A number that is calculated to summarise a group of numbers. The most commonly used average is the mean, the sum of the numbers divided by however many numbers there are in the group. The median is the middle value in a group of numbers ranked in order of size.
Perennials: cutting back. Perennials are not demanding plants, but trimming them after flowering finishes in autumn helps improve their appearance and flowering. However, you can leave some stems over winter to provide homes and food for wildlife, and then trim back in spring.utting back herbaceous perennials during autumn restores order and tidiness to the garden. However, this removes potential winter interest, in the form of height and structure, plus food and habitat sources for wildlife.
Plants have a low spreading form and they flower profusely all summer. The creeping stems will root into the soil or mulch. These plants may be perennial in southern and western Kentucky and annuals in central, northern and eastern Kentucky. If they will be perennial, they will emerge late (late May or early June) so don't give up on them too early in the spring. These plants love hot weather and plenty of water and fertilizer.