Growing Potatoes in Poly Bags
3rd May 2001
What a dreadful Spring it's been, certainly here in Anglesey, we have had the lot from sleet snow frost to regular downpours of rain with very little sunshine. It's been particularly hard to get on the ground to do any rotovating, as soon as the ground appeared to be in the right condition, down came the rains again. However us gardeners are a pretty resilient lot and nothing will stop us getting on with the tasks even though if they are perhaps slightly later than normal. Don't worry unduly about this though, particularly at this time of year as the vegetables always seem to catch up and I have yet to see a poor display of vegetables at any show, simply because we have had a late Spring.
My potatoes will be the main task this coming week and I shall be reducing the quantities to concentrate on growing them back in large polythene bags which seem to give so many people success. This year Charles Maisey who, has been British Champion for many years with potatoes when he was growing them by using large quantities of straw and manure and all lined up in deep trenches. This time he is also having a go at growing them in poly bags (as we call the large black polythene bags or pots).
Charlie will be giving a talk on how he has used both methods at my annual vegetable growers weekend which this year takes place at a different venue. The Royal Victoria Hotel Llanberis which is beautifully situated at the foot of Snowdon will host the weekend from Friday the 9th November through to Sunday 11th. The final programme has not yet been decide upon but anyone wishing to have more information, and who have not previously attended, should write to me at Llanor, Old School Lane, Llanfairpwll Anglesey or E mail me - firstname.lastname@example.org
The varieties that I shall concentrate on will be those that have done well for me in the past and regularly produce show winning specimens such as Kestrel, Winston, Maxine and Nadine. Some of you may well have found time to get your potatoes in already but I have found over the years that when I plant them at this time I always get them off to a flying start and they have always been ready to lift from mid August onwards.
The soil will be well rotovated and the potato rows opened up two spades wide and a good spit deep with a minimum of 600mmm between the each row. The next step is to scatter some 4 ounces of potato fertiliser along the bottom which is then lightly forked in. This trench is there to support the bags and when the feeding roots have worked their way through the bottom of the bag they will have further nutrient at the ready in the soil to receive them.
The pots that I use measure 12 inches across when full and 11 inches deep and each one will take in the region of 17 litres of compost. These bags or pots are not too expensive and I have been able to get a special rate for GN readers from N A Kays Horticulture of £12.50 per 100 which is only 15 pence per pot, £7.50 per 50 which is 15 pence per pot and I have also got a price for just 25 pots for the smaller grower at £3.95 which is close to 16 pence each. See the back of GN for their classified advert for terms and conditions.
The mixture to fill the pots with has already been mixed up and is as follows : 300 litre bale of peat to which I incorporated 4lbs of Vitax Q4 and 4lbs of Seagold or Calcified seaweed, a scattering of slug pellets is given to each mixer full and that"s all that's in the mixture. However for those who need smaller mixes then the ratio is 4 ounces of each of the above elements to fill up one polypot or to 17 litres. Sit the polypots in the trench next to each other and work the soil from the side of the trenches around each pot to stabilise them. As the plants are growing do make sure that the haulms are supported and use strong canes pushed into the soil at the back of each pot to which the haulms are tied using a soft strong twine.
A very important point with potatoes is to make sure that they never go dry, and when grown in a pot environment this can happen quickly particularly when the pots are getting full of roots. During June on warm humid evenings when the potatoes are on top growth sprinkle a little amount of slug pellets on top of each pot and around the surrounding soil. It's during humid warm conditions that the small black slug called the keel slug comes up to the surface and can then be dispensed with.
Give the foliage and occasional spray with a suitable insecticide to make sure that they keep clean and free from any aphids that are capable of transmitting viruses right through your potato crop.