prepare your spring garden in autumn
Without autumn-sown plants, the abundance and beauty of most gardens plummets for three or four weeks towards the end of spring.
The British countryside is at its best in May, with lanes, woodland edges and wastelands full of cow parsley and hawthorn blossom, but not our gardens. At Perch Hill, without autumn sowing of hardy annuals, the garden in mid-May is pretty dull. The last of the parrot tulips, 'Orange Favourite', drops its scented flowers. Plants such as Allium 'Purple Sensation', a few aquilegias and the early poppy, Papaver orientale 'May Queen' do their best. But swathes of the garden would have to wait a few weeks until early-flowering perennials - such as Geranium psilostemon, campanulas and Anchusa azurea, plus biennials like sweet rocket and foxgloves - are all flowering.
If I sow just 10 plants now and scatter them through the garden, it should all look good in May without any drop of the colour baton. You grow a bigger, more robust plant by sowing in the autumn and it also lives and flowers for longer. If a seed germinates now, it will form a small plant, growing a few inches before going into semi-hibernation in winter. Light intensity, hours of daylight and temperatures decrease. Growth above soil level stops, but root-growth continues.
Over winter, a large root ball develops, supporting a small amount of leaf. In the early spring, light intensity, hours of daylight and temperatures increase and the plant's away. It has had time to develop a huge root system to feed a quick-growing, plant. A seed sown in spring has pathetic prospects by comparison. The plants do fine but they won't be flower factories like the autumn-sown.
Early autumn is also quiet in the garden. You may have harvesting to do, picking flowers and vegetables, but most of the chores are coming to an end. Compare this to the rush of March and April, when there are vegetables to plant and all the half-hardy annuals to be cared for.
To direct sow now, prepare soil to a fine tilth in the border, so that you have lumps no bigger than a large marble. Then draw a noughts and crosses grid with lines 12-15in apart (check the packet). Sow seeds directly into the lines, placing them - if they're not too tiny - about 3in apart. To allow for some losses, 3-4 weeks later, thin the seedlings to half their suggested spacings and then do the final thinning next March.
Autumn sowing is like putting money in the bank without much effort, preparing a garden - already half-filled - to be bursting at the seams next year. It has too much to recommend it to be ignored.
the plants
Ammi majus
A lovely plant, similar to cow parsley but more delicate and longer-lasting as a cut flower and in the garden. I love it. From an autumn sowing, will be in flower by mid-May.
How To Sow and Grow
Easy germination and cultivation but best sown undercover and then planted out as seedlings. Space at 8in in autumn; thin to 18in in March. In a very hard winter, it may not survive - particularly in the North - so keep some under cover in 1l pots for planting out in March.
Height: from an autumn sowing, up to 6ft (twice the size of spring-sown).
Calendula officinalis 'Indian Prince'
This is my favourite marigold, a sophisticated-looking flower with deep orange petals, contrasting with dark crimson buds, centres and petal-backs. From an autumn sowing, will be in flower by early May.
How To Sow and Grow
Very easy. It will germinate and grow well from direct sowing now in any position in full sun. Thin to 6in in autumn and to final distance of 12in in March. This allows for a few winter losses. In a very hard winter, it may not survive - so keep some under cover in 1L pots for planting out in March.
Height: 18in.
Eschscholzia californica
The best hardy annual for lining paths and terraces. Beautiful, fine silver leaves and tangerine, trumpet-shaped flowers. From an autumn sowing, it should flower in May and then self-sow; the offspring will often flower in that same year.
How To Sow and Grow
Very easy in any soil. Direct sow. Thin to 6in in the autumn and to 12in in March.
Height: 12in.
Cerinthe major 'Purpurascens'
Wonderful silvery leaves contrasting with purple bell-shaped flowers. Invaluable for flowering from early spring in a sheltered spot; it keeps going for month after month. The purple bell ends in a bold yellow stripe.
How To Sow and Grow
Tough-coated seed, best soaked overnight before sowing. Needs heat for quick germination (so sow in pots inside and then plant out in October). It does well in poor soil where it flowers more prolifically than in rich loam. On heavy clay, I add grit to the planting hole. Self-sown seedlings should survive winter. Thin to 10-12in.
Height: 18in.
Centaurea cyanus
'Black Ball' is my favourite, with rich crimson-black flowers that outshine the blue variety 'Blue Boy' as a cut flower and garden plant. The deep, magenta-pink 'Red Boy' is good too. From an autumn sowing, will flower by mid-May.
How To Sow and Grow
Very easy. Thin to 8in in autumn and 18in in March. A very hardy plant (I rarely lose any from my winter garden).
Height: 4ft from an autumn sowing (twice the size as when sown in spring).
Euphorbia oblongata
The best euphorbia for flower-arranging as it has a short, robust yet open structure, forming the perfect base foliage for almost any arrangement. Will be in flower in April from an autumn sowing and then flowers on and off for nine months of the year.
How To Sow and Grow
As a short-lived perennial, this takes longer to germinate and grow than other hardy annuals. So sow it under cover, but you can plant it out in autumn and it should survive the winter. Plant out at 8in spacings in autumn and thin to 18in in March.
Height: 2ft.
Orlaya grandiflora
Another umbellifer, with larger petals than ammi, but just as lovely. Will be in flower by mid-May from an autumn sowing.
How To Sow and Grow
Sporadic germination, so this is best sown under cover then planted out as seedlings. Plant at 6in spacings in autumn and thin to 12in in March. On my heavy, acid soil, this is one of the most temperamental of these plants. Needs good roots to grow well.
Height: 18in.
Papaver nudicaule 'Meadow Pastel'
This is a biennial, but I find by sowing it in the autumn with my hardy annuals, it often does better than sowing in the more usual June. It's a fantastic, delicate-looking plant with crumpled, silk handkerchief flowers and a delicious Narcissus tazetta scent.
How To Sow and Grow
Sporadic germination, so this is best sown under cover and then planted out as seedlings. Plant out at 6in spacings in autumn and thin to 12in in March. On my heavy soil, this is one of the most temperamental of these plants and I always need to sow many more than I end up with.
Height: 18in.
Salvia viridis 'Blue'
A hardy salvia, where the flowers are minute, but the flower bracts are enlarged and brilliantly coloured. This is an exceptionally long-flowering annual, looking good - if you sow it in autumn and keep picking it - from May to September. Use it like lavender, to line your paths.
How To Sow and Grow
Easy germination and cultivation and can be sown direct. Thin to about 7in in autumn and then again to 14in in spring.
Height: 18in from autumn sowing.
Scabiosa atropurpurea 'Tall Double Mix'
Soft pom-pom flowers in bright red, crimson, mauve, pink and white. Long-lasting cut flowers will bloom, late May-December, in a sheltered spot. A velvet, crimson-black variety comes under various names.
How To Sow and Grow
As a short-lived perennial, this takes longer to germinate and grow than other hardy annuals. So sow it under cover, but you can plant it out in autumn.
