How to best protect Salad & Swiss Chard in pots from the evil Aphids and Leaf Miners?

We're suffering a lot of Aphids and Leaf Miners at the moment on salads and swiss chard.

We grow them in pots on a large patio, but they are not covered at all. What would be the best solution? We are worried about the practicality of nets over pots, as we're not sure how best to completely protect the plants, especially when harvesting.

We live right next to Epping Forest, and there is a fair amount of wind, so we are worried about airborne pests. This is also a factor influencing our choice of protection.

We're getting some great crops, but they're getting decimated, particularly the chard by the leaf miners.

Thanks loads

CFP