Strong growth and plentiful flowers can be misleading. It is rare for us even in the best of summers to have the long spells of sunshine necessary to ripen more than four trusses of fruit.
So “stop” the plants by pinching out the main growing shoot. Nip it off just above the fourth truss. Even if four trusses have not set, the stopping should be done by the third week of the month. There is nothing to be gained by leaving the plants to grow on.
Keep moisture at the roots. Allowing the soil to dry out and then trying to correct matters by soaking, only leads to split fruit. If you have the material, apply a generous mulch (see page 4) and do not let the soil surface cake hard.
Keep feeding the plants, but do not overdo it; and especially at this stage avoid too much nitrogen—sulphate of ammonia or nitrate of soda—which will only promote rank growth and fruit that lacks flavour.
It also makes the plants less resistant to disease. Let the sun get at the fruit. This does not mean recklessly cutting out every leaf that is in the way. Remember that the leaves of plants play an important part in their nutrition. Remove any dead or withered leaves from the base, of course, and then carefully thin out, here and there, to uncover developing trusses.
Keep a sharp lookout for any side shoots that you may have missed. Watch out also for blight (see June Guide) and give another spraying or dusting as a precaution.
When spraying potatoes for blight, the spray is applied to the foliage and not to the tubers (the edible spud) – but spraying tomato plants at this stage inevitably means that the edible fruits are being sprayed.
However, there are a number of blight resistant tomatoes available now that will provide a decent crop without spraying in most years.
Now is the time when the quality of plants tells. If yours are not all they should be, make a resolution to start with better stock next year. There are still too many over-forced weakly plants bought by the unwary.