I want to make good use of the greenhouse over winter and to that end I have decided to rescue some herbs from the slow autumn slump. Right now all of my herbs are looking pretty good, and it is easy to be fooled into imagining this will go on, particularly when the September days are warm and the nights are balmy. But slump they will, and within a couple of months there will be not a fresh mint leaf or chive blade to be found. Chives don’t stop being useful just because they are out of season, chopped and sprinkled over warm winter salads to give a little oniony herby freshness. Mint I use in teas all year round if I can get hold of it, particularly after the overeating of winter celebration evenings, and I long went off the dusty tea bags of dried stuff.
Making pots of herbs to grow all winter is a fairly simple task. I dug about below the soil and rooted out some clumps of chives and mint along with as much root as I could gather intact. I transferred these to some pots full of fresh soil, settled them in, watered them, and popped them into the greenhouse. The fresh compost will contain more nutrients than the pots they have come out of and combined with this warm weather and the extra protection of the greenhouse I am hoping this will result in a nice flush of fresh growth before everything slows a little later.
My greenhouse is unheated all through winter, but as a rule even the unheated stay at around 5C warmer than the outside world, and that can be enough to prevent them from dying back completely, and to keep them growing a little during warmer times. If you don’t have a greenhouse you can absolutely perform this trick on your kitchen windowsill, and in fact during colder snaps I will be bringing mine indoors to grow there. But a little cooler is better, and so out they will go on mild winter days. Keep them watered over winter, not excessively when outside but as well as you would in summer when inside – remember that you do want active growth otherwise you won’t fancy eating the leaves and all of this will have been in vain. Hold back on the watering during cold snaps outside.
Instead or even in addition to doing this you can harvest and store any of your herbs now, in water or oil ice cubes in the freezer. Before they die back and while they are still looking lovely, snip the leaves you want, chop them fine, and pack them into ice cube trays. Go for a mixture, if there is a particular mix of herbs that you like to use regularly, or stick to one type of herb per tray so that you can mix at will later. Next you can either pour water on and freeze as herby ice cubes, or do the same using olive oil, which I prefer as I can then pop a little herby oil into a dish to finish it off, a dose of good extra virgin olive oil being a thing that is rarely unwanted at the end of a dish. Either way, as long as your herbs are looking good now there is no reason to be without home grown herbs later on in the year, with a little help from the greenhouse and the freezer. How fine it will be to pop out to the relative warmth of the greenhouse and pluck a few fresh leaves when all around is frosty and dormant.