My veg plot has Nasturtiums everywhere – it’s not just that they look good, attract insects and are tasty in salads ( it’s a really punchy, peppery taste) but they are brilliant trap plants.
You can see from the photo below that they get covered with cabbage white caterpillars and aphids which is great, they are doing their job of drawing pests away from your crops. If this happens early in the season, I pull out the whole plant to get rid of the pests, and replace with a new plant. Later in the season it’s not so easy and the plants are much larger, so I pull off the caterpillars as I don’t want them pupating and overwintering.
They are easy to sow in pots, starting in spring with successional sowing, Then plant out in late spring and and collect seed in summer. You can also use the fleshy seeds as an alternative to capers.
There’s more on using trap plants and push / pull techniques to control pests in my new book The Healthy Vegetable Garden out on 2 Sept – read more here