George says: alliums, who'll buy my alliums?
As George explains below, the Dutch growers Warmenhoven, founded in 1885, have done a huge amount to popularise alliums as garden plants. My daughter and I were at the RHS Tatton Park show a couple of years ago and we were amazed and thrilled by their spectacular exhibit, which featured alliums every which way – even hanging from girders (above).
The Warmenhoven display was part of a special exhibit organised by the RHS to celebrate master growers, and it was huge, featuring all the bulbs they grow. It also included a fascinating series of photographs illustrating the history of the company.
We all have our favourite alliums, and while I tend to be loyal to ‘Purple Sensation’, I was amused by the dark red ‘Mohican’ alliums featured on the Warmenhoven stand (above) which have a little Mohican-style tuft on the top of the flower.
If you want to see spectacular alliums closer to home, the walled garden at Buscot Park near Faringdon (below) has a wonderful display.
One thing that puzzles me is that we never call onions edible alliums and we never call alliums ornamental onions. Why is that, I wonder?
Alliums grow well in borders, their bold architectural large rounded heads stand majestically with attractive flowers in colours of blue, mauve, white, yellow, pink, and purple, followed by seed heads which are also attractive throughout the summer.
When the allium flowers, the leaves start to turn a milky white colour and die. This is a natural occurrence, therefore it’s advisable to plant behind other plants to hide the unsightly dead leaves. When choosing the colours of other plants, try orange-flowering plants such as geums, or yellow euphorbia in front of purple alliums, which gives a really vibrant contrast, or for a more classic look, choose white, such as orlaya, below.
A sheltered position is ideal, away from gusty winds, which if severe will break down the stems. Alliums like sun, and no watering is necessary as they thrive in dry conditions. Only feed the bulbs in the dormant stage with a top dressing of slow release fertilizer such as Growmore.
When planting new bulbs do not add manure or compost. The roots will enjoy the extra energy, but the plant will grow too quickly, with lots of soft growth, hampering its ability to stand up in windy conditions, which will break the stems and spoil your display of flowers.
The best time to plant alliums is in the autumn. If you already have mature bulbs that need dividing, now is the time to do so. Alliums like a soil that is well drained. Planting on clay is not recommended, unless you mix a multi-based compost with the clay.
The flowering period for alliums is May/June, after the flower has passed a seed head will form you can leave as decoration for the summer then cut a long stem and use indoors in your floral arrangements.
You can also grow alliums in containers. There are varieties like A. insubricum which are suitable for rockeries and tubs, but normal varieties also do well. Use John Innes No 3 but add a shovel of grit sand for good drainage.
With regard to pests, you will find alliums are not particularly susceptible. However, problems may occur if you plant in a vegetable garden area where you have previously grown domestic onions, then you may pick up downy mildew, onion fly or onion rot. As usual, keep an eye out for our friends the slugs.
In the summer do not water your alliums in the ground or you may lose some through rot. Even in containers, water only occasionally.
Good varieties to purchase are Purple Sensation, Everest (white) and Giganteum (blue). Don’t forget, alliums are rich nectar flowers which attract bumblebees, honeybees and butterflies.
Every year at the Chelsea Flower Show, a Dutch family business called Warmenhoven put up a magnificent display of alliums, which are portrayed in all their glory. This family business has raised the profile of alliums and turned them into a must-have fashion item for the garden. Buy my onions is the cry.