Will a greenhouse help?

Hi folks,

I live in the SW and my garden is a very sunny protected spot. The problem is my veg dries out very quick in the blazing sunshine and im sometimes away for a few days with work, so it tends to dry out fast. Would having a greenhouse help with the watering by keeping the moisture inside?

Any advice would be great!

Thanks all

a greenhouse will do the same if not dry them out even more, have you tried cutting plastic bottles in half and planting them in the ground it means the water will go directly to the roots?