Black eyed susans (Rudbeckia) are popular perennial flowers that bring cheerful golden daisy-like blooms to gardens in late summer and fall. As these plants multiply each year, you may find your patch becoming overcrowded and blooms decreasing. Dividing black eyed susans by separating out clumps is an easy way to rejuvenate your plants and get more flowers! But timing is key when dividing perennials like these.
Understanding Black Eyed Susan Growth Cycles
Black eyed susans are hardy perennials with a defined active growth period. In spring, plants emerge from dormancy and undergo rapid growth and flowering through summer into fall As temperatures drop in late fall, the plants die back to the ground until next year
This cyclical pattern of active growth followed by dormancy affects when you can safely divide the plants without shock or damage.
When to Divide Black Eyed Susans
The optimal time to divide black eyed susans is either:
- Early spring, just as new growth starts
- Late fall, as plants enter dormancy
Dividing in early spring allows the new sections to establish roots before summer heat Fall division gives plants time to settle before winter
The key is to divide when plants are not actively growing yet conditions support root development.
Avoid Dividing in Summer or Winter
It’s best to avoid dividing black eyed susans in:
- Summer during active growth and flowering
- Mid-winter when fully dormant
Dividing in summer can stunt growth and flowering for that year. Winter division hampers root establishment in frozen soil.
How Often to Divide Black Eyed Susans
-
Divide clumps every 3-4 years to reinvigorate plants
-
Dividing annually is too frequent for black eyed susans to recover well.
-
Allow 2-3 years before dividing new clumps again.
Signs it’s time to divide:
- Centers of clumps die out.
- Fewer, smaller flowers.
- Overcrowding limits growth.
Step-by-Step Guide to Dividing Black Eyed Susans
Follow these simple steps for successful division:
1. Prepare New Planting Area
Dig new planting holes and amend soil with compost. Black eyed susans thrive in well-draining soil in full sun.
2. Water Plants Well
Water clump thoroughly 1-2 days before dividing if soil is dry. Makes roots easier to remove.
3. Lift Entire Clump
Use a shovel or garden fork to dig around clump and lift it from the ground.
4. Shake Off Excess Soil
Gently loosen soil from the roots so you can see the root structure.
5. Divide Root Ball
Using pruners or a knife, cut the root ball into smaller sections.Aim for 2-3 vigorous shoots per section.
6. Replant Divided Sections
Place sections in prepared holes, backfilling with native soil. Water thoroughly.
Caring for Divided Plants
Newly divided black eyed susans require extra care:
-
Water frequently until established, about 2-3 weeks.
-
Apply balanced fertilizer a few weeks after planting to encourage growth.
-
Remove spent flowers to promote additional blooming.
-
Watch for pests or diseases and treat promptly.
-
Mulch around plants to retain moisture and suppress weeds.
With proper timing and care when dividing, your black eyed susans will quickly settle in and reward you with vigorous growth and bountiful golden blooms!
How To Divide Black Eyes Susans
FAQ
Do black-eyed Susans need to be split?
When should black-eyed Susans be cut back?
Do black-eyed Susans multiply?
When should I Divide a Black Eyed Susan?
You may also want to divide and transplant black-eyed Susans when they grow too big for the space where they are planted, to prevent them from spreading into nearby plants. Divide and move black-eyed Susans when they are dormant, usually fall or early spring.
Do Black Eyed Susans need to be divided?
Black-eyed Susans will benefit from being divided every three to four years, and you have brand-new plants at very little cost that you can use or share with friends. Divide black-eyed Susans in early spring, when new growth is just beginning. Prepare a garden spot for the divided black-eyed Susans at least a day prior to making the divisions.
How do you propagate Black Eyed Susans?
You can propagate your black-eyed Susans by dividing the patch and planting part of it elsewhere in your garden, giving you more beautiful blooms across your yard. But the best time to do it is when growth is not active. This means it’s best to divide your black-eyed Susans in early spring, before the flowers begin to grow back.
How do you move a Black Eyed Susan?
When you are ready to move your black-eyed Susans, choose the coolest part of the day to reduce stress on the plants. Plant them in holes that are at least as wide as the roots so that that the roots don’t need to be turned or twisted to fit.
How do you replant a Black Eyed Susan?
When you do replant, give them the best start by digging a hole one and a half to two times the size of the roots, back fill with good quality garden soil, and water deeply. Above: Dividing black-eyed Susans, and most of the aster family for that matter, is pretty simple.
When do Black Eyed Susans Bloom?
These pretty wildflowers are members of the sunflower family, and they bloom in autumn and late summer with a golden daisy look. You can propagate your black-eyed Susans by dividing the patch and planting part of it elsewhere in your garden, giving you more beautiful blooms across your yard. But the best time to do it is when growth is not active.