This year I am trying a little experiment with weeping willow trees in the swamp. Since, I cleared out a couple acres for the goats, some of the street and neighboring houses are in view from some areas of the pasture. It would be great to plant a screen of trees, in the low marshy ground. This area gets full sun, however, there is only about six inches of “soil” before you hit the water table. Also, this area will seasonally flood (usually in the late winter/early spring) for a month or more. Also, I needed to take into account the USDA plant zone 6A conditions which can experience temperatures as low as -10° F (-23° C). What kind of tree can live under these conditions yet also will grow tall enough to act as a screen? Well, the willow tree might be the answer.
I decided to do a bit of research on these trees. The Internet seems a bit conflicting on exactly what USDA plant hardiness zones are suitable for weeping willows. Some sources seem to indicate the trees can live in 6A-9A and also 6-8. I have also seen 2A-9A (that is a a huge difference), and still others indicate 4-9. The label on the trees says 5-9. So, it seems there is some disagreement on exactly what this tree will tolerate temperature-wise. This may have to do with the confusing array of cultivars that are available. However, since they sell these trees at the local Tractor Supply, and there are many willow trees thriving in the area, I am pretty sure I am “safe” to plant one.
Regarding maximum overall size, likewise it is tough to determine. Internet sources seem to indicate somewhere between 45 and 70 feet tall. The Internet does seem to agree that these trees are very fast growers, averaging somewhere around 3- 10 feet per year of growth once established. I am sure all of this also depends on cultivar and also the overall growing conditions.
An interesting aspect of these trees is there renown ability to quickly grow a massive horde of invasive roots that aggressively seek out water. They are infamous for plugging water pipes and septic tank leach fields and for working into cracks in building foundations and tearing them apart. The clerk at Tractor Supply actually warned me of this. However, I have nothing to fear about this, as I am planting these trees in the middle of the swamp.
Some other Internet sites seem to claim that weeping willows (and other similar trees such as River Birch) will actually dry out wet soil. Again, the research on this is spotty at best. Most sources seem to indicate that a full grown tree of weeping willow size, will absorb about 80 to 100 gallons of water a day. Sounds impressive, but that is just a drop in the bucket (or swamp?) next to the amount of water in this 10 acre marshy area. Also, trees tend to absorb more water during hot, sunny days than they do during cold, cloudy days. During the heat of the summer the swamp is mostly dry anyway. If my intention was to dry out the swamp, I would need to plant hundreds of trees to have any effect at all, and then only maybe.
At any rate, I ended up buying four willows to plant as a semi-experiment. I then grabbed my grub hoe and trudged through the swamp to find suitable locations to plant. I chose a grub hoe instead of a shovel because the soil is covered with a virtually impenetrable layer of Phragmite roots. After digging about 6 inches, sure enough, I hit water and the hole immediately filled.
I know weeping willows love water, but I am not sure if they can tolerate this much! At any rate, I planted it firmly and am hoping for the best. Overall, I ended up planting for four trees in total this way. I will provide an update next year and report on their progress (Update available!…..see below). I will leave you with a few random weeping willow tree facts:
- Scientific name: Salix babylonica
- Weeping willows are native to China, but have easily adapted to other areas and are now widespread in the U.S.
- These trees have been grown as an ornamentals in the U.S. since colonial times
- They have a relatively short lifespan of around 30 years
- They are considered “weak-wooded” and do not seem to compartmentalize decay very well. Small mechanical injuries can cause rapid decay and death of the tree.
- You can easily root small branches by soaking them in water. They will develop new roots in about 2-3 weeks
- Since ancient times ( ~400 BC) the Greeks and Romans knew that chewing on willow bark was an effective way of treating fever and inflammation. The bark actually contains a compound called salicin which works similarly to the active ingredient in aspirin (acetylsalicylic acid). In fact, the invention of aspirin was inspired by the folk use of willow bark. Salicin, although effective, is very harsh on the stomach. Acetylsalicylic acid was determined to be a much milder form of the chemical with the same therapeutic properties.
- There is a great deal of myth and legend surrounding the weeping willow. Usually these revolve around the “sad” look of the tree and how this came to be. In the bible Psalm 136 mentions “By the rivers of Babylon we sat down and wept when we remembered Zion. There on the willow-trees we hung up our harps.” Nowadays, scholars generally think this was a mis-translation and the trees were actually poplars. However, the association of “sadness” with weeping willows seemed to endure.
- There is a legend that a weeping willow knocked the crown off the head of Alexander the Great as he rode his boat under it while crossing the Euphrates river. The superstitious folks at that time thought that this predicted his subsequent downfall shortly thereafter.
May 2014 Update
It has been almost exactly one year since I planted these willows trees. This past winter was incredibly harsh, even for NH. Hampstead had close to 90 inches of snowfall, and the temperature routinely dropped below 0° Fahrenheit. Coupled with this, the beavers had rebuilt their dam over the winter. This caused the water to back up and literally flood the entire swamp with about 1-2 feet of standing water.
This weekend I smashed down the beaver dam and drained away much of the water. I then trudged out into the swamp to check on my willow trees. Much to my surprise, all the trees were in good shape and leafing out nicely! Most of the trees put on about 2-3 feet of growth last year even though they were just planted.
Although they put on some new growth, it is wispy and the overall girth of the tree has not increased much, but again this is still encouraging as most trees don’t grow anywhere near this much their first year. Also encouraging is the fact that these trees survived being completely submerged in water. Even after destroying the beaver dam… they are still sitting in a few inches of water.
In fact, if you look closely you can see where new rootlets were forming on the submerged trunks.
All in all, it looks like these willow trees are going to survive this swampy terrain! I will report back next year with another update. I suspect they will put on a good deal of growth as this is their first year being fully rooted. I am also going to swing by Tractor Supply and pick up another few trees to plant!
April 2016 Update
It has been almost two years since my last update here, and almost three years since I planted these willows.
I was a bit surprised that they had not grown much in the past couple years. This one particular tree has a noticeably larger girth, but it is not much taller. I am wondering if the waterlogged soil is somewhat devoid of nutrients or if there is too much competition from the fragmites and cattails. At any rate, it is just starting to leaf out this year and is very much still alive. At the rate we are going, it is going to be awhile before this is tall enough to act as a screen.