Hydrangeas are most widely known for their flowers. The flowers are usually pretty large, and they come in a range of colors depending on the type of hydrangea.
They can be white or pink or blue, sometimes purple and red. Really the only colors that we don’t see in hydrangeas are yellows and oranges, but most people will think of blue hydrangeas, which blues are not a very common color when it comes to flowers, and that’s something that we can absolutely obtain with hydrangeas. One thing about hydrangeas is that all of them are deciduous, meaning that they’re going to lose their leaves in winter.
So if we think of an oak tree for an example, they shed their leaves in winter and then they flush new leaves the next spring. All hydrangeas do that. None of them are evergreen. Many people would consider hydrangeas to be nostalgic, and what I mean by this is perhaps you had a family member a parent, a mother, a father, a grandparent that grew hydrangeas.
That’s actually my grandmother grew hydrangeas, grew a lot of hydrangeas. I planted many of them. My grandmother’s the one that got me interested in plants and horticulture, and so when i think of plants, I think of her. When I think of hydrangeas, I think of her. So maybe for some of you hydrangeas would bring back a memory of a grandparent or a parent.
Maybe you’ve driven around, especially in the southeast, and seen a hydrangea growing near like an old homestead. The home might be dilapidated, but the hydrangea is still growing. For some of you, maybe you think of Martha Stewart or maybe you have no idea who Martha Stewart is. Hydrangeas had kind of fallen out of fashion, and Martha Stewart really championed hydrangeas, started talking about how great they were, and that really reinvigorated a lot of people to be interested in hydrangeas and and provided kind of a boost to plant breeders to develop new cultivars, new types of hydrangeas.
But unfortunately many gardeners do not have success with hydrangeas, so we’re going to talk about some of the most common mistakes and how we can avoid those. Okay, so the first mistake that many people make is choosing the wrong plant, or we could say choosing the wrong site, or the wrong plant for the site. So oftentimes when it comes to plants, people buy plants as an impulse purchase.
Some people, yes, get in their car and they go to a garden center with a particular plant or a particular site in mind, and they’re looking for a plant that fits that site. Many people get in their car and they go to Home Depot or they go to Lowe’s or they go to some other store, and they’re going to buy paint or something else, and you see these bright plants as you drive past the garden center and you just buy one because it’s attractive, but you really have no idea what to do with it or where you’re going to put it. So ideally what you do is you first determine where you’re going to plant the hydrangea, then you choose the appropriate type based on the site. So when I talk about the site, I’m mainly talking about sun exposure.
So there are hydrangeas that specifically need full sun, there are ones that do really well in nearly full shade, and there’s a lot of plants that do well in part sun and part shade. Other things when it comes to the site would be, you know, is it well drained or does it stay kind of moist? So other ways that you can help identify which type of hydrangea might do well is to just look at the other plants in that area.
What type of plants, are they doing well or are they not, and this is information that can help you to choose the right plant, but on the most basic level choose where you want to plant it and then observe that site over the course of maybe a couple of days or a week. Now used to this was kind of difficult because, you know, most of us drove and went and worked somewhere other than our house, and so it might take you a while to see this site throughout the course of a day.
Now a lot of us are working from home, so it’s actually pretty easy to just look out there every hour, every couple of hours, and see does that site get morning sun, does it get afternoon sun, is it filtered sun, what does it look like? So identify the site, primarily talking about sun exposure, and then we can talk about how to choose the right hydrangea. Okay so if you’ve determined that your site is pretty much full sun or mostly sun, really there’s one type of hydrangea that’s going to be best for that situation, and that would be panicle hydrangea.
Anyone who’s into scientific names that’s Hydrangea paniculata, but it’s named panicle hydrangea because the flowers are in this panicle or sort of a triangle shape or like an inverted cone. They’re usually going to be white. Sometimes they’ll age to pink. They might age to kind of a chartreuse color, or maybe they just turn brown, but typically they’re going to be white.
Panicle hydrangea can get pretty large, but there are dwarf or compact selections, so it’s important, again, when we think about the site not just sun exposure but how much room do you have. Some of these plants may get 10 or 12 feet tall and wide, but if you only have space for a three to four or five foot shrub, it’s important to note that so you can choose the right selection. All plants are native to somewhere. We talk about native plants. A lot of people are interested in native plants. If you are interested in plants native to the U.S., this is one that is not. It is native to Japan and China, but if you have a full sun site and you want a hydrangea, this is really going to be your best option. Okay, any type of hydrangea, or any type of plant for that matter, there are going to be selections.
We can call these cultivars or varieties, and that’s kind of beyond the scope of this presentation today to get into those distinctions, but just be aware of the fact when you go to purchase a plant, it’s going to have a tag and it should have a tag if you go to purchase a plant and there’s no tag, there’s no label, that’s probably not the best plant. You want to look for one with a label.
It’s going to have a name. It’s going to tell you what the plant is, what the name of the selection is. It’s going to have information about does it need sun or shade, how large it gets, perhaps some information about how to water or fertilize. But in any case you’re wanting to go and purchase a specific selection, so some of these that i recommend of Hydrangea paniculata would be limelight, little lime, strawberry sundae, and bobo.
I just want to say, I don’t benefit from any of these. These are not plants that I receive any money for. I’m not being paid to promote these.
These are just some plants that do well, that have kind of stood the test of time and there are some good selections of panicle hydrangea. Okay, so moving on. If you have determined that your site receives part sun or part shade, then you actually are in luck because you have the widest group of plants to choose from when it comes to hydrangeas.
If you have a part sun site, you could still plant panicle hydrangea, but just keep in mind it’s going to do best in full sun. If you have a site that receives some morning shade and afternoon sun, panicle hydrangea would still do pretty well there. But other options you have would be smooth hydrangea, or Hydrangea arborescens. Similar to panicle hydrangea, the flowers are usually white. There are a few pink selections, though these typically don’t
— they’re not quite as vigorous, they’re not quite as disease resistant, but typically they’re going to be white. This plant is smaller in size than the normal panicle hydrangea.
I would say a moderate size, about three to five feet. Most gardens have room for a three to five foot plant. These plants are native to much of the eastern U.S., so if you’re interested in natives, obviously there’s selections made, but the species, hydrangea arborescence or smooth hydrangea, is native to the eastern U.S., and some of the recommended selections would be Annabelle, which is what is seen in the picture here. Annabelle’s been around for a very long time, has large white flowers, and then Invincebell Limetta.
There are other options, though, if you have this part sun part shade site. The next one being big leaf hydrangea, or Hydrangea macrophylla.
Now big leaf hydrangea is the hydrangea that a lot of people think about when they think of hydrangeas. If you’ve ever been to Cape Cod, if you’ve ever looked at a magazine cover and seen hydrangeas, most of the time they’re going to feature big leaf hydrangea. This is the species that gives us the the widest range of flower colors.
We can have plants that are white or pink or blue, even purples and reds, so if you want blue for sure it would have to be a big leaf hydrangea. When we talk about big leaf hydrangea, this is one that’s native to Japan, so if you are interested in plants native in the U.S., this would not be a good option, but if you’re, especially if you’re wanting blue flowers, if you have this part sun site, part shade site, then I would highly recommend big leaf hydrangea. It’s best to choose a re-blooming cultivar.
Again I could talk to you for days about hydrangeas, and we’re just touching on some things today, but when we talk about big leaf hydrangeas, a lot of the older selections or older cultivars that have been around don’t flower as reliably, so there’s some newer genetics that have been developed that have this reblooming characteristic which essentially just means that they flower more reliably. So choosing a reblooming cultivar is important, and I can recommend the endless summer series. Within that series there’s different selections such as the Original, Summer Crush, BloomStruck.
BloomStruck is the plant that’s shown in this upper picture, and you see a range of colors there from kind of nearly purple to light blue, and i do want to note that when we talk about a part sun or part shade site, it is important that we consider what time of day that site receives the sun or the shade because afternoon sun is more intense than morning sun.
So for example, big leaf hydrangea would prefer in a part shade site to have morning sun and afternoon shade. That’s where it would do best. If you have this type of site, we also have the option of oak leaf hydrangea or Hydrangea quercifolia. That’s the plant shown in the bottom picture. You’re seeing a trend here where panicle hydrangeas, smooth hydrangea, and now oak leaf are primarily white in color. Some of these may age to pink, but primarily we’re talking about white flowers.
Oak leaf hydrangea can actually get pretty large. Some of these get large and widespread with age, so it’s important that you consider that. Consider that you have space for that plant, or choose one of the selections that’s more compact. There is a benefit if you’re into native plants, and that oak leaf hydrangea is native to the southeast U.S. Some of these plants can be a little bit sensitive of cold weather, so in Southwestern Virginia we’re generally okay. We generally don’t have a problem. As you move further north you may have some die back on oakleaf hydrangea. It may be a little bit sensitive to cold.
Recommended selections would be jet stream, which is what’s shown in this bottom picture, and you see very dark green, clean leaves, large white flowers, and a pretty compact habit. It’s not this big sprawly shrub. It’s nice and compact, and then also ruby slippers, which is one that flowers with white flowers that then age to kind of a ruby red color. Okay so we’ve talked about full sun.
We’ve talked about a part sun part shade site. What if you have full shade or nearly full shade. Any of the ones that we said would work in part sun part shade will do okay, but the best one for full shade would be the big leaf hydrangea. It’s going to perform the best, and it’s actually, with that range of flower colors, really gives you some bright colors in a dark shady spot. So if you look at these pictures, especially the bottom right hand corner, this is a woodland garden with an overstory of trees, and you can really see those colors kind of popping in the shade. So big leaf hydrangea would be your best option for a shaded site.
Okay so we’ve evaluated the site. We’ve chosen the appropriate plant, so now the next mistake that people commonly make is to prune hydrangeas at the wrong time. Remember that we talked about hydrangeas being deciduous. They dropped their leaves.
So this is a picture of big leaf hydrangea in the winter. What do you see? Well, kind of some ugly brown stems. And typically what people do is they go out in winter and they cut these back, and they either cut them back pretty far and even to the ground or maybe halfway back. That’s not always the correct time to prune, so the correct time to prune hydrangeas depends on the species.
More accurately it depends on when the plants set flower buds, so let’s talk about when we prune hydrangeas. Okay, so some hydrangeas we would prune in the winter or spring. Those would be smooth hydrangea and panicle hydrangea.
These two we can prune any time after the plants have gone dormant, which is they’ve dropped their leaves. Obviously these plants are dormant. It’s the middle of winter, there’s snow on the plants. So anytime after they’ve gone dormant up until early spring. We don’t want to wait until we see new leaves or new shoots emerging, but any time in that window we can prune, and I’m not going to get into types of pruning, how much to prune.
There’s a lot of different reasons you would prune different ways, but the reason we can prune these plants during the winter or early spring is that these two types of hydrangeas produce flower buds on new growth. So when they push out new growth in the spring, it will produce flower buds and flower reliably that season.