Lettuces

Overview

LETTUCE- Summer/Autum                                       Rotation group- Others

Lettuce has been the mainstay of any salad dish for centuries; it now faces competition from other leafy crops such as chicory and endive but the flavour and texture a home grown lettuce cut straight from the garden is still unbeatable. A supermarket lettuce doesn’t bear comparison with a well grown garden lettuce. Lettuce demands a fertile soil that is high in water-holding organic matter. It is a quick maturing crop that can be grown between rows of slower growing crops (inter-cropping) or areas of the allotment that are vacant, waiting for a later grown crop (catch cropping).

How to grow

Sow

The earliest sowings can be made in the greenhouse during February. The first of the outdoor sowings can be made from mid-March on-wards until late autumn.

Lettuce is grown from seed; it can either be sown into modules, trays or directly into the soil. The seeds in modules should be thinned down to one as quickly as possible, the seedlings in trays should be pricked out singly into 9cm/3ins pots, as soon as the seed leaves are fully open.

The outdoor sowings are made in shallow drills, watered with liquid seaweed just before sowing takes place. The rows are 30cms /12 ins apart and the seedlings are first thinned to 8cms/ 3ins and then 15cms /6ins apart. This is to be able to use spare plants to fill any gaps in the row at the various stages in their growth.

Lettuces do not like the high soil temperatures of summer and the seed struggles to germinate during July and August. In hot weather the seed becomes dormant in the soil.

Growing on

The seedlings in the open ground are finally thinned out to one plant every 30cms / 12 ins in order to allow them plenty of space, air and light to grow to their full size. Plant out the module or pot raised plants as soon as the roots show through the drainage holes. To prevent any chance of the transplants rotting don’t plant them too deeply, leave the base of the plants just above the soil level. Water the plants with liquid seaweed to settle them in.

Aftercare

Hoe regularly between the plants and rows to remove any competition from weeds for light, air, moisture and nutrients. Lettuce are quick growing plants so water regularly with liquid seaweed to promote rapid healthy growth.

How to Harvest

Harvesting

The Butterhead lettuce mature in around 10weeks, the larger crisp heads and Cos lettuce need around 14 weeks. The lettuce heads will only stand for about 5 - 7 days when they are mature, if they a left too long at this stage they will run to seed becoming useless. The way to prevent having to deal with a glut of lettuce is to succession sow and only keep enough plants growing to meet your immediate needs.

One way around the “feast and famine” with lettuce is to grow the cut and come again types that will allow you take several cuttings when the leaves are 8cms/3 ins tall. Two or three sowings should be enough for a season’s supply.

Issues

Pests and diseases

Millipedes and root aphids can attack the roots of plants but root aphid resistant strains of seed are available; slugs are also a major problem. Birds seem to leave the bronze/red leave lettuces alone or at least until there is nothing else to be had.

Botrytis and mildew can also be a problem in warm, wet weather. Avoid by ensuring good air circulation between plants and allowing the soil around the plants to dry out by the end of the day. Watering carefully- trying to keep the leaves and stem of the plants dry also helps. Remove any damaged or affected leaves to prevent the problem taking a hold.