Shrub Spotlight for April
Oh, Those Confusing Hydrangeas
Hydrangea shrubs can be some of the most versatile and useful shrubs in Minnesota landscapes. They can be used as a single shrub or used in mass plantings and offer us show-stopping flowers. They typically offer a flowering period much longer than other shrub types. Hydrangeas offer a wide range of shrub size, flower type and flowering color. There can be some confusion regarding the timing of pruning, issues with winter dieback, and issues with certain soil conditions changing the flower color.
Type #1 = Pannicle (Hydrangea panniculata)
Pannicle hydrangeas are probably the easiest to grow in Minnesota because they are typically like other woody shrubs. These hydrangeas do not die back to the ground in winter like the other two types. Pannicle hydrangea flower on “new wood” so they can be pruned in early spring before the shrubs leaf out in spring.
Common types for Minnesota include the following:
Limelight (6-8 feet tall, 5-7 feet wide, lime green flowers)
Quick Fire (6-8 feet tall, 4-6 feet wide, white flowers becoming pink / red into fall)
Little Quick Fire (3-5 feet tall, 3-5 feet wide, white flowers becoming pink / red into fall)
Lavalamp Flare (2-3 feet tall, 2-3 feet wide, compact with white flowers becoming pink / red into fall)
*Others include Berry White, Bobo, Fire Light, Limelight Prime, Little Lime Punch and Pinky Winky
#3 container Limelight hydrangea
Type #2 = Smooth (Hydrangea arborescens)
Smooth hydrangeas are easy to grow in Minnesota. Their growth pattern could be termed a “tweener” somewhere between a woody shrub and flowering perennial. These hydrangeas often “die back” to the ground in winter if the temperatures remain lower than normal. Some older varieties are notorious for flopping when the flower heads get too large or plentiful. Many newer varieties have tighter, stronger branching pattern. Hydrangea arborescens flower on “new wood” so they can be pruned in early spring before the shrubs leaf out in spring.
Common types for Minnesota include the following:
Annabelle (4-5 feet tall, 3-5 feet wide, large white flowers)
Incrediball (4-5 feet tall, 4-5 feet wide, large white flowers)
Invincibelle Wee White (1-2 feet tall, 1-2 feet wide, compact shrub with white flowers)
Incrediball Blush (4-5 feet tall, 4-5 feet wide, large blush-pink flowers)
#3 container Bella Anna
Type #3 = Big Leaf (Hydrangea macrophylla)
Big Leaf hydrangeas can be a little tougher to grow in Minnesota depending on soil and light conditions. Their growth pattern could be termed a “tweener” somewhere between a woody shrub and flowering perennial. These hydrangeas often “die back” to the ground in winter if the temperatures remain lower than normal. Big leaf hydrangeas are also called “mophead” or “lacecap” hydrangea. Soil pH can adjust the flower color of these hydranagea. Alkaline soils can turn flowers pink, while acidic soils can turn flowers blue. Hydrangea macrophylla produce flowers on “old wood” so they cannot be pruned in early spring before the shrubs leaf out in spring (otherwise, flower buds will be removed).
Common types for Minnesota include the following:
Summer Crush (2-3 feet tall, 2-3 feet wide, large neon raspberry flowers)
Twist N Shout (3-5 feet tall, 3-4 feet wide, pink to periwinkle blue flowers), *flowers on old and new wood
Seaside Serenade (3-4 feet tall, 3-4 feet wide, compact shrub with red or blue flowers depending on pH)
Endless Summer (2-3 feet tall, 2-3 feet wide, purple to blue flowers), *flowers on old and new wood
#3 container Twist n Shout hydrangea
Blend of hydrangea types in mid-summer in Minnesota.
