Invasives

Invasion of a garden snatchers?
What?s spreading all over and how to get rid of them

Why people plant invasives ? The problem with invasive plants ? How to get rid of the worst of the worst

There are some plants that should be banned. This makes people mad but the two shown here are toxic beauties. Though they seem harmless enough, they are not. Plant such as goutweed and Himalyan balsam are attractive but they will spread everywhere under any soil and light conditions.? Goutweed has a root run of up to 20M (not exaggerating) and it will continue to spread under sidewalks, roads, rock and any other impediment only to pop up metres away.

Why people plant invasives

Goutweed especially is often used by landscapers to cover up slopes to prevent erosion, or to grow in dry shade or simply to fill in space. Resist all these temptations?there are always other better plants. I saw a neighbours planting it a few years ago and begged him not to. When I explained why, he said ?Good I want it to cover all this up.? He pointed to a hopeless bit of earth under a tree. Well it?s covered that up and is coming up and will soon take over three neighouring gardens. If it gets into my own complicated garden, I?m a gonner. My life will be turned over to goutweed eradication.

The problem with invasive plants

The problem with these invasive plants is that you just can?t get rid of them. They have no enemies, they will elbow everything else out of the way. I know people who?ve been at it for decades and still keep finding little bits that, if left alone, will spread once again. If you start dumping chemicals all over them, you run the risk of despoiling everything else around.

If I sound angry I am.

Nurseries still sell goutweed without warnings that they should ONLY be used in containers. It?s hard enough gardening in a cold climate without these bruisers making it even more difficult. Out with the invasives.

How to get rid of the worst of the worst

  • Goutweed, Aegopodium podograria ?Variegatum?, the glamourous relative of ground elder, spreads by vicious stolons, should only be used in a metal container or on a slope where it?s completely hopeless to plant anything else.
    Cut the plant to the ground (do not pull?it just makes new mother plants), then cover it with about 15 layers of newspaper, cover that with a sheet of black plastic held down by bricks (solarization). If you find it among other plants, cut back to the ground and then dab with horticultural vinegar (powerful stuff if you can find it at the nursery).
  • Himalyan balsam, Impatiens glandulifera, is such a pest in the UK, where it has naturalized all over the country, they have balsam-bashing parties. Rip the stuff out completely. Or whack it back before it starts to seed. Each plant produces 800 seeds and can shoot them 7M away. They shade out other plants, and knock out everything in their path.
  • Japanese knotweed, Fallopia japonica (Polygonatum cuspidatum), has a bamboo look to it, silvery flowers and lethal root stock. You can start digging out the huge roots now, cutting it back to the ground but don?t let anything?not cuttings, not roots?remain in the garden, the will re-root almost immediately. Bag them and get rid of them. Then solarize as in goutweed.

You must be patient and you have years of work ahead if you are lumped with these toxic beauties. And warn anyone else you see with them in their gardens. Only constant vigilance will help us get rid of these pests.