How did Your Hydrangeas Bloom this Year?

So how did your Hydrangeas bloom this year?

One the most common questions I get, is "Why won't my Hydrangea bloom." Of course they're talking about the beautiful species called Hydrangea macrophylla (Big Leaf Hydrangea).

.... [Not sure what type of Hydrangea you have? Click here]

This plant is extremely popular because it is the most colorful of all the species. This plant can be categorized into two main groupings: Mopheads (snowballs) and Lacecaps. The Mopheads are large round clusters of sterile flowers and the lacecaps are flat heads composed of both fertile and sterile flowers. The mopheads are the most popular because we tend to love the gaudy. The lacecaps are gaining in popularity and are considered by many, including myself, to be even more beautiful because of their delicate looking nature.

The key message here is that Hydrangea macrophylla is it sets its flower buds in the fall when night temperature fall below 60F/16C. Thus the flower buds must survive the winter if they are to mature into big beautiful flowers the following summer. [We call this blooming on old wood.] This is the crux of the problem - a hard winter, an early fall freeze, a late spring freeze, or untimely pruning will damage the flower buds and result in a loss of flowers.

So what is a person to do if they want to be successful with Hydrangea?

1) Understand how and when to prune

Big Leaf Hydrangea does not require much pruning once established, but proper pruning is critical if expect to see flowers.

The best time is in early to mid-July. Prune back any non-flower stems back to about six inches from the ground. This helps to produce short stems which keeps the next crop of flower buds close to the ground where they can be more easily protected from winter damage. It is critical that you cease pruning by the end of July. This allows time for the new flower buds to form and harden off prior to winter.

2) Shut the plants down before winter

Hydrangeas will continue to grow as long as there is ample water, fertilizer and warm weather. Later season growth is tender growth and more prone to winter injury, so useful to shut the growth down before winter comes. In late summer and fall, stop fertilizing and cut back on the water. Don't worry if the plant looks severely wilted, just provide enough water for the plant to survive. This will slow down the growth, help to induce flower bud formation and make the plant less susceptible to an early freeze.

3) Mulch and Protect

In late fall, mulch the base of your plant with six to ten inches of bark or peat moss. This will protect the buds on the short stems (the ones you pruned in July). Apply the mulch after the onset of cold weather but before the temperature falls below the teens. This mulch will be removed or spread out in the spring after the danger of frost has past.

4) Grow Varieties that Bloom on both Old Wood and New wood [rebloomers]

Within the last ten years, varieties have been developed that make buds in both the fall [typical], and during the summer [atypical]. Or putting it another way, they flower on both old and new wood. This means that even if the flower buds are injured in the winter, new buds and flower will form the next summer. This is great news for those of us who live in cold climates.

The cultivars 'Endless Summer', Let’s Dance Moonlight, Let’s Dance Starlight, and 'Forever and Ever' have the ability to bloom on old and new wood alike. These are great selections for the Midwest where it is hard to get Hydrangea to bloom. 'Endless Summer' was the first rebloomer to hit the market, while the Let's Dance series is the newest generation of rebloomers. The Let's Dance series has superior flower color, overall substance and thicker, glossier leaves. They are also less likely to die to the ground in the winter.

Now I know that many people were disappointed with the Endless Summer Hydrangeas this year.

We had a long warm spell in late winter followed by weeks of freezing weather that knocked many Hydrangeas back to the ground. As a result, the old wood buds were killed, and we lost the early-season flowers, even on the rebloomers.

Keep in mind that, even with these new varieties, you get a much better flower display if the old wood buds survive the winter. Sure, if your plants die back to the ground in the winter, you will still get flowers, but they appear later in the season and there are typically fewer flowers overall. So - it still pays to prune properly, keep the buds close to the ground and protect these buds with mulch.

- Another Tip for Rebloomers Like Endless Summer -

If your Endless Summer dies back to the ground in the winter, forcing growth will deliver more flowers and sooner. Endless Summer and other rebloomers have to put on a certain amount of new growth before they will make new buds and flower. So it pays to give these plants extra fertilizer and water to push the growth. Miracle Grow once a week after any danger of frost does the job.

For some people, rebloomers are not the best choice.

If you live in a mild climate where big leaf hydrangea blooms reliably there is no advantage in growing rebloomers. You lucky people have a wonderful array of varieties to choose from, many with superior foliage and flowers. For example - consider the new dwarf cultivars sold under the CITY LINE series. These compact plants form a neat compact plant that is covered with blooms. They also have very vivid flower colors.

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(If you live in a very cold area consider Hydrangea paniculata (Limelight, Pinky Winly, Little Lamb and Quick Fire) and Hydrangea arborescens (Invincibelle Spirit and Incrediball. There are many great new vareities and they are pretty much fail proof.)


----------------Back to Hydrangea macrophylla

Flower color - How to change Flower Color

Another interesting attribute of this plant is that its flower color may change depending on soil p.H.. It is not the p.H. itself that changes the color, but it is the availability of aluminum ions that directs the color. Aluminium has greater availability in acid soils thus the blooms turn blue in acid soils. If the soil is either basic [alkaline] or high in phosphorous, the aluminium is tied up and flowers tend to be pink. The degree of color change is dependent upon the amount of aluminum ions available and the cultivar itself. It should be noted that if you are growing in a container your soil mix you may not have much aluminum availability even at low p.H. levels. Aluminum sulfate treatments would then become necessary to get blue flowers. If you fertilize your plants be aware that you will tie up the aluminum with high levels of phosphorous.

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I can't bring everything home

Most people label me as a shrub guy because I work for a shrub nursery. But I consider myself a Plantsman. I appreciate all plants; shrubs, perennials, annuals, biennials, vines, ground covers, native and exotic. I even have an appreciation for weeds. I'm a plant nut and if I had my way I would bring back just about everything I find on my plant hunting trips. But not every plant I find is right for our nursery, thus the best I can do is snap some pictures and grow them on in my photo library and share them on my blog. Here are a few plants that I would take home to my garden if I could. I'm not going to write about each plant, however if you click on the name you will find a link that gives you more detail.  

Actinidia kolomikta

Arum italicum 'Winter White'

Astrantia major 'Roma'

Brunnera 'Jack Frost'

Delphinium 'Kestrel'

Geranium 'Brempat'

Nandina domestica 'Filamentosa' 

Neillia thibetica

Primula beesiana 

Sanguisorba menziesii

Snow Day Surprise - Pearlbush Reinvented

I was just walking in our test garden and was lucky enough see Snow Day Surprise Exochorda (Pearlbush) in bloom. Surprisingly, Pearlbush is not a well-known shrub. It is hardy, heat tolerant and easy to grow. It has showy, white, pearl-like buds in the spring that give it its name. An older cultivar, Exochorda x macrantha "The Bride" caused issues for many growers due to propagation difficulties and the tendency for young plants flop- especially in a container at retail.The plant is quite elegant in the garden once mature, but as a young plant on the nursery it is difficult to train into a salable plant. Enter Herman Geers, the plant Dutch breeder that developed Wine & Roses Weigela.

Herman, like other growers, was tired of trying to grow "The Bride", so he set out to develop a better Pearl Bush. Due to the smaller size of European gardens, he set out to create a smaller, more compact plant that could look good at a young age and was easy to propagate. In 1994 Herman crossed "The Bride" with Exochorda racemosa, an upright species with large flowers. For the next 10 years he evaluated his seedlings culling out all but the best-looking plants. He conducted propagation trials on his best plants and narrowed the field down to 5 with the best rooting percentages. From breeding to evaluation, the entire process took sixteen years, and out of the five best plants, he ultimately selected Snow Day Surprise. 

Snow Day Surprise starts flowering in early April or May depending upon where you live. At first the plant is covered with hundreds of pure white pearls - the buds - which last for about 3-4 weeks. The pearls then open up into large, pure white flowers which can last another 2-4 weeks. It is hardy from zone 4 to 8. The habit is more upright than "The Bride", but matures into a compact mounded plant around 3-4 feet tall and around 4 feet wide. Like Quince, (Chaenomeles), it makes a nice splash in the spring garden.

We started selling liners (young plants) this spring, so you can expect to see plants hit the retail market over the next year or so.

--- Side Note ---

People have been emailing me that their Plant Hunter emails have looked a bit funky as of late, with the text running over the pictures. I had switched to a new version of Blogger called "Blogger in Draft," as it was suppose to work better with videos. I have since changed back to the old Blogger - so I trust that this post arrives in good order. I apologize for any previous posts that were of poor quality and I hope that I have taken care of the issue. If not, please let me  know. As always - I appreciate your comments, and your continued interest in reading The Plant Hunter.

Double Take Quince - NC State Does it Again

Europe use to be the the hot bed of shrub breeding, but not anymore. Sorry guys - but it's been relocated to Mills River in the beautiful Blue Ridge Mountains of North Carolina. Tom Ranney and his crew at the Mountain Horticultural Crops Research and Extension Center, Darren Touchell, Tom Eaker, Joel Mowrey, Nathan Lynch, Jeremy Smith and Kevin Parrusfor are a well oiled breeding machine that continues to develop one great new plant after another.

This is the team that broke the color barrier with the introduction of the first ever pink flowered Annabelle Hydrangea - Invincibelle 'Spirit'.

Now they've developed a series of quince (Chaenomeles) that look a lot like Camellias, but much hardier, called the Double Take Series.

Double Take 'Orange Storm'

Double Take 'Pink Storm'

Double Take 'Scarlet Storm

As you can see from the images the flowers are very large and have lots of petals. The color range is blessed with deep hues of scarlet, pink and orange. To make life even better they're thornless! While quince is an old fashioned shrub that is not as popular as it once was, I suspect these plants are going to reinvent this old time favorite, and make quince popular once again.

  

I love quince as it is a nice change from the typical spring flower color we get from Forsythia. The colors are rich and warm you up on a cool spring day and get you pumped about being out in your garden. These plants make a very colorful hedge. I think quince is at its best trained up a wall to show off its flowers at eye level. It's also a great cut flower and makes a very elegant show in a vase. These are very new plants, just like a lot of plants you will see on my blog, so they're not generally available at retail. There are a few mail order nurseries that have them this year, but you can expect to see them work their way into better garden centers over the next few years.

We have been trying to get them approved for Canada, but the at this time we have not had any luck with the Canadian government. Hopefully this will change soon.

What do you think?

Bloomerang Lilac Starts a Controversy

Who would have thought that Bloomerang® Purple Lilac (Syringa ‘Penda’ ppaf) would create such a controversy? First Slate magazine comes out with an article entitled “Gilding the Lilac: A new hybrid could kill the nostalgia...” and then MaCleans Magazine follows up with an Internet article titled the “Ever-blooming Lilac Wars.” It seems that some people feel a lilac should bloom only once and only in the spring. I disagree and so do the thousands of people that rushed to buy Bloomerang when Better Homes and Gardens magazine did a limited release in March of 2009. Expecting to sell just a thousand plants, BH&G sold over 11,000 plants and turned away a throng of disappointed, potential buyers.

Bloomerang Lilac is not the first reblooming lilac. In 1917 Charles Sargent of the Arnold Arboretum noted that Syringa microphylla (S. pubescens subsp. microphylla var. microphylla) “… if it keeps up its habit of flowering a second time in autumn it will be at least interesting even if other lilacs are more beautiful. In her 1928 book “Lilacs” Susan McKelvey noted that S. microphylla has “… the curious habit of blooming twice in one season.” Syringa ‘Josee’ (syn. MORjos 06F) a small leafed, pale pink flowered cultivar introduced in 1974 by Minier Nursery of France is another noted remontant lilac. ‘Josee’ is a complex cross (Syringa pubescens subsp. microphylla x Syringa pubescens subsp. patula (syn S. velutina) x Syringa meyeri subsp. meyeri) developed by Georges Morel. More recently, Frank and Sara Moro of Select Plus International Nurseries of Quebec, Canada introduced several reblooming cultivars. So why all the fuss about Bloomerang lilac?


There are a number of things that have put Bloomerang in the spotlight. From my observations, (and a good many of the 400 garden writers that trialed the plant) it is the most consistent and prolific remontant lilac to date. The initial bloom is heavy and appears in mid-May. It goes through a rest in June and then begins to rebloom in July and continues on until frost. While the summer and fall panicles are not as large as those in the spring, it puts on a very good show. Every single branch bears flowers (not just an occasional flower). One of the reasons for its propensity to flower is its strong growth. As long as it continues to grow it continues to produce new flowers. You don’t have to prune it get it to rebloom, however, a light shearing after the initial bloom results in a fuller plant with more branches and thus more blooms.

As far as its ability to bloom and rebloom I have no doubt. In the selection process, I tagged only the seedlings with the most prolific summer bloom. Each year I repeated the process and in the end I chose the three plants with the most tags. These three, strongly remontant selections, were then propagated and evaluated further in production and in the garden. Eventually we selected one plant and introduced it as Bloomerang Purple. Of the remaining two plants, one appeared special enough to introduce and should be out in a few years. 

Our Lilac breeding program continues on. I have sowed out F2 crosses and have selected five more remontant plants of various shapes and colors. I have also made crosses that draw in new genetics to obtain plants with dwarf habits, glossier foliage, better fall color and larger flowers. Many of these plants look promising but only prolonged testing and evaluation will determine which, if any, are worthy of introduction. But the plan is to offer a range plants under the Bloomerang series.


As the Product Development Manager at Spring Meadow Nursery, one of my main functions is to find new and superior plants for the Proven Winners flowering shrub line. The shrubs in this line are selected based on a specific criterion that in its most general terms focuses superior performance, improved disease resistance, ease of production and culture, compact and dwarf habits, attractive foliage, and extended or multiple seasons on interest. Adding lilacs to the line was a goal of mine because they offer many fine attributes that make them popular. Most notably lilacs bloom in the spring when people are in the garden center, they offer excellent hardiness, they’re well recognized by consumers, they’re very colorful in bloom and they offer fragrance. On the other hand lilacs typically offer only one season of interest and are susceptible to Powdery Mildew and Pseudomonas. Bloomerang addresses all of these issues and as a result is off to a very good start.


Still, I’m not sure why Bloomerang or any other reblooming lilac is so controversial. It seems to me that some people like to complain and to create controversy even where is there is none. I guess it helps them sell magazines and attract blog subscribers. Regardless, it’s strange to read comments like “ Of all the things that plant hybridizers could be focusing on, this type of indulgence is a waste of creativity… (GardenRant.com, August 9, 2009 “How much plant improvement can we stand?”). How can I respond except to say go ahead and call me indulgent and blame me for ruining the joy of lilacs. It will only sell more plants and beautify more yards.

Got Questions? Get Answers!

I suspect I have a wide mix of readers and subscribers; some of you are horticulturists and nursery people, while others are gardeners, both experienced and beginners. I think that's great. It keeps it fun.

I try to speak in a language that everyone can understand. I use scientific names and common names. I try to write articles that are interesting and educational for all my subscribers. But most of all I want to share my excitement for good plants.

But at the same time I get a lot of gardening questions. That is why am excited to introduce you to our Facebook Fan Page. I am so excited about what is going on there. I think you will be too. It is a community of gardeners looking for, and sharing gardening advice, stories, photographs and tips. It is a great place to get your gardening questions answered or to help a fellow gardener. It is a place to mentor new gardeners.

I know - many of you think I'm crazy for suggesting Facebook. I was skeptical at first. I had no interest in joining Facebook - I have a life and don't want to know what my high school friends had for lunch. But a friend insisted  that I join up and I'm so glad I did.

Check out the Proven Winners ColorChoice Facebook Fan Page and let me know what you think.

Sky Miles for Sky Pencil: The Journey from Mt. Daisen to Maryland

You migth suspect I do a bit of traveling – but plants have a funny way of traveling around the world too.

Sky Pencil, Japanese holly, (Ilex crenata) is a plant that has earned some serious sky miles. This narrow, column-like, evergreen holly was discovered in the wild on Mount Daisen, Honshu, Japan by my friend Akira Shibamichi. He then passed it on to his good friend, and my acquaintance, Dr. Yokoi, the noted variegated plant collector. Dr. Yokoi passed it on to Rick Darke (the ornamental grass guru) while he was in charge of research at Longwood Gardens in Kennet Square, Pennsylvania. (I met Rick while I was a summer student at Longwood in 1982). Rick got the plant in 1992 while on a plant collecting trip to Japan with Sylvester March of the United State National Arboretum. The USNA then propagated it and introduced it and now it’s grown by nurseries and gardeners across the U.S. and around the world.

Just to keep the story going, Mike Farrow of Holly Hill Farms nursery in Earlville, Maryland took ‘Sky Pencil’ and crossed it with a male selection of Japanese holly. His goal was to develop a very narrow, conical holly with dark green leaves. You see - vertical Plants, especially those with the quintessential Christmas tree shape are very popular, Thuja occidentalis (aka arborvitae, aka Eastern cedar), Skyrocket Juniper and Dwarf Alberta Spruce (Picea glauca ‘Conica’) are all narrow, pyramidal varieties and nurseries grow them by the acre. Mike Farrow understood this. Successful plant breeding starts with a good eye for plants and a good idea and Mike has both. (His impressive plant portfolio includes Arctic Fire Redstem Dogwood, 'Sienna Sunrise® Nandina, Bollywood Variegated Azalea and Pink Panther Echinacea).

After growing out hundreds seedlings, Mike selected out the six best plants to propagate and to evaluate further. Part of this evaluation took place in Michigan after Mike sent his six holly selections to Spring Meadow. For our part of the evaluation, we propagated and grew on about 1,000 plants of each selection. We evaluated each variety in propagation, as a one gallon crop and then as three gallons to gain a thorough understanding of it production and timing. To better understand how the plant performed in the garden we planted the hollies out on two different test gardens. Eventually we choose the best looking, best performing plant of the bunch. At this point we sent plants to about thirty growers across the country to find out how the plant performed under various climates and soils. Ultimately, after all these evaluations we took the leap and introduced Mike’s new plant as Sky Pointer Holly (Ilex crenata ‘Farrowone’ pp# 20,049).

Sky Pointer Holly has shiny, flat, dark evergreen leaves. The flat leaves make for hard living for spider mites, as they cannot hide and protect themselves under the cupped-shaped shaped leaves which are common on Japanese holly. This gem has tight, upright, conical branching which makes it a great container plant. I see many such plants used in sidewalk cafes and near store fronts for decoration. It’s hardy to zone 6 and just like ‘Sky Pencil’ it appreciates a bit of shade, especially in the winter. Growers appreciate its narrow growth habit. Narrow plants require little or no spacing in the nursery, which ultimately saves them time, labor and money.

And thus the journey continues. Last year, Spring Meadow Nursery shipped Sky Pointer liners (starter plants) to wholesale growers across North America. These growers pot them up, and grow them on for one or two years and then send them on a truck to a garden center near you. If all goes as planned, someone will buy a Sky Pointer holly. Perhaps it will be you. And after you plant it in your yard and watch it grow, I suspect you’ll think about its long journey from Honshu, Japan to your front yard.