Hydrangeas
Hydrangeas are among the most beloved flowering shrubs in the world. Their big, colorful blooms, brighten landscapes from spring through fall, making them a favorite of gardeners for generations. Native to both Asia and the Americas, hydrangeas thrive, where they receive plenty of moisture and gentle morning sun. Depending on the variety, their spectacular blooms can last anywhere from six to 18 weeks. And many of today's reblooming selections put on an encore performance throughout the season.
Click here
Bloom On New Wood
We’ll start with a variety of hydrangea called Incrediball. They BLOOM ON NEW WOOD, meaning in the spring of this year these hydrangeas were cut down by about a third, and all of the flowers you see bloomed this season on that brand new wood. They're super easy to grow, they are a native species, which makes them resilient in the area where they're growing. And, they're beautiful. Eric asks, if he were to come back after they bloom and cut them back again, will they then put out a new flush of growth, will we get any blooms later in the season? That's kind of a trick question because it depends on where you live. Here in Michigan, where we are today, they wouldn't have enough warm weather for long enough for them to reset a new bloom.
Click here
Different Forms
One thing that breeding programs really look at is DIFFERENT FORMS. Of course, there are a lot of smaller gardens today and those gardens need smaller plants, even for flowering shrubs and containers. Within the Incrediball line, there are some dwarf versions of that plant. And, there are not only dwarf versions, there are pink versions and versions that bloom in green.
Click here
Stem Strength
Modern breeding is really focusing on STEM STRENGTH. Especially with the type of hydrangea, where the stems are holding flowers that grow really fast. Growers want those stems to be extra strong, because they have great big flowers. Here they had a rain last night, thus these guys are a little bit wet and need strong stems to hold the flowers up.
Click here
Cultivars Natalie Recommends
Eric asks Natalie if there any CULTIVARS SHE WOULD RECOMMEND? Yes, the classic is Limelight. Limelight is a variety, it's been around for years and years. Lately, there's been a new variety introduced called Limelight Prime. We talked about stem strength earlier. This is a version of Limelight, that has stronger stems and a more upright appearance.
Click here
Remontant Bloomers
We’ve talked about some hydrangeas that bloom on new wood, there are also hydrangeas that bloom on old wood. Oftentimes, in the garden center, we hear terms like REMONTANT BLOOMERS. Let's talk about that a little bit. Remontant is something that is somewhat new in the hydrangea world. It simply means that plant will bloom on the old wood or new wood. They still bloom on old wood, those buds that were formed on last year's stems, but they bloom on new wood as well. So when those flowers are finished, you'll start to see those new stems coming up, and a whole new array of blooms amongst the old wood blooms. Those are remontant bloomers. They are somewhat new to the world of hydrangeas, at least in our lifetime. One thing that plant developers try to do more and more to make hydrangeas better and easier to grow is to try to tighten that space between when the old wood blooms and the new wood blooms. What results is more of a continuous bloom, rather than a bloom in the spring, waiting, and then a bloom in the fall.
Click here
Crossbreeding And Hybridization
One of the things that plant breeders do to incorporate certain traits into other plants is CROSSBREEDING AND HYBRIDIZATION. Natalie has some great hybrids she wants to show us. In the never ending quest to find just the right attributes for our flowering shrub or our bedding plants breeders work tirelessly to take the traits from one plant, and breed that into another plant. For example, if they want the dwarf qualities from one plant but want the bloom qualities from another plant some of the most exciting innovations in the world of horticulture happen in that space we call hybrids.
Click here
Tuff Stuff Series-Serata Or Mountain Hydrangea
A long time ago a series called the Tough Stuff series of Hydrangea, SERATA, OR MOUNTAIN HYDRANGEA were introduced. And those were remontant, they bloomed on old and new wood. Lots of big leaf hydrangeas have been introduced that bloom on old and new wood. They took that big leaf hydrangea and that mountain hydrangea and hybridized the two together. The reason was that mountain hydrangeas tend to be a little more bud hardy than your typical big leaf hydrangea.
Click here
Natalie’s Favorites
What are some of NATALIE’S FAVORITES? One of the first hydrangeas introduced was a hybrid mountain, big leaf hydrangea called Let's Dance Can Do. Natalie likes it because it can do anything. The interesting thing about this hydrangea is it does have more of a mountain hydrangea look, which means one can see the fertile florets in the center. She likes to say they look like little pieces of broccoli in the center, and those are the fertile florets that your pollen eaters really love. The sterile florets are the decorative ones around the outside that make up a whole big leaf hydrangea inflorescence. The two were hybridized and it produced a fuller lace cap look, a lot more of the showy sterile florets around the outside, but as a bonus also got hydrangeas that set their buds on old wood, not just at the tips of the stems, which is what they would normally do.
Click here
Hydrangeas That Bloom On Old Wood
Now, last but not least, let's talk about hydrangeas that bloom on OLD WOOD. Let's talk about some of the great selections, and then maybe anything that might be interesting or peculiar about those selections. Natalie thinks some of the most beautiful hydrangeas in the garden are Oakleaf hydrangeas. They are hydrangeas that bloom exclusively on old wood or last year's stems. They have the big, kind of rangy and curling stems and beautiful, long, panicle shaped blooms.
Click here
Climbing Hydrangea
We can't talk about hydrangeas without talking about the CLIMBING HYDRANGEA. Vertical interest is something we need to consider. And its’ an old wood bloomer. There are several different types of climbers that you might see, both part of the hydrangea family, but one is a climbing hydrangea and one is a false hydrangea vine that looks almost identical to the climbing hydrangea. Other than the fact that the little floret is going to be a single floret hanging like a teardrop on the false hydrangea vine, but the climbing hydrangea has a little florette of four little sterile leaflets.
Click here
In this episode GardenSMART visits Western Michigan, exploring one of America’s premier hydrangea trial gardens. It’s a beautiful show packed with great gardening ideas and tips. We'll discover stunning new varieties, provide some expert growing tips, plus secrets to bigger, longer lasting blooms.
HYDRANGEAS are among the most beloved flowering shrubs in the world. Their big, colorful blooms, brighten landscapes from spring through fall, making them a favorite of gardeners for generations. Native to both Asia and the Americas, hydrangeas thrive, where they receive plenty of moisture and gentle morning sun. Depending on the variety, their spectacular blooms can last anywhere from six to 18 weeks. And many of today's reblooming selections put on an encore performance throughout the season. Even after they're cut, some varieties continue the show indoors, lasting a week or two in a vase. But hydrangeas offer more than beauty. They've long been associated with heartfelt emotion, gratitude, and deep understanding, making them as meaningful as they are magnificent.
Garden Smart is visiting one of the country's premier hydrangea trial and display gardens located in Western Michigan. It's a place where hundreds of varieties are evaluated, compared and showcased. It provides an up close look at the newest introductions alongside timeless favorites. Whether looking for spectacular color, improved performance, or simply inspiration for your own landscape. There's something here for everyone.
Joining us once again is our guest host, Natalie Carmolli. Natalie has been part of the GardenSMART family many times over the years. Her passion for horticulture began when she was just six years old and today combines her background in fine arts and communications with her love of plants. She travels the country, sharing gardening ideas, practical plant care advice, and introducing gardeners to the exciting innovations happening in the world of ornamental shrubs.
Let's discover what makes hydrangeas one of the most treasured plants in the garden, plus learn how we can enjoy bigger, better blooms at home. Eric welcomes Natalie, thanks so much for being with us and welcome back to the show. Natalie returns the compliment, it's great to see you again. She's excited to have GardenSMART here and to be on the show again. In this episode we're in kind of her own backyard, so it's especially exciting. Eric comments that Natalie has the most amazing office in the world. And we're gonna see a lot of it today. Eric thinks the work that’s happening in the space of flowering shrubs is so important to the direction that modern gardening is going. It's made an enormous impact. In the last 20 years, it's hard to really underestimate how seismic that shift has been, in the way that we think about color, in the way that we think about design and a lot of that is the breeding programs and the careful process of selecting through thousands, if not hundreds of thousands, of seedlings. We find ourselves in a really amazing space right now.
We're going to be talking about hydrangeas in this episode. They are one of Eric's favorite garden plants. It would be hard to imagine a proper garden without hydrangeas. Hydrangeas have always been an easy plant to grow, some species more so than others. Definitely a favorite and breeding has made growing a hydrangea, of almost any type, accessible to every kind of gardener. Natalie is excited to be able to share a lot of that information today and to talk about some of the specific things that are being done right now with breeding to make hydrangeas stronger, more colorful, even bloom longer, all of the things that we love about hydrangeas, but with a little extra. We'll talk about a lot of the hydrangeas that are really exciting, and ones Natalie thinks people should plant in their gardens.
But first, we're going to walk through some different categories of hydrangeas so that people really understand what is this hydrangea going to do? Or, how do we prune this hydrangea, so you can get the most success out of hydrangeas in your garden?
Let's start with hydrangeas that bloom on new wood and tell us, what does that mean and give us some great examples? Natalie remembers, when she was a new gardener, someone came up to her and was asking about hydrangeas, they said, well, does it bloom on new wood or old wood? She had no idea what that meant? Was it a trick question? No. And really, it's very easy. Hydrangeas that bloom on new wood, are hydrangeas that bloom on stems that were formed in this year's gardening season.
We’ll start with a variety of hydrangea called Incrediball. They BLOOM ON NEW WOOD, meaning in the spring of this year, these hydrangeas were cut down by about a third, and all of the flowers you see bloomed this season on that brand new wood. They're super easy to grow, they are a native species, which makes them resilient in the area where they're growing. And, they're beautiful. Eric asks, if I were to come back after they bloom and cut them back again, will they then put out a new flush of growth, will we get any blooms later in the season? That's kind of a trick question because it depends on where you live. Here in Michigan, where we are today, they wouldn't have enough warm weather for long enough for them to reset a new bloom. But a lot of times, in the gardening industry, or the nursery industry, they will do what they call cycle pruning, which is they prune them when still in the container to get a flush of blooms, so that when they're on the bench at the garden center, when people are really deciding what to buy, they look like they have new, fresh blooms. But, if you're in an area where summer is long, you probably could cut them and get another flush of blooms. Here where we are, where seasons are a little bit shorter and the nights are a little bit cooler all of these blooms will turn a beautiful green color. So, smooth hydrangeas or hydrangea arborescence have a naturally occurring color change. One can't turn them blue or pink, depending on the soil. But when these age, they'll turn a beautiful kind of a dark, almost an evergreen color and that has a beauty of its own. So, if you’re in Atlanta, and want to prune them and get more flowers, you can; if you're in Michigan, watch them age naturally, they look gorgeous both ways.
One thing that breeding programs really look at is DIFFERENT FORMS. Of course, there are a lot of smaller gardens today and those gardens need smaller plants, even for flowering shrubs and containers. Within the Incrediball line, there are some dwarf versions of that plant. And, there are not only dwarf versions, there are pink versions and versions that bloom in green. We talked about the plant that aged to green, but there's one called Invicibelle Sublime that blooms perfectly green. It's absolutely gorgeous. Then a dwarf one Invincibelle Wee White that is a small dwarf hydrangea. Additionally, there are midsized hydrangeas, not as big, but in between dwarf and full size. So, there are hydrangeas designed to fit any garden.
Modern breeding is really focusing on STEM STRENGTH. Especially with the type of hydrangea, where the stems are holding flowers that grow really fast. Growers want those stems to be extra strong, because they have great big flowers. Here they had a rain last night, thus these guys are a little bit wet and need strong stems to hold the flowers up. If this was the old Annabelle, we'd be standing in front of a hydrangea with all the flowers on the ground. So stem strength is important.
Eric wonders are there other hydrangeas that bloom on new wood that Natalie's really excited about? Oh, absolutely. Hydrangea paniculata. They are those big, pointy hydrangeas. Just like with smooth hydrangeas, they have a naturally occurring color change. They will range anywhere from white to a hot pink, yet keep a white tip. Some of them are a dark, dark burgundy and those also form all of their flowers on new stems. Unlike this variety, it's not a native species, yet still super easy to grow and very, very sun tolerant. If gardeners have a place that's full sun and really hot all day, this hydrangea will not be fazed. It’s a great one for the Southeast.
Eric asks Natalie if there any CULTIVARS SHE WOULD RECOMMEND? Yes, the classic is Limelight. Limelight is a variety, it's been around for years and years. Lately, there's been a new variety introduced called Limelight Prime. We talked about stem strength earlier. This is a version of Limelight, that has stronger stems and a more upright appearance. We also talked about form. It's a little bit smaller than Limelight. So if people don't have the space for that 9 foot shrub, they can grow something that's about 6 feet tall, yet it still has that really pretty limey green bloom and its’ structure is absolutely gorgeous in the garden. It is definitely a plant that has withstood the test of time.
It shows the importance of great breeding programs. But equally important is evaluating plants before they make it to market. In the process of years and years and years of evaluation, it became clear that Limelight was a plant that had to come to market. Sometimes plants can be trialed anywhere from 10 to 15 years before they make it to the market. The really great plants that perform exceptionally well have had a huge investment made into them with all of that trialing and all of that testing, plus compensating these great breeders that bring those plants to the market.
We’ve talked about some hydrangeas that bloom on new wood, there are also hydrangeas that bloom on old wood. Oftentimes, in the garden center, we hear terms like REMONTANT BLOOMERS. Let's talk about that a little bit. Remontant is something that is somewhat new in the hydrangea world. It simply means that plant will bloom on the old wood or new wood. They still bloom on old wood, those buds that were formed on last year's stems, but they bloom on new wood as well. So when those flowers are finished, you'll start to see those new stems coming up, and a whole new array of blooms amongst the old wood blooms. Those are remontant bloomers. They are somewhat new to the world of hydrangeas, at least in our lifetime. One thing that plant developers try to do more and more to make hydrangeas better and easier to grow is to try to tighten that space between when the old wood blooms and the new wood blooms. What results is more of a continuous bloom, rather than a bloom in the spring, waiting and then a bloom in the fall. In fact, the hydrangea Let’s Dance Sky View is a continuous blooming hydrangea for that very reason. It blooms on old wood, very dependently, and then those new wood stems grow so fast it seems like there's no break at all. You just get this long, long bloom time throughout the season. Because of the old and new wood blooming habit. Does it matter when we prune them if we want to maintain shape on our hydrangea? Yes and no. Of course you have those old wood stems, which you only want to prune after they have finished flowering the previous season. Then it's pretty easy to see that new bud is forming, just look underneath the flower head and see the new bud right there by the leaflet. Basically dead head that plant and save all those old wood buds for the next season. Plants like Let's Dance Sky View, its' buds are more hardy, they look very much like a big leaf. They're gonna perform like a big leaf, but their buds are more hearty, so they're less apt to get frozen in those early spring frosts.
One of the things that plant breeders do to incorporate certain traits into other plants is CROSSBREEDING AND HYBRIDIZATION. Natalie has some great hybrids she wants to show us. In the never ending quest to find just the right attributes for our flowering shrub or our bedding plants breeders work tirelessly to take the traits from one plant, and breed that into another plant. For example, if they want the dwarf qualities from one plant but want the bloom qualities from another plant some of the most exciting innovations in the world of horticulture happen in that space we call hybrids. There has been some really exciting work in hybrids fairly recently, say during the past 10, 15 years, but those introductions have only occurred in the past few years. One of the things that Natalie finds super exciting is the hybridization of two types of hydrangeas that, conventionally, only bloomed on old wood, and those are big leaf hydrangeas, or hydrangea, macrophylla, and mountain hydrangeas, or hydrangeas serrata.
A long time ago a series called the Tough Stuff series of Hydrangea, SERATA, OR MOUNTAIN HYDRANGEA were introduced. And those were remontant, they bloomed on old and new wood. Lots of big leaf hydrangeas have been introduced that bloom on old and new wood. They took that big leaf hydrangea and that mountain hydrangea and hybridized the two together. The reason was that mountain hydrangeas tend to be a little more bud hardy than your typical big leaf hydrangea. They want those old wood buds to bloom every single spring without fail. So by hybridizing the two, one gets that extreme bud hardiness of the mountain hydrangea, but yet these fuller, more colorful flowers, that the big leaf hydrangea brings, which is arguably one of the most popular hydrangeas in the garden center. There are so many different hybrid hydrangeas.
What are some of NATALIE’S FAVORITES? One of the first hydrangeas introduced was a hybrid mountain, big leaf hydrangea called Let's Dance Can Do. Natalie likes it because it can do anything. The interesting thing about this hydrangea is it does have more of a mountain hydrangea look, which means one can see the fertile florets in the center. She likes to say they look like little pieces of broccoli in the center, and those are the fertile florets that your pollen eaters really love. The sterile florets are the decorative ones around the outside that make up a whole big leaf hydrangea inflorescence. The two were hybridized and it produced a fuller lace cap look, a lot more of the showy sterile florets around the outside, but as a bonus also got hydrangeas that set their buds on old wood, not just at the tips of the stems, which is what they would normally do. They form all their buds at the tips of the stems, then at every leaf node going down the stem on that old wood. So if they get frost, if they get pruned, let's say you want to prune these to shape they still bloom like crazy in the spring. This is one that is a romantic hydrangea that you can prune to shape in the spring, and you're still going to get beautiful flowers, because all that old wood has still set buds lower on the stems. They turn pink to purple depending on the soil. That's another interesting thing about any hydrangea that's in the mountain hydrangea or the serrata family, they change color, depending on the soil composition. But that doesn’t mean they always turn blue. Hydrangeas, like Sky View will turn blue very easily, but a hydrangea, like Lets Dance Can Do, only turns pink to purple. It's not meant to turn blue. That gorgeous color frames this whole plant.
Now, last but not least, let's talk about hydrangeas that bloom on OLD WOOD. Let's talk about some of the great selections, and then maybe anything that might be interesting or peculiar about those selections. Natalie thinks some of the most beautiful hydrangeas in the garden are Oakleaf hydrangeas. They are hydrangeas that bloom exclusively on old wood or last year's stems. They have the big, kind of rangy and curling stems and beautiful, long, panicle shaped blooms. The interesting thing about Oakleaf hydrangeas is not only do they have these gorgeous blooms and different bloom forms, but the foliage is also something that's extra special about this variety. So later in the fall, you get these colors of orange and red and brown. Just like oak leaf trees give you color, the Oakleaf hydrangea does as well.
In the world of Oakley there are many that bloom with a more open bloom, but then there are some that almost look more like a mop head type. There's one called Gatsby Moon. A whole series of Oakleaf Hydrangea, is the Gatsby series. There is Gatsby Pink which is flushing pink early in the season. And Gatsby Gal is a smaller one, Gatsby Globeball is a brand new one that's really small, like a munchkin or peewee. Those are all dwarf oak leaf hydrangeas. But Gatsby Moon has this big fluffy bloom, it almost looks like a cloud. A lot of people, when you say, mop head hydrangea, immediately go to those blue macrophylla blooms that have that great big round bloom. But a lot of hydrangeas can have a mop head style bloom, including oak leaves.
We can't talk about hydrangeas without talking about the CLIMBING HYDRANGEA. Vertical interest is something we need to consider. And its’ an old wood bloomer. There are several different types of climbers that you might see, both part of the hydrangea family, but one is a climbing hydrangea and one is a false hydrangea vine that looks almost identical to the climbing hydrangea. Other than the fact that the little floret is going to be a single floret hanging like a teardrop on the false hydrangea vine, the climbing hydrangea has a little florette of four little sterile leaflets. But, they look very similar. They hold onto the trees with little tendrils, so they don't choke a tree, like a lot of vines might, English ivy is an example. They gently grow up the trunk of a tree or any structure such as a trellis or an arch or something like that. And they bloom with glorious lace cap blooms early in the season. They're an early season bloomer, just like oak leaf hydrangeas, plus add that vertical interest to the garden.
Eric compliments Natalie, it's so much fun to learn about all the many, many new plants that are coming into the market even some that we're not going see for another year or two. And what he thinks is so impressive is the amount of work that goes into building these cultivars. It's a very thoughtful and long process. Natalie believes there's real value in some of these new cultivars. The industry doesn't introduce a new hydrangea simply for the sake of introducing a new hydrangea. It's been trialed and tested to make sure that it has some quality that fills a niche that, in many cases, a species isn't filling, or to give it a new kind of presentation that we're not seeing in the market right now, or just better performance. All of that is tested over years and years and years, so that the gardener doesn't have to test it out in their own garden. They know that it's going do what we say it's going do. Natalie knows for herself, as a gardener, it makes her feel like her thumb is even that much greener. Anybody can feel like they have a green thumb with some of these new hydrangeas.
Eric believes it is an exciting time in the world of gardening, and believes it's only going to become more so. Natalie, thank you so much for being with us. What a beautiful garden. Looking forward to seeing you again, soon. Natalie is so happy that GardenSMART was able to visit. She enjoys - all of these beautiful hydrangeas and this garden and is excited for our viewers to see them as well.
Thank you very much.
Today, we've explored one of the nation's premier hydrangea trial gardens, discovering the beauty, diversity and innovation behind these remarkable shrubs. But there is always more to learn so be sure to tune in next week as we GardenSMART.
