The 2020 Hydrangeas

The hydrangeas in bloom this year have been beyond gorgeous. I have never seen them better, and I have been growing hydrangeas for a long time. The object of my affection and admiration are white flowering varieties that bloom on new wood. Blue and pink hydrangeas that bloom on old wood – this would be the bigleaf hydrangeas, or hydrangea macrophylla –  are not truly bud hardy in my zone. Unless they have a mild winter, whilst mulched from the soil level to the tops of the branches, the flowering will be sporadic and disappointing. If yours bloom profusely and reliably in Michigan, then count your blessings. The whole point of hydrangeas in bloom is the sheer splendor that comes from abundance. A happy hydrangea is so loaded with blooms the slender stems of the shrub will bend over from the sheer weight and volume of them. If you must have blue hydrangeas in all of their splendor,  then pack your bags for Nantucket, and read no further. The Bobo hydrangeas pictured above have astonishingly good care. The entire bed is on drip irrigation – essential when hydrangeas are in full sun – and that irrigation is monitored and updated frequently. I am quite sure they are fertilizing in late winter/early spring. Some apply Hollytone, by Espoma, or a slow release balanced fertilizer. The reward is an ocean’s worth of greenish white flowers.

That is not all. Later in the season those blooms will turn towards pink, and then rose pink. The fall display is every bit as beautiful as that in late summer. Add the yellow fall color on the leaves, and you have a visual treat that is quite spectacular. A good shrub provides interest in the garden over a long period of time. Hydrangeas are particularly generous with a long period of bloom. I leave the flower heads intact over the winter – why not? That cinnamon brown color is strikingly beautiful. Of course there will be those blooms that break off and blow around, but that cleanup is manageable.

This hedge of Limelight hydrangeas was planted for a client at their restaurant many years ago. I want to say at least 10 years ago, probably more. I am quite sure that they get watered; my clients takes great care of all of their plants.The soil is that typical Oakland County Michigan airless and non-draining clay-we planted them well above grade for exactly that reason. I have no idea what pruning and feeding care they get, but I can say their maintenance company was not permitted to work this year until May. So the spring care was fast and loose. Behind me in this picture is Woodward Avenue – a main road with 3 lanes going both north and south. It is packed with automobile traffic around the clock, in the 45-50 mph range. I would say the hedge is 25 feet off the road, and endures plenty of exhaust in the summer, and an equal amount of road salt in the winter. This commercial planting is stunning.

hydrangea Little LimeThis hedge of Little Lime hydrangeas is relatively new-it was planted 4 years ago. The flowers are at that fresh green stage, as they are just beginning to bloom. This exposure is westerly, which is a great location for hydrangeas. They need at least 6 hours of sun a day to bloom profusely. I am astonished at how many articles I read that suggest that hydrangeas do well planted in the shade. I have seen plantings in shady areas that range from sporadically blooming to passable, but I have yet to see a hydrangea thrive in shade. Of all the hydrangeas, the oak leaf is the most shade tolerant. Tolerant is the key concept here. No flowering plants, with a few exceptions, love shady conditions. They tolerate them. Find a sunny spot for your hydrangeas. These Little Limes get occasional supplemental water.

I get no end of questions about spacing. I have seen spacing recommended anywhere from 3′ to 8′. This hedge was spaced at 3 feet on center, with 2 rows of plants in staggered positions. The bed is 9′ in depth, and the Little Limes have filled that right up. An 8′ spacing on a Limelight hedge will produce a series of shaggy ball shapes. A closer spacing will produce a more uniform look to the hedge. I think spacing is primarily a matter of personal taste. If you are willing to wait a few years for a group of hydrangeas to grow together, then space them out. If you are after a densely growing hedge then space them closer. If there is a specific space to fill, then space to fit that particular space. Do I think one spacing is superior and produces more healthy plants than another – sun and water being comparable – ? No.

I have 2 blocks of Limelights at home that have been in the ground for close to 20 years. They were spaced at 30″. They have been healthy and heavy blooming every year. I have had Japanese beetle damage to the leaves, and scorch when I didn’t water enough, but they perform the same as a group spaced at 4 feet apart. I can vary the style and extent of my pruning every year, and not be able to see any difference in the blooming plants.  A good friend has planted and maintained miles of blocks of Limelights in the median on a major north/south road in my area.  They are the best blooming hydrangeas I have ever seen, in a year of great blooming hydrangeas.  I asked her about the care. They routinely feed with Hollytone, and they do water. The only difference this year was that they did not prune as hard as usual. Do I think this made the difference in the performance?  Maybe, or maybe not. Do I think the weather conditions were perfect?  Our season has been very hot and dry. Would I expect this to be great for hydrangeas? Not really.

Hydrangeas will tell you when they need water. Those big thin leaves clinging to the stems-as in the above picture of a hydrangea on standard – is a clear SOS. I do err on the side of water generosity, as I believe that plants stressed from being too dry perform at a less than optimal level. Newly planted hydrangeas need very careful monitoring for water. They grow so fast that most potted plants available for sale are root bound. If that root ball goes dry soon after planting, it is of no consequence how wet the soil is a foot away. The hose needs to be aimed directly at the crown of the plant.

This is all by way of saying that insofar as gardening with hydrangeas is concerned, various approaches to their cultivation can produce healthy and beautiful plants. They are so versatile in the landscape, as this pair of pots planted with Limelights can attest. Most and best of all, they are forgiving of neglect, and respond strongly to attention and care.

I have been enjoying them for weeks now.

The Hydrangeas

Little Lime hydrangeasSometime between mid July and mid August, the Limelight hydrangeas come in to bloom. It is a moment worth waiting for. The fast growing large leaved plants bloom profusely on the current year’s growth. They are easy to cultivate, asking for not much more that some decent light and some regular water. The spectacularly large flowers are a gorgeous mixture of lime green and white. Limelight hydrangeas are known for their sturdy stems, which keep those flowers aloft in all but the stormiest weather. They do need a lot of room. A single well grown shrub can grow 8′ tall by 8′ wide. Hydrangea “Little Lime”, pictured above, is a hybrid of Limelight that only grows 4-5 feet tall, and as wide. They make themselves right at home in an informal or cottage style garden. But its relaxed habit of growth can look just as interesting in an alternative universe –  a more formal planting.

Little Lime hydrangeasThis mature size is not only friendly to smaller gardens, it looks great in a mass planting. This landscape is situated on a very steep slope, so these Little Limes are responding to the force of gravity. Some gardeners may find their sprawling habit unruly and irritating. Others will find them charming, even beautiful. They certainly endow the late summer garden with their willingness to bloom. All of the pictures in this post but one were taken on days with temperatures above 90 degrees.

hydrangea LimelightMy Limelights are 12 years old, or more.  Some years I prune them down to between 24″ and 30″ inches.  Some years I only remove the old flower heads and 6″ of stem. I always prune them in the spring, when the leaf buds begin to swell. The final result in terms of the flowering and height is fairly uniform, year to year, no matter how I prune. This illustrates the important of choosing shrubs whose mature size will fit the space that is available. I have been watering them twice a week for the past several months, as we have had very little rain.  The group to the far right in this picture get the least water, as they are difficult to reach.  They are shorter than usual, but they have plenty of flowers. How reliable they are to grow and bloom is a very good reason to plant them.

after the rainYesterday morning, after an exceptionally heavy and blustery rain, the water soaked flowers had fallen over in to the path. We’ll see what happens once they dry out. There is no staking hydrangeas at this stage.  If you are bound and determined to keep them upright, very stout and tall tomato cages need to be put in place in the spring. If the flower heads do not spring back up, I will cut some, put them in water, and let them dry indoors.

limelight hydrangeaLimelight hydrangeas can provide an easy going and breezy sense of enclosure. My hydrangeas are planted in a block, not in a single row.  Though the shrubs are very open growing, multiple staggered rows provide a dense green screen which makes my front yard garden quite private.

hedge of limelight hydrangeasGiven enough room, a generous sweep of Limelight hydrangeas can be quite architectural in feeling. Once these hydrangeas are pruned in the spring, they are not pruned again until the following spring.  Few deciduous shrubs can tolerate or perform well having been sheared. Hydrangeas are no exception. Prune to the best of your ability in the spring, and then turn loose of them. Looking for a rule?  The plants will tell you a very detailed story. Very few things bother hydrangeas.  They will bloom in part shade, but not as profusely. The flowers will be smaller, and the leaves will singe on the edges if they get too dry. I mulch them with bark fines in the spring after I prune. I water infrequently, but regularly. Outside of that, I just enjoy them.

limelight hydrangea Limelight is a hybrid of hydrangea paniculata.  Paniculata refers to the fact that the flower heads of these hydrangeas are comprised of hundreds of individual flowers arranged in a cluster around the flower stalk-this flower form is called a panicle. The individual florets will acquire a pink tinge as they age. When the temperatures cool down in the fall, the flowers will age to rose pink. I water the plants more in the early fall than I do in late summer. Truly?  The sure sign of a plant that has gone too dry are flowers that brown before their time. I do everything I can to extend the hydrangea season. I do leave the flower heads on all winter – why not?  Most of them stick tight throughout the winter for me.

August 10,2016 (64)I do not grow hydrangea Little Lime at home, but I have planted plenty of them elsewhere. Their shorter stature means there are flowers at eye level, on top of this retaining wall.  Had I planted the much bigger Limelight in this location, I would be looking in to the stems from the lower level. I recently planted a row of Little Limes in front of an old hedge of Limelights.  This will insure flowers from top to bottom.

August 10,2016 (71)The Little Limes smaller size makes them quite companionable to a host of other perennial and annual plants.

hydrangea BoboHydrangea Bobo is not related to either Limelight or Little Lime, but it is a panicle hydrangea.  Hybridized by Johan Van Huylenbroeck, the same breeder that developed the Pinky Winky hydrangea,  was patented and introduced by Proven Winners. Topping out at 3′ tall by up to 4′ wide, it is beautiful in a mass. Though this group has only been in the ground for 2 inhospitably hot and dry months, they are blooming.  By next year, the chances are good they will completely cover this large sunny area. I can cross this group of Bobo’s off my list of plantings to worry about. They’ll be back.

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Heavenly Hydrangeas

What is it about hydrangeas that makes them such a magnet for gardeners?  No doubt they are one of the showiest shrubs hardy in my zone.  They are fairly easy to care for, providing you stay away from marginally hardy varieties.  They grow fast, have big, clean, and very green foliage.  The massive flower heads speak to summer.  What could be better?  The plant hybridizing industry has focused on producing more reliably blooming “other than white” hydrangeas for the nursery trade geared to produce in cooler climates.  This “All Summer Beauty” hydrangea is more reliably blooming than its predecessors.   

The Annabelle hydrangea has been the mainstay of the summer shrub garden as long as I can remember, though I no longer plant it. Weak stems and overly large flower heads make the shrub a challenge to keep off the ground.  Given heavy rains and mid summer stormy weather, you are likely to wake up with those flowering spheres face down in the mud.  Should you have them, cage or otherwise securely stake at least 40″ tall out of the ground-in the spring.  Othereise, you will be chasing some stop the flopping solution that looks awkward and unnatural.   

This garden no doubt is the one place for 100 miles perfectly suited for Nikko Blue hydrangeas.  Once out of the nursery pot, and in the ground, they are generally known to be stingy with the flowers.  Blue hydrangeas-what midwestern gardener does not long for this plant to perform for them?  I am sure many more get sold, than deliver and please.  As no one grows hydrangeas for their shape and foliage, choose a cultivar known to reliably produce flowers in abundance in your zone. 

Flowers in abundance-perhaps this is what makes hydrangeas so attractive in a landscape.  I favor the Dutch hybrid-known as Limelight.  They are sturdy growers-there is never any need for staking.  Their hydrangea paniculata parentage is responsible for the cone shaped flowers that open green, mature white, and pink with age. The straight species hydrangea paniculata is a very wide and very tall grower.  The flowers are many, but modest, open and subtle in appearance. A hedge of panuiculata 8 feet wide by 40 feet long might make a show.  Limelight produces densely showy flower heads from a vigorous and adaptable shrub-the best of all worlds, should you be talking hydrangeas. 

Densely blooming and showy-see what I mean?  They do not ask for much-this part I am especially fond of.  They handle full sun, given sufficient water, with aplomb.  They will willingly survive part shade, and bloom better than most hydrangeas starved for sun. They grow fast.  They are fine with a serious spring pruning.  I have Limelights I prune down to within 14″ of grade-where it is my idea to keep them in the 4′-5′ tall range.   

Given a space of sufficient size, a hedge of hydrangeas provide no end of a robust visual reference to summer, lots of flowers for bouquets, screening, material for dried arrangements.  What garden shrub do you know of that delivers on this scale, and to this extent?   

Should you be thinking you might plant some limelights, I would make the following suggestions.  Locate them in as much sun as you can muster.  Do not space them any closer than 30″ on center-36″-42″ on center will fill in in no time.  They like regular moisture.  Whatever you have done to enrich your soil with compost, the hydrangeas will appreciate.  Given how fast they grow, a 3 gallon plant will catch up to a five gallon plant in no time at all.  If you plant smaller plants, be sure they get regular water to the rootball.  Potted hydrangeas become rootbound in the blink of an eye.  Lacking the water they need, the foliage will burn and drop-this is not a good look.


My landscape features 2 large blocks of Limelight hydrangeas-25 plants in each block. They are about 7 feet tall, and just coming into bloom.  In full bloom, they are glorious. In late bloom, they are beautifully moody-green, white, and white speckled with rose pink.  The show goes on for a number of months.  The limelights are just now coming on-I am ready.