Have been busy this morning digging out a 3 metre garden box. It has been there for 18 months and never really grew anything. It is right next to the boundary where the neighbor has a big pittosporum hedge.
When I put the box in and filled it with potting mix, topsoil and sand, I didn’t think to put weed mat in first. The hedge roots have completely invaded this good soil and sucked out all the goodness.
I have removed the soil, put a double layer of weed mat in, and am about to refill it with the soil I removed. This soil is choked with roots.
My question to a gardener is this. Will those roots rot down? A yes answer will save me from having to go through the soil and remove them.
This is the soil choked with the roots.
Recommendation is to fill it up and plant a couple of big rocks amongst some smaller ones!
Roundup, 245D will control any pesk weeds.
……” Will those roots rot down? “……
Yes, eventually but that’s the least of your problems.
Two layers of weedmat are not going to keep the roots of a healthy tree at bay. In fact nothing that will let excess moisture drain will stop the bloody things which is exactly the problem I faced last year.
My answer was to lay 100 x 100 macrocarpa sleepers at about 450mm centres & cover with 200 x 25 macrocarpa planks. Landscaping grade so not too expensive but more importantly untreated, then placed the frame on the platform & replaced the soil.
(cost for 3 beds 2000 x 900mm about $400)
No. You won’t stop the roots – without killing the trees. Just as nasska said.
His over engineered solution is crap. Just hack back the roots and plant as per normal.
What you put in the planter box won’t put tap roots that deep anyway. The seasonal veges will get the top layer and your neighbours hedge the run off.
Like most old buggers you are over thinking it 😃
Why not shift the boxes away from the hedge, assuming you have the room on the section.
You can stop it from happening again it just depends on wether you like the hedge and /or not the neighbours .
24D is a thistle spray. 245T is a milder version of agent orange. Neither of which I would use in my garden as they are both volatile meaning you only have to remove the cap and the fumes from the container will wipe out your garden. If you don’t like your neighbor spray a strong solution of Roundup on the fresh cut roots in the bottom of your planter box. 150ml in 5 ltrs water.
Have decided to turn it over, nail double sheets of thick plastic panelling (from IBC tanks) to the bottom. Put a layer of stones and then the soil.
Will drill some drainage holes into the wood facing the outer side. Might devise a miniture novaflo system to help the excess water escape.
Thanks for your answers.
That’ll work. 👍
Ed….The roots will rot down, but I would be inclined to remove them…All native Pittosporum/Coprosma/Myrsyne/Pseudopanax roots have a strong distinctive smell when you cut them and I have always associated it with allelochemicals.
“Allelopathy is a biological phenomenon where one plant inhibits the growth of another. How? Through the release of allelochemicals, certain plants can greatly affect the growth of other plants either in a good or bad way by leaching, decomposition, etc. In essence, plant allelopathy is used as a means of survival in nature, reducing competition from plants nearby.”
I am not absolutely certain of this, it is a strong hunch I have had for many years.
“Various parts of plants can have these allelopathic properties, from the foliage and flowers to the roots, bark, soil, and mulch. Most all allelopathic plants store their protective chemicals within their leaves, especially during fall. As leaves drop to the ground and decompose, these toxins can affect nearby plants. Some plants also release toxins through their roots, which are then absorbed by other plants and trees.”
Thanks for that Toko. I have studied ethnobotanicals as a business for the past 20 years so do know something about what you are saying. Plant extracts have been part of the business I built up and recently sold. I have a complex library of books that has built up over this time. Now they are surplus to my needs and will sell them to someone who might want them.
Ed,,,,
I had a book on NZ medicinal plants that I loaned out a few years ago and never got it back…can’t remember the name or the author now, but it was a substantial white covered paper back. The writer was from a chemistry back ground and the material in it was a bit more involved than someone sharing their grandmother’s bush remedies.
Have tried to find it on line…without luck. If it is in you book collection, I would be interested in buying it.
NZ Medicinal Plants – 1987, S.G. Brooker; R.C. Cambie; R.C. Cooper
Thanks Maggy…
I’m picking even 4×2 laid on their side to create a ar gap would be sufficient!
I made massive raised bed garden from macrocarpa too. 8×2. 16 inches high. It’s 4 inches elevated with an air gap. Plus 4 inches of driveway concrete beneath. Good luck getting in this tank. Tried some huegelkultur too. First season crops loved it.