Another summer of tomato growing brings another summer of learning. Now three years in to growing tomatoes under cover I have learnt from my previous mistakes. Having started to feed the plants very late in the first year, I now have a firm grip on watering and feeding regimes. After overcrowding the polytunnel with too many plants last year and risking blight, I reduced the number of plants and increased the spacing, which has resulted in much better air flow and more light reaching the fruits. Perhaps feeling a little smug I was preparing myself for our biggest harvest yet. However, this year’s impediment to a bumper crop has been largely out of my control. 

When the first heatwave came in July we covered the polytunnel with two spare lengths of bird netting from the fruit cages to create enough light shade to keep the temperature down somewhat. Yet, on the hottest day, when it reached 37 degrees here, the temperature inside the polytunnel was 46, despite having both doors open and regularly hosing down the floor (which rapidly reduced the temperature by 4 or 5 degrees). About a week later it became apparent that the last fruits on the first trusses and nearly all of the second trusses had aborted due to stress. So I kept up the watering and feeding and trusted that there was still all of August for them to produce plenty more fruit.