6 Perennials You Can Still Divide in December (In Warmer Zones)
Plan your best garden yet! This printable 2026 Sowing Calendar tells you exactly when to plant your favorite vegetables, herbs, and flowers for a thriving garden all year long.
Plan your best garden yet! This printable 2026 Sowing Calendar tells you exactly when to plant your favorite vegetables, herbs, and flowers for a thriving garden all year long.

Anyone who recommends gentle handling for Astilbe has not met its knotty crown. Every few years, when the plant shows signs of exhaustion, dig the whole stubborn plant up.
You must use a sharp tool (maybe a power saw, a Viking axe, or maybe just a very strong shovel) and divide the hard crown like you mean it.
Just like with Hostas, ensure every new division holds a prominent, intact, waiting bud before slicing. Those buds are your guarantee for abundant flowers.
Quick tip: Astilbe roots hate drying out. After dividing, plant the pieces into moist soil and add a light layer of mulch, this keeps the roots protected and helps them settle in fast.
And since fresh divisions appreciate a bit of insulation, here’s our guide to which plants you should mulch before winter and which ones you shouldn’t.

The Hardy Geranium is constantly trying to take over the planet, one square foot at a time. But unlike the messy division of other root masses, you only need to harvest sections from the outer edges of the mother clump. No need to excavate the entire plant!
Plan your best garden yet! This printable 2026 Sowing Calendar tells you exactly when to plant your favorite vegetables, herbs, and flowers for a thriving garden all year long.
Simply slice generous pieces from the perimeter using a clean spade.
Hardy Geranium roots easily, which guarantees you quick success in sunny or shaded spots. It also means that division now is less about plant health and more about necessary population control.
Quick tip: From experience, Cranesbill settles in faster if you trim back any long, leggy stems before replanting. It lets the roots focus on establishing instead of supporting winter foliage.

This is the reliable plant every garden needs, but even icons get cramped. Shasta Daisies are terrific bloomers, yet they require regular renewal to maintain their large, white flowers in summer.
Their division is an efficient December work because the plant is completely dormant. The clear sign for action is that notorious “dead zone” in the middle.
Simply chop out the vigorous edges, toss the rotting center to the compost heap, and water new divisions immediately after replanting. Voila! You just bought yourself thousands of guaranteed sunny Shasta days.
And while you’re in cleanup mode, my December cut-back guide helps you see which plants should be trimmed now and which ones are better left standing.