Organically kill a tree?

I have a plague of Cottonwoods in my back yard that I'm fighting a losing battle against. I cut them down, not realizing that they would sucker horribly and now my problem is about a million times worse. The trees are on top of a 4' terrace, so a stump grinder, etc. is not an option. The trees' roots are about to ruin the block terracing and are popping up suckers as far away as 15' at ground level. I'm about to lose it.
Oh and they are infested with aphids (and thusly ants) since I lopped them off.
Is there a way I can organically poison them?

The two organic herbicides that I know of are vinegar and boiling water, unfortunately both of those do a decent job on killing off the top growth but they don't do much to the roots so for plants like this that will put up sprouts from the roots, they may not work in the long run. Hopefully someone else has some ideas, those are the only ones I know of.

I would cut them off and cover the area with two layers of old carpet. You could cover the carpet with some mulch that is sold at the big box stores.

Garyt

The trick is to eventually starve the roots by constantly cutting down foliage - it may take some time.

If you have actual stumps, you can drill holes in them and fill with saltpeter (Potassium nitrate - manufactured from ammonia - is the ingredient in tree-stump killers).

Rake or hoe seedlings.

I don't know how strong cottonwood seedlings are, but you could try cardboard and mulch.

Use an acid-based herbacide like BurnOut which also contains clove oil.

Use a fatty acid (soap) based herbacide like Weed-Aside (not very strong, will put a hurtin' on the sucker, but probably won't kill it, at least not very fast).

You could also try a flamer on the small seedlings if your area is not dry (don't want to cause a wildfire).

It all requires a kind of siege mentallity, a declaration of war, knowing the battle will take a while : ))

This message was edited Aug 4, 2008 2:24 PM

This message was edited Aug 4, 2008 2:30 PM

art_n_garden - I have had tremendous success with drilling holes in the stump (after cutting down the main tree), & filling the holes with rock salt & adding water. May take several months, but this works for me! Good luck! Samantha

Thank you all so much. This is great information! I will try all of them if necessary.

CompostR, I think that you're right. I need to declare war! So far I've just been mumbling curses at them...and that never killed anything. :)

I feel your pain I have a few liquid amber trees that we got rid and the same suckering problem If you every figure out a way let me know. I am constantly digging them out. The roots of those trees are so vast though.

Will do steph! Today I pulled out a sucker growing further out from the main trunk than I ever thought possible. It was in a different level of the yard... at least 20 ft away. This is going to be a battle royale. :)

Hmmm. Good thread! I have some very stubborn crepe myrtles and nandina that keep coming back. Problem is there are other things growing there that I want to keep. Will these solutions kill other things too?

As long as you're careful that you just apply the chemicals to the thing you want to get rid of and avoid contact with things you want to keep you should be OK...but if you've got a crowded garden bed that may be easier said than done.

Do you drill a hole in the stump and put whatever it is in the hole or spread the stuff on the ground?

I'd drill a hole in the stump--it works best that way, plus if you start spreading stuff on the ground that's where you'll potentially run into problems with it damaging your other plants.

Another thing I heard, but never tried is to put straight molasses in the hole in the stump and cover it with something to keep the rain and animals out. The weather needs to be warm for this to work.

Interesting, never heard of the molasses thing. Wonder what it does technically to kill the tree?

My darn cottonwoods are still there. I never initiated war this summer, got too overwhelmed. One of them seems to have died on its own though...only 10 more to go! lol

I did plant my order of 10 free arbor day trees (for becoming a member) so that should get me in gear. I planted a red maple and a sugar maple in proximity to the worst cottonwood sucker spot so I will really want them gone this year.

Only thing I can think of is it provides food for bacteria that will help the stump rot away quicker.

I think the molasses is supposed to increase the bio activity so much that it literally cooks the stump. I had 4 large crepe myrtles planted just 6 feet away from a large window . I thought it was a very bad place to put them, so I dug up 2 of them and transplanted them to a better place. The other 2 I just keep cutting down so now I have lots of little spindly stems coming up everywhere. My war has been going on for about 8 years now, but I'm not fighting very hard. I rarely get a day off, and this war is low on my priority list.

Ecrane, you said it better than I did.:)

I heard to drill and put salt in there.........

Also starving them from light is bound to work eventually, but I will also say I tried to kill an unwanted pyracantha that way, it was right by my back door and of course very prickly! after two years I uncovered it to find pale nearly white shoots still trying to grow. I covered it back up and never checked it again before moving away! so I do not know the final outcome on that one.

Kyla

I mistakenly planted a row of 35 Poplars on my bank. They were supposed to be hybrids, but that didn't mean anything. Their roots went at least 100 feet out. I had them cut down after 5 years, and all above the bare stumps was chipped, which I used and are all gone now.

For more than 5 years I fought the stumps and suckers, with salt, blackberry killer (which I don't remember was made of). And even last year I found one sucker still trying to grow in the area. So it is a long hard fought fight.

Donna

Oh boy...that doesn't sound like fun Donna. If you only knew then what you know now.

Thanks for the explanation ecrane and silver- that makes good sense to me. And lol Kyla, someone else's war now!

My battle plan is: For the larger stumps that we chopped down- in early spring I'll drill holes and fill with salt and then as it warms up I will use the molasses trick and cut off all suckers and branches at first sight. For the smaller seedling/sucker groves with no main trunk, I will throw boiling water on them, then vinegar, then cut them down, then cover them with cardboard and old carpet. Think it will work? I'll keep you all posted.

Also, I have some clove oil that I keep around for aquarium husbandry- would that be of any use?

Plants must be way tougher than us. All that stuff would kill me, for sure. Clove oil, now, that would take away the pain of it and smell good but other than that, I don't know. ;-)

We have ended up using the weedwhacker every week on ours. It is working, after one summer of doing this, there are less than 10 coming up. Hopefully will not have any at the end of next summer.

Lol, the drilling holes and boiling water would do me in too! I didn't know about the clove oil, but someone mentioned it earlier in the thread. It was darned expensive to buy to euthanize a very ill fish, so I thought maybe I could find another use for it!

Juney, is your problem with cottonwoods also?

No, it was poplars. I never smelled wood that stank as bad as that.

Ahh, poplars. We tried to season the bunches of cottonwood that we chopped down to burn for firewood. It stank, smoked and popped. I joked that only cottonwood could irritate me in death, too.

LOL! So true!

Art, clove oil is a topical anesthetic that used to see a lot of use in dentistry. Some people still use it to numb painful teeth and gums..... if you use it that way, dilute it in vegetable oil and use a cotton swab to apply. Putting it on "neat" can really burn. ;-)

I have to kill an apple tree. I figure on chopping it down, then cutting away at the stump below soil level. I'll drill some large holes, put salt in them, then cover the sump with vinegar. Sounds like a good potato chip! We'll see what the reaction is after a bit. Maybe I'll get my dog to dig it out!

Since organiphiles are so environmentally sensitive, I am flabbergasted by the suggestion of using ROCK SALT, which will contaminate the soil and will take a long time to leach away.

Howard Garrett suggests molasses for a lot of things, but killing stumps is a new one on me. Since it will do just about anything else, why not?

I assume you wanted an "organic" solution, but if anyone is bold enough to suggest SALT, then I'll trump them and suggest what will give you the best results in the shortest time. Drilling holes in the stumps is the first step, but instead of pouring SALT (or molasses???) into the holes, if you will use 2,4-D, or glyphosate (the former is more effective), this treatment will kill the roots quite effectively without contaminating the nearby soil. Small sprouts can be sprayed with glyphosate (Roundup) as soon as they get several leaves, and they will die, roots and all.

As others have indicated, you have your work cut out for you, and I wish you luck because this will be an ongoing battle for several years, but if you rely on folk remedies using kitchen products it will be far worse.

dp - Did not realize that a tablespoon of rock salt would cause such overwhelming environmental problems. My bad. Samantha

It's a matter of principle, g_g.

Dp it sure makes sense when you explain it that way... I fight against the effect of road salting in my yard, why would I purposefully put it in my backyard near my pond and precious plants? I will consider your suggestions now, thank you for informing us and being a dissenter!

I was planning on using sea salt, not rock salt. I don't agree that the small amount I am talking about will contaminate the soil forever. Anyway, I would rather not use Roundup. I can control the vinegar and sea salt a lot better, and I don't have concerns about returning these kinds of substances to the earth.

Rock salt is just the mineral form of table salt (NaCl), etc. anyway. It will last longer in the ground, simply because the salt we use at table is ground finer and the rock salt tends to be provided in larger crystals.

That said, salt is salt. Saline soils are difficult to grow in because of this - and the same goes for over-fertilization (many artificial fertilizers have or create high amounts of salts after several years of use, and thus require a flushing of the soil from time to time). By the same token, salt will serve as a logical killer of plants where they are no longer needed or wanted. They will eventually percolate down into the soil with regular watering, making growing in that soil viable again.

Well said, J man. Of course, anything used to kill needs to be used with intelligence, whether it be salt or some other method. We all know the tales of salting the earth to make it infertile! But it takes a lot of salt fairly widespread to do that. I imagine we all also have experience with witnessing people using glyphosate -- or other more toxic substances -- with a heavy hand, unaware of its dangers. Eh. How you do something is sometimes as important as what you use to do it with. Personally I am not convinced even small amounts of glyphosate are as harmless as the companies purveying it would have me believe. It's usually a good idea to ask the question, "who benefits?" When someone tries to sell me something, whether it be an idea, a product, an attitude, or an opinion, I try to remember to ask that question. It can be very illuminating.

I hope to hear how the project of taming those cottonwoods goes!

I drill holes and put cornmeal in the holes and then cover it with a big black plastic pot--works really well in the heat of a TX summer.

edited to add--it worked really good on an "ash is trash" tree

This message was edited Feb 6, 2009 8:41 PM

That's interesting Dmj. I never heard of using cornmeal that way. Would it work if you're trying to kill something that doesn't have a trunk big enough to drill a hole in? Maybe just pile the cornmeal around where the stem comes out of the ground. In my case it would be damdinas I would be killing.

lol to damdinas and ash is trash trees! I have a Texas Ash in my front yard (Satanwoods in the back)...I got many lovely gifts from former owners. Oh and a beautiful Blue Spruce in the WORST location. But I'm not even going to worry about the ash, it is the least of my problems as it is.

I am wondering though, would it give me an upper hand to begin my offensive now while the trees are dormant and looking pretty sorry through winter? Or would that just waste my time...

Ash might be a really good tree up there Art, a lot of trees just aren't desirable down here where they will have a lot more problems due to high heat and humidity. The "ash is trash" is sorta a Texas expression.
Debbie
=)