Dividing and Transplanting Perennials in the Fall



It is time to divide a perennial plant when the center of the plant begins to look dead with no growth.  The blooms may also decline in the plant, not blooming as vigorously or with smaller flowers.  These are signs that the plant is ready to be revived by division.  Sometimes people divide for other reasons; the plant may need more room to grow or you may want to share some with a friend.  You may not want to divide your plant but simply relocate it to a new spot in the garden for aesthetics or because it needs a different location to thrive.  Whatever the reason, timing is an important consideration for a successful division and transplant.

The general rule of thumb is that spring and early summer blooming perennials should be divided & transplanted in the fall and late summer and fall bloomers in the spring.  In southern NH, October is the ideal time of year for fall division or transplanting.  The weather is cool and moist, but the soil is warm and will encourage root development.  You will want to give the plant a good six weeks to grow before the first hard frost which typically comes after Thanksgiving.  If working in the spring generally you want to divide just as the plants are emerging from their winter dormancy.  There are always exceptions to the rule and some plants just do not like to be transplanted at all, such as Oriental Poppies or Russian Sage which have long taproots.  If you are not familiar with the plant in question do your research first or ask one of the friendly employees in the perennial section at Wentworth Greenhouses.

Some common perennials to divide and transplant in the fall include:

  • Astillbe
  • Bleeding Heart
  • Daylily
  • Hosta
  • Iris
  • Peony

For a successful transplant keep the plants at the same depth, do not forget to water regularly and no fertilizer is needed until spring.  Easy as 1, 2, 3!