How to grow Alliums
Alliums are really stylish plants with tall stems and large blooms with the added bonus of being easy to grow.
Alliums are tall plants with large flower heads in shades of purple, white and occasionally blue and yellow. Alliums are bulbs which come up reliably every year, easy to grow and almost trouble free; the only maintenance required for Alliums is that the taller species need staking unless planted in a sheltered spot away from wind. The different varieties of Allium flower at slightly different times both spring, summer and autumn flowering. A measure of their attraction may be reflected in the number of images on this page.
Alliums can be planted as bulbs in the autumn but are also sold as ready grown container plants from early spring onward. Alliums prefer a sunny position in soil which is not waterlogged and are fully hardy. If your garden is on heavy soil or tends to be wet work horticultural grit into the planting area and plant, as with so many bulbs, 3 times the depth of the bulb. Buying Alliums as bulbs as rather than container grown plants is a much cheaper option. If you miss the autumn planting, there is time to plant Alliums up until early spring around February. They are very easy and simple to cultivate, plant in a sunny spot and stake the tall flower heads when they appear; definitely a green wheelbarrow plant
A real plus point about Alliums is that they look good with many of the popular garden plants. Planted together on mass they are effective as in the image bottom right, or as a single statement in the border, (top left) and the Allium illustrated is 'Globemaster' . Alliums are just made to mix with grasses and look good with Achillea (2nd image centre). Alliums are predominately purple flowering although there is a blue form, careruleum, and a very attractive yellow variety, Allium moly (golden garlic) which has umbel type flowers in the summer. Alliums have an additional bonus that the flower heads look good as they fade and the seed heads form as illustrated below right.
The downside of growing Alliums, if there is one, is that the leaves which form at the base of the plant can look a bit tired, or ragged, so its a good idea to keep the base covered with low growing plants, such as the Alchemilla mollis and Geraniums which also look well with Allium. If you are combining with other plants check the variety to ensure the flowering times coincide. To plant the combination of grasses and Alliums illustrated centre above and below left, which is easy to maintain and an attractive combination, it is essential to plant a later flowering Allium such as sphaerocephalon . Alliums are loved by bees and insects and given a warm day the large flower heads will be buzzing. They are members of the onion family and the small Allium schoenoprasum, Chives, are good to eat and make a lovely edging plant front of the border and are wildlife friendly.
Of course, the RHS always know how to put on a great display and this is Alliums on mass with grasses growing at RHS Harlow Carr, something to aspire to.
The Best Alliums to Grow
Many varieties of Allium are illustrated here. Very popular Alliums with the RHS garden merit award are: A. cristophii shorter at 60cms with spiky flower head which will self seed in the right conditions; A.hollandicum 'Purple Sensation' tall 80cms dark purple; A. Globemaster 100cmc with large deep purple flower heads. There is currently an RHS plant trial of Alliums the results of which should be known in around October 2016.Images Above: image first left Globemaster which is summer flowering and grows up to 100cm, second centre is Allium sphaerocephalon which flowers late summer and so looks very good with grasses which are at their best in late summer and early autumn. In the third image, very attractive A. Christophii which flowers in the late spring and early summer, with spiky flower heads which look very good as they fade and dry. Below: first image a planting combination of strong lime green Euphorbia palustris and A. hollandicum 'Purple sensation' which make a great contrasting combination. The second combination image centre is Allium is combined with Camassia blending soft blue and mauve, and in the third image planted on mass together Allium look impressive. In the second row is Deschampsia grass with Allium sphaerocephalon, a soft billowing grass making a rich late summer/autumn display combined with the deep purple Allium and just a little blue mixed in from the Nigella damascena common name "love-in-a-mist' which combination has been in flower at RHS Harlow Carr. Second image is A. schoenoprasum, Chives, low growing and which really does flower well for weeks and can be cut to produce fresh growth and a second set of flowers. and is illustrated below with Forget me nots and Campion a lovely planting combination. The last image shows the delicate beauty of the fading flower heads.
A. hollandicum 'Purple Sensation' with Euphorbia palustris
Allium stipitatum White Giant
Allium planted together on mass
Deschampia grass with Allium
Chives with forget me nots and Campion
Allium fading flower head
Green wheelbarrow means Alliums are easy to grow and low maintenance