Monty revisits one of his classic books, Gardening at Longmeadow, in an occasional series.
Biennials have adapted to survive the harshness of winter before restarting growth and flowering early in the new year, so now is the ideal time to plant them.
The biennials we use most here are wallflowers. The basic wallflower has yellow flowers and will seed itself and grow enthusiastically in apparently solid walls and stone – hence the name.
They like good drainage and suffer badly if they sit all winter in wet ground, so I add extra grit to my rich Herefordshire loam.
British gardening expert Monty Don, shared his advice for nurturing wallflowers this autumn. Pictured: A container with a mix of wallflowers
Although wallflowers are very hardy, it’s a good idea to pinch out the growing tips when you plant them to create bushy plants, and to remove any late, vigorous growth that can be hit by an early frost.
It’s a mistake to over-feed the soil, which will contribute to this late spurt of growth; and never give them fertiliser. The poorer the conditions, the longer they will last, and they can keep going happily for five years or more (some wallflowers are, in fact, perennials).
Many wallflowers are sterile hybrids so you can only get new plants by taking cuttings from them – or buying more seed – but many others seed themselves easily. You do not need a greenhouse to grow them – planting a line or two in a seed bed in the vegetable garden is fine.
Sow seeds in late spring or early summer, then grow on and plant out now. Thin them initially to about 2.5cm or so apart, and then again to 15cm, transplanting the thinnings to another line.
When I was a child they were as regular a presence in our vegetable garden as carrots or peas.
There are three groups of erysimum varieties of wallflower. My favourite plant of all of these, E. cheiri ‘Blood Red’, comes from the tallest group, which has 12 colours.
The Bedder Series is much shorter and compact, with flowers in four hues: bright yellow, primrose, orange and scarlet. You are likely to find these as a random mixture but they can be bought as individual colours.
Monty said wallflowers can be easily raised from seed or bought as small plants. Pictured: Erysimum cheiri ‘Blood Red’
If you’re going to grow them in containers, choose the Prince Series, which are the shortest varieties. They come from Japan in five colours, but again, you’re likely to buy them as mixed colours.
We have Erysimum ‘Bowles’s Mauve’, which flowers from March until June and is a really good addition to a border.
Although wallflowers are easily raised from seed, you can also buy them as small, lush plants.
They behave like shrubs, with a tendency to sprawl, so plant them close together to support each other. Each plant produces flowers sporadically and you need the massed effect to make the most of the colour.
Tulips are the traditional accompaniment to wallflowers and they work well together, flowering at around the same time, the tall goblets of tulip rising above the massed foliage of the wallflowers.
Always plant wallflowers first, otherwise half the tulip bulbs will be chopped up by your trowel as you go. Tulips should be placed in the ground now, and when you do this, just dot the bulbs in among the wallflowers.
Wallflowers are brassicas, and so are liable to suffer all the problems of the humblest cabbage – sooner or later they will get a virus, or clubroot, or grey mould, or some such disaster. But sow fresh seed every year and you will have a healthy new batch ready to take their place.
How to: Add to a garden bonfire
Monty advises against burning anything that can be easily recycled or composted (file image)
- Avoid burning anything that can be composted, including most packaging and soft prunings.
- You should not burn anything that can be easily recycled, such as newspapers.
- I burn all our really nasty weeds, such as couch grass, ground elder and – the nastiest of the lot – bindweed. Wood that cannot be burnt on the fires indoors is chucked on the bonfire, especially to get it going. The secret of burning such weedy material – which inevitably has soil clinging to it and a lot of greenery – is to stack it up by the bonfire and then add it little by little.
- Be mindful of the excellent winter cover that garden waste provides for wild animals – in particular toads, hedgehogs and grass snakes.
Your kitchen garden: Radicchio
Monty who tries to enjoy a salad from his garden every day, said the seed for radicchio is best sown in May (file image)
At this time of year, salads from the garden are a precious treat – and one that I try to enjoy every day. This takes some organising with choosing the right plants, and radicchio is invaluable. It is beautiful too, adding a deep carmine to a salad bowl.
Radicchio is a confusing term – it actually means chicory, but it refers to those sharing the characteristic of deep red leaves.
I grow ‘Rossa Di Treviso’, ‘Rosso Di Verona’ and ‘Castelfranco’, and all of them start life with green foliage growing luxuriantly.
As the weather cools, smaller, rosetted red leaves replace them and the green leaves, which help to establish the deep taproot, can be cut off and put in the compost heap.
This taproot will sprout 2-3 new flushes of red leaves from autumn to spring if they’re harvested by cutting close to the ground.
The seed is best sown in May, directly into warm soil or seed trays, then pricked out and grown on in plugs. The spacing in the ground should be a good 30cm.
Look out for ‘capping’ – radicchio has a tendency for outer leaves to become brown and slimy if too cold and wet. Peel away this nasty layer to reveal perfectly healthy red growth. Open-ended cloches can counter this.
Extracted from Gardening At Longmeadow by Monty Don, BBC Books, £26. © Monty Don 2012.