Protecting, Nurturing and Beautifying Landscapes in the Hamptons Since 1980

Fall Perennial Planting Tips

Perennial flowers, unlike annual flowers, are best planted in the spring or the fall. When selecting perennials, be sure to consider your planting zone and whether your garden is shady or sunny. Also think about when the perennials bloom so that you can select plants that keep the color blooming throughout the growing season. 

When you buy perennial plants, it’s really the roots that you’re planting; this is what allows the plants to return year after year. If you’re buying the plants, it’s usually either:

  • Container-grown perennials (a small plant already rooted in soil and growing): Dig a hole that’s a little wider (but no deeper) than the container. Gently loosen the roots before removing from soil. Backfill hole with soil and press around plant until firm. Water well.
  • Bare-root perennials (just the roots are sent to you, packed in peat moss or something similar): Soak the roots in water, before planting them in the ground.

Plant perennials in loose, well-drained, loamy soil to which compost has been added. Water well afterwards and add 2 to 3 inches of mulch around the plants. Group together plants that have similar water requirements.

Perennial Plant Care

  • Water deeply, especially during the first growing season. If planting in the fall, water perennials regularly until frost.
  • The soil should never be overly dry or wet. Avoid getting water on the foliage to avoid disease. Fertilize with low-nitrogen, high-phosphorus fertilizer to encourage more blooms and less foliage. Most perennials do not need heavy fertilization. A single application in spring (after the soil has warmed) is usually sufficient.
  • Mulch around plants to keep weeds to a minimum and retain moisture.
  • Put plant supports in place early in the season, before plants get too big, so as not to disturb their roots. Put supports close to the plant and gently tie the stem to the support. For clump-forming plants—like peonies—use a hoop.