Lowering pH using citric acid

Hello,

I planted some blueberries from pots last year. At the time I included some acidic
'soil improver' recommended by a local garden center (looks like fancy potting soil) at a 50/50 ratio with my pH 6.5 garden soil, but I'm anticipating having to lower the pH further.

I happen to have a bulk order of citric acid in the basement I'm not using and saw online that some people, and even some organic farms, acidify blueberry soil using it. The blueberries are right next to my container veg patch, so from May to Sep, I make a lot of trips down there with my watering can.

I'm thinking that I'll add citric acid powder to my watering can for the blueberries, but how low should I go? I guess that pH of 3 for the water in the can should be OK? Could I go lower? I'll use a soil pH meter to make sure I don't drive it down too much.

- Danny

 

OK, so just keep the watering can pH to the low end of the target soil pH. Makes sense.

 

Depends on how hard your water is, but when we had Blues we just added two drops of Cider Vinegar to a 6lt watering can and that knocked the PH down to about 4 or 5.

You could just use rain water which should be acid enough.

We used the Doff Ericaceous feed.

 

I'm lazy, I'd just add a sachet of Sequestrene to the water in spring if chlorosis had been starting to show on the leaves.

 

@Danny Hughes I would start off by measuring the pH of the soil the blueberries are in, to see if it needs to be lower.
My soil is about pH 6.5 and a number of acid loving plants grow happily, these include camellias, rhododendrons and an ornamental blueberry. I mulch these with rotted pine needles which is acidic and I have it available. I only do more if the plants become chlorotic and then I find a dose of Epsom salts generally sorts them out .
The citric acid will reduce the pH of the water you use and is a good idea if you have hard tap water and no rain water.
Citric acid is very water soluble so will wash through the soil rapidly and won't change the soil pH for any length of time.