Window dressing
Hannah Stephenson asks RHS expert Guy Barter for some helpful tips on how to grow microgreens, herbs and other mini marvels
You don’t need a vegetable patch to start growing – just a sunny windowsill.
So says Guy Barter, RHS Chief Horticultural Adviser, who is joining his colleagues in trying to encourage newcomers to grow plants during National Gardening Week.
During the week, the RHS gardens are hosting activities to showcase the benefits of gardening and inspire new gardeners to engage with nature.
Meanwhile, Guy and his RHS pals have been growing all sorts of things on their own windowsills, to prove that it’s possible to create an edible indoor veg patch.
So, what have they been growing? Guy gives us the low-down.
Microgreens The modern equivalent of mustard and cress, now a wider range of seedlings are grown, including basil, beetroot, carrot, celery, dill, kohlrabi, leek, perilla (from the mint family) and Swiss chard. Ideally use seed sold for microgreens as this will germinate well and evenly, and will be free of any unwanted materials. If in doubt, rinse seed well in several changes of fresh water before sowing.
Sprinkle seeds on to trays containing 25mm (1in) peat-free potting media or on to damp kitchen towel, in a seed tray or plastic box. Smaller containers are more manageable. Use containers with drainage. After light watering, place the seeds on a warm, sunny windowsill and allow to germinate. Plenty of warmth is needed for germination but too much heat will result in “leggy” seedlings – if this happens, move to a cooler room.
Water seedlings as required as they won’t put up with drying out or being drowned. Once they reach 5cm high, they can be cut with scissors and used as soon as possible. They will keep in the fridge in an airtight box for a day or two. Expect crops to take two to three weeks to complete their life cycle at room temperature (18-22C).
Clippings Tops and bottoms discarded when preparing supermarket vegetables can be planted in pots of peat-free potting compost, suspended in water or placed on damp kitchen towel in a seed tray, and kept in a light place at room temperature (18-22C). They will often grow and send out new leaves, which can be gathered as they become big enough, and used in salads. Best results come from leaving 25mm (1in) of vegetable below the top. The “tops” may well root and grow for some time, but eventually they will weaken and be consigned to the compost bin. Tops: carrots, swedes, turnips. Bottoms: cos lettuce, leeks, onions, salad onions.
Pumpkin sprouts
Pumpkin seed sprouts are among the quickest “crop” you can grow. Ideally use hull-less or naked pumpkin seed such as Baby Bear. Most pumpkin seeds have a hard seed coat, requiring you to “shell” the seed. Soak them in water for up to four hours at 16-18C. Alternatively let nature take its course and place your seeds in a sprouter (container with a sieve-like lid) and rinse and drain the seeds every 8-12 hours until they send out a rootlet, when they can be eaten. Don’t fill the sprouter by more than half.
Supermarket herbs
Potted herbs from the supermarket are meant to be taken home, the leaves eaten and then discarded. But if you lightly trim them for immediate use and place them on a sunny windowsill, they may regrow. Best results come from leaving 50cm (2in) of stem. Divide them into four and re-pot in a peat-free potting compost. Water with dilute fertiliser.