Using flowers of sulphur to lower soil pH

Afternoon all,

I planted raspberries (Glen Moy) in 2016 and they're not very healthy.
Last autumn I planted Joan J and they're not looking great either.

I've since discovered that the 25 ton of topsoil I used to make the raised beds and borders in that area has a pH of 7.8 which is rather too alkaline for raspberries.
Generally my soil is slightly acidic clay.

Looking at the RHS site it suggests flowers of sulphur (at 4oz per sq metre), which I have, but no mention of how often it needs to be used.

Any advice please?

 

Raspberries call fo a pH of around 5.0-6.5 Using Sulphur to reduce the alkalinity and increase the acidity of soil is IMO a slow and perhaps expensive method. Sulphur requires a degree of heat to activate it, so applying it to the open ground, the period from just as the soil is starting to warm, (spring) to when the latter cools down, (autumn). Using the general weather conditions as some kind of guide, probably treating the soil twice during that window.

Alternatively. Making use of vegetive compost/matter dug in and also applied as a mulch would be my main choice.

 

I think you have to apply it slowly over a number of years.
Chempak used to sell sulphur chips that lasted longer in the soil and broke down slowly.

I dont think there is a quick fix other that applying sulphur for a long term fix , but watering early next spring with sequestrene might just sort it out for next year.

 

Would double check your ph testing /readings as it can be a tricky thing to monitor effectively.

What about the Glen Moy you planted in 2016, have their crops been ok in 2017,18 and 19 and just gone off this year ?

Wonder if its lack of water during the dry spring as the raised bed with be very free draining ?

The worst case could be that a Virus has affected both types ?

If just down to ph, then agree with @Mike Allen , add extra garden compost or peat.

Bit surprising that the soil would still be giving a high ph after 4 years of acid rain ?

When watering our Blueberry bushes we add a couple of drop of cider vinegar to each watering can as that knocks the higher ph of tap water right down.

With such a large volume of imported soil, IF ph is the real problem, worth getting a full lab soil analysis done to see whats actually in it ?

 

Thanks all for your helpful replies.
I haven't actually tested the soil, but wondered why the raspberries were looking unwell.
I tracked down the spec of the topsoil I used and it's pH7.8 (Generally my soil is slightly acidic clay).
The raised beds were filled to a depth of about 2ft with it. I also added 4 ton of well rotted farmyard manure when the beds were made.
A couple of the Joan J are in a position were there is almost no new topsoil and they don't look so bad, so I concluded the pH was the problem - and of course I may have reached the wrong conclusion...

I planted the Glen Moy in 2016 and nothing appeared above ground until mid 2018.
I got a small harvest in 2019 and a good harvest this year.
The Glen Moy do seem to have raspberry leaf and bud mites this year. The leaves are smothered in the mites, and raspberry rust
I seem to live in an area of semi-permanent drought and all plants struggle somewhat.
I give them all a mulch in spring and autumn with home-made compost.

In the same area I grow runner beans, dwarf french beans, lettuce, blackcurrants, strawberries and various herbs - all do well.

Some photos attached