The History

While putting the Tolman Guide together, we learned that poplar trees are great soil remediators. They take up toxins from soil, cleaning the soil. I already knew that sunflowers do the same thing, and in ten years sunflowers, when planted on a brownfield, will clean the land. What I didn’t know, and was sad to learn this year, was that poplars are not ideal for urban spaces.

In fact, the poplar tree can be so prolific as to act like a weed. Because of the compaction and density of houses, poplar trees don’t grow like they would in open country, and the trees (according to three arborists, 2 certified) are weaker and prone to falling as they get older. My husband and I were quite disappointed to learn this because we had been quite pleased with the very quick shade they brought. Several of the ‘suckers’ shot up 6+ feet, some reaching 15 feet, in about 18 months!

It started with the neighbor wanting to cut down his ‘problem’ tree. He hired a tree guy (not a certified arborist) to cut down this tree he thought would impact his foundation in 40 years. This was the summer of 2007. The tree is directly on the property line, and we wanted the shade and did not want to pay this shady tree guy, so we instructed him to leave ‘our’ tree alone. Shortly after half of the tree was felled, we began noticing these weedy things in our yard. The ‘weeds’ followed the root line of the felled tree. This summer, 2008, we consulted our Audubon book and learned our prolific weeds were indeed white poplar. These suckers, as they are called, kept popping up in odd and annoying places, and they were getting more difficult to mow over; so we called in the professionals.

We had three arborists come out. Two are certified by the ISA. The low-ball bid (the first, non-certified) quoted $300 to remove all the trees. There were about a half dozen. The second, $600, and we’d get the wood chips they would make on-site. The third (Green Options) quoted $2000 but offered a home remedy. All agreed we were addressing the problem at an early, preventive stage.

The Remedy

James Kinder of Green Options saw our plight and suggested we do it ourselves. Being in the infancy of the problem, he instructed us as follows:

1. Cut all tall (tree-like, not weed-like) suckers
2. Within one-half hour of cutting, saturate fresh trunk with vegetable oil

The trees take big gulps of oxygen trying to survive after being cut, and by dousing them with oil, you effectively suffocate the tree preventing it from spreading.

Next, you have to take care of the weed-like suckers. Kinder gave us a homemade recipe for weed-killer. He told us that Roundup is actually based on a similar (or the same) base as vinegar, it just has all the unnecessary stuff added.

Homemade Weed Killer Recipe

• 1-gallon white-distilled vinegar
• 1 tablespoon dye-free liquid soap (like dish soap)
• 1 tablespoon sea salt

1. Add all ingredients in a pan
2. Boil
3. Put in a spray bottle
4. Spray on plants while hot

Next, cover the severely affected area with newspaper, then add 90% weed-free topsoil. The area should be ready for planting in about 6 months.

The Results

We noticed results with the weed killer within a few hours, most noticeably 24 hours after application. You spray the leaves of the sucker, and within a day the sucker begins to wilt. Some plants come up easily, some do not. We ordered 4 cubic yards of screened, weed-free topsoil. We covered the area, about 15′ long and 3′ wide, with newspaper, a few sheets thick throughout. Then we shoveled the dirt onto the newspapers. Then the rains came. We’ll catch up in 6 months and see how well it worked. Kinder instructed us that the few suckers that will remain should then be easy to pull up by the roots.

It’s important to remember that all ingredients are found in the kitchen. Most people have vinegar and vegetable oil on-hand. I didn’t ask what properties sea salt added over iodized salt but would conjecture the lack of iodine. Some grass was killed, but we buried the rest in soil anyway. This process is green, but do be mindful of the smell of the hot vinegar concoction; I have not had levels tested for toxicity.