The luscious hydrangea is a real eye-catcher
Karin Peebu, Risttee Horticulture Farm
According to various sources, there are nearly 80 types of hydrangea in the world. Not all of them are suitable for our climate, but some seem to flourish here as well. In Estonian gardens, the panicled hydrangea, smooth hydrangea, mophead hydrangea and climbing hydrangea are the most common. Oakleaf hydrangea, Himalayan hydrangea, rough-leaved hydrangea and hydrangea bretschneideri are somewhat less common.
Hydrangeas prefer a neutral or slightly acidic moist but not wet soil, but do just fine in regular humus-rich garden soil as well. The soil in our garden is slightly acidic: I haven’t added any acidic peat into the planting hole, but the hydrangeas are growing nicely. If I find any mould on a jar of juice or jam in my cellar, I sometimes pour the sour leftovers on the hydrangea. Any residues from steaming red currant juice or pressing apple juice are also great to mix into the soil.
How to grow hydrangeas?
It is recommended to plant hydrangeas in a site protected from winds. In my garden, I have planted them both in a place protected from winds and in the park open to winds. They flourish equally in both places. A hydrangea loves moisture. It doesn’t want any water straight on the ground, but is not a fan of drought, either. As the soils we have here are clayey, there is plenty of moisture and I haven’t even had to water the flowers during droughts. Also, mulch underneath hyndrangeas keeps the soil moist.
The smooth hydrangea is resilient
In our gardens, the most common type of smooth hydrangea is probably the Grandiflora. For many, it is associated with old cemeteries because that is indeed the growth site of lots of smooth hydrangeas. Besides, smooth hydrangeas were available in our tree nurseries during Soviet times already. Arguably, smooth hydrangea prefers a sunny or half-shaded growth site protected from winds. Yet even though we have one shrub in a completely open site, it is doing just fine. There is nothing else to worry about than the pruning in early spring. This may also be done in November so that there is plenty of time in the spring for other things. It is advised to make the cut above the third bud, approximately, so the plant should be able to bloom more vigorously then. Hydrangeas bloom from the shoots developed in the same year. Also, all old and dried up branches should be cut out. Spent blooms can be kept over the winter because they look beautiful even when dried up. However, I have been cutting off the blooms in the autumn because otherwise, by spring time, the wind will be spreading them around the garden and it is quite a tedious task to pick them up again. Some of the smooth hydrangea types can be sensitive to the cold weathers in our climate and are grown similarly to perennials, i.e., the frozen branches are cut back up to the ground in the spring. The two smooth hydrangeas of unknown type in our garden have not suffered once due to cold weather in the 20 years we have had them.
The panicled hydrangea blooms for a long time
Another type gaining popularity in our gardens is the panicled hydrangea. Indeed, these shrubs, or even small trees, are in bloom for a really long time and many types start out with white blossoms that first turn pink when ageing and then turn red, and then golden after the first harsher night frosts. Earlier varieties start blooming at the end of June already.
Combining various types blooming at different times, the beauty of the blooming hydrangeas can be enjoyed from the end of June until the winter colds. The requirements for the planting site are similar to those of a smooth hydrangea, but as a result of my own experiments, I can say that these plants are highly adaptive and manage well in sites open to winds as well. Panicled hydrangeas also love moderately moist and slightly acidic soils.
The panicled hydrangea does not need as much pruning in the spring as the smooth hydrangea, but it is not forbidden, either. All thin twigs should be cut off to facilitate the growth of strong branches, and abundant blooming. When allowed to grow freely, panicled hydrangeas will develop into round shrubs about 2–3 metres in height. If no pruning is done, there are still many blooms, but they are small. Pruning fosters the growth of larger blooms.
Tips and tricks for growing panicled hydrangeas
• The panicled hydrangea can be shaped into a small tree. You need nothing but your own imagination and some pruning shears.
• If you want to shape a short one-stemmed tree, leave one strong and straight branch and grow a round ball on the stem.
• Cut all branches sprouting from the ground and the ones growing on the bottom branch of the stem regularly.
• Do not forget to fertilise in the spring: pruning promotes vigorous growth of new sprouts, which need energy to grow.
I’ve also seen a hydrangea with 2–3 branches left and intertwined. Worth trying.
There are countless types of panicled hydrangea and it is very difficult to point out just one because they are all nice to grow. In our garden, the first to bloom is the Tardiva, which opens its blossoms in the second half of June already. Most of them burst into blossom at the end of July. The blossoms of some types vary from green to white, e.g. Limelight, while others get dark red blossoms for the autumn, e.g. Magical Fire.
The mophead hydrangea is sensitive to cold
If you want to have any mophead hydrangeas in your garden, choosing a good variety is very important. Most of the mophead hydrangeas available in our construction stores cannot survive the winter. Mophead hydrangeas bloom on the previous year’s wood, so it is very important that the previous year’s branches survive the winter. These plants can successfully survive the winter in a winter garden or a suitable cellar.
However, there are varieties that can spend the winter outside. In my garden, the Luua Roosa has been brave enough to survive for 10 years already. In the autumn, I cover the plant with a bucketful of ash. It hasn’t been in heavy bloom each year, but has definitely had blossoms every second year.
In 2012, Elle and Enno Ahse planted six different types of mophead hydrangeas in their garden. All of these plants have survived the winters and have been decorating the garden to this day. After really harsh winters, there has been less blooming, but the summer of 2019 blessed the hydrangea with lots of blossoms.
We’ve heard that mophead hydrangea types have been developed already which bloom on new wood.
The beauty of the oakleaf hydrangea lies in its bronze leaves
In Estonian gardens, the oakleaf hydrangea has not been used very much. In our garden, we have both an oakleaf hydrangea type and the variety Pee Wee. I got the plant babies four years ago from a nice person who had made herbaceous cuttings. The babies spent their first winter in a cold greenhouse and had to survive their second winter on a clear field open to winds. They did well there, too. In the spring of 2019, I planted the shrubs in a permanent site. Besides its blossoms, the beauty of this hydrangea type lies in its large scabrous leaves reminiscent of oak leaves. The reddish-bronze autumn colour of the leaves is also wonderful. The oakleaf hydrangea keeps its leaves for long and the shrubs are green even on New Year’s Eve. I saw the first blossom in the third year already. The oakleaf hydrangea prefers a site hidden from winds, and loves moisture. This is why mulching is recommended. Naturally, they grow on slightly more calcareous soils, on riverbanks and in undergrowth. The oakleaf hydrangea is a slow grower.
A few other fascinating hydrangea types
Climbing hydrangea. If you’ve ever seen a climbing hydrangea in full bloom, you cannot remain indifferent to its beauty. The climbing hydrangea blossoms all through the summer and is a beautiful sight. Humus-rich moderately moist garden soil should be preferred for growing, and watering is needed during summer droughts.
Bear in mind that a young plant grows slowly and takes about 3–5 years just to adapt. From then on, the climbing hydrangea grows about 50 cm a year. Climbing up to the height of 15 metres is no problem. The climbing hydrangea does not need pruning or covering up for the winter. The plant can also be grown as underwood. The best growing site is half-shaded, where the soil does not get too hot. In full shade, the climbing hydrangea does indeed grow faster, but blooms less. We have two of the plants in our garden, planted five years ago. We haven’t seen any blossoms yet and they are growing slowly as well.
The Himalayan hydrangea is also quite a rare sight in our gardens. With its shape, the plant brings to mind the panicled hydrangea and the growth requirements are also similar. The Himalayan hydrangea may grow into a low tree of up to 4 metres tall.
Hydrangea bretschneideri is a small tree growing up to 3–4 metres tall. Unfortunately, our tree nurseries do not offer this type very much. A few years ago, hydrangea bretschneideri could be admired in the Tammsaare Park in Tallinn; the plant is frostproof in our climate. If there is plenty of room in your garden, do not hesitate to try it out.
The rough-leaved hydrangea is a magnificent and majestic type. As the shrub is sensitive to our cold climate, it is more likely to be grown by people living on islands and coastlands where the winters are warmer. The past few winters have been rather warm in mainland Estonia as well and the rough-leaved hydrangea has survived without any coverage in several mainland gardens. The plants have not blossomed every year, though. The rough-leaved hydrangea type Hot Chocolate with its reddish-brown foliage is especially gorgeous.