I would like to introduce the new lady on my allotment Ms Poly Tunnel with her daughter Annet. Poly tunnel may be ugly but it is invaluable in a large garden, small holding or allotment.

These poly tunnels look like they are breeding faster than any plants. At least the ground is not a total mud bath like many gardens this autumn. A group this size probably needs planning permission but a more suitable garden variety will be OK without.

Types of Tunnel and Cover

Poly tunnels can have permanent fixed hoops and pole or removable ones. Clear polythene of partial net or green fabric can be used for the covering.
Cloches may be big enough for your needs but do not allow walking.
Hybrid Poly Tunnel Cloches are what you may expect with features from both.
Anti drip fabric is worth considering to protect plants from fungal problems.
Plan some irrigation to make your future gardening life easier.

Suitable Crops

Year round salad crops can be grown in the right tunnel.
The growing season for many vegetables can be extended.
Crops that you want to help along or protect from bad weather like tomatoes, cucumbers and aubergines are fine tunnel tenants.
Early sowing of onions and semi hardy pot plants can be sheltered in a tunnel.
Ornamental crops, brassicas, grapes and peppers are all suitable candidates for growing in a tunnel.

Practical Considerations

You do not want to look at a tunnel, they are seldom aesthetically pleasing. Locate where they get the sun but do not disturb your or your neighbors view.
At the same time you want the tunnel near enough to the kitchen to pick your fresh salad crops.
High tunnels to walk-in are better for old backs than low cloche like structures. You can get them with a greenhouse type apex as well as rounded domes.
Low tunnels make for easy screening or wind breaks.
Think about the availability of services such as water and power.
Any slope should run along the length not the width. I got it wrong and have to stand on a slopping path.
Trees should be avoided they can create shade, drop debris and the roots take up moisture and invade the tunnel.
Have doors at either end to help with regular problems of air movement.

Like many things in gardening a poly tunnel is what you make of it.

Photo credits
Poly tunnels in spring by SAGT CC BY-NC-SA 2.0
Allotment Update, 8th April – Root Vegetables are In! by mrwalker CC BY-NC 2.0
CRW_2517_RJ by mike warren CC BY 2.0