Thanks to John Harrison of Allotment & Gardens
Grapes can be successfully grown outdoors in the south of the countryand in sheltered spots, although to be reliable dessert grapes do need the shelter of a greenhouse. Farther north, both types probably need protection but a lot depends on the variety grown and the micro-climate.
Grapes are a climbing plant, taking up very little space, and can be successfully grown in a large container. There are two types of grape vine – those grown as dessert grapes and those for wine production.
- Grapes need a good root run and grow most successfully with a cold break in the winter. If you will be growing your vine in the greenhouse, consider planting outside the house and training the stem inside via a small hole. You will need to provide plenty of ventilation to avoid mildew, particularly as the fruits develop and ripen.
Growing grapes by planting the root outside and then training the stem into a greenhouse or conservatory is a method that was used for many years. The shelter of the house ensured a good crop and because the stem was trained high up in the greenhouse it provided shade during the summer.
Having its roots free to grow outside had benefits too. They could spread as far as they wished, taking water and nutrients from the soil. Only needing watering in dry weather.
- The best method of starting with grapes is to buy a pot-grown vine.
- The vines like a well-cultivated, rich but well-drained soil – they don’t like being waterlogged. If planting into the ground, dig a hole 30 cm (1 foot) square and one-and-a-half times as deep as the pot the vine arrives in. Add gravel to the base of the hole if you are growing on heavy clay. Fill the hole with a good compost such as John Innes No. 3, or a mix of multi-purpose compost and garden soil.
- Whether planting in a pot or into the ground, you will need to provide a framework or trellis to support the vine, and tie in the stems.
- Plant out in late February–early March. Water well and mulch.
- In summer, thin the bunches to one every 30 cm (1 foot) on the main vine. The experts will tell you to reduce the number of grapes in the bunch with special scissors, but for most home-growers this is unnecessary.
- Prune in the winter once the leaves have fallen, otherwise the vine may bleed and lose strength. Leave any shoots you want to grow over the trellis. Trim back any side shoots you don’t want to about 2.5 cm (1 inch) from the stem. Once the leading stems are the desired length, cut them after a bud.
- In spring add a couple of handfuls of general fertilizer around the roots.
- Plant February–March.
- Harvest August–October.
- The best way to tell when grapes are ready is to taste them – the skins should feel soft to the touch and the grapes taste sweet and sugary.
- Cut the bunches, leaving the stalk attached.
Pests and Problems with Grapes
- Red spidermite and mealybugs are potential problems for greenhouse growing.
- Botrytis (a mould) and mildew can also be issues. Keep the greenhouse well ventilated.
- Birds and wasps will be attracted to the ripening grapes, so try to protect the bunches as they grow with netting or the legs of old tights, and set up wasp traps.
Varieties of Grape
- There is a huge range available, for dessert grapes, wine making and as all-rounders.
- Dornfelder has a good reputation as both an eating grape and for wine.
- Eat your dessert grapes as soon as possible after picking. They will keep for a couple of weeks in the fridge.
- There are various recipes in which grapes can used, including a pudding and a conserve.