Even the smallest of spaces can be used to grow some food. Windowsills are perfect for this or to even start plants off before eventually being planted outside. Choose windowsills which have plenty of natural light and have a sufficiently wide shelf without any danger of a container being knocked accidentally to the floor by a passing child. The container should also not be too heavy - you need to be able to move it around, lift it and turn it when necessary.

You do not need too much equipment for successful windowsill gardening but make sure it is all available before you start your project. Plants can grow very fast and there is nothing worse than finding that you do not have what you need to hand.

What Can You Grow?

When choosing crops to grow on a windowsill consider the size of the window. You do not want to block all natural light into the classroom.

For small windows opt for low growing plants which can be either harvested regularly or have only a short growing season. Ideal for this purpose are lettuce, radish, turnips, beetroot, cress, mizuna and rocket. Use a mini bottle top sprinkler fitted onto a recycled water bottle to gently water the seeds in.

A larger windowsill or floor length window can be used to grow bush tomatoes or even runner beans as well as salad crops. Take care with runner beans to make sure that the canes are safely secured. Cane tops should be covered with toppers; or even chunks of blutack to prevent children falling on them and injuring their eyes. Use soft or flexible ties to secure the stalks against the canes. Stalks need to be secured firmly but leave room for growth. It is easy to damage stalks accidentally by using ties which cut into the stalks.

Propagating

Windowsills can also be used to house propagators to raise crops before they go outside. Seeds can be germinated very successfully on windowsills. The seed trays will need to be covered with cling film or a transparent plastic lid to keep the warmth and moisture in the soil.

Before putting any plants outside permanently, remember to harden off by putting them outside during the day and bringing them inside at night. This is needed for about a week. Alternatively use a cold frame that acts just like a mini-greenhouse.

Watch Out For Pests

Aphids, Red Spider Mite and Mealy Bugs are all pests that are a danger to indoor planting. Control these pests by using biological pest control, a natural way of adding predators to the soil that will attack the unwanted visitors.

Watering

Careful attention needs to be paid to watering windowsill plants. They can very quickly dry out especially in warm classrooms or when the sun is shining strongly through the windows. Be careful of scorching the plants. If the window is in direct sunlight, just stick a piece of plain white paper onto the glass during the middle of the day that acts as shade.

Mix water retaining gel into the compost before planting. Water well and the gel will expand and act as a self contained water reservoir. Plants are kept moist as the gel slowly releases its water supply. This will prove very useful over weekends when classrooms are unused and plants may be left uncared for. A watering can, ideally with a long nozzle and fine rose, is essential.