New Method for Growing Potatoes
4th Aug 1999
My potatoes look to be about the best that I have ever grown and far superior to last year when the growth was very inconsistent. I have never seen the haulms so even and so tall; even Kestrel which usually only manages to attain about two feet in height for me is now over three feet tall. This year I have mainly stuck to two banker varieties that regularly produce show winning specimens for me, Kestrel and Winston. Winston matures as a first early whilst Kestrel matures as a second early; from my experience both can usually be lifted at the same time giving you plenty of potatoes from which to select. I have also planted half a row of Salad blue and half a row of Salad red as well as some Nadine and Maxine, all for display purposes rather than in competitive classes.
I am extremely fortunate living on an island, within a few minutes walk from the sea and it's an exception to the rule for me to have to revert to spraying my potatoes against blight. I am not going to say that I will never get it but I am prepared to take this small risk in order to harvest a crop that I can eat with the knowledge that they haven't been sprayed with any fungicides. They were all planted on 4th May and using a different method to last year.
Problems Last Year
Last year they were all grown in polythene bags and the result was good although there were two problems that I encountered. The main problem was watering each bag individually which really needs to be done if you are going to get sufficient moisture into the developing tubers in the bag. The other problem was that, with such a good crop, some of the potatoes were pressing against each other in the bag resulting in some being mis-shaped, having flat sides etc and his happens as the potatoes' development are restricted within the bag. However the skin quality on them was superb and it is certainly a way of growing some very clean tubers.
New Growing System
The method I used this year was to effectively still contain them and prevent them from getting into contact with the soil but the potato rows were opened up a spit deep and slightly wider than the width of a spade. Commercial potato fertiliser and some slug pellets were then scattered on top of the soil and the whole trench was then covered over with 4 foot wide, thin black perforated polythene. This is the material that is extensively used in commercial glasshouses to cover the capillary matting on growing benches. It allows moisture to permeate through so that it doesn't develop into a soggy mass whilst at the same time it allows the small white roots to find their way through the small holes in the polythene and into the fertile soil below. The trench was then initially lined with peat based compost from gro-bags on to which the potatoes were laid approx. a foot apart. The trench was then filled to the top with more gro-bag material and I was able to plant 16 potatoes per row. In addition to the gro-bags, I also added a handful of the same potato fertiliser to every yard run of trench which was raked into the compost. The potato fertiliser is reasonably cheap as well, provided you buy it direct from a farmers' supply store; if you can share a half hundred weight bag with a fellow grower, it really is tremendous value.
As they were growing, some more slug pellets were placed around each potato haulm on a warm humid evening during early June. The reason for doing this when the humidity is high in the evening is because any keel slugs that are in the soil, which can create havoc to your potatoes, come to the surface and can be dealt with effectively.
Tying the Haulms
Tying of the haulms is also an important task, I do this by pushing some long steel bars along the row (four per row is sufficient) and tying strong twine to them which will prevent the haulms from falling over on top of each other.
Size and Condition
This weekend I shall pull up a haulm from both Kestrel and Winston to assess their size and condition. Winston in particular can get very large indeed, far too large for exhibition so it's essential to harvest them all when they have arrived at a size that I am confident will yield me a competitive dish. If I am happy with them, the haulms will be removed down to four inches or so above the soil and the potatoes left in the ground for another week so that the skins will set on them. At this point, if there are weeds around and dead vegetation, then scatter a few slug pellets around as it"s a lot better to be safe than sorry.
When I have lifted them, I will let you know whether or not the new growing system is going to be the one that I shall be using next year.