Do you recommend the all-female varieties of cucumber which are now available?
Yes, these are a very useful development. With the old-fashioned varieties of greenhouse or frame cucumbers you have to remove all the male flowers because, once the flowers are pollinated, they become mis-shapen, swollen at the ends, and bitter. This is not necessary with the all-female varieties, apart from removing the occasional male flower which may appear. (You can recognise the female flower by the embryonic fruit behind the petals). The outdoor ridge cucumbers, incidentally, can be pollinated, with no adverse effects.
When should I ‘stop’ my tomatoes?
Stopping tomatoes—that is, nipping out the growing point about two leaves above the top flower truss—concentrates the plant’s energies into maturing the remaining trusses before the cold weather comes. Outdoor tomatoes are usually stopped after three trusses in the north, and after four or five in the south; generally speaking, this means in late July or early August. Indoor tomatoes are stopped after seven or eight trusses, or—if they are growing well—you can leave them until there is no more greenhouse space. Remember that on all upright tomatoes the sideshoots must be nipped out throughout growth; this is unnecessary with bush tomatoes.
Is it possible to grow peppers and aubergines outdoors in this country?
You are likely to be really successful only in the south—and even there, the plants will probably need (and will certainly benefit from) cloche protection, especially in the early stages. Grow them in a sunny, sheltered spot. Start them indoors in heat in late February or early March, pot them up in small pots, harden them off well , and plant them out from mid-May onwards after all risk of frost is past. Nip out the tops when the plants are about 375 mm (15 in) high to make them bushy, and stake them if they are top heavy.
Reliable varieties are the aubergine ‘Moneymaker Fl’, and the F1 hybrid peppers ‘Early Prolific’, ‘Ace’, and ‘Canape’.
Can you give me any advice on growing sweet corn?
Sweet corn needs a long growing season, so is suitable only for the south of England. Grow it in a sheltered, sunny position. As the seed will not germinate in cold soil, it is best sown indoors in April in soil blocks or small pots, so that there will be minimum root-disturbance when it is planted out. Alternatively, sow it outdoors (from the end of May onwards) under cloches (or even under jam jars), which can be removed after germination. Plants should be spaced about 350 mm (14 in) apart, and grown in blocks rather than in long rows, so that they will be cross-pollinated by the wind.
The cobs are mature when the tassels have turned brown and the cobs, hanging at an angle of about 60 degrees to the stem, will snap off easily. If the cobs have to be worked to and fro before they come away, it indicates that they are not fully ripe and should be left for a little longer.