Level 2 Certificate: Principles of Garden Planning, Establishment and Maintenance

Transcription

1 Level 2 Certificate: Principles of Garden Planning, Establishment and Maintenance 3: Production of Outdoor Vegetables and Fruit Outcome 2: Understand the cultural operations used to produce outdoor food crops in a garden or allotment. 2.6 crop protection to extend the growing season. Soil and air temperatures govern when we can grow our fruit and vegetables Bed systems and crop rotation potatoes, tomatoes, courgettes, runner beans and lettuces (for example) cannot Traditional tolerate frost, vegetable so the gardens season and in allotments which we have can been grow set out them in rows, outdoors on flat varies ground. considerably across the country. Gardeners use many different techniques to extend the growing season: Windbreaks to produce sheltered, warmer microclimates warming the soil by covering it with a plastic sheet in spring, starting plants in greenhouses to plant out after frosts using cold frames to harden off plants from the greenhouse and give them protection until the frosts are over growing under cloches and low polythene tunnels growing under fleece or floating mulches choosing cultivars which have been specially bred to grow well under glass or in cold frames, to extend the season into autumn Soil covers Soil temperature, particularly if the soil is a cold wet clay, can delay the planting of crops in spring. One way to get crops like potatoes to grow away faster is to help to soil to warm up by covering it for a few weeks before planting with a mulch of plastic. Clear plastic sheet allow sunlight through and warms the soil but also encourages weed growth Black plastic is effective in absorbing warmth and suppressing weeds. Where crops are to be grown through a weed-suppressing mulch, more expensive specialist mulches (black plastic with a white or silver reverse, with the white side uppermost) will reflect light onto the crop. These plastics are also available as perforated sheets which will allow water through to growing crops. See 1

2 Using greenhouses Growing tender crops completely under glass is covered in another Unit ( Horticulture II, Protected Cropping) but most gardeners start their half-hardy vegetables and fruit under glass whether it is a greenhouse or a window sill propagator. Something all gardeners have to bear in mind, when they start sowing seeds in spring, is the TIME FACTOR. For each seed that you sow of tender plants (and not just vegetables such as tomato or courgette) consider how long will it be before you can plant it out in the garden? How big is it going to be before you can plant it out safely? How will you harden it off prepare it for the temperature changes outside the greenhouse? Cold frames This is where cold frames are particularly useful, as a transition step from the fully protected, frost free environment of the greenhouse to the open ground of the vegetable garden. Cold frames can be used to give some degrees of frost protection to plants in pots over the winter, and also for propagation. They are particularly useful for hardening off crops like runner beans and courgettes before the weather allows them to be planted out into the open garden. 2

3 Weaning and hardening off When seedlings have germinated in heated propagators, they need to be weaned from their totally enclosed environment to the main greenhouse - by increasing ventilation gradually (removing lids) and reducing the temperature. When plants have been grown under protection, they need to be hardened off by exposing them to the open air and temperature fluctuations gradually. One method is to stand the plants outside the greenhouse during the day, then bring them in each night. An easier method is to place them in a cold frame and open the lid during the day, then close it at night. Cloches and tunnels These can be used to cover outdoor seedbeds, to warm the soil in spring, and to extend the growing season into the autumn to help ripen off tomatoes and peppers. Below: Aubergines and peppers ripening at Wisley Haxnicks glass bell cloche 3

4 Fleece and floating mulches Woven fabric like fleece can also be used to raise soil temperatures, although only very thick forms can provide much frost protection. However these floating mulches can protect young seedlings from heavy rain and winds, and have added advantages as protection against some pests such as aphids and carrot fly. Perforated plastic film and fleece floating mulches need to be secured into the soil around the crop by burying the edges in trenches, or by laying bricks on top of the film. Using floating mulch remember : Weeds will thrive under the mulch Fleece and fine mesh or net can also be used over the low tunnel frames for crop protection from pests as diseases : Different types of mulch will allow different amounts of rain to penetrate you may need to provide irrigation, for example from a leaky pipe or seephose, under the mulch. The mulch has to be loosened as crops grow! 4

5 Seed rolls For some years commercial growers have used a combination of floating mulch and a preseeded mat to produce salad crops. A version designed for amateur gardeners is now being marketed. Seedbed Roll - A new way to grow your own salads and vegetables - planted as a self contained mat! All in one grow mat impregnated with seeds and a film cover that expands as the plants grow. Scientifically developed for commercial growers to conserve water yet produce chemical-free, bug-free and disease-free salads and vegetables. Now available to gardeners. Simply roll out the mat onto moist, weed free soil and the three rows of seeds will quickly germinate. The integrated grow mat repels pests and suppresses weeds. The vented compostable film cover acts like a cloche, warming the soil and air around the plants. Once rooted, the seedbed roll only needs to be kept moist for the plants to thrive and grow. No need for weeding or thinning out once mat is in place. Available in four varieties, each Seedbed Roll measures 3.6 m x.3m that can be cut to fit beds and planters, or to make successional sowings. Just lay out the seedbed roll on moist, weed free soil and cover the edges - that s it! Four varieties available, this one is: English Summer Salad: Lettuce Red Batavia, Green Batavia, Tango 5