Thompson & Morgan®
: Seed Germination Guide
Advice is given throughout on sowing seeds needing artificial heat for successful germination. However, there are a number of aspects of this fascinating branch of plant propagation best summarised here.
The first point to make is you shouldn't buy seeds of such plants until you are confident you have the facilities to raise them successfully. But this doesn't necessarily mean you have to invest in costly equipment.
All seeds need water, oxygen, the correct amount of light and the right level of warmth to germinate. Supplying that warmth could be a simple matter of giving the sown seed a place above the central-heating boiler, a temporary home in the airing cupboard or a sunny windowsill.
The pleasure of raising one's own bedding plants is infectious and one soon realises that something a little more spacious and controllable can be had for very little cost. That something could be an electrically heated propagator capable of accommodating two or more standard size seed trays, using no more power than a 100-watt light bulb but thermostatically controlled to give the precise temperature for successful germination.
Of course, remember a tray of seedlings is the starting point. Pricking out the seedlings (Pricking Out) follows and will involve accommodating several more trays or many more pots right through to the hardening off stage. You will appreciate enthusiasm for this rewarding hobby can soon take the gardener from a small propagator to the hankering for a greenhouse.
However large one's ambition, one should never forget quite small safeguards are necessary and top of the list is cleanliness. Trays and pots should be sterilised before use. So too should the cover of the propagator or glass of the greenhouse. Fresh compost should be used at the start of the season and emerging seedlings should be treated with Cheshunt Compound to prevent damping off.
Some seeds remain viable for a year or more after the packet seal has been broken, but it is advisable to carry out a germination test before the correct sowing time. Saved seeds require precisely controlled conditions to maintain a reasonable germination rate. The major seed companies, of which Thompson & Morgan® is one of the longest established, have become popular because they provide high quality seed of guaranteed viability. It is often a false economy to save small amounts of seed from one year to the next.
Most seeds germinate best if the tray is covered with a sheet of glass or plastic to retain the moisture in the compost. Some require dark to germinate and this can be provided by keeping the tray in a light, warm position while it is covered with a sheet of newspaper.
A daytime temperature of 65-75F (18-24C) is suitable for most undercover seeds and a drop at night to about 55F (12.5C) is permissible. When the seedlings have emerged, however, the daytime temperature should be lowered to about 65F (18F) and the seedlings given a light position which is away from direct sunlight.
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