This stunning fashionable plant, with large globes of rosy-purple crowded spherical umbels, Allium 'Purple Sensation' is a darker, richer purple than the mauve of its parent. They are popular in both architectural and formal planting plus the long lasting flowers are ideal for cutting.
Held aloft and rising up to 3ft or so before they break, the buds are like a conurbation of Turkish domes. The dense, rich-purple globes appear in early summer held high on erect stems above strap-like, mid green leaves, they never need staking. Extremely easy to grow, the seedlings have a lust for life and only take three years to flower.
Alliums look spectacular grouped in a pot, or in a sunny border, dotted in groups among ornamental grasses, or as part of a Mediterranean scheme. The plants can be allowed to self-seed to make impressive clumps. Plant en masse to be sure to have cut flowers, they flower earlier in full sun an a little later in shade. The flower stalks dry well and can be used in arrangements or they can be left outside to provide winter interest as they look good covered in frost.
The flowers last a long time and help fill that awkward gap between the later spring bulbs and the perennials. By the time the papery tunic on the alliums has broken, the garden is in full swing and caught between spring and summer
Allium hollandicum “Purple Sensation” has been awarded the RHS Award of Garden Merit (AGM).
The RHS Herbaceous Plant Committee described “Purple Sensation” as:
"A bulbous herbaceous perennial to 90cm, with short basal leaves dying down by flowering time. Flowers small, vivid rosy-purple, in crowded spherical umbels. Attractive seed heads."
Sowing: Sow at any time of year.
The seeds can be sown directly where they are to flower at any time of year, or can be sown indoors, the seedlings over wintered in the greenhouse and then planted out in the following spring.
Allium seeds need a period of moisture and cold after harvest before they will germinate, usually this is necessary to either allow the embryo to mature or to break dormancy.
If sown indoors in warmer weather, the period of dormancy can be artificially stimulated by placing the moistened seed in a refrigerator. It is best to sow them on moistened, well draining compost, seal the container in a polythene bag and leave everything in the refrigerator for 3 to 5 weeks at around 4 to 5°C (39 to 41°F). The seeds must be moist whilst being pre-chilled, but it doesn't usually benefit them to be actually in water or at temperatures below freezing. After prechilling bring out of the fridge to 13 to 16°F (55 to 60°F)
Light seems to be beneficial and so pre-chilled seeds should have only the lightest covering of compost over them, and the seed trays etc. should be in the light. Compost should be kept moist but not wet at all times. Germination should occur 18 to 21 days.
Prick out each seedling as it becomes large enough to handle, transplant into 7.5cm (3in) pots or trays to grow on. Gradually acclimatise to outdoor conditions for 10 to 15 days before planting out.
Plant out in spring into fertile, well drained soil. Add grit when grown in clay soils to improve drainage. Remember that the foliage dies back as flowering commences; you may wish to place this behind a smaller plant to disguise its foliage. When planting try to plant in groups of at least 3 or 5 as they do look much better in clumps.
Prepare the soil prior to planting by cultivating up to 30cm of soil, on heavier soils add a couple of handfuls of grit under each Allium before planting to improve drainage. Alliums grow well in most soil types but do prefer to be planted in well-drained sunny spots. The bulbs of Alliums vary tremendously in size so the best advice on planting depth is to plant Allium bulbs at a depth of three to four time their depth in the soil. On light soils, increase the planting depths to help anchor the taller varieties. The soil around Alliums should be kept moist during the flowering period.
Alliums can also be used for naturalising in grassland or similar areas, however please note that as they do not flower until late (May-June) you will not be able to cut the grass until they die back in July.
Alliums in pots:
To plant in pots ensure you have a sturdy deep container (the height and weight of the taller alliums will cause smaller containers to topple over), put crocks in the bottom to allow for drainage and then add about 10cms of potting compost. Place the Allium bulbs on top of the compost so that they are not touching the outside pot or each other. Cover with at least 20cms of potting compost and firm down. During the winter months ensure the compost is kept moist but not too wet and protect from frost. When you see the first signs of growth in the spring (March-April) increasing the amount of water to ensure the compost does not dry out.
Cottage/Informal Garden, Flower Arranging, Flowers Borders and Beds, Gravel Garden or Rock Garden.
Alliums can be left undisturbed from year to year and as long as they are well fed will continue to flower. If you do need to lift them wait until the flower stems and leaves have turned brown and break off when touched. The bulbs can then be dug up (around July) and their offsets removed. After they have been cleaned of soil, leave in a cool light place until they can be planted again in September. Only replant bulbs that look healthy and of a good size.
All members of the Allium family are disliked by many insects and animals. They can be used to protect valuable planting areas against mice, moles, slugs and snails, Even dogs take no interest in the flower beds that they inhabit.
Allium hollandicum is a species native to Iran, synonym Allium aflatunense.
Undoubtedly the process of growing, selecting, hybridising and multiplying bulbs in horticulture may well have led to considerable deviation from the original description of this plant in 1904. Allium hollandicum 'Purple Sensation' is a deep coloured strain believed to originate in 1963 from a selection by J. Bijl.
There are estimated to be around 700 species within the genus, and many cultivars. There are perennials and biennials, ranging in height from 10cm to 15 metres (4in to 5ft) or more. They are mainly from dry and mountainous areas, all from the Northern Hemisphere, and they have adapted to live in almost every plant habitat on the planet, from ice cold tundra to burning, arid deserts.
They were prized by the ancients as possessing medical and aphrodisiac qualities as well as flavour. The Romans are sometimes held responsible for their wide distribution by taking them wherever they went.
Allium hollandicum 'Purple Sensation' is one of many hybrid Alliums developed by Jan Bijl in Holland (the magnificent 'Globemaster' perhaps his most fantastic hybrid).
Purple Sensation is a deep coloured strain believed to originate in 1963, it is often incorrectly called Allium aflatunense 'Purple Sensation' or described as a garden hybrid from Holland named Allium ×hollandicum 'Purple Sensation'.
- Additional Information
Packet Size 25 Seeds Family Alliaceae Genus Allium Species hollandicum Cultivar Purple Sensation Common Name Syn Allium aflatunense. Other Common Names Ornamental Onion, Dutch Onion Hardiness Bulbous Perennial Flowers Late Spring to Early Summer Height 60 to 90cm (24 to 36in) Spread 30 to 38cm (12 to 15in) Position Full Sun to Partial Shade Germination 30 - 365 days