Scottish Rock Garden Club Forum

Bulbs => Bulbs General => Topic started by: David Nicholson on March 18, 2016, 07:48:56 PM

Title: Sulphate of Potash
Post by: David Nicholson on March 18, 2016, 07:48:56 PM
I've just bought a pack of Westland Sulphate of Potash and it looks different to the stuff I've had previously. My previous stuff was quite white and very fine in structure, almost a powder. This is quite 'grainy', almost looks as though they've added sharp sand to it. Has anyone else noticed this please?
Title: Re: Sulphate of Potash
Post by: Maggi Young on March 18, 2016, 08:15:42 PM
We have a new packet - as yet unopened - will have a look tomorrow.
Title: Re: Sulphate of Potash
Post by: Hoy on March 18, 2016, 08:39:51 PM
I don't know the brand you use, but I am used to granulated sulphate of potash. It is easier to handle than the powder.
Title: Re: Sulphate of Potash
Post by: Cfred72 on March 20, 2016, 07:22:11 AM

With us, it is prohibited to use the chemical. they sell us the potassium vinasse.
Title: Re: Sulphate of Potash
Post by: Maggi Young on March 20, 2016, 11:34:50 AM
With us, it is prohibited to use the chemical. they sell us the potassium vinasse.
It amounts to much the same thing, I believe. There are various types of Kalium fetiliser available in different countries - the main feature is that they have potassium as the main ingredient.
Title: Re: Sulphate of Potash
Post by: mark smyth on March 20, 2016, 11:47:52 AM
Westland ... still ripping people off with their "top soil" which is a mix of peat and sand
Title: Re: Sulphate of Potash
Post by: Tristan_He on March 20, 2016, 08:35:11 PM
Are you sure Mark? I've used this quite extensively for my new rockery and have never noticed any sign of peat in it. There is some fine sandy material as one would expect from topsoil.
Title: Re: Sulphate of Potash
Post by: David Nicholson on March 20, 2016, 09:54:38 PM
Probably green waste and sand but highly unlikely to be peat.
Title: Re: Sulphate of Potash
Post by: mark smyth on March 20, 2016, 11:11:43 PM
You haven't seen the scale of peat extraction David. Follow the river north and at the top end of the arrow shaped lough there's a huge brown blotch on the landscape
http://binged.it/1RYKTyC (http://binged.it/1RYKTyC)

Up to last year Westlands "peat free" compost bags contained "50% peat" - westland's quote. They changed the label but is it still 50% peat?
Title: Re: Sulphate of Potash
Post by: Maggi Young on March 21, 2016, 12:07:27 PM
We have a new packet - as yet unopened - will have a look tomorrow.

 Our stuff looks the same as ever :  white powder
Title: Re: Sulphate of Potash
Post by: johnstephen29 on March 21, 2016, 03:28:41 PM
Hi mark is peat extraction for horticulture still a big business in Ireland? Where I have family in mayo it is used for the house.
Title: Re: Sulphate of Potash
Post by: mark smyth on March 21, 2016, 05:04:34 PM
Yeah two kinds of extraction both of which is destroying habitat. People are destroying some natures reserves because they says its their right to dig peat/turf. The mickey mouse police don't do anything to stop them
Title: Re: Sulphate of Potash
Post by: Tristan_He on March 21, 2016, 07:04:48 PM
Hi mark is peat extraction for horticulture still a big business in Ireland? Where I have family in mayo it is used for the house.

There is also no excuse for this practice in this day and age in a 1st world country like the Republic of Ireland. It's not as if there are no alternative sources of energy.
Title: Re: Sulphate of Potash
Post by: johnstephen29 on March 21, 2016, 08:21:25 PM
Hi Tristan, your right it's not, but old habits die hard as the saying goes. People in some parts of Ireland have been cutting the turf for a long, long time, some of these plots have been in the same family for years.
Title: Re: Sulphate of Potash
Post by: Tristan_He on March 21, 2016, 08:32:33 PM
Hi Tristan, your right it's not, but old habits die hard as the saying goes. People in some parts of Ireland have been cutting the turf for a long, long time, some of these plots have been in the same family for years.

(Sigh). I know. In many ways these are the saddest types of environmental damage, the ones just done out of habit, in spite of it not being necessary or profitable (and sometimes not even in the interests of the person doing the damage). There are examples all over the place, and it's very difficult to get people to change their approach.
Title: Re: Sulphate of Potash
Post by: David Nicholson on March 21, 2016, 08:47:37 PM
.........They changed the label but is it still 50% peat?

Mark, was that meant to be written as a statement or a question?
Title: Re: Sulphate of Potash
Post by: mark smyth on March 21, 2016, 09:02:52 PM
well, if it was 50% peat and they changed the label it could still be 50% peat and they are lying to us

I asked them about their top soil not being top soil but a mix of peat and sand and whatever. Their answer is "We do not put any peat into this product and so it is unusual and unfortunate you have received a product in this condition". Time to buy another bag and repeat my mix some in water test
Title: Sulphate of Potash rate
Post by: Paul Cumbleton on September 22, 2016, 02:22:28 PM
Hans J asked me (in a personal message) about when using sulphate of potash on its own, what rate to use if wanting to dissolve it first and water the solution in (rather than sprinkling the powder  onto pots like Ian Young does). He wondered if 1 gram per litre of water would be a reasonable amount to use. I thought my reply might be of general interest, so I'm posting my reply here:

Yes, 1 gram per litre would be a sensible amount to use for sulphate of potash. I have a conductivity meter that I use to measure the strength of fertiliser solutions. The units of measurement are microsiemens (μS). So I dissolved 1 gram of sulphate of potash in 1 litre of water and measured the resulting solution. The reading was 1817μS. How does this compare to other fertilisers? I have measured many other fertilisers before and I find that if made up at the full strength as recommended on the packet, they very commonly come out at about 2000 to 2500μS. Rather than giving you grams per litre, many powdered fertilisers for amateurs come with a scoop in the packet and they tell you to put a certain number of scoops in a certain volume of water. If you actually weigh the content of the scoop and do the maths, you will find that for the vast majority of fertilisers, full strength equates to 2 grams per litre. Here are my readings from the conductivity meter for a couple of commonly used fertilisers made up at the full recommended strength (2g/l):

Miracle-Gro (NPK = 24 - 8 - 16)            : 2500μS
Chempak No. 8 (NPK = 12.5 - 25 - 25) : 2410μS (often used by alpine growers in the UK)
The sulphate of potash at 1g/l was        : 1817μS

Note, these were made up in our local tap water which on this occasion started out at 170μS before adding any fertiliser.
You can see that 1g per litre of sulphate of potash would produce a solution of reasonable strength. If you were to use a rate of 2g per litre (like many of the balanced fertilisers) this would produce a reading of over 3600μS which would be very strong indeed. So I would stick with the 1g/l as a guide.

Paul

 
Title: Re: Sulphate of Potash
Post by: Hans J on September 22, 2016, 04:02:02 PM
Hello Paul  :D

Many thanks for your interesting work !

I have  watered today all my winter growing bulbs with this 0,1 % solution :
Acis ,Sternbergia ,Scilla ,Galanthus and many of my South african bulbs ( exept the summer growing )

For watering I have used rain water ....the rain water here is not acid ...it is more or less neutral ( ph 6,5 - 7,5)
so I have add  vinegar essence ( 25% ) ...so I have now 6,0 - 6,5 PH
In case I have not enough rain water I must use domestic tap water ...it has also around 7,0 PH ...but total hardness of 10 °  :-\

Paul - what you think ?
Should I watering again with Potassium Sulfate ( 0,1% ) in maybe two month ?

Best wishes
Hans
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