Dividing Overgrown and Floppy Perennials
Overcrowded, poor flowering and floppy perennials can be invigorated with a shovel and a bit of your time and energy.
Dig and divide perennials to improve their overall appearance and create new plants to use or share.
The best time to divide spring bloomers is in fall, fall bloomers in spring and summer blooming perennials in either spring or fall. But most gardeners have found the best time to divide is when you have the time and can provide good proper post transplanting care.
Use a sharp spade to dig up the clump. I like to lift the clump out of the soil and use a linoleum or garden knife to cut the plant into smaller sections. Discard and compost the dead center. Divide into four, six or eight pieces.
Prepare the soil for replanting by adding compost or organic matter. Plant and water to get your new plants off to a good start.
A bit more information: Divide repeat blooming daylilies like Stella D’oro every few years to keep them blooming throughout the summer. Threadleaf coreopsis also benefits from regular dividing. Digging and dividing every few years keeps this plant reblooming without deadheading. And I would much rather dig and divide a plant every few years than deadhead those small flowers for even one season.