I ask this question myself of the UK importers of the Ingenua range. It seems to me that given the parasols made from the same fabric could be used all year outside, then why was this not recommended for the Shadesail?

The main answer relates to the tension underwhich a Shadesail is under. A parasol canopy has a frame to support it when it is wet. However, a shadesail requires high tension through the ropes and poles to support it. When wet, the shadesail becomes very heavy. This is likely to first show in the tensioner ropes which will fray quite quickly.

So, I asked, why don't we simply reinforce the ropes using the ring at the end of the sail? The answer is that the not only will the ropes fray, but the sail itself will be carrying too much weight for its own good and will start to deteriorate.

The final answer therefore, is that you can use it all year if you choose to do so, but don't expect your shadesail to last. The estimate I got from the importers was that the sail was unlikely to last more than 6 months of UK winter weather. And the issue of wind in winter pulling on fraying ropes increases the chance of uncontrolled breaking and a loose shade sail flying around. So the manufacturers do not recommend all year use.