Gardening: Plug in for colour

Why do people still try to grow geraniums from seed when the modern – and often cheapest way – is to pop down to the garden centre or B&Q to buy plant plugs?
GROWTH INDUSTRY: Geraniums can be persuaded to bloom virtually year-round.GROWTH INDUSTRY: Geraniums can be persuaded to bloom virtually year-round.
GROWTH INDUSTRY: Geraniums can be persuaded to bloom virtually year-round.

These small but perfectly-formed little geraniums just need tending until the threat of frost has passed and they can go outside, into the soil or, more often than not, into containers.

And then, come autumn, dig up the healthiest, repot them and bring them indoors somewhere light and frost-free. You should see them flowering again before next spring when they can be trimmed and tidied and prepared to go outdoors yet again.

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And yet...the lure of sowing from seed never dies. One of the main reasons is that there are far more varieties available than what’s on offer as plugs, but seed is expensive, so gardeners need to make sure they get it right first time – and there are often a lot of losers.

You can start as early as you like, and some geranium aficionados sow geranium seed on New Year’s Day, although it is far more common to wait until the end of February.

Because the seed is so costly, you want every single one to germinate, and this means you need to have somewhere where you can keep a constant temperature of at least 65F. So, either a centrally-heated room or a propagator or heated greenhouse.

Sow the seeds into a pot or tray filled with proprietary compost, then water, and either cover each pot with clingfilm to keep in the heat and moisture, or stick them in that propagator.

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Allow two to three weeks for the first green shoots to appear, then take off the film. When the first set of leaves have developed, repot each tiny geranium into its own 3in container filled with fresh compost.

From then on, it’s a case of giving them plenty of light (but not hot sunlight), watering them and potting them on as their roots expand until the threat of frost has passed.

Here in the North, that is normally the end of May, but in milder areas or where the gardener is prepared to protect containers from the cold and wet, that could be several weeks earlier.

Geraniums are pretty good at looking after themselves, but it pays to deadhead, water and feed regularly to encourage many weeks of continuous flowering.

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