Sowing seeds indoors and getting great results is really easy as long as you follow a few basic guidelines.
How to Sow Annual Seeds Indoors
You don’t need any chemicals or expensive equipment. Please note that good hygiene is essential to prevent seedings damping off and dying.
- Use clean seed trays or module trays. If possible use new ones or scrub out your old ones with hot water and a drop of bleach. I love terracotta pots and old wooden seed trays but for starting seeds I have found that plastic is best.
- Use a nice fresh new bag of seed compost (there are many to choose from… a light compost with small particles is much cleaner and easier to handle and your seeds will easily be able to push their way through)
- Fill your seed trays or module trays to the top with compost and firm applying even pressure so that the surface is level. This will help your seedlings germinate evenly.
- Wash and dry your hands thoroughly (sorry… hygiene again!) then scatter a pinch of seed thinly across your seed tray or sow just a few seeds per cell. Resist the urge to go over the same tray again with more seeds. Most seeds will germinate and that tiny pinch will produce a lot of lovely plants for your garden.
- Cover the seeds with sieved compost. Use a garden sieve or an old plastic colander for this. If the seeds are roughly 2mm long then cover them with 2mm of compost, if they are 3mm then cover them with 3mm of sieved compost and so on.
- Label each tray with the date and name of plants sown. If you use a pencil or permanent marker pen you’ll be able to read the label in a few weeks time! This is especially useful if you sow several similar plants. The photo below shows Salvia viridis… commonly known as Clary Sage. Without the labels I wouldn’t know which seedlings were all blue and which were the Bouquet Mixed which are pink, white and blue.
- Stand the seed tray in a clean tray of fresh slightly warm water until the surface of the compost is moist. The water will draw the seeds into the compost and the surface will sink a little.
- Allow excess water to drain way from the soaked seed trays then cover them with a plastic lid or a sheet of cling film to keep the moisture in. Most hardy annuals need a a warm (16°C-20°C) dark place to start the germination process. A boiler room, airing cupboard or even a corner of a warm room in your home is ideal. If it’s not dark just cover your seedlings with a dark towel or something similar.
- Check your seeds every day for shoots then remove the plastic lid/clingfilm and move the tray to a cool light place such as a windowsill or greenhouse when it looks like most have germinated. Hardy annual seedlings can cope with much lower temperatures once they begin to grow.
- Allow the tiny seedlings to grow on and water from below when the compost looks dry. When they are large enough to handle pot up into larger cell or small pots and feed each week to encourage root growth.
- Acclimatise your young plants to conditions outside by hardening them off. Move them outside each day for a week so they become used to the cooler temperatures. Once they are hardened off (foliage becomes tougher/not as soft) and you are sure there is no chance of frost then it’s safe to plant them out.
- Woo Hoo! Pat yourself on the back and pour yourself a gin and tonic. You’ve done it!
Many Hardy Annuals take just 12 weeks from seed to flower so you can look forward to some beautiful flowers like this in just a few weeks time.
There’s nothing like picking a bucket full of beautiful blooms you have grown yourself.
Is this the year you have a go at sowing seeds in your garden? Happy Gardening! Gillian 🙂