Being typical gardeners, we always want to stretch the range of vegetables that we grow and how long we grow them for, but sometimes that's just not possible in our climate. So, we use tunnels. We have four of them next to the veg plots and we use them to grow tender plants or to extend the growing season.

The tunnels are fairly small (about 2x3 metres or 6x10 feet) but it is amazing what a difference a bit of protection can have, and how much you can produce in a small space.

Currently we are using one tunnel to try out different varieties of a single crop.

In another one we grow veg using the deep bed system. This means that the two borders in the tunnels are slightly raised and they are never walked upon. This tunnel helps to extend the season by having a few crops ready in spring, whereas outside they won't be ready until early summer. We also use the deep beds to try out some hungry climbers such as climbing beans and courgettes that we can train up obelisks.

A third tunnel has a more permanent crop - asparagus. Although the plants do get some protection from the tunnel we still have to grow a pretty tough variety from France called 'Cito' (this has a very fine flavour and beats shop bought asparagus hands-down). It can still get quite cold in spring and we have noticed the asparagus we grow outside the tunnel (same variety) can be distorted by the cold winds and blackened by the frosts.

The fourth tunnel houses our blueberry bushes. Growing them in the tunnel enables us to closely monitor the watering and feeding of these plants, as they prefer acidic conditions. We water them with rainwater, and the plants in pots are in an ericaceous compost. Having them in the tunnel also protects the fruits from the birds.