Sowing the seed

Sunday, 04 November 2012

Seeds of the belladonna lily, Amaryllis belladonna

Those who have seen the wonderful David Attenborough series Kingdom of Plants, screened recently on ABC TV, will have enjoyed the amazing time-lapse photography showing the growth and change of plants through the seasons. I particularly liked the sequences showing the germination and development of seeds. I have always been fascinated with raising plants from seed, from my very youngest days when I watched my father tend his wooden seed boxes set out on the tin roof of our wood heap. He grew many flowering annuals and vegetables from seed (as punnets of seedlings were not really available at nurseries in those days) and I can still picture him gently lifting up the sheets of masonite that covered the boxes after the seed had been sown to check their progress. It seemed a miracle to me then that the tiny, dust-like seeds he planted could transform into beautiful flowers and vegetables - and it still does seem miraculous. A few decades ago, I was madly keen on growing seeds of all different sorts, and used to send away to England and the USA for rare and unusual varieties. As a member of several plant societies, I was eligible to receive a quota of seeds every year collected from various gardens, including the Royal Horticultural Society garden at Wisley in Surrey. It was very exciting when the parcels of seeds arrived and I had visions of all the wonderful and exotic plants that would be mine as soon as the seeds germinated. I imagined myself introducing new plants to my gardening friends in Sydney that had never been grown here before!

Aquilegia chrysantha, which I grew from imported seed many years ago

Alas, not many of these seeds did ever come up and of those that did, few were very suitable for our climate: at that stage I was in my cottage garden phase and in thrall to cool-climate shrubs, perennials and bulbs. However, I loved the thrill of sowing and waiting for signs of life from my punnets, and still have a few specimens that I did succeed in growing from seed, and I treasure them greatly, both for their ability to survive in such a different climate and as a reminder of my younger, more naive gardening self. Some of them include the gorgeous golden-yellow Aquilegia chrysantha (in bloom at the moment), the delightful spired Campanula rapunculus (also in flower now and which has self-seeded through my garden), dainty Linaria purpurea in its pink, white and purple forms (also a keen self-seeder), and a quite unusual species Geranium which I haven't actually ever seen anywhere else: Geranium oxonianum 'Walter's Gift' (or at least a variation of it, with veined pink flowers and interestingly dark-marked foliage).

Herb and vegetable seedlings growing in some of Mr Fothergills kits, ready to be transplanted

Nowadays, I tend to grow herbs, vegetables and annual flowers rather than the rare and unusual - and it has become a lot more difficult to import seed from overseas, so I get my seeds from local sellers or from the plants of friends. I did learn a few things during the peak of my seed-sowing years. One was that seeds can have different requirements in order to sprout - such as needing to be left in the fridge for months on end, or to be kept in total darkness after being sown, or conversely needing light to germinate and therefore not needing to be covered by seed-raising mix. Some seeds need a high temperature to germinate; others need to be exposed to fire or smoke. Some have to be sown in situ in the ground, as they are almost impossible to transplant. I used to have a little handbook put out by the seedsmen Thompson and Morgan which listed many seeds and their individual requirements - that was in the pre-internet days and I am sure now all that sort of information would be readily available online. Luckily most herbs, vegetable and annual seeds don't generally require more than very basic conditions to germinate!

I found that it is best to use a proprietary seed-raising mix (as potting mix is too rich and can often contain fungi that attack the baby seedlings). I fill punnets two-thirds full with such a mixture then provide a top layer of a well-draining, stable, inert substance such as Vermiculite, Perlite or fine Kaolite. This seems to provide protection from damping-off problems that can occur if the top layer of the punnet is too moist or is invaded by algae. I water the punnet by placing the container in a water-filled tray until the seed-raising mixture is saturated. The seeds are sown and are covered with a thin layer of Perlite (or similar) - unless they need light to germinate - then the punnet is placed into a humid environment such as a clear, lidded, plastic box and placed in a shaded position. I have a little electrically heated propagating box that is useful for seeds that need warmth to germinate but it is not essential.

Basil grown from seed; Valentino variety from Italy

Once the seeds have germinated, the punnet should be removed from the plastic box and kept in shade for a few days. Gradually move the punnet into semi-shade. The seedlings should be fertilised with a very weak solution of soluble fertiliser (add a pinch to a tray of water and place the punnet into this tray until moist). I found this to be one of the most valuable tips, as without fertiliser the seedlings don't grow well at all. Once the seedlings have two to four true leaves, they need to be transplanted into bigger containers (I use my children's old school lunchboxes, with holes punched in the bottom!). I half-fill these with potting mixture then add a top layer of seed-raising mix, saturate it in a water tray then transplant the seedlings into it, spacing them pretty well, as they will never grow well if overcrowded at this stage. An old knife is useful for this procedure. You need to be ruthless and discard the seedlings you don't need! These containers are kept in shade for a few days and moved gradually into a sunnier position. The seedlings can be planted out into their final spots once they are well developed. They need to be fed regularly with a weak solution of soluble fertiliser.

Growing plants from seed is rewarding and much cheaper than buying seedlings in punnets. There is a range of seed-raising products available in nurseries for those who are just starting out, such as some of Mr Fothergill's kits that I have been trying out this spring: mini propagators with lids to keep in the moisture and complete with seed-raising mix that just needs water added, and jiffy peat pellets that can have seeds planted in them and then be planted out without the need to prick out the seedlings. My seeds have done well in these. Try a packet of seeds today!