over heated and too wet. the haulms were cut when I had decided that the potatoes were of the right size and in the right skin condition. They have to be cut prior to them starting to have a netted and rough skin pattern which you can then never properly clean up.
There were two mistake that I made with this system which will be corrected for next year, the pots were initially filled with compost to within an inch or so of the rim and the potatoes pushed down into the compost. After the compost settled after watering, the level lowered and when the pots were removed a number of potatoes had been exposed to the sun and were no good for showing, they should have had another layer of compost added to the top of the pots as they were growing.
The watering was carried out religiously using a hose pipe at the rim of the pot, this however had the effect of disturbing the compost and again exposing the potatoes. Because I"m so pleased with the system I'm contemplating for next year setting up an irrigation system so that each pot will have a small pipe attached to it from a main run which will gradually and gently soak the pot over a longer period of time but without disturbing the potatoes growing on the upper level of the bag.
There were much heavier crops than the above when they were eventually emptied, indeed some were so heavy that the side of a couple of bags had split open. Another huge benefit of this system is that you can sort and grade the potatoes with the bags in the garage so that you don"t have to wait for a dry day to carry out the work. Once they were grade and earmarked for different classes in different shows, they were kept still unwashed, in layers of compost from the bags in large plastic buckets. Each bucket had a label stuck on the side to remind me what was in each one, they are then washed as late as possible prior to whichever show they are required.