GARDENING Growing vegetables to harvest in winter

Sowing for over-wintering crops and winter harvesting


Organic growing
Hans Wieland

I have always sown a few crops for the polytunnel for overwintering, but while on a visit to organic market gardener Jim Cronin last November, during the spell of heavy frost, he really opened my eyes. Jim was still harvesting and selling lots of produce at the farmers’ market in Killaloe. His secret? “Hans,” he said, “get yourself a copy of ‘The Winter Harvest Handbook’, by Eliot Coleman.”
First published in March 2009, Elliot’s book on growing organically is one of the best that I have come across in recent times. So, after the visit to Jim in Clare, I have been reading and re-reading this gem of a book – and I’ve been talking about it at The Organic Centre to students and staff and recommending it to growers. I even brought it to my local GIY group in Sligo.
The book is more than timely. Last winter, the second in a row with sub-zero temperatures, left growers and gardeners struggling with crops during the cold months. We are better prepared for the next one coming round the corner. Coleman, who farms in Maine in USA, answers the question “How do you produce first-rate food all year round in northern places?” Since he began commercial year-round production in 1995, he has recorded the ‘evolution’ of his system and in the book describes the crops, tools, planting schedules and harvesting techniques he uses.
The winter harvest he practises at Four-Season Farm has three major components than we can apply in Ireland as well:

• Cold-hardy vegetables
• Succession planting
• Protected cultivation

Coleman sums up the winter-harvest concept as follows: “In a world of ever-more-complicated technologies, the winter harvest is refreshingly uncomplicated, because all three of these components are well known to most vegetable growers. What is not well known is the synergy created when they are used in combination”.
The book comprehensively covers everything from getting started and the yearly schedule to specific topics like sowing, weed control and pests and diseases.
He also addresses the much discussed topic of reduced sunlight hours in the winter and concludes that “limited sunlight, while important, is only one of the factors that cause plant growth to slow down during the winter. The effect of below-freezing temperatures is also significant.” Accordingly, his cut-off point for new sowings is the end of October, and he says that cut-and-come-again winter crops, for example, like spinach, claytonia or tatsoi, continue productive re-growth after harvest during the winter months so long as they have established root systems.
At The Organic Centre, we have recently sown oriental greens like mizuna, pak choi and tatsoi, which we will harvest from the polytunnels right through the winter for sale at the farmers market and local restaurants. We sow in modular trays and germinate in the ‘hardening-off’ area – the propagation shed would be too warm.
Soon, I will sow one of my favourite over wintering salad leaves: corn salad or lambs lettuce, or ‘Ackersalat’ as we say in Germany. It’s a very hardy annual with small nutty-flavoured leaves, ideal for winter salads. If you want to have spinach throughout the winter, Matador is a good all-year-round variety. And yes we do need to talk varieties, as in a lot of cases this makes all the difference between successful growing and failure. Bulls Blood, a beetroot variety can be grown for leaves throughout the winter to add colour to salads. Its crimson leaves are sweet and tasty. I would also have a few parsley plants in the tunnel, as the leaves will be much softer than the ‘out-wintered’ ones.
August is the time to start sowing for winter harvesting, and Eliot Coleman’s book is a great help – an investment in a copy will surely repay you many times over.

Hans Wieland is joint manager of The Organic Centre, Rossinver, Co Leitrim, which offers courses, training and information in organic growing, and runs an Eco Shop and an online gardening store. For more information, visit www.theorganiccentre.ie, e-mail info@theorganiccentre.ie or phone 071 9854338.
Questions or comments? Contact Hans at living@mayonews.ie.