Pentas plants, or Pentas lanceolata, can become leggy if you don't stay on top of pruning. You'll know it's time to cut these plants back when a few of the branches are taller than the rest of the ...

"Pruning smaller perennial plants also helps them achieve easier recovery in spring," continues Ian. "Plants such as clematis, peonies, salvia, yarrow, and irises are great examples of this." 3.