Buckthorn control

[John Mc]

I have a lot of buckthorn on my property. I've done a lot of work on it off and on over the years. Most of my treatment has been putting glyphosate on cut stumps. With the right concentration, I've found it to be very effective. 

I've always avoided doing this in the spring, since I've heard the glyphosate won't "take" during the flush of spring. However, recently I've fallen behind in my management plan work. I've got some time to work on it now (off work until a broken bone in my foot heals up). Is there any point in doing cut stump treatments now, or am I just wasting my time?

If there is no point in cut stump treatments, is there something else I can be doing? I don't have herbicide options other than glyphosate, since you have to have a license to buy and apply anything else in VT. I do have a friend with a license, and I could work "under his supervision" with other stuff, but getting our shcedules to mesh may prove difficult.

[ahlkey]

The problem you have with doing treatment prior to-leaf out is the tree sap is rising at this time and will reduce the amount of herbicide taken up by the tree. That will reduce your results significantly. Anytime after leaf-out you are fine.

[John Mc]

Thanks, Ahlkey. That's what I've been doing up to now (and usually well after leaf out).

I was hoping there was something that is effective now, while I have some time on my hands. I'm hesitant to cut and treat now, wait for the inevitable sprouting, then cut and treat again, because I'm concerned that the small sprouts won't take up enough to kill the root system.  Also, if I have to go back to cut and treat again, what's the point of my initial cut and treat?

[ahlkey]

Just a thought.  I know of business a couple of hours away from me that treats Buckthorn by taking a hatchet and cutting off a portion of the bark stem and spraying it with 25% Garlon-4 mixed with Diesel Fuel or Crop oil prior to leaf-out.  My son worked for him for awhile. 

[John Mc]

I've heard of that being used around here as well. Do you remember what season it is most effective in? I think I recall some folks doing that method or basal bark treatments in the winter.

Of course, in VT, I'd have to hire someone to be legal. I can't buy Garlon without a license. (Not that that stops a number of people I've run in to.)

[ahlkey]

Yes he applied it during the Winter.

I have often wondered though if you used glyphosate at with a higher concentration say 33% glyphosate  to crop oil/diesel fuel would you see positives  results?  It sure would be nice to discover an approach that would work, be cost effective, and be undertaken during the winter months when times are slow.  I can get Garlon here but it is expensive while glyphosate is cheap.   

[John Mc]

I typically use around 33% glyphosate for my cut stump treatments, I buy a concentrated roundup clone and dilute it with water. I don't mix it with diesel - that's not necessary for cut stump treatments (and I believe the Roundup and other brands already have a surfactant in them). It's been effective when I apply from late June into October (I haven't tried much outside that date range). If I go below about 25%, results tend to get spotty.

[ahlkey]

33% seems high as I believe the standard recommendation is 20%.  However, I do mix it 50/50 which gives me almost 25% depending on the glyphosate used.    I use a drip sprayer with the blue dye which I believe helps but the key for me it getting it apply immediately after cutting.   

[John Mc]

I can get by with 25%. When I tried 18% (the "concentrate" bought at the hardware store), I found that +/-30% of the stumps still resprouted. I never tried 20% - I just figured that was too close to 18% to make much of a difference.

25% killed the vast majority. At 33%, I rarely see any survivors unless I waited too long to treat after cutting.

I do agree treating as soon as possible after cutting is a key. Usually, I'll cut 5 to 10 saplings, then stop to treat right then. I might push that to 15 or 20 if they are all right in the same area, so I can cut quickly with the brush saw, then treat.  (This would go much faster if I had someone to follow me with the glyphosate, but my wife is just not into this stuff.)