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alij

By Alij

United Kingdom Gb

Just started to dig over a very dry bed where we have had a conifer tree cut down as it had grown too large all around the bed is this dusty grey appearance in the soil and around the roots of a rose bush that I have dug up



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Answers

 

it is a fungal mycorrhiza and perfectly ok. nothing to worry about. it lives with the roots of plants and helps them to take up nutrients. Many garden centres now sell packets of fungal spores but really its a con as the soil has millions of spores in it. So unless you are planting into sterile soil/compost in pots it is a waste of money.

welcome to GoY too :o)

26 Mar, 2019

 

Funny you should say that SBG.every time I see Monty scattering Macrorhizal on plant roots I think...what is that doing tothe natural balance of fungus in the soil? ‘ makes no sense to me. As you say...bit of a con at best.

26 Mar, 2019

 

at one of our HPS meetings we had Prof Alastair Fitter talking about this very thing. his professional work has been about these fungi and he ribbed the group about being good Yorkshire people spending money on spores that the companies couldn't actually identify which species they were using and were surplus to requirements as the soil is teeming with them. he has challenged companies like David Austen roses about the waste of money in selling these sachets.
he was an excellent speaker.

26 Mar, 2019

 

Thank you! That confirms it. :)

26 Mar, 2019

 

That is very interesting as the Macrorhizal is not cheap to buy. Maybe Monty has been conned too?
I put six trees into my new garden last year and for each I sprinkled Macrorhizal around the wet roots and each tree has taken beautifully - maybe I was just lucky?

26 Mar, 2019

 

I never heard of anything like this - fungal mycorrhiza packets. My soil is naturally very rich. They do sell boxes of lady bug beetles which is also a waste of money. As soon as you put the ladybugs out in the garden, they fly away, except for the dead ones, lol!

27 Mar, 2019

 

Thank you everyone that is really helpful & explains why the rose has thrived anyway even though in a very dry bed. Also dug over lots of worms which suggested to me that the underlying soil was healthy.

27 Mar, 2019

 

I got my 'Mantra' from Alan T on Groundforce programmes in the 80s..."It wants to grow" :)

27 Mar, 2019

 

There is a good time to use mycorrhizal fungi though, and that's if planting new roses where roses grew before - the addition of the fungi into the planting hole seems to remove (or perhaps reduce) the risk of 'rose sickness'. Otherwise, I really don't consider it necessary...

27 Mar, 2019

 

Yes, Bamboo is correct in its use when replanting roses in an existing rose bed. David Austin recommend their own brand of Rootgrow. I did happen to attend a talk by the Rootgrow people some time ago and was impressed with its use for planting trees in what was regarded as contaminated soil. I have used it when planting a yew hedge and it seemed to do the trick as far as I'm concerned.

27 Mar, 2019

 

I've never seen anything like this and I have a pretty decent collection of healthy roses. Something is off about this photo.

27 Mar, 2019

 

Jimmytheone: what kind of contamination? I've discovered an area of soil in the border that has a low wall to next door, and its quite obvious that someone has dumped either engine oil or diesel over the wall,so its hydrocarbon contamination. I've planted fairly near, but otherwise had to avoid the area - just wondering if Rootgrow might help...

27 Mar, 2019

 

Thats a good point...and actually, that was what I thought it was designed for Bamboo. But nowadays you see them chucking it on everything on the telly.

27 Mar, 2019

 

I feel about Rootgrow as I do about bonemeal - recommended for everything, but only marginally useful in most circumstances. Still, in the case of bonemeal, they've got to get rid of it somehow, and rootgrow and its lookalikes are just a way to make more money... its almost always about the money!

27 Mar, 2019

 

Bamboo, I think they were alluding to the contamination left by old industrial sites. If you have soil that has old engine oil dumped on it, I would say that most of the soil would have to be removed first. You could email them and see what they have to say on the matter.

28 Mar, 2019

 

but it doesn't reduce rose 'sickness' according to prof Fitter. the soil has all the fungi it needs. if you push the rootgrow people and believe me he has and all his papers are published, they couldn't even name which fungal spores they were offering.

The early work in the 80's showed fungal benefits to plant growth and commercial enterprises 'jumped' onto this fact to sell a product that wont harm the garden but has limited potential in healthy soil. Many of the packets of fungal spores have contents that don't grow. it is a waste of money.

As for contaminated soil with oil there are fungi and bacteria that break it down as this is an ongoing research area but I don't think anything is available for the home gardener. In the past I have just bagged it and taken soil to the tip.

28 Mar, 2019

 

Thanks Jimmy and Seaburngirl... on contaminated soil like we have in that patch, professional clean up companies apparently use a spray which contains hydrocarbon consuming bacteria,then just keep applying organic material, but obviously, that treatment spray is not available to either professional or amateur gardeners. Because the dumping was most likely done about 11 months back,when that area of the garden was neglected, overgrown and essentially derelict, its likely a bit too late to remove the soil... so currently, I've just piled a mix of compost with lots of perlite mixed in so you can see where it is, in hopes that eventually, it will clear. Fingers crossed it doesn't leach sideways too much... I'm still wondering if oyster mushroom spawn will help, because oyster mushrooms do absorb hydrocarbons, just not sure whether the spawn will survive being applied outdoors on ordinary soil.

As for Rootgrow,its interesting that they don't even know which mycorrhizae are in the packs! But I'd still use it in a bed where roses have previously been if I wanted to plant more, as one of those 'just in case it works' things - might be lucky with the mix of mycorrhizae, and one packet isn't very expensive. I certainly used it 6 years ago for just that purpose, though the fact the new roses grew on well does not necessarily mean it was the rootgrow of course.... at the time the RHS were suggesting its use for such circumstances.

28 Mar, 2019

 

This is all very timely for me as I'm just about to plant a "Golden Wedding" rose (guess why...) near to another elderly rose that is well past its best. Just been waiting until we went to a nursery to get a packet.So decision time - to buy the packet or not....

28 Mar, 2019

 

Eileen is right. Those packets are a waste of money. Just a single teaspoon of average garden soil contains over a billion microbes & each one plays a specific role. We can't even ID them all.

28 Mar, 2019

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