Hydrangeas are a beautiful staple of any garden. One of the most popular plants, the hydrangea is the quintessential shrubs around. Did you know that they are among the most googled plants? This must mean that they must be somewhat of a mystery to many gardeners. I can't say I find that surprising. There are a 70-75 species and over 600 varieties! That's quite the family tree! Not to mention there is always a question about pruning and flowering. I'm going to see if I can demystify this garden shrub that seems to have so many people scratching their heads.
We'll start with the basics. There are 6 main types of hydrangeas and I'll discuss each in detail. Bigleaf Hydrangea. Bigleaf hydrangeas consist of two varieties.
The first is the Mophead hydrangea. These seem to be among the most confusing hydrangeas. Also the most popular, the bigleaf or mophead hydrangeas are known for large flowers. These hydrangeas have large, dark green leaves with toothed edges. The blossoms ae made up of large, showy flowers. Also in this variety are Lacecap Hydrangeas. The blossoms of lacecap hydrangeas consist of tight buds in the center surrounded by showy flowers. Some of the Mophead hydrangeas are pH influenced, which means that the color can change depending on your pH. These Bigleaf hydrangeas come in white, pink or blue. Not all hydrangeas can change color based on pH.
Mountain Hydrangeas. These are similar, although not as common, to the Bigleaf Hydrangeas. The mountain hydrangeas tend to stay a little smaller in size. They have lacecap flowers that are typically blue or pink in color. One of the things I like most about these hydrangeas, are the difference in the leaves when compared to their Bigleaf counterparts. The leaves of the Mountain Hydrangeas are a lighter color green and they're fuzzy! We have one of these mountain hydrangeas in our garden in Killingworth, CT and I just love it!
Smooth Hydrangeas. These also have unique foliage. The leaves are somewhat heart-shaped, and like their Big Leaf counterpart, they display a toothed edge. The difference in these leaves are their matte finish. It has a texture to the leaf that feels much more like a perennial leaf than a shrub leaf. Most of the Smooth, or Annabelle hydrangeas are white, but in recent years, plant breeders have developed varieties that are pink in color. They flower from late spring to mid summer. This is an Annabelle hydrangea that we planted as part of a garden in Branford, CT.
Panicle Hydrangeas are next on the list. The leaves on these hydrangeas are a medium green and are noticeably thinner. They also have a rougher texture. There are many varieties of hydrangeas, but no species of hydrangea has as much variety as the Panicle Hydrangea. These shrubs range in size from 3 feet tall to 12 feet tall and wide! All of these panicle hydrangeas bloom white, but some fade to shades of pink or red. These hydrangeas can also come in tree form, so there is a size for everyone! This particular bobo hydrangea is a dwarf hydrangea in one of our gardens in Durham, CT.
Oakleaf Hydrangeas are the easiest hydrangea to identify based on it's leaf shape, which as you can imagine, looks just like the leaf on an oak tree. Much like their cousin, the panicle hydrangea, all oak leaf hydrangeas bloom white, however, many have been specifically bred to have their blooms quickly turn to a deep pink or even red. Most hydrangeas benefit from a little shade in the afternoon, however, the oak leaf hydrangeas can take a fair amount more shade then other species. The leaves of this hydrangea turn multiple shades of deep red in the fall, making it a standout in just about any garden.
Climbing hydrangeas are the last hydrangea on our list. This is a beautiful and vigorous climbing shrub. This large, woody vine will attach itself to most surfaces so care should be taken where planted. Most vines, especially climbing hydranges due to their sheer size, can cause damage to houses. If you want to plant it along a fence, be sure it's a sturdy vinyl fence and not wood. If you decide to plant it near your house, I strongly recommend installing a trellis, leaving a little room between the trellis and your home so the vine doesn't accidentally latch onto your home. Never allow any type of vine to climb up a chimney or along your house. The tendrils of the vine can reach underneath siding and cause the mortar in chimneys to weaken. Hydrangea vines produce beautiful, airy white blooms and prefers some protection from afternoon sun. If you have a place for this beautiful blooming vine, you won't be disappointed as this climbing shrub is a strong performer. It is deciduous so be aware that in the winter you will be looking only at the woody vine, but that in itself offers a certain beauty in the winter when covered with frost or snow.
There are so many hydrangeas (did I mention over 600 varieties??) to choose from. The hydrangea breeders have done an exceptional job in creating hydrangeas that meet almost any need. With the exception of the climbing hydrangea, just about every species has dwarf varieties such as Hydrangea Macrophilla 'City Line Paris' that grow only between 1-3 feet tall. Larger Macrophilla (Big Leaf) hydrangeas include endless summer which get to be about 5 feet tall.
The other hydrangea species that have a wide variety of sizes are the panicle hydrangea. They can be like comparing a chihuahua to a great dane! Hydrangea paniculata 'bobo' is a dwarf panicle hydrangea that only gets to be about 2-3 feet tall. Then there is Hydrangea paniculata 'Limelight' which grows to be roughly 7 feet tall.
Smooth hydrangeas can also be small or large. Hydrangea Arborescens 'Invincibelle Wee White' is a delicate Smooth Leaf Hydrangea that grows between 12 – 30 inches. Then we can move onto the traditional Annabelle Hydrangea, Hydrangea Arborescens 'Annabelle' which matures at 5 feet.
Oakleafs also come in both dwarf and large sizes.
More information about hydrangea varieties can be found right on Monrovia's website at: https://plants.monrovia.com/search?w=hydrangeas
Hopefully I've shed some light on hydrangeas. There is still a lot to know so I'm going to continue this hydrangea series by discussing care, as well as pruning of hydrangeas.