Sometimes the simplest and most common of plants are the stars of the garden. This yellow Welsh Poppy, Meconopsis cambrica, comes to life in the low-angled rays of sunshine at the beginning and end of the day. Considered by many gardeners to be a weed because it happily and freely self-seeds wherever it is happy, this diminutive gem has the knack of placing itself brilliantly. We wouldn’t be without it.