Thursday, August 4, 2016

Hydrangeas: Care Basics/ Old & New Varieties

Hydrangea macrophylla 'Blue Wave' in the Heritage Garden, Annapolis N.S.

If you have been following this blog for awhile, you'll know that I like hydrangeas. Not only do the bloom for ages, it's interesting to watch the flowers change in color and appearance as they age. Even when the blooms fade to tawny-brown and are covered in frost crystals or white winter snow, they have a certain melancholy beauty.

So many shrubs bloom in the spring, but hydrangeas offer flowers that look attractive from mid-summer well into fall. Given the appropriate conditions, they are also pretty easy to grow. A range of sizes and flower colors means there is a hydrangea for almost any garden.

A few key Hydrangea Terms:

Lacecap (Hydrangea paniculata 'Quick Fire')

Lacecap refers to the arrangement of florets that make up the flower. In a lacecap hydrangea, there are a large number of smaller florets surrounded by an outer ring of showy florets. 

Mophead refers to big, round, ball-like hydrangea flowers.

Mophead (Unknown cultivar)

The two flower types combined in a Mississauga, Ontario garden


Key Terms for Pruning: Old wood simply describes growth from the previous season. Big leaf (H. Macrophylla), Mountain (H. Serrata), Oakleaf (H. Quercifolia) and Climbing hydrangeas (H. Petiolaris) all flower on old wood. 

New wood describes the growth that a hydrangea has in the current season. Smooth (H. Arborescens) and Panicle (H. Paniculata) hydrangeas both flower on new wood.

Six Basic Types of Hydrangeas:


There are six main types of hydrangeas grown here in North America. 


Hydrangea Macrophylla (seen on the left) also known as Big Leaf, Florist's Hydrangea, Mophead or Lacecap
• Hardy to USDA zone 5.
• Blooms on old wood: Do not prune!
• Old wood needs protection in winter
Varieties: Endless Summer Series, Cityline series, Abracadabra series of hydrangeas

Hydrangea Paniculata (seen on the right) also known as Panicle Hydrangea or PeeGee Hydrangea
• Hardy to USDA zone 3.
• Blooms on new wood: Prune in late winter or early spring
Varieties: 'Bobo', 'Firelight', 'Limelight', 'Little Lime', 'Pinky Winky', 'Quick Fire', 'Little Quick Fire'


Hydrangea Arborescens (on the left) also known as Smooth or Annabelle Hydrangea
• Hardy to USDA zone 3.
• Blooms on new wood: Prune in late winter or early spring.
Varieties: Annabelle, Proven Winner's Incrediball series, Invincibelle series, and Spirit series

Hydrangea Petiolaris (on the right) also known as Climbing Hydrangea
• Hardy to USDA zone 4.
• Prune right after it flowers.

Hydrangea Serrata (not shown) also known as Mountain Hydrangea
• Hardy to USDA zone 5.
• Blooms on old wood so, do not prune.
Varieties: Proven Winners Tuff Stuff series.


Hydrangea Quercifolia (shown above) also known as Oakleaf Hydrangea
• Hardy to USDA zone 5 with some winter protection.
• Blooms on old wood so, do not prune.
Varieties: Proven Winners Gatsby series.

Private Garden Niagara-on-the-Lake

Selecting a Hydrangea:


Generally we tend to think one plant/one set of growing conditions, but hydrangeas are quite varied in both their attributes and their preferences. Most hydrangeas like morning sun (4 hours of sun) and a little shade in the afternoon, but some hydrangeas will cope better with sun and dry conditions than others. Hydrangea Paniculata are the most sun tolerant and can even take full sun in a northern garden zone.

Hydrangeas have shallow roots so generally they like plenty of water, especially when getting established. That being said, hydrangeas offer varying levels of drought tolerance. For example, I have a Big Leaf Hydrangea (Hydrangea Macrophylla) that mightily resents the dry summer we are experiencing this year. It wilts even in the morning sun, unless I pamper it with water. A little closer to the house is a Hydrangea Paniculata 'Quick Fire' that is dealing with the lack of rainfall like a real trooper. 

The best thing to do when selecting a hydrangea is to carefully read the plant label, or even better, do a little research with regard to each hydrangea's compatibility to your garden's growing conditions before you head to a garden centre or nursery to make your purchase.

Private Garden Niagara-on-the-Lake

Planting a Hydrangea:


Hydrangeas can be planted in the spring or the fall. Once you have chosen your location, dig a hole as deep as the root ball and twice as wide. When it comes to soil, hydrangeas like moist, well-drained soil, but never wet feet. If your soil is poor, amend it with some compost or leaf mold. 

Set the hydrangea in the hole. You want the top of the root ball to be level with the soil. Backfill and water well until it is established. (Tip: Laying down a layer of mulch after planting will help the soil retain its moisture.)

Private garden, Glen Williams Ontario

Pruning:


If you are confused about when and how to pruning a hydrangea, you aren't the only one! 

But here's the thing: Many hydrangeas don't require regular pruning. Hydrangeas that flower on old wood (Big leaf, Mountain, Oakleaf and Climbing hydrangeas) will do so with little more than the removal of spent flowers and any dead wood in the spring. 

Hydrangeas that flower in new growth (Panicle and Smooth hydrangeas) can be pruned in the spring, just as the new growth begins to appear. 

Why isn't my Hydrangea Blooming?


Proven Winner's has a great little chart with some suggested reasons as to why your hydrangea is failing to flower: Why isn't my Hydrangea Blooming?


A quick look at Cultivars both old and new:


Every year there are new introductions. It's hard to keep track of them all! Here's a quick look at some old classics and newer cultivars.

Patrica & Loren's Garden, Mississauga, Ontario

Larger Shrubs:


Hydrangea arborescens 'Annabelle' was discovered in the 1960's. It was the first smooth hydrangea with mophead flowers. 'Annabelle' prefers sun in the morning and shade in the afternoon. It is easily grown in average soil garden soil. Annabelle blooms on new wood, so prune it back hard in late winter/early spring. Height: 3-6ft, Spread: 3-6 ft. USDA zones: 3-9. 


'Invincibelle Spirit' was introduced to the market in 2010. I found it took a few years to get established and look like anything special in my garden, but now I find I like its small, delicate looking rose flowers. The flower stems are a little thin for holding up such big flowers, but they don't seem to require any extra support. Blooms appear mid-July and carry on into the fall with the flowers fading in color as they age. 'Invincibelle Spirit' prefers full sun, but will tolerate part shade. It blooms on new wood, so prune in late winter/early spring. Height: 4-5ft inches. Spread: 4-5ft inches. USDA zones: 3-8.


'Limelight' has flowers that emerge celadon green and age into shades of rose and burgundy in the fall. 'Limelight' prefers sun in more northern gardening zones and a little protection from afternoon sun in warmer regions. To prune it, cut back your shrub by one-third its total height in spring.  Part sun to sun. Height: 6-8ft, Spread: 6-8 ft. USDA zones: 3-8.

'Quick Fire' in my garden


'Quick Fire' blooms a bit earlier than most hydrangeas. Mine has been flowering for a few weeks. Already the flowers are shifting from white to a deep fiery rose. With a summer as dry as the one we've experienced, I am glad that it is drought tolerant. This is a big, upright shrub, so set aside a good sized space for it. The only pruning I have had to do so far is to remove the spent flowers in the spring. If you do need to prune a 'Quick Fire', do it in late winter early spring. Part sun to sun. Height: 6-8ft, Spread: 4-6ft. USDA zones: 5-9.

Hydrangea 'Pinky Winky' in the garden of Marion Jarvie

'Pinky Winky' This is a tall, upright shrub with white blooms that turn pink at the base of the flower in the fall. These two-toned flowers can reach up to 16" in length. This hydrangea is drought tolerant and adaptable to a variety of soils. Prune 'Pinky Winky' in late winter or early spring. Part sun to sun. Height: 6-8ft, Spread: 4-6 ft. USDA zones 3-8.


Of all the cultivars of Hydrangea paniculata, Hydrangea 'Phantom' has the largest flower clusters (approximately 15" in size). The flowers emerge pale green in early summer, mature to be white in summer and then turn rose by early fall. This cultivar needs moist, well-drained soil that is slightly acidic (pH 5.6 to 7.5) and full sunTo ensure large flower heads this hydrangea needs to be pruned hard to about 1 foot above ground level in early spring (March or April depending on your zone). Height: 6-10 feet if left unpruned and 4ft if pruned in spring, Spread: 6-10 ft if left unpruned and 4 ft if pruned. USDA zones: 3-8.

Smaller, More Compact Cultivars: 

These have become a huge favourite of mine because they stay relatively small. I find the compact size of these hydrangeas make them very versatile. I start with 'Bobo' which is a brand new introduction that is getting a lot of hype.


'Bobo' forms a low rounded mound of green foliage and has white flowers that turn pink in the fall. Bobo adapts to a variety of soil conditions and requires a moderate amount of moisture. It blooms on new wood, so prune it in late winter or early spring. Part sun to full sun. Height: 30-36 inches. Spread: 36-48 inches. USDA zones: 3-8.

A little size comparison of a Big Leaf hydrangea (foreground) and an Annabelle Hydrangea.
Private Garden, Burlington, Ontario.


Hydrangea Macrophylla 'Blushing Bride' has white semi-double florets that mature to a blush pink or blue depending on your soils pH. The shrub's shape is rounded and growth upright. This hydrangea likes, moist, well-drained soil and part-shade. Height: 3'6", Spread: 3'6". USDA zones: 4-9. 


Hydrangea Macrophylla 'Cityline Vienna' has pink or blue flowers depending on your soil's pH. This hydrangea likes moist, well-drained soil that has been amended with a little peat moss, leaf mold or compost. Pruning is not generally needed, but if you need to do some pruning, do it immediately after it flowers. Height: 1- 3ft, Spread: 2-4 ft. USDA zones: 5-9. (may need winter protection in more northern garden zones.)


'Little Lime' is the little sister of popular 'Limelight'. It has greenish-white flowers (see image on the left) that turn deep rose-green in early fall (see image on the right)It blooms on new wood, so again, prune it in late winter or early spring as needed. Part sun to full sun. Height: 36-60 inches. Spread: 36-60 inches. USDA zones: 3-8.


Companion planting:


What makes a great companion plant for a hydrangea? 

Anything that blooms mid-summer. If your hydrangea is sun/part shade dayliles and ornamental grasses are a nice choice. In the picture below, a blue hydrangea is combined with red and orange daylilies. I have also seen more greenish hydrangea flowers combined nicely with peach and cream daylilies.

Hydrangea macrophylla 'Blue Wave' in the Heritage Garden, Annapolis N.S.

Climbing Hydrangea paired with a range of hosta in Joe's Brampton, Ontario garden.

Astilbe with a hydrangea in behind it.

If your hydrangea is a cultivar that likes more part-shade conditions hosta, phlox, ferns and astible are a few of the many options.

Two different varieties of hydrangeas mixed with hosta and Astilbe.

A picture of my garden in August from a few years back.
Phlox, Rudbeckia Tiger Lilies with a hydrangea standard in the background.

After looking at all this inspiration, I think you'll know why I like hydrangeas as much as I do.

Bookmark this post with a PIN.


19 comments:

  1. OH NO!! I pruned when I should not have.
    I have 5 hydrangeas, all in gorgeous leaf, but absolutely no blooms this year, not even a hint.
    Thank you so very much for all of this information, Jennifer.
    I truly, truly appreciate it.
    Have a wonderful weekend, my friend.

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    1. Glad the post was helpful Lisa. Hopefully you'll get flowers next year.
      I have a couple of shrubs of an old variety of Big Leaf hydrangeas that I inherited when we moved in. They aren't really hardy here, so most of the old wood dies each winter. (I have tried protecting them, but it seems to make no difference.) Because the old wood dies each winter, I never get more than a couple of flowers.
      I have a few newer varieties of Big Leaf hydrangeas as well. I have to say that they are way more fussy than the Hydrangea Paniculata.

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  2. Even the young fella who helps me in my garden is confused. He keeps telling me his hydrangeas don't bloom. I will refer him to this post. Jennifer, your 'wild abandon' way with color has influenced me since I found your blog. I have been a monochromatic gardener; all soft colors. Heaven forbid orange should find it's way into my garden - yikes! Yellow had to be more like cream. Because of you, I have introduced more colors and now my garden is much more appealing. My most outlandish color choice this year were two, TWO, Westerland climbing roses. They're ORANGE! I have a few tiger lilies way off in the veggie garden only because my grandmother loved them. I'm moving them into my main garden. Your garden photo above is one of a few that inspire me. Soft pink and peach roses will probably always be my favorite, but you have shown me how a riot of color will compliment, rather than overtake them.....if done correctly. How did I manage to get this far along in life without knowing this?! I'm working on it.

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    1. You made my morning Annie! Thanks for the positive feedback. Working with color used to be my day job (I worked for years for a wallpaper manufacturer in the art department), so my approach to color is somewhat fearless. Funny enough I find myself getting a greater appreciation for soft pinks and peaches! I bet your new orange roses will be terrific though. Like your grandmother I adore orange tigerlilies. Have a great weekend!

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  3. My Limelight died after one season :( Trying again with a different variety in a different spot in my garden. Fingers crossed!! Thanks for the tips!

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    1. Oh no! That's too bad Anne. I hope the new spot works out better. Make sure you water the hydrangea well into the fall especially if there isn't sufficient rainfall. They really don't like to get too dry when they are trying to get established.

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  4. Very very interesting post, Jennifer! I love your hydrangeas, especially 'Quick Fire'. I have 2 varieties of them: hydrangea paniculata and Hydrangea Arborescens. 2 years back I bought 'Limelight'. What can I say? They all are pretty but... paniculata has very weak branches and after rain the flowers are heavy and branches break. Did you notice that?
    So I do the plastic net around the paniculata's branches and tie it.

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    1. The hydrangea paniculata that I have are all pretty self-supporting ('Quick Fire', 'Little Quick Fire', 'Little Lime' and a few PeeGee Standards). The new 'Bobo' is really nice, but is perhaps not as upright as I would like.
      In my experience it seems to be the smooth hydrangeas that have the weaker stems and need some support. I know one gardener who uses stakes. If the netting works, then maybe stick with that.

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  5. An excellent reference for all of us hydrangea lovers! I have had trouble the last two years getting my 'Endless Summer' to bloom. A friend who works for one of the big plant breeding companies told me a possible reason is a late frost. These hydrangeas need to grow so many petioles before they will bloom, and a late cold snap can stop that. He gave me a new variation on 'Endless Summer,' which I'm not sure is on the market yet. It's supposed to be shorter and less likely to be damaged by a late freeze. We'll see how it does for me next year. Love the paniculatas--you can't go wrong with those!

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    1. I have one hydrangea which I am pretty sure is an Endless Summer hydrangea (clearance item). I find this variety of hydrangea to be pretty fussy. They hate any afternoon sun and really dislike dry conditions. As with your experience, mine blooms in a minor way (despite being in a sheltered spot close to the foundation). Interesting to hear what your friend about cold snaps inhibiting blooms. I look forward to hearing how the new variety does.

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  6. This is a post I have to save. Never had any luck with hydrangeas but was always fascinated with the oakleaf and now I'm thinking maybe I can do the short variety and not kill it. You have a stunning collection. The long bloom season is a must for me. I will get back here before purchasing any short varieties. Thanks for a very informative post.

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    1. Glad you found the post helpful Patsi. There are certainly some nice compact varieties of hydrangeas to choose from.

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  7. I just bookmarked this page also. I just love hydrangeas but never had a lot of luck with them in Idaho. I might plan on planting one (or two) in our fenced garden area next year. Great post! Beautiful photos.

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    1. I hope you have better luck next spring Victoria.

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  8. Thanks for your beautiful pictures. I have always loved hydrangeas too but have found that all but my limelight hydrangeas fail to bloom since I moved to my zone 7 Virginia house. I have my well established bushes in areas with varying amounts of sun and they all get plenty of water. I suspect the deer nibble the flower buds, but if you have any other thoughts, I'd be grateful. My limelights are in full blazing sun and are magnificent 10 foot shrubs covered in flowers. The flowers tend to be white rather than green, but otherwise they thrive in hot full sun.

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    1. Limelight hydrangeas need 4+ hours of sun to bloom. If they are getting that I suspect you are right about the deer damage. I wonder if one of the deer repelling sprays might help?

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  9. Excellent post, Jennifer. Lots of good info.

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  10. an excellent post with great information. I especially love my Annabelle and Pinky WInky but all of my hydrangeas are loved. This year I tried taking cuttings of my Pinky Winky to root for my music teacher. I think because they are so woody is why they wouldn't take. I've tried 3 times with failure each time. Maybe I'll have to buy one for him.

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  11. Great information on hydrangeas, Jennifer! I've added a few more to the garden here and they are wonderful. I haven't tried 'Incrediball' yet, but if it's as good as 'Annabelle' and doesn't flop, well, what am I waiting for?

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