Diarmuid Gavin: Waiting for wallflowers
They may not look like much now, but come spring, wallflower blooms are a sight to behold
Published 23/10/2016 | 02:30
Way back in the late 1980s, one of my roles as a horticultural student on secondment from the Botanic Gardens in Dublin was to spend a few winter months based at the wonderful St Anne's park in Raheny. Along with gaining some expertise in taking hardwood cuttings from the park's numerous shrubs, I helped plant multiple pots with winter flowering bedding.
Concrete pots would be lined up in rows, 20 deep, 10 wide, and we would race up and down inserting flowers and bulbs into a fresh compost mix. When complete, they'd be loaded on to a lorry and dropped in the centre reservation of O'Connell Street and in other prominent city locations.
We like our parks and cities to be decorated with flowers each season and soon small armies of municipal gardeners across Ireland will be busy planting up parks, public gardens, pots, tubs, barrels and roundabouts with spring bedding. Hundreds of thousands of pansies, bellis perennis, primulas and polyanthus, along with buckets of tulips and daffodil bulbs, will be bedded in for winter before they wake with a flourish and provide our beloved and traditional display of colour early next year.
One of the main ingredients of this spring cocktail is the oft unsung wallflower. As with its namesake at a dance, it does look pretty ordinary at the moment, but come the spring it turns on the charm with flower power and fragrance. And I sense that wallflowers are a plant whose fortunes will soon be revived as gardeners are beginning to re-evaluate its contribution to our plots and consider new ways of using this early flowering floral jewel.
Let's take a closer look and show this perennial favourite some appreciation.
Wallflowers have been in these islands for over a thousand years. It is believed that seeds of it were carried over from the continent to Britain on stone which was used to build William the Conquerer's castles during the Norman invasion, and admiring landowners soon brought them to us.
And from this and its name we get the first clue of how best to cultivate it - it grows happily in stone walls, so ideally grow in a free-draining soil and do not feed it. It's a plant that will thrive on poor soil. Too much nitrogen and it will grow fleshy leaves and topple over in winter storms. It's a member of the cabbage family and so can be prone to the same problems such as club root and downy mildew. Keep it lean and let it devote its energy to the production of flowers and seeds.
Generally speaking, wallflowers (Erysimum), are short-lived perennials, but practically speaking are treated as biennials. This means that they are grown from seed in the first year and establish roots and leaves; in the second year they flower and when finished flowering are discarded.
There are exceptions to this. Probably the best known Erysimum is Bowles's Mauve which will last a few years before getting too leggy. It is a quite remarkable plant - in my garden it seems to have had flowers on it permanently for over two years and I'm definitely replacing it when its time is up. E. mutabile can also keep going for a little longer than two years and is curious for its sweet flowers that change in colour from yellow to mauve.
If you have sown seeds in the spring, your plantlets should be ready for planting out now. Take some care to protect them from slugs and snails as the unseasonably warm weather means these garden pests are still hungry. Otherwise you can buy them now as small plugs from the nursery or garden centre. Pinch them out before planting to encourage bushiness.
Traditionally they are planted with late flowering tulips and some lively combinations can be achieved as there is a wide selection of colours available in different hues of orange, red, yellow, purple and white.
Mix Fire King, a traditional warm orange wallflower with orange tulip Prinses Irene or contrast with maroon Tulipa Ronaldo. Erysimum Ivory White and pink Winter Joy will make a relaxing arrangement with Tulipa Shirley which is white with some purple edging, and the double soft peony-like pink blooms of Tulipa Angelique. Sweet Sorbet has a lovely trendy mix of purple and orange flowers on each plant. Vulcan on the other hand keeps to a single colour with its crimson flowers but it has the benefit of a delicious scent, and Blood Red will make an eye-catching display in a container or window box.
Take cuttings of those you like next summer and pop them in seed trays in a free-draining gritty compost and all going well, you'll have plugs to plant out this time next year.