How do you stop a tree stump regrowing?

[#1]

One method to kill a tree stump is to use Manutec 1kg Epsom Salt. You drill into the stump with an 8mm or 10mm drill bit. You drill as many holes as you can and as deep as you can, and then fill the holes with Epsom salt. Once all the holes are full, put some water in each hole until they are saturated but not overflowing. 

The Epsom salt in large quantities draws the moisture out of the stump, thereby dehydrating it. It should kill off the stump in approximately one month depending on the size of the stump. Cover the stump with a piece of tarp to prevent it from getting wet by the rain. 

Please make sure to wear appropriate clothing, gloves, goggles and a mask when using either salt or glyphosate. 

Of course, before you start cutting any trees down you should also check with your local council on the rules and regulations regarding cutting trees on your property. Some will require you to have a permit if the tree is of a certain size. - EricL

An alternative is to use glyphosate diluted 1 part glyphosate to 6 parts of water and injected into the trunk in the same way - 8-10mm diameter and about 20-30mm deep. The herbicide needs to be in contact with the cambium layer - the green wood immediately beneath the bark. This is where it is absorbed and carried throughout the tree and roots via the sap system.

Either of the options given may take several weeks to work, especially when the sap flow is sluggish due to cold air and soil temperatures. - Noelle

[peternearhos]

Hi Eric,

I am using epsom salts to poison a fig tree stump and roots which are affecting paving.  I have drilled lots of holes and filled them up with epsom salt and wetted them.  Some of the epsom salts seems to have dissolved and the holes now filled with water.  Should I replenish the epsom salts while waiting for them to take effect?  Cheers Peter

[DIYGnome]

I don't have much of a green thumb but I sure can kill off plants, drill-to-kill and adding undiluted roundup to the holes is extremely effective 👍

Council bylaws mostly prevent "stump burning" which reduces the dead stump to ground level (or better), but an axe and shovel will suffice...  

[JacobZ]

Hi @peternearhos,

Topping up the epsom salts probably isn't 100% necessary, but considering you are aiming to kill the stump, it won't have any negative effects.

The aim is to dry out the stump, so covering it and reducing any moisture getting to it is going to be more important, remember this is not a quick process, so be patient and try to avoid checking it too frequently.

Let me know if you have any further questions.

Jacob

[Mikmak]

Do either of these methods run the risk of poisoning the soil/plants growing in the vicinity of the stump and its root network?

Also, would this be an effective way to kill off a stump and its active regrowth, if the stump is located in an area that requires regular watering to keep the surrounding plants alive over Summer? 

For reference, last year we had a pittosporum tree cut down but the stump was left untreated, and it is now sprouting down the length of the garden bed.

(The stump is at the bottom right of this photo, and regrowth continues to pop up beyond the water butt.)

 

[MitchellMc]

Welcome to the Bunnings Workshop community @Mikmak. It's wonderful to have you join us, and many thanks for your question about killing a tree stump.

Injecting glyphosate into a tree stump will not harm surrounding plants, as the herbicide is absorbed into the tree's vascular system and doesn't leach into the soil. Similarly, the Epsom salts method is unlikely to affect nearby vegetation, as it acts locally within the stump itself.

Using glyphosate injections is an effective way to kill off the stump and its active regrowth, even if the area requires regular watering during summer. To apply this method, drill 8-10mm diameter holes about 20-30mm deep into the stump, ensuring they penetrate the cambium layer—the green layer just beneath the bark. Dilute the glyphosate at a ratio of 1 part glyphosate to 6 parts water and inject it into these holes.

To enhance the effectiveness, especially in a regularly watered area, consider sealing the holes with Blu Tack or similar material. This will help prevent the herbicide mixture from being washed out, ensuring it remains in contact with the cambium layer. Note that the process may take several weeks to show results.

Please let me know if you have any questions.

Mitchell
 

[Noyade]

Informative thread!

I have no idea about gardening or what this tree is/was - but like @Mikmak it keeps sprouting further along.

I thought it was dead. I cut it down years ago.

I started drilling it just now - it's alive!

[Noyade]

How many holes do you recommend?

[Noyade]

And a fantastic tool for the job! 👍

[MitchellMc]

That section looks rather dried out and old @Noyade. I'd be looking for a spot further along near where it is spouting and drilling in there. The stump might have died off and it's thrown new roots out elsewhere.

Several holes are enough, but you typically want them closer or through the side of the trunk so the poison is sucked up by the cambium layer and distributed through the root system/tree. Drilling the holes into the centre of the trunk won't allow the poison to be sent around the tree.

Mitchell

[Noyade]

Thanks @MitchellMc 

I will continue to search and drill.