Raising annuals indoors From Bedding Plants Looking after seedlings After pricking out, the pots or boxes do not require as high a temperature as was needed for seed germination; nevertheless, a relatively high temperature, even for just a few days, helps root growth to start promptly. I stand my pricked-out seedlings on a heated mat giving a root temperature of 60F (15C), with a minimum air temperature of 45F (7C). In fact, with care in watering and attention to good ventilation and disease prevention, night air temperatures of just above freezing will still produce good plants. I find that the stage when the seedlings are moved off the mat and on to the open bench is generally governed not so much by choosing the optimum stage of growth, but by the need to find space on the mat for the next batch. Most gardeners are limited for greenhouse space and even the addition of high level shelves and the utilization of the space below the benches may not provide enough scope for moving the plants to the next stage at the very best moment. Fortunately, bedding plants are tough and adaptable and can usually cope with less than perfect conditions as long as growing techniques are adapted accordingly. Some plants like antirrhinums, calceolarias, gazanias and other almost-hardy plants are best grown as cool as possible to encourage branching and prevent lanky growth. They will do best if kept just frost free. For most people, the space problem is at its most acute at the stage when the plants are developing well and in need of spacing out, whilst still requiring protection from the last spring frosts. This is the hardening-off stage when plants are acclimatized to the outside world after being cosseted in artificially warm conditions for the first months of their life. For windowsill gardeners, the sill of an unheated spare room in the house may be a convenient spot for a period, followed perhaps by a windowsill in the garage. There may be space for a small cold frame in the garden for the final stage or plants can be moved outside during the day and moved back to the garage when frost threatens; or they could be left in a sheltered porch. For gardeners with more facilities, a cold frame is the answer, and the bigger the better, hence the earlier suggestion of a home-made frame. Some cold frames are so expensive that a cheap aluminium greenhouse seems a better buy. But whether you use a cold frame or cold greenhouse for hardening off, the idea is to expose the young plants increasingly to outside conditions by reducing their protection. This is done by opening vents or removing frame lights on blue-sky days, then on chillier days, while closing them at night when frost threatens or in spells of cold wind or heavy rain. For the last couple of weeks before planting, the plants should have the maximum possible exposure to the weather. During this period the young plants should never be allowed to dry out and should be fed every 10-14 days, depending on the weather, with a general purpose liquid fertilizer. They should also be protected from slugs and inspected regularly for other pests and diseases. Most modern varieties are bred to branch well from low down to create a bushy plant without the need for pinching out, but older kinds may need their tips pinched out and this should be done when the plants are relatively small. In general, I am against routine pinching, and prefer to rely on giving the individual plants sufficient space for their natural branching to develop. The advantages of a greenhouse Raising plants on a windowsill Using a propagator or heated mat Choosing pots and trays Compost/Potting soil Seed sowing technique After sowing the seed Pricking out the seedlings Planting out   Raising annuals indoors Annual Manual ©copyright 1999 Graham Rice. All Rights Reserved. All Images Digitally Watermarked.