Seed Sowing

As spring arrives us gardeners start to get ready for the coming season and a major part of this preparation is seed sowing. Sowing seeds and nurturing them through germination into strong healthy plants is without a doubt one of the most rewarding tasks in gardening. Watching nature work its magic is something that I never tire of seeing. Wherever you sow your seed, be it on a kitchen windowsill, in a greenhouse or garden shed, following a few basic rules will aid your chance of success. Foremost is hygiene, have a good spring clean before sowing. All pots and trays should be scrubbed clean with biodegradable detergent. Staging, worktops and the interior of the greenhouse can also be done at the same time.
Now a decision has to be made as to which growing medium is to be used. There is a variety of seed composts available on the market but in general any medium that is not overly heavy, water retentive or high in nutritional value will suffice, personally I use coir and vermiculite. Coir is a by-product from coconuts, making it a renewable organic resource. The only downside to coir is the air miles involved in bringing it to this country although storage and transportation are easier now as it comes in dehydrated blocks slightly larger than a brick. When you are ready to use it place your coir brick in a tub, pour on the required amount of water and within ten minutes you have 10 litres of hydrated coir. Into this I mix vermiculite to help with moisture retention.
A seed has enough resources within it to germinate and grow up to the two-leaf stage. Warmth and moisture are the keys to unlocking these resources; some seeds also need light (e.g. primroses). All seeds have different germination temperatures, most will germinate between 15°C - 20°C. Seedbeds need to be moist but not excessively wet, as this may encourage damping off, a condition where soil and water-borne fungi attack the seedlings stem base causing it to die. Some seeds need special attention (e.g. chitting or stratification) when sowing them but in general I fill my trays with the coir mix, broadcast my seed over this, cover with a thin layer of vermiculite and water gently, individual seed in pots are done exactly the same way. Larger seed such as broad bean or sunflower I push gently below the surface of the coir before covering them with vermiculite. Whether you sow your seeds in trays, pots or plugs is a personal choice. You will need to think about the amount of space you have as I always find I never have enough. Timing is important too, what type of soil do you have? How early in the year does it warm up? My new garden is still in the creation stages and I have a heavy clay soil that is slow to warm up, so I sow my seed slightly later, this avoids having an overflow of plants hardening off in the cold frames while I wait for the right planting conditions.
Once the seedlings emerge and go past the two-leaf stage then its time to pot them on. Again we need to choose our growing medium. There are many ready-made types of potting compost available but personally I use a mix of three parts organic compost, one part coir and one part worm cast. Organic compost tends to dry out quickly which is why I add the worm cast. This not only helps with moisture retention but is also rich in nutrients. Worm cast can be purchased or you can invest in a worm bin and produce your own. It is a fantastic way of turning compostable kitchen waste into a nutrient rich soil improver. Place this new medium into your pots and prepare it by dibbing holes ready to receive your seedlings. When you lift your seedlings use a thin pointed object (e.g. a pencil), slide this under the seedling and tease it up whilst holding it by a leaf. Always hold the seedling by the leaf, should it break off it will only damage the seedling, where-as if you are holding the stem of the seedling and it breaks the seedling will die. Once the seedling has been transplanted into its new home it should be gently watered in. As your potted-on seedlings grow up brush your hand over them occasionally, this simulates the wind blowing and will stimulate root growth. The original medium you used to germinate your seeds can be put onto the garden, each year I have a different area where I do this on as often seeds that did not germinate will now do so, last year this happened to me with asparagus.
Sowing seed outside depends a lot on your soil and your local microclimate. If you have a light soil and live in the south of England then you will of course be able to sow earlier than people with heavy soil or people living further north. For early spring sowing the temperature needs to get above 5°C regularly. At this temperature the grass will start growing and of course weeds will start to emerge. Work your soil into a fine tilth and sow your seed as directed on the packet. Beware of weather though; often we have a nice warm period in March only for it to turn cold again in the beginning of April.
It is always good to experiment with new ideas, soil mixtures and environments. Last year I grew carrots in plugs, the seed sowing process was long, fiddly and tedious but in the end the results were worthwhile. The carrots that I sowed directly into the soil performed poorly while the plugs did extremely well. I was able to avoid the main period of carrot fly activity by planting them out later and of course there was no thinning needed. At the moment I am trying out two/three year old leaf mulch in seed and potting composts. I hope this will mean I can reduce the amount of coir I use.
Do not be afraid of mixing up colours, vegetables with flowers or different leaf textures. Make your garden your own. The important thing is that you enjoy your garden be it big or small. Growing it from seed whilst helping nature along without trying to control her is to me the real essence of what gardening is about. Once your plants have grown up we can then look at seed saving along with the sowing of varieties threatened by extinction due to commercialisation, but that as they say is another story.
Copyright © Gary Spencer-Holmes 2006