Saturday 4 June 2011


You can raise seedlings easily indoors, saving you money and giving you a larger choice in the variety of plants you grow. You may only have a sunny windowsill in your house or perhaps a heated greenhouse, but all can be used to start off seeds indoors.

You will need to select a suitable container for sowing seeds. You need a shallow tray or half pot, and seed trays are ideal.  You may wish to plant seeds in cellular trays. Larger seeds can be planted in pots, or even peat pots or old toilet rolls. Ensure you thoroughly wash the containers prior to use as diseases can be carried in old soil, and avoid wooden trays as these are hard to sterilise.

Fill your container with John Innes 'seed and cutting' compost to 2cm below the surface.  Press gently on to compost with some cardboard or similar to level the surface, but do not compact the soil. Sow your seeds in the compost. Cover seeds gently with fine compost or vermiculite to depth twice diameter of seed.  A sieve works well for this purpose. Do not cover fine seeds as these should be left on surface.

Water gently, or stand pots in a bowl of water to soak if the seeds are fine. You need to keep moisture levels high and the soil warm so cover your seeds with either a sheet of glass/Clingfilm or place inside a propagator.

Place your seeds in a bright position but not in full sun.  They need warmth of 65-70f to germinate.  You may wish to used a heated propagator or place on a window in a heated room. As soon as seeds germinate remove the transparent covering. Turn the pots every couple of days to avoid seedlings bending towards the light. Do not allow the compost to dry out and water as necessary.

Seedlings are ready to prick out when they have developed their first set of true leaves.  They can be transplanted into cellular pots, a new tray or individual pots filled with John Innes seed and cutting compost. Carefully remove then with a pencil or dibber, holding onto the leaf gently, and place in a cellular pot or new tray at 3cm spacing's. Keep in shade for 2 days after transplanting to establish. Water as necessary.

When seedlings have established after pricking out they are ready to be hardened off outdoors.  Do not plant seedlings directly outside without hardening off as they are unlikely to survive.

You may wish to place your seedlings in a cold frame. Close the cold frame every evening for several weeks, and only open on dry, frost free days. A week prior to planting you can leave the cold frame open night and day. You could make a makeshift cold frame with some bricks and a sheet of Perspex or glass.

Alternatively, you could place your hardier seedlings outside in a sheltered spot, bringing them in to the house each night for several weeks.  Windowsill seedlings can be moved to an unheated room for several weeks and then moved out into the garden for a week prior to planting.

For related articles click onto:
Grass maintenance - laying turf
Grass maintenance - sowing a lawn from seed
Herbaceous borders
How to build a cold frame
How to make compost

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