Over the winter period, we have been drying eggshells in the wood stove prior to making them into shell grit. As the weather warms and the stove lit less often, they dry in the glasshouse. I am trialing the crushed shells around new seedlings, as it is supposed to stop snails.
This is already doubtful as a technique as my snails are more adventurous, the leaves on some of my zucchini already have holes after only a few days. Crushed eggshells are fed to the chooks, put into compost or added to the soil to replace calcium.
The wire guard is to stop the dog walking on the plant and to prevent the rabbit having a meal. The plastic pipe is to aid watering in the summer and get the water onto the root zone. This system worked well last year especially for the pumpkin as it grows and you forget exactly where it started.