Handy tips for building and maintaining a window box

The advantage of making your own window boxes is that you can tailor them exactly to the space you have available. Here are some tips to help you create the perfect window box.

Before being filled, this box could be attached to a wall with strong metal brackets.

You will need: 

• Exterior grade plywood cut to size
• Drill with shovel bit
• Length of 25 mm (1 in) × 25 mm (1 in) batten
• Tape measure
• Pencil
• Exterior wood adhesive
• Screws
• Screwdriver
• Clamps
• Cardboard
• Saw
• Wood preservative
• Paint

1. Determine the dimensions you require, then buy the plywood for the sides, ends and base cut to size. Drill holes in the base for drainage.
2. Measure and cut four short battens for the inside corners and two long ones to support the base. Use the adhesive and screws to attach the corner battens to the ends. Drill pilot and clearance holes and countersink the clearance holes so that the screw heads lie flush.
3. Fix battens along the bottom inside edges of the back and front sections. Clamp the back section into position, using cardboard to stop the clamps damaging the wood, and screw the two ends into place. Fix the front into place using the same method.
4. Saw a 25 millimetre (one inch) × 25 millimetre (one inch)notch into each corner of the base section and drop it into thebox to rest on top of the two long battens. Treat inside and out with wood preservative then paint as you wish.

• Planting: Add slow-release fertilizer and water-retaining gel granules to the compost before you plant. For full impact, choose simple colour schemes such as red geraniums with ivy, or pastel petunias with silver-leaved helichrysum. For north-facing windows choose ferns and busy lizzies. Plant generously.
• Feeding: Apply a measure of general liquid fertilizer every three or four weeks as plants mature.
• Water: Water regularly, as near to plant roots as possible. If you live above other people, or if your box overhangs a pavement, put a drip tray under the box so that passers-by don't get showered.

Keep these tips in mind and get started building your ideal window box today!