I’m far from a subject matter expert but I thought I would share a few methods that have been successful for me, in hope that it can help shorten your learning curve on dealing with invasives if you’re just getting started. I have tried many methods and herbicides over the years but I have narrowed my approach now to (3) main methods and utilize herbicides that contains over 40% Glyphosate. I have not tried Garlon 4 but I have heard that success rates can be even higher than Glyphosate, for the price and availability, Glyphosate works well for me.
I have had my best success, this time of the year when plants are storing energy for dormancy- the herbicide take up seems to work better in late fall. I focus on Buckthorn and Honeysuckle; Buckthorn receives the priority if I’m short on time because it has no nutritional value and becomes a diuretic if browsed by deer. Buckthorn also is supposedly a winter host plant for soybean aphids- although you see it in every fence row in farm country.
I’m doing larger scale projects so I invested in good equipment- any sprayer, squirt bottle of axe/machete can achieve the same results. If you have trouble identifying invasives, start by looking in your area for the last thing that’s has foliage after all the leaves are gone and the first thing that has foliage in the spring.



Method #1 Foliar Spraying
If I have immature buckthorn/honeysuckle with shoot sizes, pencil diameter to a quarter size- I Foliar spray directly on the leaves with a concentration mix of about 3oz. of herbicide to 1 gallon of water. I use a backpack sprayer for this application.

In this picture you can see last years dead honeysuckle that was foliar sprayed and new shoots that need spraying and attention now.

Method #2 Cut Stump
For everything roughly, a quarter diameter and larger, I’ll cut off completely close to ground level and spray with 100% herbicide. Spraying immediately after the cut seems to be the key- I have read you should do it within an hour of cutting.



Method #3 Hack & Squirt
Once you’re over a quarter diameter in size and beyond you can be into 16’ to 20’ trees especially with buckthorn, I worry about herbicide drift when I’m spraying that high and dropping brush with cut stump techniques on the understory covers plants that need spraying and is a hassle. I make two incisions about 1/3 to ½ way in and squirt with 100% herbicide.


I usually wait at least two full growing seasons and return with my clearing saw if plan to replant that area with more desirable plants.
Good Luck

Goats and sheep are the answer.

The goat in Jurassic Park would probably last longer than in my woods

Excellent comeback, eagleye.

The Jurassic Park I know eat crepes and takes selfies.

Cut stump treatment: 50:50 mix of 2,4-D and oil (Nebraska Herbicide Guide) - paint or spray the stump (cambium). Honeysuckle is extremely susceptible to 2,4-D on the foliage when actively growing in the spring/early summer, so much so, that it was eliminated from the NRD tree planting list over 20 years ago due to cropland drift. Trimec (non registered herbicide) or Crossbow (registered) herbicide are very effective against your buckhorn/honeysuckle intrusions but are non-discriminative to most broadleaf species. 2,4-D and Trimec are easily available at your local farm store. Crossbow will be available at a herbicide outlet with a Cert Pesticide License _Private License is easier to get than a Commercial - sometimes on line with an at home computer self taught process. ................. my take. ................... the mike

P.S. Glyphosate is only a fair woody control herbicide. The others mentioned above are way better to kill the plants the first time through if you follow the directions. Your saw and a 1.5-2 gal. hand pump sprayer are excellent tools to handle brush problems where you can cut/and spray or just spray as you go. And use a surfactant (dish soap is the cheapest) with the above herbicides to cover leaf foliage thoroughly............ again my experience....... the mike

MIke,
Very interesting- how much dish soap would you add to 1 gallon of herbicide- I'll try it today

normally recommended at a table spoon per gallon of dish soap to glyphosate solution

we went with the 10 minute rule

I have mostly used the Gel RTU because it is a small jug to carry and I am small time in my brush removal I cut then coat the stump.

I also was always dragging the brush away to a pile so I wasn't concerned with the issue of smothering other plants

I'm going to add some Dawn this morning- heavy frost last night- should I wait for the sun to dry things out or doesn't matter?

if your spraying the cut ends I don't think the dew/frost will matter much , it is about the absorption though the fresh cut that kills

on that bigger stuff if you can ring the bark 1/2 inch deep all the way around and spray it that might work well also

trees live and die on the outside layer of new wood under the bark

this is why emerald ash borer kills a mature tree never going more than an 1/8 inch into the wood

when you see an ash with one side having a few leaves and you take an ax and start barking around the trunk you fine one narrow path of live under the bark that the borer didn't get too yet , that is the perfect time to take those down as they still have good holding wood on the stump and don't run the risk of dropping too many limbs on you while sawing
if you wait till they start dropping big limbs in the wind , you don't want to be under them while sawing widow makers are no fun.

Watching.

Moosetrot

Soap is an Ionic surfactant and will reduce the effectiveness of glyphosate which is why only non-ionic surfactants are recommended. I would not use it with Roundup. For the typical petroleum based CONTACT herbicides, adding most surfactants that help reduce the surface tension (beads) of water droplets, AND mix with oils are better than the herbicide alone. "Thorough Coverage" of the actively growing leaf matter is the Bible for those petroleum based products. CCO (concentrated crop oil) is a product recommended by some manufacturers, but usually a little soap will do just as good. And a teaspoon per gallon (added as the very last component) is ok. Make sure its added after everything (including the H2O) otherwise you fight a lot of suds. ................................ the mike

I have been painting Crossbow undiluted on the larger Buckthorn stumps after I've cut them off. It has been 100% effective. For the new emerging plants I use diluted Crossbow and just spray the foliage. That takes care of them very well.

I also have a prickly ash problem in addition to the Buckthorn. Prickly Ash is easier to kill by skinning a sliver of bark off and painting it with Crossbow. You can kill the smaller Buckthorn plants by this method too, but the bigger trees you need to paint the stumps.

I've been searching for the larger trees that drop the black berries and kill them first. These are the ones responsible for the new spreading, emerging plants.

I've been eradicating a lot of buckthorn lately. This time of year buckthorn sticks out almost as if it is neon green.

don't the birds eat the buckthorn berry's ? seem like the partridge love them , always shoot a few birds by them

I put. bottle of $1.25 store food coloring in tank so I can easily tell where I've already treated.

Either they don't eat them in my woods or we don't have enough grouse around.

That's a good idea.

Tonight I encountered a couple old buckthorn trees so big I used a powersaw to cut them down, then treated the stump with garlon.

It's so easy to spot this time of year that I deal w/ a lot of it after dark w/ a headlamp.

Birds eat the berrys Dahlgren, but it is a laxative for them.