Wednesday, September 14, 2011

Lone Rose Eradication

It’s not unusual while out walking to come across a single specimen of an invasive plant. How to handle the situation seems to be a subject of some debate. A good example is this lone Multiflora Rose that I found in the woods. At the moment, this rose isn’t causing much of a problem. Lack of sunlight has caused it to produce long, spindly canes and there is no evidence of fruit production. In time, the canes may catch in tree branches where they will be supported. Future growth will move up through the tree in like manner until sunlight is reached. Then fruit will be produced and the birds will begin distributing seed in the surrounding area. It’s just as likely that the rose will eventually die, but I always expect the worst.

Four of the seven canes on this rose are already dead. This is typical of roses growing in the woods. The bushes seem to go into a cycle of decline and resurrection. Early season growth is rapid because of the more open woodland canopy. When the canopy closes in mid-summer, energy production is reduced and the rose becomes stressed. The result of the stress can be die-back of top growth or a reduction in root mass. In either case, the plant takes a step backwards and has to rebuild itself. The speed at which these things occur varies depending on weather patterns and other environmental factors.

Just cutting the canes off at the base is a waste of time. This action causes little harm to the rose and sprouts will quickly grow to replace what was removed. Multiflora Rose also has the ability to develop shoots from shallow surface roots. A severe pruning may just invigorate the bush and result in even more canes.

Years ago, I did some experimentation with manual removal of rose plants and found that buried roots had a very small chance of surviving to produce new top growth. I also discovered that this manual removal was only practical on medium sized plants with a base that wasn’t much bigger than my fist. Before doing any cutting, I use my knife to loosen the soil and trace the pattern of the roots. My goal is to cut all roots at a point enough below the soil surface that they are unlikely to sprout.

There’s always a vertical root beneath the base of the plant. I start by jabbing my pruners under the base and cutting the main root. I then follow the horizontal roots outward to the point where they are covered by about an inch of soil and cut them. In case you're wondering, the knife and pruners are always with me when I walk.

After removing the plant, I spread the leaf litter back over the bare soil. Some criticize this method by saying that the rose will grow back. I’ve already learned that it rarely regrows and if I haven’t killed it, I’ve surely given it a significant set-back. Others criticize that I’ve created an area of disturbed soil into which a seed from an invasive plant can fall and take root. I think that having conditions where an invasive plant might develop is a much better situation than already having the invasive plant in place. I do things because they produce positive results for me on my property. There are so many unique variables in play that it’s often hard to see why a particular management method is successful one place and a failure in another. That’s why I always apply new management techniques in small doses and carefully monitor the results before deciding if the method is good or bad. As for the Multiflora Rose, even if all I accomplished was to delay its dominance by a couple of years, I can’t just walk away and leave that one plant in an otherwise invasive free setting.

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