Panicle Hydrangea (Hydrangea paniculata)
One of the easiest hydrangeas to grow, as it blooms on current season’s stems, Hydrangea paniculata flowers start out white and change a rosy pink as they slowly age. Panicle hydrangeas bloom on the current season’s stems, and can be cut back by about one third their height in early spring. Hardy from Zone 3-9, they prefer full sun, but also do well in partial shade. Panicle hydrangea grows anywhere from three to 10 feet and has conical-shaped blossoms that typically contain both fertile and infertile flowers.
One of the most important breakthroughs on this species was the introduction of a variety called ‘Limelight’. Almost as soon as word got out about its huge, bright lettuce-green flowers, this 2006 landscape innovation began winning awards for its stunning presence in the garden.
Since then, several new varieties have come out, but ‘Limelight’ is still one of the best. Smaller stature with sizeable flowers and strong stems are what hybridizers are looking for in panicle hydrangeas. Newest varieties include:
- ‘Bobo’: If you like your hydrangeas smothered in bloom,‘Bobo’ should be your choice. It’s compact, reaching just three feet tall, and its blooms age to a dusky rose.
- ‘Diamond Rouge’: Billed as the reddest panicle Hydrangea, this new variety offers large flowers that turn red earlier than other cultivars on four foot plants.
Oakleaf Hydrangea (Hydrangea quercifolia)
This American native hydrangea makes a statement from mid-summer into fall. With panicles of creamy sterile and fertile flowers that age to rose, it doesn’t stop there. Hydrangea quercifolia’s large, oak-like leaves turn a gorgeous deep red in fall. Hydrangea quercifolia is probably one of the tallest shrubs you can grow; its dwarf varieties top out around three to four feet. It blooms on previous season’s stems, prefers partial shade, and is hardy from Zones 5-9.
Standard varieties, the tallest of which is ‘Alice’, can grow to eight to 10 feet tall. There is a double-flowered form called ‘Snowflake’, which has been a staple in hydrangea-expert Michael Dirr’s Georgia garden. Flowers on this variety look double because of the way its new sepals (infertile flowers) sprout on top of older ones. ‘Snowflake’ grows up to eight feet tall and 10 feet wide.
One of the best, and most compact varieties is ‘Ruby Slippers’, reaching just three to four feet tall.
Whether you’ve had the success of Martha Stewart or have thrown in the towel on the blue Hydrangea, there are so many varieties to add to your landscape that are cold hardy, heat tolerant, and forgiving of untimely pruning, you’re bound to find one (or several) that you’ll fall in love with.
- Sterile florets – these are the showy flowers that make up the mophead (snowball) form of Hydrangea species macrophylla, arborescens and serrata.
- Fertile flowers – tiny and indistinct, these are more obvious in lacecap type flowers
- Remontant – A remontant Hydrangea is capable of blooming on both old and new wood.
- Old wood vs. new wood – Old wood refers to stem growth from the previous season, while new wood is grown in the current season.
- Mophead – a style of bloom found on hydrangeas that consists of rounded clusters of sterile florets as on ‘Annabelle’ and ‘Endless Summer’.
- Lacecap – flat flower head composed of both sterile and fertile flowers.