How to Prune Annabelle and Incrediball Hydrangeas
The two most forgiving hydrangeas in Canada, and the one decision that sets how big the flowers get.
How to prune Annabelle and Incrediball hydrangeas is the easiest pruning question in the hydrangea family. Both are smooth hydrangeas (Hydrangea arborescens), and both flower on stems that grow this year, so a spring cut cannot take away any flowers.
That is also why they come back after a Prairie winter. The University of Massachusetts notes smooth hydrangea may die back to the ground in an especially cold winter and still flower the following summer, because its buds form on the new growth.
Annabelle and Incrediball pruning at a glance: Prune in late winter or early spring. Either cut all stems to the ground for the biggest heads, or leave a low framework for more, smaller heads on sturdier stems. Remove weak and dead stems at the base. On a new plant, wait a season or two before any hard cut.
Wait a Season or Two on a New Plant
The University of Minnesota’s advice is to let a smooth hydrangea grow for a season or two before doing any serious hard pruning. A young plant needs its leaves to build roots. Once it is established, it says, prune in spring down to the ground, or not at all if you want a larger shrub.
The Three Choices
| What you do in spring | What you get |
|---|---|
| Cut every stem to the ground | The largest flowers, on long new stems that are the most likely to bend. The University of New Hampshire recommends this for larger, more robust flowers. |
| Cut to a low framework | More flowers, a little smaller, held on shorter, firmer stems. A common compromise; the height is your choice. |
| Leave it alone | A bigger shrub. The University of New Hampshire notes old stems still flower, but the flowers are small. |
Whichever you choose, the University of New Hampshire says last year’s dried flowers can come off any time from late winter through spring, and N.C. State advises removing weak and damaged stems in early spring.
Why the Heads Flop, and What Helps
N.C. State is blunt about Annabelle: white flowers on weak, floppy stems that need staking or support, and big clusters that bend and droop after a heavy rain. Annabelle’s heads can reach about 30 cm (12 inches) across, according to the University of Massachusetts, which is a lot of wet weight on a thin stem.
Incrediball is sold by its breeder as a stronger-stemmed smooth hydrangea. That is the breeder’s claim; we have not found an extension trial that measures it, so treat it as a likely improvement rather than a fix.
General guidance: three things help more than the variety. Leave a framework instead of cutting to the ground, so the new stems branch from something woody. Thin out the weakest stems at the base in spring. And put a support ring over the crown before the leaves cover it, so the stems grow up through it and hide it by June.
Set it over the crown in spring, before the new stems are knee high. The stems grow up through the grid and hold the white heads off the lawn after a summer storm.
Affiliate link — GrowersGuide.ca may earn a commission on qualifying purchases, at no extra cost to you. See our affiliate disclosure.
Sun, Water and Canadian Winters
The University of Massachusetts says smooth hydrangea prefers part shade and ample moisture; N.C. State adds that it will take full sun only with consistent watering. A dry, sunny bed is the other common cause of drooping, because a wilting stem cannot hold a flower up.
For Canadian winters, smooth hydrangea needs no protection at all. On this site’s zone guide it is a reliable choice in Zone 2 and 3 gardens, where it may die to the ground and still flower. Leave the dead stems standing until spring; they catch snow over the crown, and there is nothing to gain by cutting them in fall. The Hydrangea Winter Care in Canada guide covers the types that do need help.
Pruning Tools
These are soft, thin stems, so a sharp pair of bypass shears does the whole job; a lopper only earns its place on an old, neglected clump with woody bases. Compare the other hydrangeas you grow on the one-page pruning chart, and see How to Prune Limelight Hydrangea for the panicle types that grow alongside them.
Smooth hydrangea stems are soft enough for the shears alone; keep the lopper for the woody bases of an old clump.
Affiliate link — GrowersGuide.ca may earn a commission on qualifying purchases, at no extra cost to you. See our affiliate disclosure.
Frequently Asked Questions
When should I prune Annabelle hydrangeas in Canada?
In late winter or early spring. Annabelle is a smooth hydrangea that flowers on new wood, so a spring cut costs no flowers.
Should I cut Annabelle hydrangeas to the ground?
You can once the plant is established. The University of Minnesota says to prune established smooth hydrangeas to the ground in spring, or not at all if you want a larger shrub. Cutting to the ground gives the biggest heads on the floppiest stems.
How do I stop Annabelle hydrangeas from flopping?
Leave a low framework instead of cutting to the ground, thin the weakest stems in spring, give the plant enough water and some shade, and set a support ring over the crown early in the season.
Is Incrediball better than Annabelle?
Incrediball is sold as a stronger-stemmed smooth hydrangea. That is the breeder's claim; we have not found an extension trial measuring it. Prune both the same way.
Should I prune a new Annabelle hydrangea?
Not hard. The University of Minnesota advises letting a smooth hydrangea grow a season or two before any serious pruning.
Do Annabelle hydrangeas need winter protection in Canada?
No. Smooth hydrangea can die back to the ground in a very cold winter and still flower the next summer, because it blooms on new wood.
Sources
- University of Minnesota Extension — Pruning hydrangeas for best bloom
- University of Massachusetts Amherst Extension — Growing Hydrangeas
- University of New Hampshire Extension — Pruning Hydrangeas
- N.C. State Extension Gardener Plant Toolbox — Hydrangea arborescens
- Canadian zones and frost dates: this site’s city data, from Natural Resources Canada and Environment and Climate Change Canada.