The headline says it all. “I have seen weather forecasts for March ranging from snow and ice to it’s time to garden in short sleeves. Who knows? The only thing to do is listen, view or download your local weather forecast and react accordingly,” says Linda Lane, managing director of the family owned greenhouse business, Griffin Glasshouses.
Each month Linda writes a brief column on what fruit and vegetables to grow in a greenhouse. This month she identifies problems with changing weather conditions, the importance of cleanliness and how to plant now and beat the supermarket salad crop shortages.
“If you overwinter plants, it is time to deadhead and de-leaf, clean out the rubbish and weeds from the surface of the compost and start to water, gently at first, with a monthly dose of liquid feed or slow release pelleted compost. Take off all diseased or damaged shoots and do NOT leave any of this rubbish inside the greenhouse – dispose of it immediately,” says Linda.
She advises greenhouse gardeners to be on the lookout for emerging pests that begin to renew their destructive ways with the rise in temperature.
“Once everything is sorted out and the greenhouse is neat, tidy and clean – even if you don’t overwinter plants – it’s time to get sowing. I’ve always got half full bags of compost hanging around but for the new season planting I always buy fresh and keep the old for outside use.”
Cleanliness and hygiene are extremely important in a greenhouse and Linda says to make sure all pots and seed trays are washed and lightly disinfected before use. She planted broad beans outside in October and they are now emerging in her garden, but she will be potting up some more in the greenhouse for a later crop.
“I use 8cm (3") pots with two beans per pot. Most vegetable seeds can be planted in March. Follow instructions on the pack but do check the “Sow Before” dates on seed packets and never use out of date ones. Place the pots or trays in a sunny situation and as far from the glass as possible. The sun will warm them up in the daytime and then cover at night with horticultural fleece to maintain that all important germinating heat. Keep them moist but not soaking.
I start tomato, cucumber, aubergine and sweet pepper seeds in a heated propagator which is switched off during the day, unless it’s extremely cold,” says Linda.
“Salad crops are already like summer snow in many supermarkets and green grocers. Broad leaf varieties of lettuce can reach maturity in under ten weeks, so get sowing and remember sequential sowing every three or four weeks will keep you in salads until Christmas,” she adds on a positive note.