Yellowing blueberry plant

[It never rains..it pours]

As I understand it some red leaves this time of year is normal and especially if cold weather however if they dont green with age then its a sign of low nitrogen. On that note read they are a bit picky what form of Nitrogen they have, but cant say I know whats best

[magicmarigold]

Ah see I was wondering if it was the cold, it's been pretty chilly here recently, I'll have to see if there's any improvement when it heats up a bit next week

[monkeyboy]

I bought Verve ericaceous compost but it was really light and fluffy, like shredded bark and coir, i could tell it wouldn't hold water at all.

I ended up going down to B&Q because I couldn’t find the packet that i had. B&Q sell only the Verve ericaceous soil and it matches up with what you stated - too light and fluffy to hold water.

I’ll add some ericaceous soil from homebase and may add perlite. I also picked up some liquid feed with chelated iron in it.

[lottie dolly]

Verve is all my 4 plants have ever been in,they are absolutly fine,every year i top up with the same,not even fed em,mostly rain water,odd occations tap water,2 of them are several years old now,

[magicmarigold]

Just thought I'd update incase anyone else has red leaves and panics, after a few days of glorious sunshine both my blueberry plants are turning green again, hurrah, just a very slight tinge of red to a few of the leaves but overall looking alot better.

[monkeyboy]

Well I bought a digital ph meter off amazon. Shoved it into the soil. pH 8.6. I don’t know how accurate it is but if it’s correct, no wonder the plant is struggling.

[Snadger]

I have rhododendrons in the garden so guessed that if the pH was good enough for them blueberries should be ok!
I have two plants in a herbaceous border and they are thriving. I mainly grow them for there decorative foliage effect.

[It never rains..it pours]

Well I bought a digital ph meter off amazon. Shoved it into the soil. pH 8.6. I don’t know how accurate it is but if it’s correct, no wonder the plant is struggling.

Probably the one that i had which died when potted up in size using B&Q compost was in similar ph, know when tipped it out the roots never ventured out of thier original pot soil. Never had ph tester then though to say. Sulphur powder off ebay if what I now use mixed in

[bario1]

Well I bought a digital ph meter off amazon. Shoved it into the soil. pH 8.6. I don’t know how accurate it is but if it’s correct, no wonder the plant is struggling.

How is it possible that an acidic compost can give an alkaline reading??

[fishpond]

How is it possible that an acidic compost can give an alkaline reading??

Either the meter or the soil is not right, but you can test the meter further by checking normal grow bags/bags of compost.
They would normally give reading in the region of 6.5 to 7.

[Snadger]

If your tap water is alkaline and you use it to water plants in ericaceous compost it will eventually turn the colloidal aspect of the compost from acid to alkaline methinks.

[Jay-ell]

When I planted mine I added ericaceous compost but also used ferric sulphate (often used as a lawn moss killer) to quickly drop the pH of the bed.

After that an annual sprinkling of garden sulphur lets the bacteria produce sulphuric acid which keeps it acidic.

Plants are looking healthy and this year are covered in flowers. Unfortunately they aren't polination compatible. Boo hiss.

Note to self. NEED SULPHUR

[monkeyboy]

Yesterday I bought some Miracle-Gro ericaceous soil (Homebase didn't have any other brand). I topped up the Verve compost with this miracle-gro stuff and also added a liquid feed.

Either the meter or the soil is not right

Yup I agree so I ran some tests just now:

Plain tap water = 7.1
Filtered tap water 6.2
John Innes compost = 6.7
Miracle-Gro ericaceous compost = 5.4

Now it rained overnight so the soil was wet with rainwater and not tap water (which is what I normally use to water the plants with).

If your tap water is alkaline and you use it to water plants in ericaceous compost it will eventually turn the colloidal aspect of the compost from acid to alkaline methinks.

Yup I've read that. The problem is the garden is too small for a waterbutt (nowhere to put one) so I've been relying on tap water.

When I planted mine I added ericaceous compost but also used ferric sulphate (often used as a lawn moss killer) to quickly drop the pH of the bed.

I have ferric sulphate to green up the lawn and to kill moss (depending on how strong or weak I make the solution). Maybe I should add it to the blueberry soil? Any ideas on concentration?

[magicmarigold]

My garden is too small for a water butt so I just have a water bucket... I only need to use it for blueberries, everything else will have to have tap water. When rain is due I just move the bucket to the middle of the patio for optimum rain collection, infact I just use anything without holes in then tip it all into the main bucket when the rain has stopped.
Not sure how I'll manage over summer yet but we shall see.

[bario1]

Plain tap water = 7.1
Filtered tap water 6.2
John Innes compost = 6.7
Miracle-Gro ericaceous compost = 5.4

Seem like reasonable readings... guess you’ve found your problem!