Regal Alliums adorn the Main Border at Harlow Carr at the moment and they are looking spectacular! What strikes me most about the display is how well they are suited to our beautiful naturalistic landscape. Whether you are stood at the top of the border or sat on our green oak carved seats mid way, the view is mouth watering!
The vista you will see before you include ~ 4 - 5ft vertical Allium stems topped with a mixed array of shades of purple and white globe-like umbel flowers, standing gracefully above developing perennials.
Over the last few days the weather here at Harlow Carr has been equally inspiring with crisp blue skies and warm temperatures. These are the types of conditions Alliums really enjoy, not surprising when you consider where Alliums originate, which are predominantly dry and mountainous areas of the northern hemisphere.
Dry conditions are not usually associated with Harlow Carr and our northern climate! So how do we get the best display?
The key to success is to ensure free draining soils which are both moist, fertile and in full sun. When planting Alliums in late autumn and if soil conditions are heavy, add plenty of grit and break up soil compaction. A general rule of thumb is to plant the bulbs at a depth which is four times the diameter of the bulb. For example ~ Allium hollandicum ‘Purple Sensation' AGM would be around 15cm (6ins) or Allium sphaerocephalon around 8cm (3ins). For added winter protection you could apply a layer of mulch to the surface of the soil after planting.
A good tip when planting Alliums, to avoid the look of unsightly leaves, is to plant the bulbs amongst other plants. They work particularly well with grasses like Molinia and Carex and herbaceous perennials like Nepeta and Geraniums.
Growth will start in early spring with the emergence of their leaves, don't be too concerned if you notice that the tips of the leaves become brown and shrivelled as this is part of the normal growth of the bulb and is a result of the bulb putting its energy into developing stems and flower.
The flowers are not only beautiful they are also a rich source of nectar and pollen for bees and other pollinating insects. Once the flowers have finished don't be tempted to cut them down immediately. Allow the seed heads to develop and dry in the summer sun. By mid August the Allium heads will be bleached dry and will look equally spectacular growing amongst mature perennials.
By late September the stems will start to collapse, cut them back and clear away the old foliage. We usually save and store the best of the stems for Christmas displays.
Our collection contains around 4000 bulbs including the following varieties ~
Allium hollandicum AGM
Allium hollandicum ‘Purple Sensation' AGM
Allium nigrum
Allium schubertii
Allium cristophii AGM
Allium sphaerocephalon
Allium giganteum ‘Mont Blanc'
One of my favourite combinations is Allium sphaerocephalon with Nepeta 'Six Hills Giant' Centranthus rubra and Rosa ‘Gertrude Jekyll' AGM
Alternativively try Allium ‘Purple Sensation' AGM with Carex elata ‘Aurea' AGM rising orbs of deep purple against sulphur yellow leaves!
Wow!!
Dean J Peckett ~ Garden Manager