Window Boxes

Window boxes look lovely and add character to the outside of houses. They are fairly easy to fix into place, easy to plant up, and easy to maintain. As such, they provide a wonderfully easy way of creating additional gardening space, whether you have a large garden anyway or just a small town flat. They also provide a perfect 'private' windowsill garden for a child!

My younger daughter had her first window box a couple of years ago. We filled it with simple flowers (nasturtiums) and she kept it watered and picked off the deadheads regularly. But the best part for her was when a pile of caterpillars made their home there - we could literally watch them munching away at the leaves, knowing we had provided them with a perfect spot to safely grow and change into butterflies!

1. Types of Window Boxes
2. Planting a Window Box
3. Useful Tips

Types of Window Boxes

Commercial window boxes are usually available in plastic, clay or wood. The benefits of buying them are that you usually get the fitting instructions and bits and pieces with the box, which is useful if you have never fitted one before! The clay or cement boxes are usually heavy enough not to need securing, providing your window sill is stable and deep enough and you don't live in an area battered by hurricanes and strong winds ...

You can also make your own out of wood - or at least make a wooden frame (which can be painted) in which to place the plastic one. Ensure the fittings are secure and rust-proof, and that it is the right size for your windowsill!

For some of them it is also a good idea to have a drip tray which fits underneath, as this avoids (at least to some extent) water marks from trailing down the outside walls if overwatering. Try to find the largest, deepest window box possible for your space, as this lessens the likelihood of it drying out too quickly.

Window boxes are also not solely designed for window sills. While the container itself remains the same, different fittings allow them to be hung over banisters on balconies or fitted on fences. And there is no reason not to use one on top of an otherwise plain wall to add extra interest!

Planting a Window Box

If you are positioning the window box on an outside windowsill, it is a good idea to screw it into place BEFORE filling and planting it, as they can be heavy to lift once filled - not only that, but it is difficult to screw through potting compost! If using brackets to fit the container on balcony railings or similar, this is not a problem and you can do all the messy work at ground level :)

How to Plant a Window Box

You will need: a window box, potting compost (if possible with fertilizer already added), some gravel, pebbles or hydroponic material, and plants or seeds of your choice. In this example we have used three geranium plants, grown from seed indoors previously.

	Put a layer of gravel, pebbles or hydroponic material at the bottom of the window box, approx. 1 inch thick, to help drainage. In this example we have used the hydroponic stuff, due to its water-retaining capabilities.
	Fill to about 3/4 full with either a peat-based potting compost or some other compost which has good moisture retaining properties. Press this down gently with your hands. Use moist but not dripping wet compost. We include hydroponic material in the compost to add to the help it retain moisture.
	With your fingers, make a small hole where you want to plant the flower and insert. Press them down firmly with your hands, ensuring the compost is level with the 'soil mark' on the stem of the plant. Leave about an inch from the compost to the top of the box.
	Water generously and don't worry if the plants look a bit wilted to begin with - they will pick up within a few days. If you have planted seeds, keep the box in a warm place until the seeds have germinated and the young plants have established themselves, then slowly acclimatise them to living outdoors.

Useful Tips

Remember that potting compost uses up most of its nutrients within the first 6-8 weeks, hence it is a good idea to include liquid fertiliser frequently when watering, or inserting fertiliser sticks into the compost. Also, window boxes need VERY regular watering, especially if south-facing.

The majority of window boxes have a lip or line on the inside of the container about one inch from the top. This is your guide for how high to fill the potting compost. The 1" gap between top of compost and rim is to help ensure enough water reaches the plants.

Instead of planting bedding plants in the window box, you can also start them off early on the inside windowsill, growing flowers from seed or spring bulbs for an early colourful display. Or consider planting herbs, vegetables or strawberries for a change! Some nice effects which last all year round are achieved by planting evergreens such as ivy or small conifers.

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