Amsterdam is currently enjoying a warm start to October so it feels a little odd to be thinking about protecting herbs from frost damage but this weekend we removed the drip trays from the roof pots and had a look to see how much fresh produce might be expected over winter.
I’ve built up a collection of potted herbs on our roof and balcony, which can happily withstand Amsterdam winters. Herbs which don’t survive are not replaced and just a few are brought inside before the frosts. Some survive by self-seeding, others are winter hardy evergreens and perennials. Water trays are removed in early autumn and a couple of pots are moved to more sheltered spots. I don’t bother with insulation and only harvest lightly through the coldest months. An occasional plant is lost when temperatures really plummet but overall this relaxed approach makes potted herb gardening much easier and cheaper. Finding self-seeders such as nigella, rocket, borage and calendula in interesting places when spring arrives, is a pleasure that it also brings.
Wild rocket (Diplotaxis muralis) is one of the few herbs I harvest in quantity from the roof come mid winter and it can still be sown from seed in October. It tastes stronger, even more peppery, in winter and I really like the warmth it adds to dishes. Wild rocket self-seeds quite readily and is a hardy perennial. Although at its best in summer, it goes on producing vitamin and sulphur rich leaves throughout the winter months. After Patrick Whitefield recommended it during a 5 day permaculture course, I sewed a handful of seeds amongst other herbs and have had plenty to pick from ever since.
My friend Elodie uses wild rocket from sand dunes in summer, to make a great pesto. I often use the leaves in salads and, at the very end of cooking, tear them into root vegetable soups. I’d like to grow more herbs that can be eaten fresh throughout winter and would love to hear about any successes or suggestions you have.