A lovely window box can give your house an instant lift. They tend to need refreshing seasonally, and as winter sets in, it’s a great time to add a bit of cheering colour, texture and interest to your exterior. Here are a few pointers.
Think about aspect
How much sun is your window box going to get? Evergreen shrubs like Skimmia japonica ‘Rubella’ and box are fine in shade, as are plants like cyclamen, hellebore and evergreen ferns. For south facing positions you could use sun-lovers like lavender, which will still have nice silvery leaves in winter or evergreen herbs like rosemary, thyme and ornamental sage. Or for a bit of zing you could go for orange Solanum ‘Thurino’ with its bright orange fruit or fiery pink ornamental grass like Pennisetum ‘Fireworks’, nice teamed with rich plum heuchera. For a festive look combine red berried Skimmia japonica ‘Pabella’ or red cyclamen with silvery Calocephalus brownii (Silver Bush). Heathers also prefer sun.
Keep it simple
Limiting your colour palette will avoid things looking too busy. You can’t go wrong with an all green and white colour scheme – very pretty for Christmas – or purple and silver, say with ornamental kale or cabbage set off with silver foliage. And try to limit your plants to one, two or three different varieties. As a rule of thumb choose plants that generally compliment each other, but with an element of contrast to lift the whole scheme.
Opt for an evergreen skeleton of something like box or Hebe interpersed with shorter bedding plants that can be changed seasonally. A row of box with a striking band of winter-flowering pansies or viola for colour and a small delicate ivy trailing down in front is a classic look. Or try Muehlenbeckia complexa or Helicrysum petiolare as a nice alternative to ivy. Planting in odd numbers works best, so choose three key plants and repeat them or go for symmetry, with say some tall ferns or grasses in the middle and plants mirroring each other either side.
Harmonise with your exterior
Before you go mad at the garden centre think about the colours of your door and paintwork and even interior – a friend recently bought red berried plants for her window box only to find they looked all wrong from her purpled- hued sitting room. And bear in mind the style of your house. A mass of one plant such as heather, cyclamen or evergreen grasses looks elegant and contemporary, especially if it’s in a zinc or black trough. Neatly clipped box interspersed with cyclamen is smart and looks more traditional if in a terracotta box with swathes of ivy.
Get stuck in
Choose a container with drainage holes and cover them with a layer of broken terracotta pots or grit to prevent the drainage holes getting clogged up with soil. Arrange the plants in their pots until you’re happy, then knock them out and plant them up. Fill the gaps with compost, firm down and water. Water when the earth feels dry – but equally make sure they don’t get too soggy. In wet weather it might be worth raising the window box up on feet to avoid this.
The main thing is that because the planting isn’t permanent you can experiment and have fun. These are some guidelines but, of course, it’s all a matter of personal choice and if you’re feeling bold, and wish to stand out, clashing colours and more adventurous mixes can look amazing.
Barbara Samitier is a garden designer who lives in Peckham Rye.
This feature first appeared in the November 2015 issue of SE22 magazine.