Clear up the greenhouse

Clear pots, seed trays, tools and composts out of the greenhouse as soon as you finish using them. Pests adore the nooks and crannies in a pile of containers or loose compost, and they'll emerge to infest your plants; compost is also a great host for fungal disease. Moving it all to the shed, where it can't do any harm, keeps your greenhouse shipshape and your plants healthy.