"There is a bit of a stretch coming in the evenings" a friend said to me in mid-February, what he meant was our hours of day light are increasing again. With this extra daylight comes gardening thoughts of seed sowing and propagation.
Summer bedding plant seeds availableThis is what horticulture is all about, raising summer bedding for your colourful designs. Summer bedding plants that require a long growing season can be sown indoors from early February onwards. What bedding plants can be grown from seed at this time? The varieties that fall under this mantle include varieties such as Ageratum ( floss flower ), Allysum, Antirrhinum ( snapdragon ), Begonia, Dianthus ( Carnation ), Dahlia, Lobelia, Tagetes ( marigold ), Nasturtium, Viola ( pansy ), Pelargonium (bedding geranium ), Petunia and Salvia. All can be grown from seeds indoors in early February. The seeds for these annuals and more will be available in garden centres and through mail-order.
How to prepare your seed trays, cleaning
Any trays or pots that you intend sowing seeds in must be washed in preparation for sowing. Particles of previous year's compost can harbour disease and mould spores. To ensure a clean environment for growing, wash the heavier covering of old compost off with a hose. Follow this by plunging the containers into water containing a disinfectant such as 'Jeyes fluid' this is available from most well stocked hardware stores. Scrub off any stubborn compost with a scrubbing brush, do this whilst in the disinfectant. Rinse the containers well under running water and leave them to dry. Use this method on window boxes as well particularly if you have a build up of old compost and your planting tends to finish flowering far too early.
Bedding plant seed propagation
So down to business, to get these seeds to germinate this time of year will require a either heated propagator, green house or warm window sill. Here we look at the window sill method....... Use a clean plastic seed tray (as detailed above). Place a sheet of wet newspaper in the base of the tray to prevent compost being washed through the holes.
Fill the tray to within 1cm of the top, firm gently with a piece of board or fingers to remove air pockets. Check that compost surface is roughly level, adjust if required.
Lightly moisten the composts surface and sow your seeds according to the packet instructions regarding spacing and covering. Firm gently with a board after sowing.
Restrict light to the seeds with a sheet of brown paper if instructed on the seed packet. Cover tray with a sheet of glass and place on a window sill in a centrally heated room.
Dealing with emerging seedlings (pricking out etc.)
Once your seedlings break the surface, you must remove the brown paper if used and prop up the sheet of glass to allow air flow. A few days later remove the sheet of glass completely. Turn the seed tray every few days to stop the seedlings growing lopsided towards the light. Water the compost when needed to stop it drying out. Use a mist gun rather than a watering can to avoid washing out the seedlings. Keep an eye on the seedlings and when the first set of true leaves appear then they are ready for transferring. True leaves are usually the first set of leaves that emerge after the original germination leaves.
Transfer the seedlings to one by one into their own individual cells in a 24 cell tray, this practice is known as pricking out. Hold the seedling by its leaves and loosen it from the seed tray with a dibber or even a pencil. The 24 cells should be filled with potting or multipurpose compost. Make a hole with your dibber to accommodate the seedling in the compost and firm lightly with the dibber. Keep the seedlings out of direct sunlight for a day or two after pricking out. Water when needed.
Seeds, composts, dibbers and cell trays are available in garden centres, most hardware stores and through mail-order.
Hardening off seedlings
Once the seedlings are sitting upright again after their ordeal of pricking out, I would advise hardening them off. Hardening off is the way your bedding plants will get used to outdoor conditions. Usually, none of these plant seedlings are placed outdooors in beautiful mild summer weather. So if we continue with the assumption that you do not have a greenhouse, I would now advise you to move the 24 cell tray to an unheated garage or shed window sill.
Remember turn the tray every few days to stop the plants growing lopsided towards the light. Leave the windows in the shed closed for approx 12 days. After that time open them on frost-free days. Leave the windows open day and night at least 2 weeks before planting your bedding out. Three days before planting out move your plants to a spot outdoors that is sheltered from harsh winds.
Back to articles >>