A profusion of spring annuals

Friday, 01 October 2010

Centranthus calcitrapa, an annual form of valerian, in the garden of Sandra Wilson in Sydney

A visit this week to a lovely local garden reminded me of the value of self-seeding spring annuals. Like many gardeners, I don't seem to have time these days to plant out a lot of annuals for spring, but there are a number of them which obligingly come up year after year of their own accord, creative lovely soft informal effects. They are particularly useful when there are bare patches between cut-back shrubs and late-appearing perennials, as they fill in gaps and then can be removed once the garden starts to fill in again in late spring. They give a pretty cottage-garden effect that is often hard to achieve using perennials in our climate.

Cynoglossum amabile

Some of these easy-going spring annuals have been familiar to me since childhood and I grow them in my own garden. Forget-me-nots (Myosotis sylvatica, ht 30cm) with their tiny, pale blue eyes of bloom are irresistible when they first open in spring. I love to see swathes of these growing beneath trees and shrubs - though by the end of the season, I am equally glad to see the end of them, as their seedpods stick to clothes and animals in their determination to spread themselves around the garden. There is an unusual white form that does quite well in Sydney, and even more rarely, a pink version. They will take some shade. Cynoglossum amabile (ht 50cm) is colloquially called the Chinese forget-me-not and it has larger sky-blue flowers in greater profusion. This form also self-seeds, but not quite to the same extent. There are also white and pink forms of it but I have never found them to be as robust as the blue one in Sydney. It flowers into early summer.

Primula malacoides

Primula malacoides (ht to 30cm) is another annual that will grow in shade and is a determined self-seeder. I haven't deliberately planted it for years but they pop up everywhere and look so pretty with their tiered layers of simple flowers of pink, white or mauve. Also in shade, biennial honesty (Lunaria annua, ht to 75cm) comes into flower now and is a determined self-seeder. The basic type has plain green leaves and a purple flower but the white-flowered form with white-variegated foliage is a truly lovely plant and if you discard any seedlings that don't have the leaf variegation and don't grow other forms nearby, it should continue to proliferate in your garden for many years. The silvery seedpods are attractive later on in the year.

Lobularia maritima in the garden of Sandra Wilson in Sydney

In sunny spots, I enjoy the prolific Viola tricolor (ht 15cm), or Johnny jump-ups, which appear in their hundreds every spring. They have such cute, cheerful little flowers of purple and yellow; I also have a pure black version, 'Bowles' Black', which also has begun self-seeding in my garden. Sweet Alice or alyssum (Lobularia maritima, ht 20cm) with its honey-scented fragrant little bobbles is another favourite - I remember it growing in my grandmother's country garden in the 1960s, where it came up every year on its own on the edges of her paths. The most common form is white, but there are also pink and purple varieties.

An annual form of Silene in the garden of Sandra Wilson in Sydney

My friend grows less common annuals in her garden and one of the loveliest is a form of Silene (possibly S. coeli-rosa, ht 45cm), which is sometimes (incorrectly) called Viscaria or Lychnis, with hot-pink flowers. It forms sheets of colour in a sunny spot and comes back regularly every year. She also grows an annual form of valerian (Centranthus calcitrapa, shown at the top of the blog), which has minute pale pink flowers clustered in crowded heads like the perennial form. She also grows love-in-a-mist (Nigella damascena , ht 40cm) which has soft, feathery leaves and amazing whiskery flowers of blue or white, or even pink. Virginia stock (Malcomia maritima, ht 20cm) was another old-fashioned annual that I noticed growing in the garden, a pretty mixture of dainty pink, mauve and white blooms.

Orlaya grandiflora

A very unusual annual that has circulated amongst my gardening friends over the last few years is Orlaya grandiflora, a lovely annual with white flowers a little like a miniature Queen Anne's lace. It has soft ferny leaves and comes up every year in a hot, dry spot in my garden. It comes from the Mediterranean region, as do many of these spring annuals that thrive in hot, sunny positions in our gardens. Another self-seeder for a similar spot is the petite daisy Leucanthemum paludosum (ht 15cm) - which has simple white flowers, just right for spring.

Though tedious, it is important to thin out self-seeding annuals when they are small, to give them room to grow into sturdy plants. It is also necessary to leave parts of the soil without a mulch cover, otherwise the self-sown annuals won't appear. I try to leave patches of soil where possible - though then of course, I get lots of weeds!

Some of these seeds are available by mail order - others are passed from gardener to gardener in the time-honoured tradition. I came home from my garden visit with some seedlings of the annual Silene, which I have planted in the hope that they may self-seed for me next spring ...