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or just about any other place where concrete consumes

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Plant Profiles

Gold-leaved Spring spirea

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Spring-blooming spirea is a cloud of delicate white flowers in early April.  They may be small, but they are innumerable.  The tiny five-petaled blossoms crowd long stretches of the twigs and branches.

 

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But the real show is just beginning.  The foliage of 'Ogon' is gold, and it begins to emerge just as the flowers peak.

 

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The leaves match the color of the flowers' yellow stamens, too.  In another week, the flowers will be gone, but the foliage will have expanded into a graceful display that lasts through to frost

 

 

Here's how to grow this talented shrub:


Latin Name

Spiraea thunbergii 'Ogon' 

Common Name

Gold-leaved Spring spirea

Family

Rosaceae, the Rose family.

What kind of plant is it?

Deciduous shrub.

Hardiness

Zones 4 - 7.

Habit

Multi-stemmed and mounding.

Rate of Growth

Fast. 

Size in ten years

Left to grow free-range, eight feet wide and tall.

Texture

Delicate in flower and in leaf; free-range shrubs are irregularly twiggy when out of leaf.  Sensitive pruning improves everything greatly.  See "How to handle it" below. 

Grown for

its flowers in early Spring:  Tiny five-petaled pure-white flowers by the thousands crowd the twigs and branches.  It's a snowstorm of bloom so early in Spring.    

 

its foliage:  Exceptionally narrow leaves are gold instead of the medium- green of the straight species, transforming a shrub that is merely pleasing after flowering into one that is truly exciting. 

 

its toughness and endurance:  Spiraea thunbergii is so hardy and so persistent that, as long as it isn't overgrown by weeds, it could be expected to survive on abandoned property indefinitely.  In this sense, it's a peony among shrubs.

Flowering season

Early Spring, just before the new leaves expand: As early as forsythia and PJM rhodies—and a welcome antidote to them both. 

Color combinations

The white flowers of 'Ogon' go with everything; it's the yellow foliage that follows that guides what colors you associate with this shrub.  Although the color mellows in Summer, it is still definitely yellow.  You can be confident about combining with red, orange, yellow, and the goes-with-everything mixers of burgundy, blue, white, green, and gray.  The leaves are so delicate that you could even mix the shrub with neighbors in pink and rose if those colors come from flowers with prominent yellow stamens.   

Partner Plants


'Ogon' provides opportunities for textural and coloristic pairings, and the shrub's flexibility with colors means that there's a wide range of them.  The small narrow leaves are a natural contrast for any sun-loving plant with leaves that are round or large or both, such as smoke bushes, ornamental cultivars of rhubarb and horseradish, almost any hydrangea or viburnum.  If they also provide a contrast in color, the effect is more powerful still.  'Velvet Cloak' smoke bush has especially dark leaves.  The leaves of 'Lemon Wave' hydrangea are sectioned in yellow, cream, and green.

 

'Ogon' can be used both as a solo and as a group.  What about having an informal hedge backed by a "formal" hedge—one that's clipped, I mean—of evergreens?  For once, yew is not the ultimate choice: Its needles are too similar to the long narrow leaves of the spirea.  Holly or box would be very satisfying, both in leaf color and shape—and that they both "take a trim" so well.

 

If you were committed to cutting all of its stems to the ground immediately after flowering is through—the "radical" way to prune; see "How to handle it" below—'Ogon' could be surrounded with later Spring bulbs, such as tulips or alliums.  They come into their own in May, while 'Ogon' is originating its new shoots in response to its April pruning; the shoots quickly lengthen, and would hide the bare ground that the bulbs leave behind as they enter dormancy in June. 

 

What about hellebores?  The twiggy growth of annually-pruned shrubs of 'Ogon' is attractive, and not so dense or lengthy that it would hide the hellebores in the Winter.  And the April pruning lays the shrub low for a few weeks just as Spring is gathering steam, which is just the time that the flowering of the hellebores can be at its height, especially if the Winter has been rough.

 

In the same spirit, 'Ogon' could partner a colony of Eremurus.  These bulbs send up thrilling tall spikes of flowers in early Spring, and the foliage goes dormant, it seems, even before the spikes are fully open.  Annually-pruned shrubs of 'Ogon' would give sun and heat access to the Eremerus colony during its foliage and flower's brief Spring foray above-ground, and also hide the nearly eleven months of bare-dirt dormancy that follow.  Eremerus are shallow-rooted and, when they are able to enjoy terrifically sharp drainage, very long-lived.  But they need their space, their heat, and their ventilation.  You can't hide the colony by overplanting with annuals, nor surrounding with lush perennials, either of which could cast the colony into relatively cool and possibly damp shade.  But could even Eremerus begrudge a few feathery branches of 'Ogon' as long as they were just at the edges, not hogging the view directly overhead?    

Where to use it in your garden

Even though 'Ogon' is a star only for the week or so that it's in bloom, the shrub is an asset to any garden where it's hardy.  Because the flowers are a sudden surprise when so many other woodies are still bare sticks, site 'Ogon' where you and your guests can welcome it in person:  Near the front of a bed that's close to paving.  A single yearly pruning (see "How to handle it" below) is all that's needed to keep the shrub in proportion, and that near-the-paving position makes it all the easier   

Culture

Full sun and any reasonable soil as long as it's not too dry.  The shrub thrives in part-shade, too, but the foliage color is not nearly as vivid.  Growth is fastest with good nutrition and ready access to water.  Spiraea thunbergii isn't fussy about drainage; average is fine.     

How to handle it:  The Basics

Although 'Ogon' thrives when left to grow on its own recognizance, the shrub is smaller-scale and much more graceful when out of leaf if it receives some confident pruning each Spring.  Because the flowering arises from buds that originated the previous season, delay pruning until after flowering is complete.  It's a regrettably brief show, so you won't have to wait long:  Give the bush another week, and it will be time.

 

Spirea thunbergii is propagated by cuttings, and suckers freely at the base.  So prune this bush the same way as species and cultivars of other "suckerers" with Spring bloom, such as Kerria, Forsythia, StephanandraWeigela, and Syringa.  There are two choices: to prune incrementally right after flowering, or radically.  For the first, cut down any or all of the tallest branches right to the ground, or as low as you can reach given the density of growth and the width of the colony at ground-level.  The tallest branches are also the thickest, so you can work on your knees (and quite possibly on your elbows, too) without having to back out from under the shrub to check on its overall profile.

 

The advantage of incremental pruning is that the shrub maintains a steady presence even though it never gets too large.  The disadvantage is that you can't experiment with the tightly-scheduled interplantings mentioned in "Partner Plants."

 

The radical approach is often the choice when other priorities have intervened, and you've only slowly realized what a haystack your 'Ogon' has become when untended for even two years, let alone three or four.  Incrementalism would be time-consuming and awkward.  You'd be on your knees and elbows more than a few minutes trying to access and then extract the oldest growth without mangling the new.

 

Don't bother with such niceties.  The moment the shrub is through flowering—or even, before, if you're desperate or that's your best timing—cut every last branch down to nubs.  The shrub will resprout promptly, and the new shoots will be two or even three feet by frost.  Next Spring it will be in full bloom.  

How to handle it: Another option—or two?

A really old clump could become bare in the center.  It can be lifted and divided in either Spring or Fall.  If it doesn't separate into individual clumps all by itself in the course of the dig-up, chop the clump up to release newer portions from older.  All of this manhandling will be easier when the shrub has been cut to the ground, so this would be a follow-up project to a radical pruning. 

Quirks or special cases

None. 

Downsides

Without a yearly going-over right after blooming is through, the shrub quickly grows into an unattractive haystack of twigs.   

Variants

The straight species is also worth growing, especially if your garden or your taste would rebel at the gold foliage of 'Ogon'.  Each of the green leaves of 'Mt. Fuji' has a white stripe down the center, but the shrub reverts so often that the variegation is more likely to look like an ailment than an asset.  The buds of 'Fujino Pink' are rosy, but the flowers themselves are only faintly pink; the leaves (thank goodness) are green, not yellow. 

Availability

On-line and at retailers.

Propagation

By cuttings and by division of older clumps.

Native habitat

Spiraea thunbergii is native to Japan and China.  'Ogon' was identified in Japan.  

 
 
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