Species
(Type)

Bloom Interest

Height

Features & Notes

Hydrangea paniculata
(Panicle Hydrangea)

Late July -
Late October

2-15+'

New cultivars have strong stems & upright flowers. Cultivars of interest:

• Bobo doesn't require pruning.
• Little Lime Punch is the reddest paniculata.
• Tardiva provides a great option for pollinators in late summer.
• Vanilla Strawberry has red stems. In shady areas, it is dark pink by Thanksgiving.

Hydrangea arborescens
(Smooth Hydrangea) &
Hydrangea radiata
(Silver-leaf Hydrangea)

Late May -
August

1.5-5'

Flowers mature to lime green; radiata leaves have silver underside; pollinator magnet

Hydrangea quercifolia
(Oakleaf Hydrangea)

Late May -
September

4-9'

Cinnamon bark; Excellent red/purple/dark orange fall foliage

Hydrangea quercifolia is the replacement for burning bush, which is an invasive species. The leaves go red.

Hydrangea macrophylia
(Bigleaf Hydrangea) &
Hydrangea serrata
(Mountain Hydrangea)

Late June -
August

3-6'

These are the ones with the most pinks and blues; however they are the ones deer love most.

In our area, it can emerge too early & soon die (especially when we get a frost after unseasonably warm weather). Winter protection needed if inconsistent flowering

Avoid the Fairytrail Bride cultivar: it has zone 7 in its lineage and is questionable about its ability to thrive in this environment.

Hydrangea anomala
(Climbing Hydrangea)

Late June -
July

60-80'

Cultivars of interest:

• Petiolan's Firefly is recommended.

Early bloomer, but fades fast.

Peeling bark, clinging vine; Slow to establish. Lacecap flower patterns (vs. Mop head) support pollinators better.

The vine is heavy, so new ones need to be staked. Also, they must be tied up or they will become ground cover (like a giant shrub).

Species
(Type)

Fertilization & pH Adjustment

Hydrangea paniculata
(Panicle Hydrangea)

Hydrangea arborescens
(Smooth Hydrangea) &
Hydrangea radiata
(Silver-leaf Hydrangea)

Higher organic matter, well drained

Hydrangea quercifolia
(Oakleaf Hydrangea)

Higher organic matter, well drained

Hydrangea macrophylia
(Bigleaf Hydrangea) &
Hydrangea serrata
(Mountain Hydrangea)

Higher organic matter, well drained. Fertilize with more phosphorus & potassium, less nitrogen. Apply on:

• Mothers' Day
• 4th of July
• Memorial Day
• Labour Day

For color, pH is the determinant

• pH < 5.5 = blue
• pH > 6.5 = pink

High Phosphorus ties up Aluminum. Aluminum makes the plant blooms blue.

Sulfur can be added every 2nd year using Osmocote Plus, but a soil test is recommended to ensure that is needd. When added, it needs to be placed below the mulch.

Hydrangea anomala
(Climbing Hydrangea)

Well drained soils

Species
(Type)

Blooms on

Pruning

Hydrangea paniculata
(Panicle Hydrangea)

New wood

Can prune to tree form. Cut low/thin for largest flowers. Try shorter cultivars for less pruning.

Hydrangea arborescens
(Smooth Hydrangea) &
Hydrangea radiata
(Silver-leaf Hydrangea)

New wood

Fall/Spring cut to ~6" for x-large blooms. No pruning = more small blooms. Thin new shoots for larger blooms.

Hydrangea arborescens: Cut down in late Fall/early Spring

Hydrangea quercifolia
(Oakleaf Hydrangea)

Old wood

After flowering if needed for shaping or rejuvenating.

Hydrangea macrophylia
(Bigleaf Hydrangea) &
Hydrangea serrata
(Mountain Hydrangea)

Old wood
Old & new wood

Late fall, cut above 3rd bud. Cut back dead stems on 10 May.

Mulch for winter. Mulch must be kept away from stems when not winter.

Spring prune dead stems after leaves emerge.

Hydrangea anomala
(Climbing Hydrangea)

Old wood.
No blooms? Low light, or young.

Only to shape or remove odd stems extending away from the vine.

Species
(Type)

Sun

Hydrangea paniculata
(Panicle Hydrangea)

AM Sun, PM shade for color fading in flowers. Some cultivars take more sun without browning flowers.

Hydrangea arborescens
(Smooth Hydrangea) &
Hydrangea radiata
(Silver-leaf Hydrangea)

AM sun, PM shade best. 6 hrs for strong stems

Hydrangea quercifolia
(Oakleaf Hydrangea)

AM sun, PM shade a must for faded flower color.

Hydrangea macrophylia
(Bigleaf Hydrangea) &
Hydrangea serrata
(Mountain Hydrangea)

AM sun, PM shade a must for lasting blooms

Hydrangea anomala
(Climbing Hydrangea)

Part sun to shade; AM sun and PM shade best

About this Site

eMail comments to me at GardeningBoK @ Gmail.com.