Towards the end of last month the greenhouse started looking very sorry for itself indeed. Although frosts have not come yet, the tomato plants that have been filling the greenhouse with greenery, scent and fruit all summer have been abandoned for a couple of weeks, after their final harvest, and have now slumped and yellowed. A thorough clear out was certainly due, and I have cleared everything to the compost heap and made the place spick and span. The question now is… what next? With the greenhouse clear and clean and ready for action, what to fill it with at this cold and dark moment in the year?
The best answer I have found to this is winter salads. With the right varieties and a little planning, you can keep picking fresh leaves long into winter. Especially in a greenhouse or under a cold frame, hardy salad crops such as winter lettuces, pea shoots and Asian salad greens come into their own.
Why grow salad leaves in winter?
Fresh leaves brighten winter meals at a time when most garden produce is root-based or stored. The cool conditions of autumn and winter often work in salad leaves’ favour too, with plants producing crisper, more flavoursome leaves, and much less likely to bolt than they are in summer, when many salad leaf plants will threaten to run to seed every time the weather turns hot and dry. It’s also just a good feeling, and good sense, to make use of greenhouse bed and benches that would otherwise stand idle.
The reliable performers: pea shoots, hardy lettuces and winter greens
Pea shoots: Pea shoots are one of my winter dependables. While the main crop of peas is spring-sown, pea shoots – the young tendrils and leaves of pea plants, harvested when they have grown just a couple of inches – can be grown in greenhouse modules, trays or pots even now. They deliver a sweet, tender leaf with the fresh flavour of pea, requiring only a small amount of compost and good winter light. Buy cheap packets of marrowfat peas and sow them thickly.
Winter lettuces and salad leaves: There are several “winter” or “hardy” lettuce varieties such as ‘Winter Crop’ and ‘Marvel of Four Seasons’ that have been bred to withstand cooler temperatures. Sow these lettuces under cover in the greenhouse in late autumn, and they will grow on through winter into early spring.
Other salad greens such as winter purslane/claytonia, spinach, corn salad/lamb’s lettuce and land cress can also prove remarkably hardy and are definitely recommended for your winter salad leaf list.
Asian and spicy leaves: Salad mustards, mizuna, mibuna, and other oriental leaf greens are also worth trying. They are forgiving of low light and cooler conditions, and provide lovely peppery winter-salad interest.
Indoor growing ideas
If you weather cools suddenly or if you find that nothing is germinating, it is worth starting any of these indoors on a kitchen windowsill. Start seedlings off there and then transfer them to the cool greenhouse as soon as they are large enough.
But you can also just keep them indoors and grow them as micro leaves, tiny little punches of flavour to sprinkle over salads and into sandwiches. Generally strongly flavoured crops work well here – celery, onion, basil and coriander, for instance – but you can also grow beetroot or chard seedlings for their colour. Sow seeds thickly across the surfaces of pretty pots or over seed trays, water and wait. Micro leaves can be harvested as soon as they are an inch or so tall.