Fertilizer or pH issue?

[Inkfin]

My blueberry plants are in pots with 5-1-1 (pine bark-peat-perlite) soil-less media. They have been fed with low strength ammonium sulfate in city water adjusted pH with battery acid (city water here has a pH of 8.6 with lots of bicarbonates). Constant acidification of water has, however, caused the media pH to drop under 4. I have been trying to revert the pH with plain city water and current media pH has been around 4.5-5.0. Lately, I have been observing some sort of nutrients deficiency (don't know what micronutrient deficiency causes this) indications on some of my bb plants.

I really haven't been able to find any suitable fertilizer for blueberry in my area. All the big box stores and one single local nursery in the entire town sell acidic fertilizer for azalea that contains either potassium chloride or nitrate nitrogen, which are not safe for blueberries. I thought lacking of complete fertilizer (other than just the nitrogen) is to be blamed. I turned the problem to one of the well experienced blueberry grower in the forum and I have been advised to start over with new plants as low pH causes roots stop growing, media usually water logs and plant never recovers even if repotted, they are most likely at their terminal stage before collapsing.

Has anyone faced this kind of situation? Anyone has solution/suggestion to rescue these plants?

[penandpike]

You can try spraying them with some good water soluble complete fertilizer (MPK+micros+some extra chelated Iron).

[The Figster]

this is a good idea

[AscPete]

I'm currently growing plants in a 3-3-1 (Pinebark-Peat-Perlite) potting mix and use Espoma Holly-tone as the primary fertilizer with regular Miracle-Gro All purpose as the water soluble supplement with a water pH of ~6.5 and I have not had any issues with poor growth or chlorosis even with the excessive rains that we've experienced this summer. The plants started off this spring as 2" - 6" stubs because they were all girdled by voles and mice this past winter and they're currently 2 - 4 feet tall.

BTW, I can't view your attached photos.

[don_sanders]

Interestingly, the only one of my blueberry bushes that looks any good is the one in the shade along the tree line that was eaten to the ground but what I assume was a rabbit. The rest of them whether in ground (3) or in pots (2) all have poor growth and/or chlorosis. The other three in ground were treated the same as the one along the tree line except they get more sun and weren't cut to the ground.

Maybe I should cut the rest to the ground this winter.

[fruitnut]

Pull the biggest one out of it's pot and see if the media is indeed waterlogged. If the plants aren't big enough to have completely filled the pot with roots then don't try to pull from pot. Instead dig down on the edge of the pot and see if the lower 2/3 of the media is waterlogged. That's about what water logs in those that go bad.

If not water logged quit using the untreated well water. That could be the issue and if so the problem should clear up.

Once the pot is full of roots, pH is right, and plants growing nice and green, quit acidifying other than that needed to treat well water. Use rainwater if possible. If not be careful about acidifying well water much below 5 and certainly not below 4.5.

[Thepodpiper]

Inkfin, just curious how your bb's turned out?

[figgrower]

I think that this is a ph issue. Fertilizing with composted chicken manure/pine shavings seems to work wonders for blueberries.

[Inkfin]

Yes, it was pH issue (details below) and has been resolved. I have been staying away from chicken manure as it raised the soil pH, however, I read somewhere if you compost chicken manure with citrus (specially lime and lemon) peel the resulted pH will be suitable for blueberries. I have yet to try that method.

[Inkfin]

Inkfin, just curious how your bb's turned out?

Based on extensive research, I concluded, the issue above was certainly related to pH; mixed up of over correcting city water high pH, Ammonium sulfate fertilizer in 5-1-1 media dropped the optimal pH for blueberries and caused Al toxicity. According to research articles, "Insoluble Al in soil is solubilized under 4.5-5.0 pH and enters into root tip cell and ceases root development." Few of the many Al toxicity symptoms are stunting, small, dark green new leaves and pale mature leaves and yellowing death of leaf tips, overall stunt growth (clearly visible in most of my plant pictures above). Fortunately, all the plants recovered completely by increasing the Ca, Mg, and K concentration in the medium. Here is a new picture (same plants but here the warmer than normal winter has confused the plants whether to swell the bud or ripe the berries or both at the same time?)

[Thepodpiper]

Glad you have figured out the problem. I had a ph problem myself last summer in just one pot. The leaves of the plant turned reddish as if it was starting it's fall colors and when I checked the ph of all my potted bb's just that one plant was well below 4.

[fruitnut]

Based on extensive research, I concluded, the issue above was certainly related to pH; mixed up of over correcting city water high pH, Ammonium sulfate fertilizer in 5-1-1 media dropped the optimal pH for blueberries and caused Al toxicity. According to research articles, "Insoluble Al in soil is solubilized under 4.5-5.0 pH and enters into root tip cell and ceases root development." Few of the many Al toxicity symptoms are stunting, small, dark green new leaves and pale mature leaves and yellowing death of leaf tips, overall stunt growth (clearly visible in most of my plant pictures above). Fortunately, all the plants recovered completely by increasing the Ca, Mg, and K concentration in the medium. Here is a new picture (same plants but here the warmer than normal winter has confused [ATTACH=CONFIG]n65318[/ATTACH] [ATTACH=CONFIG]n65319[/ATTACH] the plants whether to swell the bud or ripe the berries or both at the same time?)

Excessively low pH definitely stops root growth. I'm glad to know it's Al toxicity.

What material did you add to raise Ca and Mg? Is that how you raised pH?

[SmyFigs]

I have had this same issue with my fig plants. Can someone tell me how to best balance the ph level on potted figs? Thx!

[SmyFigs]

I have had this same issue with my fig plants. Can someone tell me how to best balance the ph level on potted figs? Thx!

[fruitnut]

Figs are 180 degrees different than blueberry. Figs like alkaline pH, ie above 7, Blueberry require acidic media, ie 4.5-5.

So add some limestone, like a handful of finely ground, for each pot when planting figs. Using well or municipal water will also increase pH so use that on your figs.

Limestone will slowly kill blueberry, like in months.

[SmyFigs]

Thanks, Fruitnut! I guess thats something that is available at Home Depot.? My figs are in 1 gallon pots. How much lime should I add?

[fruitnut]

Not hydrated lime. That's quick acting and caustic. You need limestone which is mainly calcium carbonate with some magnesium carbonate. I mix a handful in a wheel barrel full of fig media while mixing. The exact amount isn't critical. It's slow acting even when finely ground and nearly inert in large chunks.

[Inkfin]

Excessively low pH definitely stops root growth. I'm glad to know it's Al toxicity.

What material did you add to raise Ca and Mg? Is that how you raised pH?

Yes, at low pH, aluminum begins to solubilize and accumulate at the root apex that causes inhibition of root growth and development, interferes with the uptakes transport, and use of Ca, Mg, P, K, and water by plants, and thus inhibits cell elongation and division (according to research articles).

I dissolved Calcium sulfate and Magnesium sulfate in city water and watered the plants as well foliar feeding the entire plant. Dissociated calcium and magnesium sulfate helped to bind with Al3+ to form Al-hydroxyl-sulfate or aluminum sulfate complexes. Neither of CaSO4 or MgSO4 raise the pH. In my case, pH was raised directly by city water (my area city water has pH of 8.6).

Btw, Legacy is one of the bb cultivars that is resistance to Al-toxicity, there maybe more Al-toxicity resistance bb cultivars that I am unaware of.

[bahamadan]

How do you test pH Inkfin?

[Inkfin]

Dan,
I have been using two different pH meters:

1) cheap digital LCD pen PH meter like this one (http://www.ebay.com/itm/New-Digital-...gAAOSw7PBTo87u) for flow through water to get an idea how is the overall health of medium pH is.
(please note that all my plants are in containers and that makes it easy to measure the pH of overflow water after watering the plant with known pH (by adjusting the neutral pH 7 before watering).

2) Soil pH meter like this one (http://www.ebay.com/itm/261675290397...%3AMEBIDX%3AIT) or (http://www.amazon.com/Mudder-Tester-...=soil+ph+meter).

Seems like they have the same or similar principle but would like to try the one that is made in Japan like this one in the future (http://www.ebay.com/itm/New-Soil-Aci...sAAOSwr81URv7R).

[SmyFigs]

Ah, that's what it is....limestone! Okay, I will do this! Thanks!

[bahamadan]

Just curious what you guys are using to test pH? I have a bb that's not doing so well, and I bought some lab rat pH test strips to see what my irrigation water is like but the tds of my city water is too low for the ions to affect the strips much so it's hard to get a clear reading, and its been raining so no chance to test the fertilizer solution yet. The strips have worked on all three buffer solutions I bought to verify they were accurate ( pHs 4, 7 and 10) and on saliva, 3.3% sulfuric acid etc.

[Visceral]

Inkfin,
In your original post you said you were using low strength Ammonium sulfate. But then you say you got AL toxicity which is Aluminum toxicity as far as I can tell. Is that what the research says will happen with AS?

[Inkfin]

Visceral, I have not seen any research article directly correlating ammonium sulfate causing aluminum toxicity. But in a simple way, sulfuric acid lowers the soil pH and at lower pH aluminum (Al) in soil is solubilized and that causes aluminum toxicity. When you fertilize with ammonium sulfate, plant takes in the ammonium ion from the fertilizer, a hydrogen ion is pumped out of the plant and soil is being acidified. In my case, I had been adjusting the city water with sulfuric acid and fertilizing blueberries with low strength ammonium sulfate which eventually caused accumulation of too much sulfuric acid causing the aluminum toxicity.

[Visceral]

Ok thanks. I also have also been using adjusted water with ammonium sulfate as a fertilizer. Based on browning leaf tips, I'm thinking I had a similar issue of too low ph. Mine were in ground, so I thought it would all leach away more than in a pot. I ran a lot of city water over the plants and they made it thankfully.