How would you grow an effective barrier of annoying vegetation?

April 6, 2006 2:31 AM

How would you grow an effective barrier of annoying vegetation?

What sorts of plants could be grown to discourage people from climbing over a fence? I am thinking of things such as poison ivy, nettles, and various thorny plants. Poison ivy might be a little too much for the gardener and for the invader, whereas nettles are less damaging and have various friendly uses, but are nettles enough? How about some particularly thorny vines? For a northern climate, what's the right plant and how would you cultivate it?

posted by pracowity to home & garden (22 comments total)

I don't think this is a good idea.

Build a sturdier fence if there's some sort of security issue... but this sort of passive-agressive approach seems like it would be a moral (and perhaps legal) no-no.
posted by cadastral at 2:41 AM on April 6, 2006

For Northern climates? Blackberry brambles. Big, gnarly wild ones with thorns like shark teeth. Dense, thick, grows fast and hard as hell to wade through.

Warning: may attract bears, bees, small hungry children and dirt-hippies on mushroom-fueled berry-picking expeditions.


Southern, drier climates? Cholla or bottlebrush cactus. (The first one in that search is a monster. Ow.) I can't think of any plant with more of a serious ouch factor, as in "please call an ambulance. I think I'm slowly bleeding out of about 10,000 stinging, barbed holes" ouch.

I've seen unattentive or sloppy hikers just barely tap an outlying segment with their booted foot and the next thing they know some tenacious son of a bitch of a plant has managed to attach itself and work a few hundred or few thousand needles through thick hiking boot leather and armored sole, effectively trapping the foot inside like some perverse botanical imitation of the swords-and-basket stage magic routine. Which leads to the further insane fun of having to attempt to extract said foot from boot to attempt to remove the needles. (Here's a hint: Find a modern hospital with lots of sharp tools, strong painkillers and a gurney with four-point strapdowns. If that's not possible, carefully cutting the boot off is usually easier then futilely trying to pull all the needles out. The needles only like to go one way, anyway, and they like to go in and through.)

Warning: Like firearms, bottlebrush/chollo is statistically more likely to greviously injure or maim the property owner themselves, or the property owner's beloved children or pets. Not to mention random passerby, nuns, cute bunnies and entire shortbus-loads of small, special children.


Note that your locality may have "man trap" laws that may make this sort of thing illegal, if not questionable.

Also note that if you're a property owner you may be legally accountable for injuries sustained on your property even by tresspassers and actively offending criminals.


What's the dealio, pracowity? Dope smoking kids on the lawn? Dope smoking kids inside the house trying to sneak out and get on some lawn?

Perhaps we could suggest an alternate solution.

Though I'm all for creative usage of offensive plants to protect private property, and anything else that leads to saner attitudes towards personal responsibility. "You got all cut up by my cactus while trying to hop my fence looking for bikes to steal, and now you want to sue me? You gonna apologize to my cactus for stepping on it first?"
posted by loquacious at 3:32 AM on April 6, 2006

A couple suggestions for northern areas are Rosa rugosa and bramble (raspberries and blackberries and kin). Both will form an impenetrably thorny thicket over time, are easy to grow in full sun to light shade (more sun if you're growing for flowers/fruit but full sun isn't necessary for thorns), and are very foregiving about soil/moisture. Both are readily available and relatively cheap around here (New England, USA). You can also dig up rooted starters from anyone who already has a patch. If you plant an area heavily at first with either you'll have a barrier within a year. You'll need some way to keep people out in the meantime. Neither is especially invasive so that you'll have to worry about them taking over your yard if you turn your back.

Barberry (Japanese is the only species available around here, other species elsewhere) works for a more formal hedge. Acanthopanax (aka Eleutherococcus or Siberian ginseng) grows in deeper shade. Neither grows as robustly as the first two I mentioned.

Poison ivy is a very vigorous and invasive plant where it's native (North America) so deliberately growing it where it isn't native (e.g. Poland - based on your profile) is horribly irresponsible if it's even legal and available. Don't do it. Besides, poison ivy's effects don't show up for hours or days so it wouldn't be an effective barrier anyway. Plus it'd cover your whole yard very quickly and you'd be really really sorry.

Nettles would only be effective for a few months of the year and even then I don't think it'd be that much of a deterrent. You can walk through a patch with long pants and sleeves with minimal discomfort.
posted by TimeFactor at 3:35 AM on April 6, 2006

Rose bushes have pretty aggressive thorns, and they look nice, too. Nobody will accuse you of being hostile if you plant roses, even if that's your intent.
posted by Kirth Gerson at 3:40 AM on April 6, 2006

Raspberry bushes grow like mad in my part of New England and are painful (I know, I'm the one who cuts them back). I planted three little ones and in a year and a half they covered an area about 20 ft. wide. Painful, yet delicious. Very little maintenance, if any (unlike roses, although their thorns are much larger in general).
posted by theredpen at 3:48 AM on April 6, 2006

Another vote for the berry bushes. Tasty summer fruit a bonus!
posted by twistedonion at 4:03 AM on April 6, 2006

unless of course people would hop the fence to get the berries. . .
posted by lisaj32 at 4:16 AM on April 6, 2006

I'd vote for the roses. I started a cutting off a wild rose and it covered a 6' bed the first year. It likes sun, but grows like the weed it is with little encouragement, and has a bazillion thorns per inch. Looks pretty, but you coouldn't stand to poke an arm into it to get into mischief. Comes up from the roots if molested (the neighbors tried that experiment.) Doesn't take over the place, and easy to discourage if you pull it up by the roots. If you started with cuttings about a foot long and just stuck them in the ground, they'd all take root and go nuts by the end of the first summer.
posted by unrepentanthippie at 4:21 AM on April 6, 2006

"As in 'please call an ambulance. I think I'm slowly bleeding out of about 10,000 stinging, barbed holes." made my day.

That is all.
posted by disillusioned at 4:32 AM on April 6, 2006

I'll try berries and roses -- good for the birds and the bees -- and see how that goes. With luck, I won't have to resort to anything that yells "Feed me, Seymour" through the window.
posted by pracowity at 4:36 AM on April 6, 2006

I've never heard a cholla cactus talk, but they sure look hungry. Regardless, berries and roses'll probably suit you better. Most cacti don't like frost or snow.

I often see cholla and other viciously-spined cacti planted beneath windows and other weak security points at homes all over Arizona, but then Arizona has one of the loosest firearm carry laws in the US and is often still quite "Wild West" in it's sensibilities. It's not entirely uncommon to see a civilian openly carrying a handgun in a visible holster even in the Phoenix Metro area.

disillusioned: Making the morbid funny seems to be a knack I have, but I don't overstate the case. If you ever find yourself in the Southwestern deserts of the US, pray for sturdy shoes, step carefully and slowly and watch yourself. Even marginally tangling with a cholla can maim you pretty good, and people often snag the break-away segments on pants or shirt hems, only to have the heavily barbed segment swing around and embed itself in something fleshy. (This is why one of its names is "jumping cactus")

Accidently tripping and falling into one wholesale is survivable, but not an experience easily forgotten. I'd seriously, honestly rather dive into a bin of (clean) hypodermic needles or x-acto blades.
posted by loquacious at 4:58 AM on April 6, 2006

Northern: stinging nettles
Southern: kudzu

Neither solution will make you popular with the neighbors, but that's your point, innit?
posted by beelzbubba at 6:42 AM on April 6, 2006

I've found roses to be tempermental things that don't like a heavy winter. Rasberries on the other hand are almost unkillable if they get enough water.

loquacious writes "I've seen unattentive or sloppy hikers just barely tap an outlying segment with their booted foot and the next thing they know some tenacious son of a bitch of a plant has managed to attach itself and work a few hundred or few thousand needles through thick hiking boot leather and armored sole, effectively trapping the foot inside like some perverse botanical imitation of the swords-and-basket stage magic routine. "

Yet another reason to not lament winter.
posted by Mitheral at 7:07 AM on April 6, 2006

I'd go with some holly bushes. They are dense and really scratchy and itchy. I won't trim mine without gloves and long shears. There is no way I'd try to climb over one (barring life and limb emergencies). As a bonus they look pretty nice, do well in winter and have pretty (and poisonous) berries.
posted by oddman at 7:52 AM on April 6, 2006

Holly? How do you grow holly?
posted by pracowity at 7:59 AM on April 6, 2006

I'd say holly as well. It's pretty, it's pretty universally known as an ouchie plant, and if the rest of the holly-tree-world is like the one my parents have, it'll survive a nuclear holocaust.

My folks cut down a holly tree along side of their house when I was a kid. They left the stump, thinking it would die and they could remove it easier.

They were wrong. Booooy were they wrong. The stump - less than 6 inches in diameter, turned into a 20 foot tall holly tree by the time I was eighteen.
posted by FritoKAL at 8:21 AM on April 6, 2006

Blackberries, at least in North Carolina, are hideously invasive and I curse the previous owner of my house who apparently thought that they were a good idea around the property boundaries. They're doing their level best to take over my whole yard and I'm not having any luck discouraging them; I think I need a full suit of plate armor to wade in and pull them out by the roots. So I want to speak for future generations who may live in your house: please, please go with the holly or the roses, not the berries.
posted by mygothlaundry at 8:49 AM on April 6, 2006

Yeah, what mygothlaundry said... if you put in blackberries, be prepared to have them springing up all over your lawn, forever. They seem to send out exploratory roots deep underground, which emerge as unkillable sprouts, which cannot be removed without major excavation. And probably not even then. Attempting to remove them by chemical means will lead to small circles of curdled death surrounding perfectly thriving blackberry sprouts, which will mock you with hollow laughter.

The berries are yummy, though.
posted by ook at 9:00 AM on April 6, 2006

Another vote for roses here. Rosa Rugosa is a very hardy, very thorny sub-species of rose that grows quickly and can cover a fence well with a little training. Most kinds can survive very cold winters unscathed, all the way down to zone 2, unlike other kinds of roses which may not be hardy except to zone 5.
posted by Asparagirl at 9:25 AM on April 6, 2006

I'm suprised no one's suggested a bougainvillea. We have one - it can make you bleed. Its thorns are (guesstimating) 2-3" and are woody (they're very tough). It's been dry season for a while, the rest of our lawn is brown and it's still doing well. We are in Zone 9b (C.FL) with very sandy soil. So it seems pretty hardy.

Here's a couple links about how much people hate the thorns. They have a reputation for being used to discourage people from breaking & entering or whatnot (ie. planting them by windows). Plus, they're pretty! And we haven't had any problems with it trying to spread itself all over the yard or anything - just one in one place and it's stayed there for years.
posted by mojabunni at 11:24 AM on April 6, 2006

Bougainvillea looks great, but it's a tropical plant and I'm on the Baltic coast. It's going to be just a degree or two above freezing every night this week.
posted by pracowity at 11:33 AM on April 6, 2006

In northern California, the non-native Himalayan blackberries do spread invasively, but native blackberries are less aggressive. I'd check what's native in your area. In other words, I think mygothlaundry's central point was probably not "never use blackberries" so much as "don't use plants that will spread uncontrollably in your area -- whatever those may be."

I'd ask a local nursery or ecologist to recommend some thorny native shrubs or vines.
posted by salvia at 5:40 PM on April 6, 2006