Seed growing guide for beginners
RAISING PLANTS FROM SEEDS IS AN ENGAGING AND REWARDING WAY TO ADD COLOUR AND VARIETY TO YOUR GARDEN
FOR those making their first foray into growing seeds, hardy annuals are the best place to start (see pages 18–19).
These seeds can either be planted indoors from March, or straight into the ground if it is sufficiently warm.
Many colourful bedding plants need to be started off indoors in March and transplanted outdoors in May. These are called half-hardy annuals and won’t survive frost. They include French and African marigolds, lobelia, cleomes, busy Lizzies, petunias, zinnias, gazanias, cosmos, molucella, felicia, helichrysum, brachyscome and amaranthus, all of which can be grown inexpensively from seed.
To grow plants from seed, first pick a bright spot such as a kitchen windowsill. The temperature needs to be about 18–21 degrees so you may need to use a heated propagator. The idea is to wrap the seeds in warm air to trick them into growth. The warm, damp environment is perfect for mildew; many seed companies anticipate this and dress the seeds in powders to prevent fungal outbreaks.
You need a seed tray or small pots for growing. Improvise by recycling yoghurt cartons or egg trays, ensuring they are clean and have drainage holes. Place seed compost in the pots, as it has the correct texture and nutrient level for seeds. Fill containers with compost to within about an inch of the rim, firm down gently and water the compost.
Sow your seeds according to the correct depth and space listed on the packet. Some (such as lobelia, begonia and petunia) are hard to handle, as they are as fine as dust, so mix with some fine sand to spread. Use a sieve to lightly cover the seeds with a layer of soil. Label so you know what you’ve sown.
Water very carefully without causing disturbance, either using a fine rose on a watering can or recycle a kitchen detergent sprayer, creating a fine mist. Cover the cartons or tray with a
piece of glass or cling film. If using a heated propagator, close the lid.
Germination takes from 7–21 days to occur. When the seeds start sprouting, remove the cover on the pots to get air flowing and prevent fungal diseases.
As soon as the ‘true leaves’ appear on your plants (the second set), begin to pick out seedlings for potting on. True leaves are the second set of leaves that grow on the plant after the first nutrient-gathering set of leaves have grown.
With a dibber or blunt pencil, gently tease out the seedling, holding it by its leaf, and pot in ordinary compost in a 3in pot.
Keep your seedlings moist and fed fortnightly. Be careful not to saturate seeds or seedlings, as this can cause them to rot.
When a seedling has three to four true leaves, it’s large enough to plant out in the garden, once it has been ‘hardened off’.
‘Hardening off’ is the term used to introduce the seedling to the outside environment. The process takes around a week, during which time you should place the plant outside in a sheltered area, increasing the number of hours it spends outside each day.
Halfway through the week, you should begin introducing the plant to natural sunlight until it is spending all day in the sun. Bring the box in every night until you have completed the ‘hardening off’ process and are ready to plant.