How to grow scilla
Grown under trees or naturalised in grass, scillas give a beautiful wash of colour in spring. John Grimshaw, director at the Yorkshire Arboretum, recommends his favourites and gives his expert advice on growing them. Photographs Jason Ingram
In early spring, scillas spangle the ground with their six-petalled flowers in shades of blue, varying sometimes to white or pink, and occasionally almost mauve. As highlights in the garden, or as gems in a pot, they are delightful.
The classic species is Scilla siberica, with nodding, rich-blue flowers in March – the name is a little misleading as it comes from no further east than the Caucasus. When happy it will self-sow to create a great carpet – ideal in thin grass or under deciduous trees and shrubs.
Where to grow scilla
In the garden, scillas work best when they are allowed to naturalise. For a big, bold effect, some scillas can be planted densely in grass to create a blue river, but I prefer to see them in what Arabella Lennox-Boyd calls 'millefiori' plantings, creating a changing spring carpet of ‘a thousand flowers’ in short grass under shrubs and trees.
Choosing species carefully makes it possible to have a long season, starting with the icy pallor of S. mischtschenkoana ‘Tubergeniana’ in February, opening at ground level with Crocus tommasinianus before the stems elongate to their full height of 10cm, and continuing well into May with the upright spikes of Scilla litardierei.
In one of my favourite plantings, at Colesbourne Park in Gloucestershire, Scilla luciliae is sprinkled through short grass full of native primroses (Primula vulgaris), wood anemones (Anemone nemorosa) and celandines (Ficaria verna), creating a mesmerising effect for just a few days each spring.
As with most bulbs, scillas don’t thrive in heavy clay, or permanently wet places; well-drained soil of any type will suit them well. They should have plenty of light in the growing season, so avoid planting them under evergreens.
How to plant scilla
For naturalising, scillas should be planted as generously as possible, flung out to plant where they fall, in hundreds or thousands. Ideally the tip of the bulbs should be about 2.5cm below the surface, but there’s no point in precision with such things.
Scillas have the capability to adjust their depth in the soil by means of contractile roots that pull them deeper if necessary. The next generation of seedlings will suit themselves and flower in three or four years, so the patch should spread quite quickly in good conditions.
How to grow scilla in pots
To really make a show when potting scillas, pack them densely in the pot as the display will not last long, especially if brought inside. Don’t try to force them too much; plunge the pots outside and only bring them in when the noses are showing – they will rapidly develop and come into flower with a slight increase in temperature.
Afterwards place them back outside and continue to feed and water them for the rest of the growing season. In a mixed planting, use them as the top layer of the ‘lasagne’ with larger and later-flowering bulbs below. Read more of our advice on planting bulbs in pots.
The best scilla to grow in your garden
Scilla bithynica flowers in March and early April and spreads very rapidly to create a soft-blue wash. Ideal under deciduous trees and shrubs where there is space for it to spread. 15cm. AGM*. RHS H6, USDA 6a-8b†.
In the wild in western Turkey, the starry flowers of Scilla luciliae open in alpine meadows as snow melts, giving it the name 'glory of the snow'. In the garden, it gives a brief, bright pop of blue, close to the ground. 5cm. AGM. RHS H6, USDA 3a-8b.
The widespread Scilla bifolia has tiny, starry flowers in blue, pink or white. It can be enjoyed close up in pots, but is perhaps best planted in large swathes in the garden. It seldom reaches more than 7.5cm but often starts flowering when much shorter. 7.5cm. AGM. RHS H6, USDA 3a-8b.
A misunderstanding about its origin led to this handsome Mediterranean plant being named Scilla peruviana. Grow it in full sun in a sheltered place for flowers in late spring and early summer. 20cm. RHS H4.
Scilla sardensis from western Turkey has bright-blue, upward-facing flowers with very little white at their centre. Like S. luciliae and S. forbesii, it was once placed in the Chionodoxa genus; all die down quickly. 7cm. AGM. RHS H6.
Scilla x allenii
Scilla bifolia often hybridises with the former Chionodoxa species, giving intermediates. Formerly called x Chionoscilla, it is now known as Scilla x allenii. 12.5cm. RHS H6.
Scilla siberica ‘Spring Beauty’
This stocky plant produces several flowering stems with abundant, rich-blue, nodding bells; a good choice for densely planted pots as well as the garden. One of the best. 10-12cm. RHS H6, USDA 2a-8b.
S. greilhuberi comes from the Caspian forests in Iran and prefers slightly shaded conditions and moist soil to support its lush leaves. Taller than most with nodding flowers, it suggests a relaxed bluebell. 20cm. RHS H6.
Scilla mischtschenkoana ‘Tubergeniana’
This scilla begins to open its exquisite, glacier-blue flowers at ground level as soon as it emerges in February. Plant in short turf, or enjoy in a pot. 10cm. AGM. RHS H6, USDA 4a-8b.
Scilla ‘Pink Giant’
Another former Chionodoxa, this big, bold plant gives a generous show of soft-pink flowers in early April. As it is sterile, it doesn’t produce seed and needs to be multiplied by division. 15cm. RHS H6, USDA 3a-8b.
Scilla liliohyacinthus has a big bulb with scales like a lily, but small flowers in blue or white produced on erect stems in late April and early May. Its rosettes of glossy, green leaves are very attractive. 25cm. RHS H6, USDA 3a-8b.
Although it has been cultivated for centuries, the wild habitat of Scilla amoena is unknown. Commonly known as star hyacinth, its strikingly bright-blue, star-shaped flowers appear in April. 10-20cm. RHS H6, USDA 3a-8b.
Scatter generously through grass alongside other early flowers to create a millefiori effect through the spring. As with all bulbs, only mow once the foliage has disappeared. 10cm. RHS H6, USDA 3a-8b.
Where to see and buy scilla
• Avon Bulbs, Burnt House Farm, Middle Lambrook, South Petherton, Somerset TA13 5HE. Tel 01460 242177, avonbulbs.co.uk
• Beth Chatto Nurseries, Elmstead Market, Colchester, Essex CO7 7DB. Tel 01206 822007, bethchatto.co.uk
• Cotswold Garden Flowers, Sands Lane, Badsey, Evesham, Worcestershire WR11 7EZ. Tel 01386 422829, cotswoldgardenflowers.co.uk
• Hergest Croft Gardens, Hergest Estate Office, Ridgebourne Road, Kington, Herefordshire HR5 3EG. Tel 01544 230160, hergest.co.uk
• Kevock Garden Plants, Kevock Road, Lasswade, Midlothian EH18 1HX. Tel 0131 454 0660, kevockgarden.co.uk
• P de Jager & Sons, Church Farm, Ulcombe, Maidstone, Kent ME17 1DN. Tel 01622 840229, dejager.co.uk
• RV Roger, The Nurseries, Malton Road, Pickering, North Yorkshire YO18 7JW. Tel 01751 472226, rvroger.co.uk
• Tinnisburn Plants* Upper Millsteads, Canonbie, Dumfriesshire DG14 0RY. Tel 01387 371453, tinnisburn.co.uk *National Collection holder
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