As I mentioned recently, one of our greatest challenges in the garden this year has been the new polytunnel. Having long discussed getting one, the prospect of being locked down in Somerset for the best part of the growing season meant that we were finally able to commit to the daily tending and watering requirements that weekending here meant we could never manage. Although the idea of this additional responsibility caused Dan’s mum, who was staying with us, some sleepless nights, the reality has been, in most ways, much easier than anticipated.
Our motivation for getting one was primarily to realise the unfulfilled desire to be more self-sufficient. We grow almost all of our own hardy fruit and vegetables, resorting to the greengrocers only for those things either grown under glass or imported. Although the novelty of being able to grow a whole range of tender fruit and vegetables was exciting, at the time we decided to go ahead there was a lockdown run on vegetable seeds, which meant that we weren’t able to source the everything we wanted to try. So we settled for what effectively became a trial of tomatoes. Having only grown very reliable outdoor varieties of tomato here previously, there has been much to learn and Dig Delve provides us with a means to record that learning for our future reference, as much as to share it with you.
Our first lesson was to discover that late March was very late to be sowing tomatoes under cover. We started the pots of seeds off on the airing rack above the range in the kitchen, where they were quick to germinate, before being moved to the cold frames.We were then lucky to have such good, warm weather in April, that the seedlings grew away strongly. However, because steel supplies were being diverted to make emergency hospital beds, every week the delivery date for the polytunnel would get pushed back by another fortnight. Very quickly the plants went from being just perfect to plant out to needing to be slowed down by moving them out of the frames.
Eventually, the polytunnel went up over a couple of days at the end of May and the tomatoes immediately went straight into grow bags. Having realised that there was not time to prepare and cultivate the section of pasture where the polytunnel was to be sited, we settled for organic grow bags and put down a membrane to suppress grass and weed growth. Next month we will take up the membrane and install a board edging to make two, low raised beds for cultivation over the winter and for the future. We have seen the effects of the late sowing and delayed planting out all through the growing season, with some varieties being slow to get going, and some just not cropping as heavily as we feel they ought to have done.
The next challenge, and one related directly to growing the plants in bags, was getting the watering regime right. When the plants are small their uptake of water is less predictable than when they are more mature and daily watering (twice daily in hot weather) is needed. This difficulty in judging when and how much to water in the early stages led to a combination of both under and over watering, which stressed the plants when they were around 90cm tall and just as they were starting to set their second trusses, which almost all aborted. None of them suffered from blossom end rot, though, which is also caused by erratic watering and so, with the benefit of hindsight, it became clear that things had also been exacerbated by the fact that I didn’t start with the potassium seaweed feed nearly soon enough. I now know that feeding should start as soon as the first truss has set and continue weekly through the whole growing season. The lateness in feeding also affected the ripening of some varieties, most notably the larger plum and beef tomatoes, which developed ‘greenback’, where the shoulders of the fruit fail to ripen, which is also caused by a lack of potash. Not all tomatoes are prone to this, however.
Although we had a heavy harvest of the first trusses in late July and early August, this meant that there was a significant gap in production during August, aggravated by the cold and cloudy weather that typified that month. It has only been since temperatures started to rise in early September that the ripening has started again. With some continued sun and the doors to the polytunnel kept closed night and day now, I am pretty confident that we will still have a good amount of ripe tomatoes to freeze and preserve for the winter.
Apart from those hurdles, the general maintenance of the plants has been very straightforward. The only puzzle was how to manage the plum tomato ‘Roma’, which I treated like all the other varieties, which indeterminate type. These are the cordon varieties that keep growing upwards and require pinching out and tying onto a support. Noting that it wasn’t responding as the others I did some Googling and discovered that it is a determinate or bush-forming variety, which should be allowed to grow freely. This may be what has been responsible for the very light crops with this variety.
We have had no pests to speak of and, when it did look as though there may be a risk of aphid proliferation, I quickly saw a polytunnel ecosystem establish itself with the arrival of ladybirds and hoverflies and, when the slugs arrived, I soon found that I was disturbing a frog and a toad while watering, as they sheltered in the damp protection of the grow bags.
Apart from the watering and feeding, all that has been required is a weekly session pinching out side shoots, tying the vines onto their canes, removing any yellowing foliage and giving the floor a sweep. In fact the thing that has taken the most time has been the harvesting, preparing and preserving of the fruits when the gluts, few as they have been so far, have come. As the autumn weather starts to turn from Indian summer heat to chill, I forsee only one more busy weekend of peeling, chopping and bottling ahead of me. That has been another learning experience which I will write more about another time.
Due to the seed shortage the varieties we were able to get hold of in March were limited to the most widely grown and popular, some of which, like ‘Gardener’s Delight’ I remember my grandfather growing, and which, with ‘Sungold’, Dan and I have been growing since our days in Peckham. They are popular because they are easy, hardy and productive, and also delicious. Others, such as the beef tomato, ‘Marmande’, Dan has grown for clients, while others were new to us and were chosen to have a range of colours and sizes to choose from. On our list for next year are ‘Costoluto Fiorentino’, ‘Purple Ukraine’ and hardy Russian variety ‘Moskvich’.
Tumbling Tom Red
Tumbling Tom Yellow
Words and photographs: Huw Morgan
Published 26 September 2020