Preparing for indoor seed sowing
Some of my seedlings in small pots
Whilst soil conditions are still unsuitable for seed sowing out of doors in most places, the first indoor sowings will be getting under way any time now. Last time, I talked about seeds old and new. Before going on to the process itself, a word about the utensils, containers etc. I may make some very obvious points for experienced gardeners but be assured it pays to emphasise these elements every time.
Clean containers are vital, by all means re-use pots, boxes and margarine tubs but be sure that they are clean. In my early days, everything was washed in a tub of water laced with sterilant. A word of warning though, if you go down this route, be sure that the containers are thoroughly rinsed with plain water to remove any remnants of the detergent - it can burn seedling roots. Nowadays, most people will get away with giving containers a thorough brush out to remove loose remnants of old soil and old roots because we are now in the age of plastic which is much easier to clean.
May I also remind you to clean the watering can and the roses, the water butt or any other storage vessel. They can be the source of disease.
Why am I being so picky? We start some outdoor crops indoors at this time either to be able to harvest them early as part of a plan to be self-sufficient and/or to achieve a greater yield because you have given the plants a much longer growing season. Bulb onions would be a good example of this latter point. If you sow the seeds into a dirty pot, they may pick up a bit of infection with the result that you have to start all over again. You may just have lost a potential month's growing time and you can't get it back until next year! Don't be careless.
Now that you have clean containers, what size is required for the job in hand? We are back to that piece of string again, let me say that so many people waste seed by sowing far too many for their requirements. My sowing unit for small seeds is a 7 to 9cm pot (the three to three and a half inch pot in old money). For bigger seeds that can be readily handled individually, I would space sow them singly in cells. For broad beans, sweet peas etc I use the opening book type (with hinged cells so the root systems can be removed without damaged). Some people save up the cardboard inner from toilet rolls for this job!
One more thought, before you get the process under way - where are you going to accommodate the pots of sown seeds? Truth to tell, many will germinate perfectly well sat on a windowsill, the pots sitting in a little plastic tray. If the surface of the compost is left open to the air, it will tend to dry out quite quickly; adversely affecting the germination process and constant damping over would not be an acceptable way to over come the problem. That is why we tend to place the containers inside a tray with a clear plastic cloche-like lid. Some models may even have a heating cable incorporated enabling you to raise the temperature inside to speed up germination. Indeed there is one long and slender in shape especially suited for use on a window ledge, which accommodates a number of quarter size seed trays, ideal for raising a range of types at the same time. Whatever method you use, it is important that you make provision to shade the unit from direct sunlight - that would scorch little emerging seedlings.
Next time - the growing medium and my sowing technique.
Jim McColl presents BBC Scotland's The Beechgrove Garden.