VOLCANIC ROCK DUST

[lez]

I read an article about volcanic rock dust from scotland I think and am tempted to try it. You can get it from B&Q's. Has any one ever tried this dust? and if so do they think it does the job or not? The write up said about atrial farm and claimed it really inmproved the soil mineral content. I would be interested to hear from any that have used it. Happy Gardening to all.

[Colin Miles]

There have been discussions on this on this site - see
http://www.kitchengarden.co.uk/forum/viewtopic.php?f=4&t=11219&hilit=volcanic
and see Johnboy's comment.

[peter]

Do a search of old threads on here and you'll find it had been discussed a few times, inconclusively.

[lez]

I treid doing a search and came up blank. That is why I posted. Perhaps I used the wrong terminology. I mwas suprised when my search turned up blank. But Happy Gardening to all.

[lez]

Many thanks Colin for the link. I had been using the wrong terminology to do my search. I am on sandy soil and this is why I'm interested. I have read articles but wanted to see if any one has used it who wasn't trying to sell it as the articles were/are all biased to sell it. Johnboys comments are his opinion and obviously he has never used it. As for him sayng it's an expensive waste of time, well the cheapest blood, fish and bone or chicken pellets I have seen are £10 for 7kg's. I did some shopping about and found that B&Q stock it under the verve tradename at £5.98 for 10kg's. Having seen other adverts this seems reasonable to me. So I have purchased some to see if it does make a difference as my ground has only had composted manure and compost on it. 10 years is a long time and if the minerals are missing then let's revive the ground. I have also started to lime as a test showed my ground to be acid. This done it has made a big difference to cropping especially brassica's. Still a bit of open debate is good and I am learning all the time. Happy gardening to all.

[Geoff]

Regret too late to say "don't do it!"

Harrod Horticulture "Rockdust is a fantastic natural source of minerals which helps to rejuvenate soils, helping boost soil fertility and plant growth - and each 20kg bag covers an impressive 40 square metres."

So based on your B&Q price - 30p /sq metre

Fish, Blood and Bone application is usually given as 70 gm/sq metre so at your prices 10p / sq metre. I actually think that is a bit of a low application rate but anything less than three times would be cheaper.

I bet you can't find an analysis for rock dust anywhere but a fertiliser it is not whereas FBB will do some real good. You might be able to beat the prices you have found for FBB and chicken pellets at http://stores.ebay.co.uk/Elixir-Garden- ... 34.c0.m322 even with the hefty shipping charges. To save even more use Growmore but please don't get into rock dust alchemy.

[lez]

Hi Ya, Geoff, ut that way I see your point. as you nsay the application rate for b/f/b does seem low. I am only going to try a small area and as shipping rates are so high is why I went to b&q. I wonder how much it works out with shipping then? Still only a trial and as for alchemy that's way above my head, and analysis another reason I am asking. I only want to improve my crops. cheers anyway, happy gardening to all

[lez]

Hi Ya again, Having reread the article I see now that the initial outlay could be very high even though they say it will last 5 to 10 years. I suppose a heavy ground will hold nutrients better than my sandy soil. Quite an expense and would you reap the benefit. Judging by the cost of the humble spud this year, then yes maybe. They do say to use along with compost so now I have invested in a couple of bags I will give it a try with open mind. I think thier application rates are a bit over the top. Happy gardening to all.

[Johnboy]

Hi Les,
With very light sandy soil there is an experiment you can do to help retain moisture and nutrient. If you are interested please PM me.
JB.

[Tony Hague]

I have also started to lime as a test showed my ground to be acid.

Is that a proper test or one of those electrical pH probes ? If the latter, don't trust it. They are a joke. I have tried a couple, and neither come close to working. A paste of garden lime and water registers as acid on mine.

[Biffa28]

Volcanic dust contains all of the micronutrients needed by plants, which allow them to take up the macro nutrients properly. So there will still be a need for nitrogen potassium phosphorus and silicates to be present. That said , my reason for posting here is to point out that this dust contains *every* element, including the toxic heavy metals, which may be absorbed along side the useful elements. So if you are planning on consuming whatever you grow using this dust, just bear it in mind. For those put off by this info, there are companies who formulate micronutrient mixes with the lowest possible toxic elements (well below 60 ppm) but the cost of these is quite a bit more than this rock dust weight for weight.