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Myrtle's easy when the conditions are right.

 
 
 
 

NEW Plants to Try!

Louis tries to capture the exact words to describe the fleeting but deep pleasures to be found in these Summer-into-Autumn incredibles.

 
 
 
 

New Gardening to Do!

Allergic to bees? You can still have an exciting garden, full of flowers and color and wildlife.

 
 
 
 

A Gardening Journal

Evergreen Barberry

One of gardening's mysteries is why the deciduous barberries—Berberis thunbergii in particular—are omnipresent even where evergreen barberries are also hardy. This is Berberis replicata, so desirable and yet so rarely planted it doesn't even have a decent common name. 

Berberis replicata fingers foliage spines 11141 320

This shrub is hardy to coastal Maine, deer-proof, with quality foliage & fragrant flowers—and it doesn't seem to self-seed. Under any name, it's essential.

One of gardening's mysteries is why the deciduous barberries—Berberis thunbergii in particular—are omnipresent even where evergreen barberries are also hardy. I get it when you're gardening in, say, Lake Placid: Whatever's hardy in Climate Zone 4—Berberis thunbergii included —is what you love.

 

But there are a number of evergreen barberries of garden interest in Zone 6, such as Berberis dictophylla, x gladwynensis, jamesianajulianae, x stenophylla, and soulieana. I hope to trial all of them. If I can figure out where to site a raised bed filled largely with gravel and sand for plants that thrive in dry climates that experience a Zone 6 winter—think northern New Mexico—I'd trial B. trifoliolata, too. 

 

This evergreen, hardy-in-Zone-6 barberry is Berberis replicata, so desirable and yet so rarely planted it doesn't even have a common name beyond the generic of evergreen barberry. Under any name, it's proving to be a winner.

 

Berberis replicata fingers foliage spines 11141 640

 

The needle-sharp spines make the evergreen foliage inaccessible to browsers, while fragrant yellow flowers in May, and burgundy-hued new foliage spring into summer, ensure interest that's at once sustained and diverse. This shrub is anything but a one-season wonder.

 

Admittedly, the spines can be painful to humans, too, but they also provide showy contrast to the glossy dark leaves. 

 

Berberis replicata fingers foliage spines 11141 cropped 640

 

Thankfully, Berberis replicata doesn't seem to need maintenance or formative pruning if your goal is for it to assume its natural mounding habit. If ever you have the yen to prune it—see some surprising options in the second "How to Handle It" box, below—make no fast moves.

 

Berberis replicata Thuja occidentalis Umbraculifera Lysimachia nummularia Aurea 111417 overall 640

 

In a "What was I thinking?" mistake, I planted my Berberis replicata cheek by jowl with a mounding umbrella-shaped dwarf arborvitae, Thuja occidentalis 'Umbraculifera.' Both could grow two or three times as wide, which would make the unobstructed top-to-bottom full sun that each prefers impossible.

 

I'll give the barberry this year to grow undisturbed, so that this spring I can enjoy its flowers and burgundy-colored new foliage unimpeded by transplanting. But in early spring of 2019, I'll either move it so that it and the arborvitae both have all the room—and, therefore, sun—they could ever need, or begin training it in situ as a standard, so that its canopy of foliage will be elevated above that of the thuja.

 

Berberis replicata Thuja occidentalis Umbraculifera 111417 closer 640

 

Berberis replicata usually adopts a mounding habit. This limits choices for nearby foreground plants, which could shade out the shrub's lowest growth. In the shot above, you can see the totally-prostrate stems of Lysimachia nummularia 'Aurea', which is an ideal companion in that it rarely achieves more than an inch in height. See "Partner plants," below, for others.

 

 

 

Here’s how to grow this tolerant, durable shrub.

 

 

Latin Name

Berberis replicata. The species name derives from the subtle downward-curling edge of the foliage, which in latin is known as "being replicate."

Common Name

Evergreen barberry

Family

Berberidaceae, the barberry family.

What kind of plant is it?

Evergreen shrub.

Hardiness

Sources vary, but all include Zones 6 and 7. Some extend cold tolerance even to Zone 5; others extend heat tolerance to Zone 9a. Try to purchase plants from a nursery in your region of the country, in hopes that they’ll have first-hand experience with its hardiness near you. In my Zone 6b garden, Berberis replicata is thriving.

Habit

Spiny, multi-stemmed, densely-branching, and mounding. Especially when young, branches tend to arch outward and downward; height seems to be achieved as much from later branches having no choice but to pile atop older ones, as from direct upward growth.

Rate of Growth

Medium.

Size in ten years

Three to six feet tall and wide. In Zones 6 and 5, mature size is likely to be towards the smaller end of this range.

Texture

Dense when mature; irregular and open when young.

Grown for

its broadleaved evergreen foliage: Leaves of Berberis replicata are reliably evergreen wherever the shrub is hardy, which makes it a valuable addition to the palette of broadleaves. While gardeners in Zone 7 and warmer have increasingly wide choices for evergreen foliage, in zone 6 and colder, every option is welcome. That the shrub’s spines make the foliage nearly impossible for browsers to reach makes Berberis replicata not just a hardy broadleaf, but a deer-proof one. 

 

The leaves of Berberis replicata are narrower due to their rolled—“replicate” in horticultural terminology—edges, giving the foliage an interesting needle-like texture somewhat similar to that of rosemary.  

 

its flowers: Daffodil yellow, profuse, and (reportedly—I’ll pay closer attention this season) fragrant, the flowers repay a closer look: Their petioles are cherry red, as are bits of the ring of sepals directly above them. They are a cheerful addition to the May scene, and merit careful pairing with plants also featuring both colors; see “Partner plants,” below.

 

its imperviousness to browsers:  Can any garden ever have too many plants that deer ignore?

 

its year-round interest: With evergreen foliage, spring flowers, colorful new foliage spring into summer, colorful spines and young stems at all seasons, Berberis replicata sets a high bar, no matter the season.

 

its cultural tolerance: Berberis replicata is at home in soil of normal richness and moisture retentiveness—but also in those that are dry and/or nutrient poor.

 

its diversity of uses, which are both functional and ornamental: Thanks to the long sharp spines, Berberis replicata would make a formidable barrier. It is also visually engaging enough to be planted as a solo specimen, and responsive enough to pruning and training that it could form an unusual hedge or even simple topiary.

Flowering season

Late spring, typically in May.

Color combinations

The bright yellow-and-cherry-red flowers are ephemeral, but if you can manage it, having nearby companions that are gossiping about those colors at the same time would be subtly inspired. 

 

The young burgundy foliage contrasts well with the green of mature leaves, and is showy for much longer than the flowers. It's also a stylish foil to the greenish-yellow of the first-year spines and stems. (Older spines and stems are tan, which sustains the contrast with the dark foliage.) If you had to choose among companion plants, go for those that interact well with burgundy foliage or the yellow spines and stems.

Partner plants

Its mounding and often full-to-the-ground habit usually make foreground companions that directly abut the barberry impractical unless they are truly prostrate. My shrub is fronted by that most prostrate of groundcover, Lysimachia nummularia ‘Aurea’. It won’t shade out the lowest Berberis stems, and is unlikely to climb up into the shrub’s dense stems, either. It's a nice match for the shrub's yellow spines and stems, too. If your soil is moisture-retentive, Ajuga pyramidalis 'Metallica Crispa Purpurea' is also strikingly low; its bizarre, shiny, crinkled, deep-purple leaves would be an intense textural contrast, while their dark hue would call out to the burgundy of the young Berberis leaves.

 

If your spacing ensures full sun for even the lowest of the front Berberis stems, you needn't front thie evergreen barberry with exclusively prostrate choices. In drier soil, any number of larger-leaved succulents would work, from the ajuga-sized Sempervivum to upright clumping Sedum. There are dark-leaved forms of each, too. In soil rich enough that it doesn't dry out, the dizzying range of Heuchera cultivars would be irresistible. Perhaps Obsidian, whose large, near-ebony leaves would make the shrub's young purple leaves seem bright. Or Citronella, whose acid-yellow leaves jive with the shrub's stems and spines.

 

At the back or sides of Berberis replicata, keep in mind that taller plants shouldn't cast excessive shade. Reserve these larger-scale combinations for spots where the front of the bed—where the Berberis would likely be—is to the west or south of all the taller stuff behind it. Provided this orientation is possible, then either the gold-leaved Physocarpus opulifolius 'Dart's Gold' or Cornus sericea 'Erika the Blond' would be stunning. (My Cornus alba 'Aurea' is similar to Erika, but now much less available.) The barberry would also be great on the sunny side of tall yellow-friendly herbaceous plants such as Miscanthus sinensis 'Zebrinus' and Alcea rugosa. If your Berberis is reaching its largest mature size in your climate, Acanthus mollis could be at the side or even the front. The dusky-plum bracts of its flowers would (thank goodness) arrive after the bright yellow of the Berberis flowers—but would harmonize elegantly with the shrub's darker new foliage, which continues to emerge well into the summer.  

Where to use it in your garden

As is so often the case, providing the maximum tolerated amount of soil drainage and even dryness in winter maximizes hardiness. Berberis replicata is likely to thrive on slopes, and could be marvelous atop retaining walls or ledges, where its tendency to mound and cascade could be highlighted, and where drainage is normally fantastic.

 

This shrub is terrific as an occasional mounding specimen at the front of beds, or, planted in a line but allowed to grow free-range, as a broad "berming" fronter for tall bare-shinned shrubs, or as a carefully-pruned hedge. If at the front of a bed, the challenge to front it with still lower plants needs to be handled thoughtfully; see “Partner plants,” above. If your garden allows, siting Berberis replicata so that it can extend its mound onto abutting paving would be ideal. It wouldn’t be too generous to allow two feet of paving for this shrub's eventual debouchement.

 

When Berberis replicata is associating with plants that are much taller, keep them to the east or north of the shrub lest they cast shade on this sun-lover. In other words, if you use this barberry in a larger-scale mixed border, it had better face south or west if the barberry isn't to be cast into shade by early afternoon.

Culture

Full sun is preferable (but light shade is tolerated) in almost any soil that provides good drainage; Berberis replicata will not tolerate soils with poor drainage.

How to handle it: The Basics

In Zones 6 and 5, plant in spring only; in zone 7, planting in the fall is also an option. In the first month or two, ensure enough water for establishment; unless your soil is particularly lean or your ambient rainfall unusually sparse, little or no supplemental watering will ever be needed after that.

 

If you’ve allowed enough room for this shrub's likely free-range growth in your region, neither formative nor maintenance pruning will be necessary. If, though, you’re growing Berberis replicata towards the cold end of its hardiness range—and, particularly, if providing the full-sun exposure it enjoys also means that it is exposed to sweeping winter winds—you may find some winter-killed stems by early spring. Cut back to live portions before growth resumes; new growth will fill any gaps or hide any bare stubs in only weeks.

How to handle it: Another option—or two?

Especially if Berberis replicata is grown as a natural-habit soloist, it could happen that old plants might have become overly irregular, or might have shaded themselves out at the bottom, such that renewal is desirable. No problem! In early spring, cut all stems down to just inches; new stems will emerge shortly.

 

The shrub’s dense habit also lends itself to unexpectedly trained shapes. As with other viciously-armed shrubs and trees that respond beautifully to careful pruning—such as hardy orange, ornamental quince, pyracantha, and any number of bloodthirstily-prickly roses—encounters with the painful spines of Berberis replicata are just the price of admission if you want to play in the professional league of creative pruners.

 

If Berberis replicata were planted as a hedge, it doesn’t just need to be an informal one with maximal free-range width. True, I can’t see this species being pruned to a tight smooth surface, like that achieved by several-times-a-season sheering of box or yew. But an annual, single, pruning in early spring would result in a loose but discrete outward cascade of new growth that would burgeon through the summer. The burgundy foliage of new growth would be maximized, while the cross-sectional profile of the hedge could be much a narrower than usual. 

 

To form this Berberis into such a hedge, plant small plants every foot. Starting their second year, prune tips lightly in early spring, then let new growth extend ad libitum the rest of the season. Year by year thereafter, prune peripheral stems back only as needed to foster the overall profile you desire. Keep in mind that the profile will feather and fatten over the season as new growth matures; eventually, you may be pruning well into older growth every few years to keep the shrubs gracefully in check.

 

Intrepid gardeners could take advantage of this shrub’s naturally dense and lightly-cascading habit to select a central stem and train it up a permanent stake. Cutting side branches away on the way up, but then letting natural growth resume at the top after the stem has reached its desired height, should result in an unusual—but unusually well-formed—standard. Giving the canopy the same early-spring going over that you would if growing this shrub as a hedge would also result in greater-than-normal density of purple-leaved new foliage.

Quirks and special cases

The stems of Berberis are dimorphic. Long shoots, which are often wand-like their first season, don't form leaves that photosynthesize. Instead, those leaves are modified into spines.

 

Spines is the correct word for them, not thorns. In my profile of ferociously-spiny castor aralia, I explored the specific horicultural meanings of the terms spines, thorns, and prickles. To recap: Sharp protective structures that develop from modified leaves, as these of barberry do, are termed spines. If they develop from modified stems, they are termed thorns. If they develop from the plant's surface—the bark or epidermis—they are termed prickles. Roses have prickles, hardy orange has thorns, and barberries have spines.

 

A short shoot develops from a bud at the base of each spine, and bears the photosynthetic leaves.

Downsides

The flip side of this shrub’s tolerance of dry and lean soils is its intolerance of soils that are too moist. Poorly-draining spots would likely be fatal. For soils that are well-draining but heavy or rich, try to avoid sites on level ground: Even the slightest pitch away from the plant will enable surface water to slide off to the side, not just penetrate into the soil directly beneath. See “Where to use it,” above.

 

Its spiny, dense, mounding habit can make Berberis replicata a magnet for detritus: Larger leaves that are shed in the fall, let alone wind-blown trash, can become trapped in the shrub’s rigid skirts. Don’t plant this barberry in multiples as a groundcover, lest trash becomes inaccessibly caught in the middle. Do consider planting evergreen barberries in a line—either as a pruned hedge or an informal barrier, in other words—so that you’ll still be able to fish out anything trapped beneath any one individual.

Variants

I’m not aware of any variants of Berberis replicata.

Availability

Online and at destination nurseries, such as this one.

Propagation

By seeds or cuttings.

Native habitat

Scottish botanist George Forrest discovered Berberis replicata in its native Yunnan, China, in 1917. He is reported as having brought back to the West over thirty thousand specimens of the many plants he identified in repeated expeditions to the Far East, and his name now appears in thirty-odd genera. Among them is Acer pectinatum subs. forrestii, long thriving in my garden.

 
 
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