Soil pH and Our Blueberries

It’s hard to tell in the above photo, but we have blueberry bushes in front of the house. Dan transplanted them there several years ago, after he finished our first keyhole garden. It looks pretty when the butterfly weeds and 4 o’clocks are blooming. It looks messy when they aren’t. 

July being blueberry month for us, we’ve been keeping an eye on those blueberry bushes. But we’ve been disappointed that the berries are small and hard. That something was wrong, was evident by the leaves.

But what? I got out my copy of The Organic Gardener’s Handbook of Natural Insect and Disease Control (an excellent resource and highly recommended), and quickly discovered the cause.

The link will take you to its page on Amazon, where only used copies are now available. It would be a shame if this is out of print. It’s an excellent book for identifying problems.

In the section of leaf symptoms for diseases, I found a picture and description that matched, with a diagnosis of iron deficiency or overly high pH. From page 377 . . .

Plants affected: acid loving plants including blueberries . . .

Prevention and Control: Symptoms of iron deficiency appear when the soil is not sufficiently acidic. Symptoms commonly occur on susceptible plants growing near buildings because lime that leaches out of the concrete foundations raises soil pH. In most cases, iron is present in the soil in adequate amounts, but plant roots cannot absorb it if the pH is not in the appropriate range for that plant. 

I wouldn’t have thought of this because we have fairly acidic soil here. But these bushes are indeed fairly close to the foundation of the house, so it all fits. The quick fix is to spray the leaves with a chelated iron solution, which I don’t have.  But I could water with with diluted whey, which I do have.  The long term solution is to increase acidity in the soil by adding peat moss or sulfur. Or mulching with evergreen needles, which we have handily. 

So, I couldn’t save the fig trees, but hopefully, we’ll see the blueberries recovery and have a better blueberry harvest next year. Hopefully, everything will be better next year!