Many gardeners know and grow annual and biennial umbellifers from seed, but there are some superb perennials that return year after year, giving a light touch to the border.
One of the most refined is Cenolophium denudatum, also known as the Chelsea Cow Parsley or Baltic Parsley. It’s easy, long-lived and never needs staking. The shiny green, ferny foliage is topped by greenish-white domes of tiny flowers in early summer. There’s also a May-flowering, dark-leaved form of our own native cow parsley, Anthriscus sylvestris ‘Raven’s Wing’. This will produce seedlings, but only half will have dark foliage, so it’s best deadheaded.
Later-flowering examples include the handsome Himalayan Selinum wallichianum, an August-flowering plant dubbed The Queen of the Umbellifers. This needs rich soil because Himalayan summers tend to be wet and cool. The flowers are rather ordinary but the emerald-green foliage and purple sheaths are truly magnificent and, given a wet summer, this statuesque umbellifer can reach five feet in height.
There are knee-high cool pinks too. If you have rich soil, plant Pimpinella major ‘Rosea’, an early summer performer with slightly fuzzy flowers. The more feathery-leaved Chaerophyllum hirsutum 'Roseum' is easier on poor soil.
How to grow umbellifers
Many umbellifers are tap-rooted so it’s vital to seek out young plants that are still developing, rather than mature ones. You can grow many from seed and Derry Watkin’s Special Plants (www.specialplants.net) sell many. The key thing with growing umbellifers from seed is to provide warm temperatures of 50C because, just like parsnips and parsley, they refuse to grow until the weather warms up. There are long-lived perennials on offer, but many are short-lived perennials, or biennials.
Where to grow umbellifers
There’s an umbellifer for every situation from damp meadowm to woodland shade, to full sun. If it’s spring-flowering, it will almost certainly be a woodlander in need of some shade in summer. If it’s grey-leaved it will need full sun and, if it flowers in the second half of summer, it will need good soil and an open position.
How to use umbellifers
Froth is the border filler, but it won’t do on its own. You will also need statement plants with strong architectural stems, such as angelica, as well as verticals. Sword-shaped leaves, or spires will add focal points too.
Frothy plants for shade and woodland
Many of the early grasses will add froth and air among other woodlanders at the same time the bluebells flower, usually in early May, or perhaps a month or so later.
One of the best of the finely beaded grasses for shade is Bowles’s Golden Grass (Milium effusum ‘Aureum’). The beaded awans shine and shimmer and this grass also produces yellow foliage that endures in winter. However it does self-seed and will need controlling. The wood millet, Melica uniflora f. albida, is a white-flowered grass with nodding, one-sided awns. You could also use the taller wood sedge, Luzula nivea, in deep shade. This produces tufts of white flower above good green foliage that’s serrated along the edge. These grasses have all been used in Chelsea Show Gardens to good effect.
Airy flowers for shade could include:
Spidery-stemmed epimedium and ‘Amber Queen’, which produces branching stems in summer.
Astrantias, which are stunted umbellifers that form pincushions, also add an airy presence.
The deep reds, such as ‘Gill Richardson’, like shade as does the green-white ‘Shaggy’.
However the perpetual-flowering astrantias such as ‘Roma’ and Buckland’ are best in brighter light and even in full sun.
If the area is wilder, Sweet Cicely (Myrrhis odorata) is an attractive addition with white flowers in May and aromatic, green ferny foliage. It produces large black seeds and does pop up unannounced, but the leaves are good in stewed rhubarb because you need less sugar. So it’s a
Frothy plants for well-drained sunny spots
The ultimate sun-loving frothy plants is Gypsophila, known as Baby’s Breath. This member of the Carnation family (Caryophyllaceae) often finds its way into bouquets, but certain forms make good garden plants for a hot spot although you must be wary about slugs and snails. They can kill a plant by cropping off the first shoots. The pale-pinks are softer in the garden than the whites and Gypsophila repens 'Rosenschleier' (literally veil of roses) is the finest. It will reach a foot in height (30cm) but billows out to form a wider mound. Many nurseries do not sell gypsophila, but Beth Chatto sells four named varieties - www.bethchatto.co.uk.
Early season grasses can also add froth and the tall Golden Oat Grass (Stipa gigantea) splays out golden heads of triangular oat flowers on tall stems and these can rise above alliums, or roses, or later herbaceous plants. They gleam in summer sun, constantly tremble and they do keep a presence into late autumn. Most stipas prefer sun and well-drained soil and, once planted, they hate disturbance. On average they live for five years or so. They won’t divide easily so it’s best to start again.
You can also create a haze of lime green using a shrubby umbellifer called Bupleurum fruticosum and this will proiduce masses of tight umbels in August, looking very fresh. This is hardy, but tends to have a lifespan of ten years. it’s difficult to strike from cuttings so you may need to buy another whilst the first is still productive.) from Chris Pattison - www.chris-pattison.co.uk
Carrot-like plants prefer full sun and drier conditions and the moon carrot, Sesile libanotis is a short-lived perennial British native (usually found in Cambridgeshire or the South Downs) that is well worth growing. The white flowers age to produce a wonderful skeleton. from Sampford Shrubs (www.samshrub.co.uk), who also sell the grey-leaved S. gummiferum. The latter really does need a hot spot though.
Frothy plants for good soil and full sun
Thalictrums, or meadow rues, are having a revival and there are several new forms including ‘Elin’, a tall form (2.5m ) that produces young, dark foliage that ages to grey-green before then lavender flowers appear. There are also others, including ‘Black Stocking’, a purple-flowered form with almost black stems and green lacy foliage. The flowers are small and fuzzy.
There are also reliable old favourites that include the lilac-flowered T delavayi ‘Hewitt’s Double’ and this had daintier foliage than T. aquilegifolium and flowers a month or later, usually in July. In windy gardens most of these need staking. The green-flowered T. lucidum is entirely different, with ridged corky stems and high-gloss divided foliage. This August star is tall, but supplies a cloud of flower from late-July and August onwards. Try Crocus (www.crocus.co.uk) Beth Chatto (www.bethchatto.co.uk) and The Plant Specialist (www.theplantspecialist.co.uk)
Tall sanguisorbas will also add a fluffy presence and Avondale Nursery (www.avondalenursery.co.uk) holders of The National Collection, sell a whole range. They can also supply the tall, airy white Crambe cordifolia - although the cabbage-like foliage is a magnet for slugs and snails - and a refined, tidier lady’s mantle called Alchemilla erythropoda. This low-growing, acid-yellow is for the front of the border, should you find the commoner A. mollis too invasive.
Finally two personal favourites are Bronze fennel (Foeniculum vulgare ‘Giant Bronze’), grown for smoke-like puffs of dark foliage in May, and Seseli hippomarathrum, right, a small, pink-flowered umbellifer that flowers in late summer for many weeks on end. The latter is also available from Avondale Nursery (www.avondalenursery.co.uk).