Giving hedera a chance

H. helix 'Ritterkreuz' is one of many slow-growing, well-behaved ivies that are good for containers. It is also the Ivy of the Year, 2010. Photo by Rachel Cobb, courtesy of www.ivy.org.

While researching this topic recently, I was surprised to discover that bans on Hedera helix (the English ivy family) have been considered or enacted in several states (Oregon has one). Supposedly, it’s escaped from private properties to run wild over public areas throughout the Pacific Northwest and Virginia, to name two of the biggest problem areas.

However, the ivy that's overrunning these sites is H. hibernica (Irish ivy), which is a much hardier and faster-growing cultivar than its helix cousins, many of whom are sweetly decorative miniature, curly, or variegated varieties used mainly in pot culture.  I got most of this information from the American Ivy Society, but a quick google search demonstrates the majority opinion: English ivy is a thug that needs to be wiped out.

I use ivy as an evergreen ground cover in my back garden and I’ve never had a problem with it, simply devoting an afternoon each spring to pulling it away where I don’t want it. It forms an attractive dark green framework around the tapestry of ground covers (lamium, gallium, geranium) and perennials (hellebore, Canadian anemone, columbine) I use in this tree-shaded area. For a garden like mine, where turfgrass, even if I wanted it, would probably never grow among all the tree roots, and where it’s uncomfortably cold half the year, evergreen ground covers are most welcome. Buffalo has always been a haven for ivy; the Botanical Gardens here has the world's largest collection, mainly H helix types, most of the dainty variety.

I've always found ivy to be a pretty plant (perfect around a Victorian house), and now that I’ve seen more of the new gold-variegated types on the Society’s web site, I am wondering if I can replace some of my ordinary ivy with some hardy gold varieties. 

If I lived in Oregon, I might feel differently.

Comments

[Diana at Garden on the Edge]

I spent a whole summer removing English (Irish?) Ivy from a backyard in North Carolina. I have seen the damage it did to siding on a house, even pulling morter from between bricks. I have pulled it of public places by the garbage bag load. The only good thing about this plant is that it does pull up easily and doesn't come back too rapidly so that it can be managed without chemicals (it is also a haven for rats who can travel under the leaves, safe from many predators).

Good for you that you can keep yours under control. I wonder what the next owners of your house will think of it.

[how it grows]

I spent a few minutes on the Ivy Society site but didn't fine the information about the Irish ivy. I didn't see much about its invasive properties on the site either, as a matter of fact. Living in Virginia, I totally agree that it should be banned. This is probably one of the biggest plant pests we have. And though you might be able to control it by pulling it once a year, in reality, once a year is a lot more often than many people do yard work. And once it's out of control, it's pretty much unstoppable and very difficult to kill.

[Tara Dillard]

A zillion years ago a hedera lover said, The smaller the ivy leaf the slower it grows.

I fell in love with H. 'Gold Heart'. It's now growing on the brick wall by my frontdoor.

3-4 feet of it are pulled off each year. Not much effort for easy beauty & lushness.

Garden & Be Well, XO Tara

[Rosella]

I don't care whether it has a brogue or an Oxford accent, "ivy" is a monster around here (Virginia). It grows with the speed of light, smothering everything in its path and, if it is allowed to get up into the trees or onto walls, changes into its fruiting form so that the birds can help spread it. I read somewhere that the increase in carbon in the atmosphere increases the growth rate of vines, and I do think that the ivy grows faster now than it used to. Meanwhile, my ivy eradication program is only partly successful and I still have lots of it, but constant vigilance is helping (some).

[Joseph Tychonievich]

Invasiveness is totally climate dependent -- in colder places, ivy simply isn't the thug it is in mild-winter climates. That may change as the climate changes, but I'm happy to grow a lovely hardy white variegated ivy in my garden (the only zone 5 hardy variegated one I've been able to find -- I got it from Arrowhead Aplines)

[Tibs]

You only have to pull it back once a year?! Wow. I am jealous. My ivy, obvious a no good irish ivy, had to be trimmed back every couple of weeks. I got over a foot high and had roots big around as my forearm. I found this out when I pulled out all the stuff I planted years before on the hottest, highest humidity 4th of July ever. I have never been so dirty or smelly in my life. I still find little starts of it. So what did I replace it with? Creeping Myrtle. Go figure.

[Dan Mays]

The "information" on the Ivy Society site is specious at best.

Can any regular gardener even tell the difference between the English or Irish ivies? Since it is so easy to find these things mislabeled at the garden center, it is doubtful. BOTH the English and the Irish are invasive -- although percentages vary upon location.

Come on people. It is time to assume some personal responsibility. I am always amazed at the number of people "justifying" their own potential thug because they have never seen a problem with it. These are usually the same people who spend little time in the wild.

If you can't make better plant choices than ivy, you really are not trying very hard. Do a little research and expand your horizons.

[Graham Rice]

And see my blog post from January: http://tinyurl.com/yef5u3o

In a comment Suzanne Pierot, President American Ivy Society, says: "The problem with ivy in America is that there is such confusion as to what "English Ivy" is. In the two states (Oregon and Washington) that have problems, it is Hedera hibernica, the Irish or Atlantic Ivy, not Hedera helix the true English Ivy, that is causing most of the problems. There are many cultivars of true English Ivy Hedera Helix, that are very slow growing and would not cause problems."

[Dan Mays]

Sorry, Graham ... This "information" provided by Ms. Pierot was shown in the latest American Gardener Magazine issue for what it is: B.S.

She kind of overlooks reversion as well.

[Eliz]

It depends on which experts you quote. I have seen articles with pages of footnotes on both sides of this. I certainly did not base my post on one person's opinion. But I don't think minds will be changed here. From what I see, people either think ivy is workable in the American garden or they're convinced it's a hopeless thug. I''m still leaning to the former option.

[rainymountain]

Ivy can certainly grow to a mature fruiting vine here in zone 5b which makes it a potential problem. I have banned it completely indoors and out since I saw the rampant damage it does on the Canadian Pacific Coast and in England where it covers many hedgerow trees.

[Karen Russ]

A. Hedera hibernica is in a separate species now. A few years back it was considered a variety of Hedera helix. Being sure which is which is pretty difficult. I sure wouldn't bet on nursery labeling. Species that are in this kind of taxonomic flux tend to get re-classed frequently for a while. They're often in flux because they interbreed more than proper species are supposed to. (See also Hedera canariensis (Algerian Ivy) now moved to Hedera helix L. ssp. canariensis) Don't place bets on Hedera taxonomy.

B. I'm not to convinced that it's only H. hibernica that is a problem any way. According to the USDA PLANTS database, H. hibernica is only found naturalized in NC & SC. Clearly Hedera of some species are invasive in many other states. My bet's on H. helix.

C. Hedera species sport extremely readily. The cultivars - including the small leafed ones - are often/usually unstable and revert frequently. This is a very well know problem of Hedera. Public gardens with Hedera collections have to keep up a steady rogueing schedule to keep their cultivars true.

D. While spreading by vegetative means makes Hederas quite weedy, and can lead to invasiveness when planted next to a natural area, the real problem occurs when

E. Plants become mature and begin producing berries, which are then spread by birds to who knows where. Don't fool yourself that you'll live forever and keep the Hedera on your property from becoming mature.

F. I've seen a lot of definitely H. helix cultivars go to maturity and begin producing berries. Birds seem to enjoy them. I've seen an awful lot of Hedera growing wild in areas rather distant from any yard or houses.

G. The relatively safe bet if you really, really want those cute Hedera cultivars - grow them in containers and never, ever let the vine touch the ground. Better yet, grow them as houseplants. Better yet still, learn to love hostas or some other fun plant with lots of variation that isn't know to be a menace.

[Hilda]

Here in Atlanta, ivy rivals kudzu as a rogue. It comes into my yard from my neighbor's, and it's a constant fight to keep it at bay. While I agree that there are some beautiful and slow-growing cultivars, these are not the norm here -- or at least they don't escape yards and gardens to become a neighborhood pest. I agree that the species form of English (or Irish) ivy should be banned from garden centers. People who plant it don't do enough research to realize there are far better choices.

[Tracey]

I grew up in the North - and always loved the look of ivy - where it seemed to just slowly creep around beautiful old homes. Upon moving down to Virginia, however, I was constantly told about the rampant evils of ivy.

Yet, I still have a nostalgic draw to it - so I grow ivy in big containers.

[Graham Rice]

Hedera helix is native in England, it climbs hedgerow trees - that's its natural place in the world. Is it to be condemned for doing exactly what it's naturally adapted to do? And it's a fantastic wildlife plant.

[Linda]

Anyone gardening in the Pacific Northwest needs to be aware of invasiveness! Ivy (of any variety), Daphne laureola, Buddleia davidii, Ilex aquifolium are all making the forests ill in Washington and Oregon.

[Liisa]

Graham, I fear you miss the point. H. helix is native in England, NOT Oregon. It's not a fantastic wildlife plant if you love the native Oregonian wildlife. The forests in WA and OR are some of the last forests this country has -- I wouldn't sacrifice one tree to ivy. If it's native to England, by all means, let it flourish there!

[Michelle]

Ivy as a groundcover here in California is synonymous with a voluminous RAT habitat.
With so many fantastic viable plant choices available here in the west it is difficult to understand why someone would choose ivy as a bank or groundcover.
Though I can see why some gardeners agree to plant it for their customers : job security.

[Karen Russ]

Kudzu is also an inoffensive plant in it's native Japan where various other organisms keep it in check. Move it to the Southern US, and it takes over entire forests, roads, cars, houses & slow moving cows. Invasive exotics are just that because they are exotic, not growing in their natural habitat with all the natural counter balances. There are plenty of exotic plants that aren't menaces, but Hedera spp. have well proven themselves as big problems on both East and West Coast US.

[Tibs]

"The forests in WA and OR are some of the last forests this country has"? Sounds like this poster is one of those that believes anything not on the east coast or west coast isn't worth a plugged nickel. Lots of forests in the midwest, Haven't you heard of the Great Smokies and the Appalachian mountains? And yes, there are virgin forests still here. Wayne National Forest in Ohio is huge. Sorry, I just get tired of the tired old fly over states mentatlity.

Another nasty invasive vine is honeysuckle. It smells wonderfully but it is another thug.

[Karen Russ]

Hey Tibs, I suspect there were a couple of words accidentally left out of that post. Such as "some of the last

large expanses of virgin

forest left..." Also notice the "some." I think that considering you just inadvertently placed the Smokies and Appalachians in the Midwest, some slack can be cut for minor miswording.

[John]

My question is "are we really gonna win this battle?" Really! The list of invasive species grows longer and longer each day. The amount of effort and work it takes to control some of these thugs is enormous. I just don't see it happening. As soon as someone comes up with a "cure" either the thug evolves a new strategy or a new thug shows up.

I tell people concerned about ivy in their yards to just never let it climb up a wall or a tree. Without height they are locked into their juvenile stage and don't set seed. And there are places in the yard/garden where nothing else will provide what Hedera helix will. Getting an entire planet of gardeners to change their view of what a shade garden should look like is never going to happen.

[Mary Ellen]

Yes to all the above AND: The point is that you cut yours back to keep it in line. Most homeowners who plant ivy as a groundcover let it cover EVERYthing. It's completely overtaken the woods behind my house and I'm constantly hacking it back from my neighbor's fence. Once I year I go back and cut it from the base of the trees, just to help steward the area while I'm living there. Personal responsibility indeed.

[Botany Buddy]

Wrongo on the nomenclature! Hedera helix is the culprit that is overrunning the Southeast and the Northwest and it is far more cold hardy that the Irish cousin, by about 20 degrees. While I do like a nice ivy in a pot, it is plain irresponsible to plant one that is known to be invasive in the ground, even if you have every intention of keeping it under control. At some point something might happen to you and you might not be able to keep it under control.

We have to get over this gardeners as gods complex and stop believing that through our superior gardening skills we can make anything alright if it suits our needs. This is especially true of professional designers who give up control of the things they create. We must remember that we inhabit the earth, not own it. Our mortgages are really leases. I have been as guilty as anyone for using invasives, and we probably all use things now that we have no idea will do harm in the future, but in the meantime we have a responsibility to educate ourselves and do our best not to justify things with our superior skills as gardeners that we know might do harm down the road.

To the Author...the invasive status for ENGLISH Ivy begins in zone 6. Hedera helix varieties are hardy to about -10 degrees. The invasiveness is created by the ability of it to climb and spread and in zone 5 and lower the winters will keep it predominately on the ground. Also once the plant gets high enough, it has the ability to produce a viable seed. It is much like a climbing rose and it doesn't like to bloom (therefore fruit)unless it hangs. The fact that the roots on tree trunks can't survive many zone 5 winters prevents the plant from reaching this stage. You should be alright in Buffalo, but South of the Mason Dixon line the species should really be avoided regardless of the variety.

Thanks for letting me rant!

[Liisa]

Wow Tibs, I said "one of the last" -- not "the last". Bitter much?