Winter Crops from the Greenhouse

NVS Home - About NVS - Grow & Show - Web Links - News - NVS Shop - Contact

Winter Crops from the Greenhouse

I am always surprised that many gardeners who grow excellent summer crops in glasshouses fail to use them for vegetable production in winter and early spring. The excuse often given is that winter crops impede the cleaning and disinfecting of the glasshouse. However, this can be overcome if the crops are container grown so that they can be lifted easily and placed in temporary quarters, such as a frame, shed or even covered with agryl fleece in a sheltered corner outside, until it is safe for the plants to be returned on completion of the cleaning.

Lettuce

A small sowing of the lettuces 'Kwiek' and 'Little Gem' are made early in October and the resulting seedlings pricked out into standard seed trays of Chempak potting compost at a spacing of six rows of four plants (24 in all). These are grown on in the best light possible and are covered with agryl fleece in frosty weather. In December the plants are moved into 3 and a half-inch square pots of Chempak compost; the pots are placed twelve per tray in standard tomato trays to facilitate easy handling. Grown in this way the plants make rapid progress if watering and feeding (with Chempak 2) are carefully controlled to avoid splashing the leaves. Being raised in the pots allows air to circulate under the leaves reducing the threat of Botrytis and other fungal infections.

Cutting begins early taking alternate plants as soon as they are large enough. They will be good leaves but not fully hearted. The 'Little Gem' plants taken this way make excellent salads. The plants remaining are left to grow on as hearted lettuce and cut as required. Using this method fresh and tasty lettuce can be cut as they are needed over an extended cropping period at a time when commercial supplies tend to be insipid-and expensive.

Potatoes

I obtained some 25 litre plastic tubs in which hotels receive cooking fat and, using a Stanley knife, made a number of drainage holes in the bottom. On 5th February I half filled each drum (six in all) with a compost of two parts good soil (from a part of the garden that had not grown potatoes in recent years), one part peat and one part sharp sand. To sixteen gallons of this mix I added one Chempak potting base. Three well chitted tubers of the early potato 'Maris Bard' were set in each drum and the drums placed in the glasshouse. They stayed there until the haulms were showing strongly. By this time glasshouse space was becoming short so each morning when I opened up I lifted the drums into the open garden and each evening when I shut down I lifted them back onto the central path. In very rough, frosty weather they remained inside. As the haulms grew they were top dressed with the same compost as before and supported by canes and string.

The reason for moving the plants daily was to give me room to work and avoid overcrowding plants when the house was full of other crops. However, from my experience the haulms made much stronger growth than on plants grown entirely indoors and this resulted in better crops. The first potatoes were taken on 3rd May by delving into the drums with bare hands, removing the best and leaving the others to grow on.

This article originally appeared in the Members Bulletin, the journal of the National Vegetable Society, which is sent quarterly to members. You can Join the National Vegetable Society here

Grow & Show

Grow & Show From Medwyn General Gardening Growing for Show Growing Fruit Growing Herbs Month by Month Gardening Vegetable Growing General