Louis Raymond experiments in his own gardens like

a mad scientist, searching out plants that most people have

never seen before & figuring out how to make them perform.- The Boston Globe

…Louis Raymond ensures that trees can grow in Brooklyn…

or just about any other place where concrete consumes

the dirt and skyscrapers shield the sunshine.- USA Today


NEW Trips to Take!

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.


Plant Profiles

Non-flowering Tree Ivy



This evergreen shrublet is the oddball even among its cohort of weirdos, the adult ivies.   So, of course, I had to plant lots of it. 


First quirk, those leaves.  This cultivar of adult ivy is grandly named 'Conglomerata Erecta'.  And indeed, the leaves are "conglomerated"—gathered into groups—and so densely they could have been the model for "Pringles" potato chips.  They're in two tight ranks, one on either side of the vertical burgundy stems.




Next, the flowers.  This is the adult form of ivy, one of whose defining traits is that it flowers.  But 'Conglomerata Erecta' is the hair-shirt monk of the clan: No matter that it's an adult, it's resolutely asexual.  No flowers, ever.




Like all adult ivies, 'Conglomerata Erecta' is most at home in full sun; it leaves shady haunts to juvenile ivy.  And it absolutely demands fantastic drainage.  See "How to handle it" for strategies that help this eccentric plant look its best.



Here's how to grow this quirky broadleaved shrub:

Latin Name

Hedera helix 'Conglomerata Erecta'

Common Name

Adult Ivy


Araliaceae, the Aralia family.

What kind of plant is it?

Broadleaved evergreen shrub.


Zones 6 - 9.


Low and sprawling, branching so freely it forms irregular mats.  The foliage is in two distinct ranks, opposite from one another, putting all the leaves in the same narrow plane.

Rate of Growth


Size in ten years

Perhaps two to three feet tall and wide, but probably less.


The planar habit of the foliage and erect branch tips create a miniature organ-pipe texture.  Free-range growth is irregular in overall profile.

Grown for

its lack of flowers:  Although 'Conglomerata Erecta' is an adult form of ivy, it still doesn't form flowers.  This makes it a good choice where the flowering adult forms of ivy could self-seed into the native landscape.


its habit:  small pointed leaves, heavily veined in chilly white, are in two tight ranks up either side of matte-burgundy stems.  The top foot or so of growth is held erect, but lower growth is fully "in repose" against all neighbors, be they horticulture or hardscape.  If those neighbors are upright, the ivy achieves greater height; if not, the ivy sprawls outward in mats.  The erect portion of the stems—always the newest portion—is loathe to branch, but older portions below it branch freely.  Branching may also be enhanced by the stems' decreasing verticality regardless of the age of the growth; older growth is the most branchy—and always the less vertical, leaning on adjacent plants, into stones, or down onto paving. 


its rarity: Juvenile ivy—the familiar self-clinging vine—covers countless square miles of ground, wall, and tree bark.  It's a noxious weed in many states, especially those with milder climates: the Pacific Northwest, e.g., or the Southeast.  Adult ivy that sprouts from juvenile ivy is almost inevitable if you let your juvenile ivy climb, and let it grow undisturbed for a few years.  Typically, juvenile stems become more likely to "go adult" only when allowed to climb—and only when they reach the top of whatever they're climbing.  You'll have adult ivy sooner, then, if you grow your ivy up low walls.  Adult ivy growing on its own roots, though, not those of the juvenile stems from which it sprang, is a bit of an achievement:  As ivy matures from juvenile to adult, it loses its juvenile habit of sending out roots anywhere stems touch something solid.  Getting adult ivy cutting to root, then, is difficult.


its non-vining habit: It's ivy, yes—but it's not a vine at all.


its ease of propagation.  Adult ivy is normally difficult to propagate, because its stems have lost juvenile ivy's freedom of forming roots.  'Conglomerata Erecta' is so easy to propagate that it can be available from wholesalers as flats of rooted cuttings.  Mats can be pulled apart into individual plants, and stems can even be rooted.  Provided you can provide the warm and well-drained circumstances it requires, you can plant 'Conglomerata Erecta' en masse and still not break the bank.

Flowering season

None:  'Conglomerata Erecta' does not form flowers.

Color combinations

With its dark burgundy stems and dark leaves veined in bluish-white, 'Conglomerata Erecta' is fairly neutral.  But if you are celebrating sublety, pink, rose, and white would be completely in synch, whereas orange and red would be jarring.  Pale yellow and cream are possible; school-bus yellow would be a stretch.

Partner plants

Full-sun partners that also crave good drainage include Sedum 'Angelina', all yuccas, yews, junipers, and euphorbias, and Sophora davidii.  Handily, all of them are available in the cool colors that go best with 'Conglomerata Erecta'. 


Shady partners for good drainage include hostas, ferns, aucuba, nandina, and mahonia.  'Conglomerata Erecta' is not itself a shade-craver, so plant it on the sunny side of all of these.

Where to use it in your garden

As is typical for "own-root" adult ivies, 'Conglomerata Erecta' is full to the ground, so it looks great planted at the front of a bed—ideally, one bordered by a wide walkway so the ivy can slowly spill out over it.  Its sprawling habit is especially appealing in conjunction with large natural stones, where the ivy can lean into vertical fissures and achieve some extra height.  South-facing spots are ideal, because the stone absorbs sun year-round and so provides additional heat to this tree-ivy, which always benefits from any possible enhancement to hardiness.


Almost any soil as long as there's fantastic drainage in Winter.  Full sun is best.

How to handle it: The Basics

In my experience, adult ivy is much more susceptible than juvenile to dying in the Winter in a Zone 6 garden, let alone Zone 5.  Anything other than fantastic drainage seems to put the plants at risk; I write this after having killed more than a few adult ivies by attempting to grow them in my rich, often heavy, and often poorly-draining soil.  In Zones 7 to 9, though, adult ivy can be a plant-it-and-forget-it shrub that thrives in almost any soil, sun or shade.  I still marvel at old specimens on the UCLA campus, with thick trunks to make any rhododendron envious.


Adult ivy that is branching from juvenile (which is, by a long shot, the norm) is as hardy as the juvenile; my hunch, though, is that adult ivies on their own roots are less hardy overall than their juvenile form, even with excellent drainage.


In Zone 6 and below, then, plant adult ivy only on a slope, and only with substantial shelter nearby: large rock outcroppings, dense evergreens (needly, please, to contrast with the broad leaves of the ivy).  Spray with antidessicant, especially if the bush is growing where it gets Winter sun.  And good luck to you.

How to handle it: Another option—or two?

'Conglomerata Erecta' is most often sited where its free-range growth is welcome—nestled into the creases and fissures of erupting ledge, say.  But unlike typical adult ivy, the plant is very easy to propagate and naturally grows as a multi-stemmed clump.  It's responsive to clipping, too.  On all three counts, then, it's a candidate for a low hedge. 


I'm attempting just that, and have planted a large circle of the 'Conglomerata Erecta' on a raised bed (for drainage) and with an outer ring of dwarf box (for extra shelter).  The ivy is persisting and, slowly, "hedgifying" itself.  I prune the tips back in early Spring.  I also angle wandering stems back into alignment and hold them in place by shallow burial—not so much because I hope they'll root, but so they'll branch out more readily.  And so the stems get extra shelter for that portion of their length.

Quirks or special cases



Below Zone 7, adult ivies are fussy in their demands for shelter and excellent Winter drainage.  When and if you can establish them, they are trouble-free.


Because any juvenile ivy will, given enough time, enter its adult phase, it's conceivable that there would be just as many varieties of adult ivy.  And there are hundreds of different flavors of juvenile ivy.  You're much more likely to see these growing from the upper reaches of long-established colonies of juvenile ivies, though, than as own-root bushes, because it can be so frustratingly difficult to get adult ivy cuttings to root.  Nonetheless, own-root adult ivies are, occasionally, available, and with variegated leaves as well as all-green leaves.  'Poet's Ivy' is one to try. 


On-line and, rarely, at destination retailers.


Own-root adult ivy is usually difficult to root, which is why the plants are uncommon and often expensive.  'Conglomerata Erecta' growth is naturally multi-stemmed, and the mats can be pulled apart into separate plants.  Its availability as rooted cuttings also suggests that it has retained some of its juvenile capability for rooting.

Native habitat

Hedera helix is native to Europe and Western Asia.

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