Growing a garden means committing to a vision. Whether you’re planting for vegetables, herbs, or butterflies, the process is the same. You select what you want to grow, work out a design, and then do the hard work of planting, tending, and weeding.

It’s that last job that can be the most difficult. If you’re like me, you don’t always know what is a weed and what isn’t. One little green seedling can look much like another, particularly when you’ve spent the past two hours in the hot sun.

A ...