[Stonehenge]

I saw Voodoo post about this particular plant, so I thought I'd ask - Rhamnus frangula 'Columnaris', Columnar Buckthorn, I believe is on the list of invasive weeds in MN and is illegal to sell and to plant there. It's still legal in Wisconsin, and honestly, I do use it. I'm aware of it's propensity to spread far and wide, with the bird-delicious berries being sown everywhere. But I have yet to find a deciduous plant that can do what this does, which is grow very narrow and tall. I had a nursery recommend a Peking Cotoneaster (Cotoneaster acutifollus, I believe) as a replacement, but they are much fuller and more leggy than the buckthorn.

What would be a suitable replacement for this plant, so I can continue to be in the good graces of my fellow landscapers?

[VoodooChile]

I've yet to see a nice columnar Buckthorn...in fact here in Zone 4b/5a (depending on microclimate) they mostly seem to be 3/4ters dead, leading me to question their hardiness classification, which Dirr gives as zone 3. Then again, maybe it is just bad nursery production, compounded by poor planting practices, that has rendered all I've seen "dawgs".

If a plant is predisposed to a quick death, can it be invasive?

Dirr mentions invasiveness several times in his entry on Rhamnus frangula, and if all else fails, trust in Dirr and higher taxes.

Replacements in the shrub category are scarce; I have several lists of fastigiate trees, and have seen some like the Newton Sentry Sugar Maple that are an impressive 30' tall and maybe 4' wide (Delavan Arboreteum, Delavan WI)...but I don't think those would do, would they?

Maybe try a multi-stemmed fastigiate understory tree that can have exterior-stems removed periodically to keep an upright form: say 'Regent' Serviceberry or 'Golden Glory' Cornellian Cherry Dogwood. Some of the newer Arrowwood Viburnum cultivars (like Morton ('Northern Burgundy')) would fit the bill and not produce so much height.

If you are willing to go with a conifer, there are plenty of choices.

Just wondering Stonehenge, in what situations do you use these columnar Buckthorns? Maybe there is a different design approach that wouldn't rely so much on columnar plants...

[VoodooChile]

Just ran across these Columnar Buckthorn last week, and the lead wants me to make things look better, but not replace any plants!!! Supposedly these were put in just last year...

[Stonehenge]

Those look awful - and hard to believe because I don't think I've ever had a buckthorn look that bad. Nothing to do with me, because I've killed plenty of plants, just that that stuff is usally pretty hard to kill.

[Lawn Lad]

This is a funny thread... Vodoo gives good ideas for alternative plants. I know I can learn a thing or two from ya. Buckthorn is one of the worst offenders in messing up the shapliness of hedges/plantings. When pruning we remove the 3 D's first thing (dead, diseased, damaged). In reality we remove The 3 D's and B - to include Buckthorn or any other weedy plant growth that is considered foreign to our plantings like volunteers, etc. I never understood why anyone would plant buckthorn particularly when someone told me that it will only live 15 or so years. I don't know the particulars - but what a horrible plant. I love getting a new customer with lots of pruning - we sure do remove a fair bit of buckthorn.

[Paul]

I don't have to deal with tight areas very much but I think this plant might show a better habitat...... Amelanchier Canadensis "Prince Williams" It's habit is 10' tall and 6' wide and a slow grower. It can be maintained narrower. Added pluses are nice flower and great fall foliage

[Stonehenge]

Voodoo, my use of these guys is usually in places where I want to create a seasonal screen and don't have much room to do it. I can sometimes employ 'green fences', an arbor/trellis with vines, but often there is not room in the budget for something like that just for a screen.

The Arrowwood may fit the bill - I'm not sure I should count on my clients providing any level of maintenance to keep something within a certain spread/size. Then again, maybe that's an opening for a future add-on service.


Mmmmm....pretty Buckthorn berries.....

[VoodooChile]

Stonehenge,

Two things occurred to me today while thinking about this thread and killing Prickly Pear Cactus.

First, maybe all the columnar Buckthorn I've seen look so bad because of poor pruning practices. I know some shrubs, like Highbush Cranberry, don't respond well to shearing and topping. They don't seem able to heal end wounds well, and entire stems die-out making for a very ratty plant. This usually occurs when the Highbush Cranberry is being asked to remain 6' tall, and wants to be 20'...after all, why do they call them "Highbush."

Maybe columnar Buckthorn are the same way...I do know those in the picture really wouldn't need pruning in that site (if they were alive), but that doesn't stop folks from reaching for the shears...

Pruning with a Purpose is rarely Practiced.

Second, what about ornamental grasses? We are struggling to come up with a compact-sized deciduous fastigiate shrub, when there are ample number of grasses that fit the bill.

'Karl Forester' is very upright, and Calamagrostis x acutiflora 'Stricta' gets 6-7' tall while only 24-36" wide. 'Blondo' Miscanthus tops out at 8-9'. Panicum virgatum 'Northwind' hits 6' while only 30" wide. All four I've named take light-shade (some more than others), and are four-season grasses, retaining upright foliage through Winter, adding movement and color to the Winter landscape.

I was a bit intimidated a couple years ago when I started to introduce grasses into my designs, but they are so versatile, self-sufficient, low-maintenance, and shack up so well with so many other perennials, I've really come round and frequently think grasses first, before I resort to woodies.

[VoodooChile]

LawnLad,
Three cheers for your dead buckthorn! Few things provide more pleasure than topping a buckthorn, cutting through its sparse shallow roots, and ripping it right out the ground. I've killed thousands, if I've killed one. Happy to hear you're in the trenches, slaying the fell-beast!

[justgardens]

There are Columar Barberry 'Helmond Pillar' ( hard to find in stock)10' ht. and a Viburnum called 'Pathfinder' that gets only3-4' wide and 5-6' tall. There is also a columar Boxwood but the name escapes me right now.

[Bill Schwab]

Ah do I ever miss Serviceberries! They need 500 freeze hours to survive and we never freeze. What about Chicago Lustre Viburnum, or how bout columnar Hawthornes? An Illinois native used everywhere by the God Father of landscape architecture..Jens Jensen

[agla]

The first question that I would ask to fill your request for an alternative to Buckthorn would be how are you using it. It is rare to see where I am. When I do see it, it is in a crappy looking hedge.

The picture posted above shows it being used as a foundation/AC screening plant. It seems to me to be a poor choice for that regardless of health or invasiveness. In that case, the need to replace it with a similar form seems pointless.

Form follows function, or so it should be. The question should be "what plant can I use to_____________?". Create a hedge, a border planting, add a vertical element to a foundation planting, ... The function is going to stear the response in varying directions. In many of those cases Buckthorn may not have been high on the list to begin with.

Here we have other plants on the invasive (not yet illegal) list. Barberry, European Bittersweet, Autumn Olive, English Ivy, several Honeysuckle, Privet, Rose of Sharon, Burning Bush, Norway Maple, to name a few. Of these, I have noticed some tendencies toward reseeding or spreading. The only ones that I notice as a big problem are Bittersweet, English Ivy, and Honeysuckle.

No matter what you have to stop using, there is usually something that can replace its function, if not its form.

[VoodooChile]

But agla, you must admit that with plants, form is an integral part of function.

In Stone's scenario, he needs a narrow upright deciduous screen. It's the form of say a Norway Maple that doesn't allow it to succeed in this function...

...or maybe I've misunderstood you?

[agla]

I am trying to point out that replacing a Buckthorn with a Cotoneaster will work in a border planting, but not as a narrow hedge plant. I am also pointing out that the form of the Buckthorn did not work effectively in the picture above and replacing it with a different form would be a better solution than to mimick it.

The point is that sometimes we get in the habit of using certain plants when they may not be the right plant for the particular circumstance. If we have to rethink using Buckthorn, it might be a good time to rethink the form of the plant for the circumstance while we are at it. Rather than having a single one form fits all substitution, it may depend on exactly what we are trying to do with it.

[justgardens]

Stonehenge,