I planted 1 black eyed Susan 2 years ago, now I have at least 10 of them. I want to replant them as border near my fence. Is this time of the year good for replanting or I should do that in spring?
This is the first year I am doing a big cleanup in my backyard, preparing the ground for spring. Should I put new soil in now or in the spring?
Thank you for contacting the Toronto Master Gardeners with your inquiry.
The golden flowers and black centers of black-eyed Susan (Rudbeckia fulgida ‘Goldsturm’ ) are a welcome addition to any perennial border. These cheerful plants have a long bloom time (July-September) and depending upon the weather I have seen them flowering well into the end of October. Even after the petals have fallen off, the seed heads provide beautiful architectural interest to the winter garden and as an added bonus provide much needed food for those birds that remain in our cold climate. A good rule of thumb to follow for transplanting any perennial is if they bloom in the fall, divide and transplant them in the spring. If they bloom in the spring, divide and transplant them in the fall.
However, black-eyed Susans are very hardy perennials that stand up well to the stress of being relocated. As a result, the best time to transplant them is when they are dormant (early spring or fall), well before the first frost. This will cause them the least amount of stress. Planting them in the fall, again well before the first frost, has its advantages because it gives their roots time to become established before winter sets in, which will get them off to a faster start in the spring.
It is a good idea to add compost to your garden every year, it is never too late. Top-dress around perennials using organic material such as compost, shredded leaves or well-rotted manure. If using leaves as a mulch, consider leaving this on the beds in spring. This organic matter will soon decompose and add nutrient to the soil. Oak leaves are the exception because decomposition typically takes a long time.
The Toronto Master Gardeners Guide to dividing perennials will give you more information. https://www.torontomastergardeners.ca/gardeningguides/dividing-perennials-a-toronto-master-gardeners-guide/
You may also wish to read our Garden Guide on : Putting the Garden to Bed