Recently I was asked to give a consultation by a perspective client. I love these! The consultations that is! It allows me to snoop through someone’s yard. I love finding out about their taste, gardening habits and how much or little work they put into their garden. Some home owners are very knowledgeable and passionate about their gardens. Other’s are one or the other, but more so over-conscientious about the appearance over their yard.
One of the questions of concern from this home owner was why her hydrangeas were not big bloomers. Did they receive adequate lighting? Were they getting enough moisture? Too much fertilizer? Improperly pruned? Bingo! They were cut down every fall. While some hydrangeas bloom on new wood, a lot of the colourful varieties of hydrangeas sold bloom on old wood. The client’s hydrangeas were a Hydrangea Macrophylla type which can be known as a florist hydrangea and they do not like nor require hard pruning.
Picture of Hydrangea macrophylla
There are four main types of hydrangea. Hydrangea aborescens, which most people know of as the big white ball hydrangeas. This is a variety called Annabelle Hydrangea. They are a great, easy hydrangea, perfect for cutting and enjoying indoors and excellent to use as a border or individually in your landscape. There are new varieties out that have increased bloom size and stem strength as well. They require to be pruned to four to six inches from the ground every spring. This will ensure larger flowers to enjoy and usually stronger stems.
Picture of Annabelle Hydrangea or Hydrangea aborescens
Another very common type is Hydrangea paniculata. This type of hydrangea may be known as the cone shaped variety or tree form. It’s true that the flower shape of this particular hydrangea is cone shaped and the stems of the hydrangea are very woody and stiff compared to some of the other varieties. You can choose from a wide variety of panicle hydrangeas…and you should! They are easy to maintain and offer a lot of interest year-round in the garden. Like all of the hydrangeas, you can cut this one to enjoy indoors as a fresh flower. If you want to dry this one, it holds up well and you can use it for decorative displays in wreaths or containers. Pruning the panicle hydrangea is pretty easy. You want to reduce the size to your desired level. A Limelight variety hydrangea can grow 3-5’ in a year and you may wish to keep the height lower to start. However, all plants have a maximum height. Don’t be afraid of choosing one that will give you a big impact. Removing the spent flowers is the minimum that you should be doing, as well as removing damaged or interfering growth. Once every three years or so, I like to prune my client’s panicle hydrangeas down by a good third. It looks drastic when I do the spring pruning. However, it allows the garden to look fresh and well kept. The Panicle Hydrangea is available as a standard as well. It is a great option to add height in the garden or to use as a topiary or in pots. They provide great seasonal interest as well right up to the point that they are pruned.
Some of my favourites include: Hydrangea paniculate ‘Limelight’, Hydrangea paniculata ‘Bobo’, Hydrangea paniculata ‘Silver dollar’. I could go on and on!
Picture of Hydrangea paniculata
Oakleaf Hydrangea or Hydrangea quercifolia is a stunning hydrangea with amazing fall colour. Some people find this hydrangea a little daunting and it is an under-planted variety. As this variety ages, its bark exfoliates and can provide dramatic winter interest. Oakleaf hydrangea has panicle or cone style flowers with… you guessed it… ‘oak’ shaped leaves. The colour of these flowers is usually white. There have been many new recent introductions that are more prolific in their bloom and total landscape appearance, if given proper light in the garden. The popular misconception with hydrangeas is that they are a shade plant. Not true! They can tolerate sun and often bloom more consistently with full sun, but need adequate moisture. This type of hydrangea does bloom on old wood which means that you do not heavily prune the Oak Leaf hydrangea. That being said, you can reduce its size, although this might delay or forgo its bloom for that particular year. Removing dead branches and spent flowers is also beneficial.
Hydrangea serrata- A Mountain hydrangea. Most varieties of these hydrangeas bloom exclusively on old wood. However, newer varieties bloom on both new and old wood. This variety can be white, pink, purple, blue, colour changing and even lace cap varieties. This is a very romantic, cottage type plant that is very hardy in the garden and the newer varieties claim to be successful re-bloomers.
Hydrangea macrophylla or Florist or French hydrangea. DO NOT heavily prune. Only remove spent flowers and dead or interfering branches.
Hydrangea aborescens or Mop Head Hydrangea. Prune to a height of 4 to 6 inches from the ground in the spring
Hydrangea paniculata is a cone shaped hydrangea and hydrangea topiary. Prune off dead, damaged branches. Remove up to one-third of the plant once a year in late winter or early spring.
Hydrangea serrata or mountain hydrangea can be lightly pruned late winter or early spring. Newer varieties are re-blooming and colour changing.Hydrangea quercifolia or Oak leaf hydrangea blooms on old wood. Remove damaged branches or reduce height late winter or early spring.