The seed sowing season is about to start in earnest and over the next couple of months my window sills will be stuffed with seed trays and pots as I grow vegetables and flower plants for my allotment and garden. I prefer to start seeds off at home rather than directly into the ground for several reasons. Last year, the seeds I sowed directly germinated very patchily because of the very dry spring, whereas the seeds started off at home germinated well as it was easier to control their growing conditions. I also find that if I can nurture a plant to a reasonable size before planting out they are less prone to pest attacks, slugs in particular love young seedlings, but I wouldn’t be able to grow the volume of plants I do without my cold frames.
When we first moved here we realised, sadly that there wasn’t the space for a greenhouse, which was even more annoying because we were offered one for free. The compromise came in the form of a sturdy, 5ft by 3ft cold frame from the Greenhouse People. It cost £250, which felt like quite a lot to spend on a cold frame, especially since money was tight as we were doing quite a bit of work to the house and garden but I wanted something that looked like it would last. Two years later and with a newly acquired allotment I knew one cold frame wouldn’t be enough so I bought another but this time I went for the cheaper option. Well I certainly have proof you get what you pay for. The second cold frame took twice as long to erect and wasn’t very well designed. It has perspex lights rather than glass and annoyingly the perspex has a habit of working it’s way out of it’s fittings and slipping down exposing plants to the elements. Despite the second cold frame’s shortcomings it has still provided me with the extra space I need.
In February and March you will find hardy plants such as broad beans, sweet peas and early peas in my cold frames and then towards the end of March and into April, as these hardy plants are moved to open ground, they are replaced by hardy flowering plants such as antirrhinums, sunflowers, scabious and cornflowers that will form my cut flower patch. Half hardy and tender plants sown indoors in April will gradually move to the cold frames in May. By the end of May, with the danger of frost having receded and all the plants now in their final growing place, the cold frames fall quiet for a while. But it isn’t long before they have filled again with sowings of biennials such as sweet williams, honesty, sweet rocket and wallflowers, sown in July to flower the following spring. Then in September I start off hardy annuals such as orlaya and scabious that will overwinter in the coldframes and can then be planted out in early spring to provide an early show of flowers.
This all sounds very organised but invariably some plants are slow to germinate, or the weather makes life difficult. Last spring was so warm and my plants grew so quickly that my cold frames were bursting at the seams but it was still only the start of May and too early to plant out, in case the weather changed and there was a late frost.
It’s not just for providing protection for young seedlings that I wouldn’t be without my cold frames, they have been useful places to overwinter plants that can cope with cold but just don’t like sitting in wet compost. Winters here in Wales tend to be wet so I move herbs, succulents and alpines into the cold frames so they stay dry, protected from the winter rains.
Of course, like anything cold frames have their problems. It is really important to keep on top of ventilation. Even in early spring the warmth of the sun on the glass can make temperatures underneath rise, causing young plants to wilt. On mild days in autumn and winter ventilation is important to stop damp air lingering and fungal diseases such as botrytis flourishing. It’s also essential to keep an eye out for pests, in particular aphids and slugs. Aphids multiply rapidly and in a confined space will spread quickly from plant to plant and if slugs find their way into your cold frame full of young, juicy seedlings. Well, lets just say it will be like a banquet for those loathsome creatures. I speak from experience, the damage caused by slugs unleashed in a cold frame can be heartbreaking. I don’t like using slug pellets, even though I buy the ones that aren’t supposed to be dangerous to wildlife but I now find a scattering in the cold frame is the best way to keep on top of them. Birds and hedgehogs don’t go into the cold frame so there is no danger of them coming into contact with them.
What wouldn’t you be without in your garden or on your plot? What piece of gardening kit has really made a difference for you? I’d love to hear your thoughts.