Sourcing seedlings is with us throughout spring, summer and autumn. It’s a costly business but growing you own plants from seed is super-saving like you’ve never known it before. For the cost of a packet of seed and a bag of seed raising mix (about $12 in all) you can grow $80 worth of garden centre plants. And by following the sowing instructions on the back of the seed packet you can almost guarantee germination. So why isn’t everyone doing it? The answer lies in after-germination care. It’s not rocket-science but it does require vigilance and attention to some specific details.
Let in the light
While most seeds are happy to germinate in darkness, once they emerge through the soil, their tastes swiftly change. They need lots of light and it should be delivered as directly as you can manage. Popping them on a window ledge is adequate as long as you remember that the sun moves – which means you’ll need to move your seedlings to follow the sun. Keeping them on a tray indoors can simplify this but better still, once they are through the ground, move them into a greenhouse or cloche where the light hits them directly from above, encouraging them to grow straight up rather than to lean towards the sun.
Ways with water
A seedling’s root structure is in its infancy. When the first centimetre of growing medium dries out, the seedling simply has no longer roots to go in search of moisture. Surface watering should be such that moisture penetrates the growing medium to a depth of 2-3cm. There’s no point in a ‘once-over’ with the watering can. If time permits, the best way to water seedlings is by sitting their container in water so the moisture is soaked in from the bottom up. If this is done thoroughly, soaking 2-3 times a week should be sufficient. Once the containers have been removed from the water, raise them off the ground so they drain quickly and thoroughly.
Seed raising mix is not a well balanced growing medium. Its main purpose is to provide seeds with a fine soil so that their germination and growth is not inhibited by rough material such as sticks and small stones. Seeds will germinate in it but put on very little growth after the first week unless fed. While do-it-yourselfers can supply nutrients in the form of liquid animal manure and seaweed, there is always the risk of introducing fungus to seedlings in the early days of their lives. For this reason, some people prefer to use a soluble commercial plant food. Once you’ve been growing seedlings for a while, you will come to know which are in the ‘hardy’ category and can tolerate a home brew, and which are more delicate and are best fed with a commercial solution.
Disturbing the soil
Whether your aim is to leave your seedlings in the container in which they germinated, or to transplant them out, ‘disturbing the soil’ after a few days of growth will help the young plants spring into life. Disturbing the soil involves lightly cultivating between the tiny plants to a death of just a few millimetres. I use the tines of a kitchen fork to do this. The disturbance lets air into the soil, something that is essential for root growth. If your seedlings have failed to grow, this ‘micro-tilling’ will almost certainly give them a new lease of life and they may well double their size in 2-3 days.
Ditch the damping-off
‘Damping off’ refers to fungus disease which settles into young seedlings and cuts a swathe right through them. Fortunately, there is one simple way to ensure it doesn’t catch you out, and that is by carefully following the advice above. If you have neglected your seedlings, or simply haven’t been able to avoid damping-off, be sure to rinse containers out with a sterilising solution before sowing your next batch.
Raising seedlings is infinitely rewarding and cost saving in your own garden – and the perfect solution to ‘what do I give my gardening friend as a gift’. Have fun!