Growing alliums makes me happy. I love their versatility, their diversity and their sheer brilliance in the spring borders. They are equally at home in cottage gardens, amongst perennial grasses, in containers and as an architectural feature throughout contemporary planting schemes. I’ve grown quite a few varieties over the years and have reliable favourites which always make it into the garden alongside new additions each year, chosen either for their striking colours, interesting shapes or to extend my allium season. With their dramatic globe-flowers fading to structural seed heads, alliums create interest in the garden for much of the spring, summer and into autumn (as I type, the tall ‘Cristophii’ in the back border are still punctuating the late summer rosemary growth).
Allium flowers delight the bees – in fact at RHS Tatton Park Flower Show this year on the allium stands, it was hard to decide whether the displays were there to celebrate the flowers or their apian companions. This adaptable plant can be used in so many ways in gardens and containers, depending on the size and height of the flowerhead and the density of planting. Alliums can be planted in the next few weeks in borders, cut flower patches and pots – so here are my favourites, either planted in my garden or to be added this year…
This is my absolute favourite allium for its graceful shape and rich crimson-purple starry florets with deep smoky plum centres. It has real presence in the border, but is subtle enough to co-exist happily with other alliums (I grow it in the narrow herb border beneath the espalier apple trees alongside ‘Cristophi’, ‘Purple Rain’, ‘Purple Sensation’ and ‘Sphaeracephalon’). At around 75cm high, they create continuity throughout the long, narrow border without being imposing and the thick stems make them ideal for cutting.
2. Purple Rain
I first grew this allium a couple of year ago and was delighted by its spreading firework flowers. As a cross of A. ‘Purple Sensation’ and A. ‘Cristophii’ it is a reliable allium with sturdy stems up to about 1m. I grow it beneath the windows in the front gravel garden where it thrives and, unlike many of the bulbs in the back garden on our clay soil, in the front sandy soil by the foundations ‘Purple Rain’ has proved consistently perennial.
3. Mount Everest
Another of my front garden alliums, A. stipitatum ‘Mount Everest’, creates a striking contrast dotted within drifts of purple alliums such as ‘Purple Sensation’, or it can be planted en masse for greater impact and set off against the dark foliage of shrubs like Sambucus nigra ‘Black Lace’ and Cotinus coggygria ‘Royal Purple’. The creamy white flowers also emphasise the fresh green allium foliage and the pea green eyes at the centre of each floret.
‘Cristophii’, or star of Persia, lives up to its name with its spiked purple florets touched with silver. At around 50cm and with its imposing, yet intricate globes, it encourages the eye to focus on the details in a border, which in my garden always includes bees feeding from the florets. ‘Cristophii’ is a reliably perennial allium and the seed heads are long-lasting. Last year we collected the ageing seed heads and after a few weeks drying in the shed, sprayed them silver to use in a Christmas display with dogwood stems and fairy lights.
5. Red Mohican
I met this allium at Chelsea last year and have been wanting to add it to the garden ever since. Its funky topknot gives it a modern charm which would add a sense of fun to a border and I love the rich burgundy colour dotted with creamy white florets. A rather more expensive cultivar than some, this would be good to dot through a border with white alliums or the darker A. atropurpureum.
6. Purple Sensation
One of the most popular alliums, A. hollandicum ‘Purple Sensation’, marks many people’s first foray into allium growing, mine included. Its bright purple spheres create impact in large drifts, but also look spectacular under planted with blue Camassia leichtinii or the greenish-yellow flower clusters of Marsh Spurge (Euphorbia paulstris). It’s an affordable allium, so can be bought and planted in greater numbers than some of the rarer cultivars.
These small, late-flowering drumstick alliums are a cheerful addition to the July garden. They can be planted in swathes against paths and border edges to soften the margins and lead the eye through the space. ‘Sphaerocephalon’ also look great mixed in with grasses such as Deschampsia cespitosa and Stipa tenuissima. I’ve been growing this variety for several years and unlike the larger alliums in the back garden, not only is ‘Sphaerocephalon’ reliably perennial, it also self-seeds along the path edges. With its tight, rich blackcurrant heads it creates a dramatic flash of colour and can be bought in bulk to create maximum impact as it is the cheapest allium bulb available.
Allium bulbs should be planted in early autumn, so this week is a great time to place an order or start getting your bulbs in the ground. They prefer well-drained soil in full sun, so if you have heavier soil (as I do), it is a good idea to use a handful of grit (about 5cm depth) under each bulb to improve drainage. They should be planted at 3-4 times their own depth to help ensure they remain perennial. Smaller alliums should be 8-10cm apart and larger ones 20cms. After planting, firm down the soil to remove air pockets and add a balanced fertiliser in spring on poorer soils.
What are your favourite individual alliums and combinations? What spring bulbs are you most excited about planting this autumn?
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