Gardening Blog

Gardening Blog: Hydrangeas

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My father was a good gardener. He grew beautiful roses, tasty vegetables and edged his beds in disciplined lines of annuals, like alyssum and petunias. We didnít have an easy relationship, so I never knew if he liked gardening or if he did it because it was expected of him, but he definitely excelled at the English Country Garden.

In the front of our house, holding pride of place, were two large Hydrangea bushes. I can remember my father gathering old nails when we did some demolition project or other and throwing them under the hydrangeas, saying they helped with the flowers colour and sure enough he was right.

The hydrangeas in our front yard were of the common Mophead type. They grew waist high, enjoyed sunlight from noon on and flowered prodigiously. The flowers started out blue, turned a delicate and washed out pink late in the summer and waited for the frost, coloured an equally pale lime green.

The other hydrangea which fits in a normal back yard garden is the Oakleaf or lace-cap hydrangea. The leaves are indeed like exaggerated oak leaves and the flowers are a combination of many large single male flowers around the outside bottom, and a domed centre of tiny female flowers; hence the lace cap designation. Oakleaf Hydrangeas have an additional benefit. The leaves stay on the bushes in the winter and turn a lovely red rust colour when the weather cools. If you have snow, they are a warm sight to see on a blustery day.

The third type, the Paniculata Hydrangeas (PeeGee) grow on bushes much too large for the average garden and wonít be discussed here except to say they might be a major feature on a front lawn instead of an ornamental crab tree, for example, but they are messy and automatic target for neighborhood boys. I love them, but unless I acquired an estate, I can live without them.


In my experience, hydrangeas like partial sunlight. Iíve grown them facing North or South, but always they get dappled sun for approximately half of every day. When setting out the plants be aware that they are not deep rooters. Dig a shallow hole in well drained, fertilized soil and rake the soil you moved back up under the plant. Lightly cover the top of the roots, tamp down the soil and do not bury the plants crown.


I only fertilize them in the early Spring, with a low nitrogen fertilizer as you donít want to overdo leaf production at the expense of flowers. There have been reams written on pruning hydrangeas and battles fought over when and how to prune them. Iíve discovered a pretty much sure fire way to prune them and have flowers every year. For my Mopheads and Oakleaf hydrangeas, I prune only in the Spring before the leave buds have broken but when you can see which canes are quickening. Cut out only the dead canes and those that cross others at such oblique angles as to malform growth. One the shrubs have reached medium height, removing 5% to 10% of the canes each year will keep them healthy, well ventilated and blooming. It doesnít matter if they bloom on new or old wood if you donít remove it. Perhaps this is a little unorthodox but the hydrangeas have been in the same place for almost fifteen years and still look lovely and bloom generously.


One your hydrangeas have established themselves if you want more, you only have to take material from the original plants to make new ones. There are two methods to do this. First, you can slip off new shoots, take all green stem, near the top of the canes, apply No. 2 rooting hormone to the bottom of the cuttings and put them in water or soilless planting mixture. When roots are established, put the cuttings in 4 inch pots and when they are close to pot bound plant them out. If you have a place in your house with strong sunlight or grow lights, planting out should be the following Spring. The second way is even simpler; take a low growing cane, close to the ground and pin it to the soil with a stone. Be judicious, donít crush it. Then heap soil up over the area on the ground and leave it for a season. The following Spring, it will be rooted to the soil. Then you can separate it from the parent plant with your secateurs, ease up the roots with your spade, and plant it in the new location.


Just a caution that Hydrangeas forced in green houses for seasonal gifts are not the same as stock bought from a plant centre or green house. They may have been cloned and forced, with light and hormones, to grow the biggest flowers in the least time possible. Once they are done, I have never gotten them to flower again. Leaves in abundance but no blooms and Iíve tried in a variety of climate zones. I have two sources of information and plants that I have used and trust for you to try, but there are literally hundreds on the web. Like Lilies, if you can find a green house that grows hydrangeas in your microclimate, it might give you a natural advantage. Otherwise the web now has plant shipping down to an art.