Plant a window box for spring, summer and autumn
by Rhiannon James
Window boxes are a great way to bring the scent and colour of flowers close to the house so you can enjoy them without even venturing outside. Replanting them every season can sometimes become a bit of a chore, but it’s possible to create window boxes that’ll keep on blooming through the spring, summer and autumn – the secret is to use bulbs. Even in a small container, you can plant layers for different seasons all at the same time, giving you an ever-changing, flower-powered display with the minimum of effort. Put ready-grown bulbs such as miniature daffodils and grape hyacinths that you can enjoy straightaway on top, slot in some small summer-flowering bulbs below and at the bottom of the box, hide away some autumn-bloomers that’ll sit happily in the darkness until it’s their time to shine.
Things you’ll need
1. A window box
2. Some horticultural grit
3. Compost (bulb compost is preferable but not essential)
4. A selection of spring, summer and autumn-flowering bulbs. For our spring layer we used ready-grown Narcissus ‘Tête-à-Tête’, Iris reticulata ‘Harmony’, Muscari ‘Mount Hood’, Anemone blanda and winter aconites. For your late spring / summer layer you’ll need small bulbs that can sit below the spring flowers (at a depth of about 8-10cm in our window box) so we used Freesia ‘Single Yellow’ that has scented yellow flowers and Triteleia laxa ‘Koningin Fabiola’ (blue flowers) – both of these bulbs also produce blooms that are good for cutting. For the autumn layer, pick bulbs that you can plant near the bottom of the container (about 10-15cm deep in our window box) – we used nerines. Remember to pick bulbs that suit the conditions outside your windows – will your container be in the sun or in the shade?
Step by step
1. If there are any large holes in the bottom of your window box, cover them with a few pieces of broken pot, and add a thin layer of gravel to help drainage.
2. Then you can start planting – the layer of autumn-flowering bulbs goes in first. Add compost to the window box until you reach the right depth, put the bulbs in and then cover them over with more compost.
3. Next, add your layer of summer-flowering bulbs and cover with another thin layer of compost. As you’re using a small container, it helps to pack the bulbs in a bit closer than it says on the packet, to make sure you get maximum impact.
4. Finish by adding your ready-grown spring flowers. You might need to remove some soil from the bottom of the roots to fit them into the container – do this fairly gently so you don’t damage the plant.
5. Water the container well and you’re done!
6. Once your spring plants have finished flowering, all you need to do is to remove this layer from the window box and replace it with fresh compost. You can replant the bulbs in the garden or in pots and they’ll flower again the following year. Your summer-flowering bulbs will then take over the show in your window box. If you think you might have a few gaps, you can sow some hardy annual seed straight into the window box. We’re planning to add some dwarf cornflower (‘Dwarf Blue Midget’) seeds in April to flower through the summer months. Alternatively, you can push in a few plug plants. Once your summer-bloomers have finished, repeat the same process to give your autumn bulbs space to flourish.
7. The window box will need very little care over the year, just make sure the compost doesn’t dry out.