Plants That Live for Hostile Takeovers
“I shall watch with interest the list you plan to publish. I hope that none of my recent plantings appear in it!” The list referred to is that of plants that become pests in the garden--ones that should, perhaps, have warnings posted next to them at nurseries, just like those warnings appearing next to toxic chemicals because the Safe Drinking Water and Toxic Enforcement Act came into effect a few Saturdays ago.
Tomatoes are not on the list, though they could be, because they often pop up as seedlings after using certain soil amendments that contain sewage sludge (the seed somehow survives the whole sewage treatment and composting process).
Aggressively Stubborn
But a surprising number of common plants did make it onto the list, so many in fact that it is apparent that many plants are popular because they are so aggressively stubborn about staying in the garden--you just can’t kill them even if you should decide to.
One reader noted that he will never again plant anything that garden books say “grows fast” after some bad experiences with elm trees and a few fast shrubs: “My advice is not to go looking for instant shade or instant greenery.”
Topping our list, with the most nominations from readers, was Algerian ivy, perhaps the most common plant in Southern California and, judging from the comments received, one of the most stubbornly persistent.
Some of the descriptions of Algerian ivy read like a Stephen King novel: “It grows a foot and a half high, rats, mice and spiders live in it, pets get caught in it and it looks absolutely ghastly. You have to keep cutting it off the walks and it invades flower beds. The more you try to dig it out, the more it comes back.”
Hillside Erosion Fighter
Ivy sounds absolutely delightful compared to another ground cover that’s often sold through the mail, crown vetch (Coronilla varia ). This one should probably be banned from California, for though it’s tough and useful in colder climates, it is a noxious weed in our mild climate. “It’s great for erosion control on hillsides, having roots that must go all the way to China, but never --but never --let loose this demon in your garden.”
Next on the list of “demon” plants is an asparagus fern, but not all asparagus ferns. The one in question is the ferniest of the bunch, the one seen in florists’ bouquets with “fronds” roughly triangular in shape-- Asparagus setaceus --but its delicate appearance is apparently misleading.
The stems are armed with thorns “making it a bloody proposition to pull out,” and it spreads by seeds and roots. “I am cursed to keep trying to dig it out. I recently noticed a few volunteers on the other side of the property (75 feet away) and what is more disturbing, noticed it starting to grow on the chain-link fence at the head of my parking stall, 42 miles away in Orange County. Surely the runners aren’t that long, but the plant may be capable if given the chance.”
Warning: Creeping Fig
Nominated by many was the creeping fig (Ficus pumila , also called Ficus repens ). “This little darling should come with two types of warnings. The first to graphically spell out the coverage of one little gallon-size plant. My friend had one completely cover her entire back wall in no time (the Sunset Western Garden Book says it can ‘envelop a three- or four-story building’). The second warning is about the invasiveness of the root system. After she told me the horror she went through to remove her one plant, I immediately pulled out the seven I had planted along the side wall.”
Another reader noted that “it grows into the mortar of block walls” and warns “just wait until you try to get it into trash cans. It grows so intertwined I end up having to cut it into chunks.”
Another vine that made it onto our list of menace plants is honeysuckle. Actually two honeysuckles qualified--Japanese honeysuckle (Lonicera japonica ) and giant Burmese honeysuckle (Lonicera hildebrandiana ).
“I have performed two dusty, wearying major cleanups of honeysuckle in the past three years, at two different houses.” This reader, who must now qualify as an authority on the subject of Japanese honeysuckle, noted that while it beautifully covered a 40-foot fence, “it also encased a chicken coop that I wanted for a tool shed” and “had spread--ground-cover style--over about 100 square feet of prime flower bed area.”
Burmese honeysuckle apparently deserves the name “giant.”
Weekly Patrol Mission
“We planted a vine of it to grow over our aviary for shade. We removed the aviary and the original plant in 1980. We were still trying to get rid of it in 1987. We had a crew come in on at least two occasions to dig it up from the bank where it had taken over like a ground cover. It would have been fine if it had stayed on that bank, but I found it growing in flower beds 100 feet away from the original plant. I finally took to going on weekly patrols with a spray bottle of Roundup. I had the feeling that if I didn’t, I would wake up to discover it had grown over the house.” (Roundup is a herbicide--glyphosphate--also sold as Kleenup, and is used by many readers to get rid of their menace plants. It also happens to be on sale today at any Builders Emporium for those who have yet to get rid of theirs.)
This by no means concludes our list. At the moment we have an astounding 60 varieties of menace plants and will include the others in a future installment. I will mention two others now, however, because we recommended planting them a few weeks ago.
Impossible Golden Yarrow
They are perennials. “Golden yarrow has roots that crisscross and are virtually impossible to eradicate” and “Physostegia virginiana should definitely be on your list of objectionable plants. It spreads by roots and rootlets and if you try to dig these plants up, you must get every single root. If you fail in this task, a forest will spring up. I once saw this plant in a nursery with the tag of ‘Obedient Plant’--that was a misnomer for certain!”
I grow both of these plants in my own garden and have for years, and yes, they spread, but I have kept them under control--so far--and can’t imagine not growing them because they have such pretty flowers. Perhaps I’ve just been lucky with these two. But you have now been warned, if a trifle after the fact.
To the lady who wrote “I will follow your column more closely in the future,” thereby hoping to avoid planting any of these menace plants, I can only say I’m sorry; even garden columnists plant things they later regret, beguiled by fast growth and pretty flowers.
