Sow seeds in the warm
Warm late-winter days bring a sense of urgency to bear. “Must finish off all outstanding jobs and get the seed sowing started” is a thought running through this fellow’s head right now.
However, it is tempered by a note of caution. We’re all aware of the surprises our weather can dish up over the coming weeks.
In early March, there’s a strong case for holding back on outdoor sowings. The ground is generally moist enough, but low soil temperatures inhibit germination, seeds may rot. Keeping vegetable seed packets closed until conditions improve later in the month is a smart move.
However, certain early vegetables can be sown in pots or cell trays now and will germinate under cover in moderate warmth of circa 15 Celsius.
When you can muster a 15 to 20 temperature band later in the month, more half-hardy annual bedding plants can be started.
With the germination of early seeds accomplished, conditions that support sturdy, uninterrupted growth must follow. This entails a slightly lower temperature and good light conditions.
We’ve recently washed down all the greenhouse glass to increase light intensity, it’s the lack of artificial heat that hinders our rapid progress.
However, as March proceeds, warmth from the sun is entrapped within the greenhouse. The temperature can rise to 25 Celsius then fall to negative figures overnight. Too big a fluctuation for tender young plants, but we can regulate it!
By opening the door and ventilating an unheated greenhouse mid-morning then closing-down mid-afternoon. The heat residue carries deep into the night. On nights when frost is forecast, a protective fleece covering for young plants is standing by.
Plants of a bronzeleafed Primula Garryarde Guinevere (purplish-pink blooms and yellow eye),and those of Polyanthus Vera Mixed were both lifted from the garden and potted recently.
They’re starting to bloom on the greenhouse staging but some will go out for Easter. Alongside them are potted strawberries, chrysanthemums and dahlias, now shooting, plus a collection of streptocarpus that overwintered in the conservatory. They have great potential.