Ian Young

Blueberries seem to be pretty finicky about soil moisture as well, so I wonder if that is your limiting factor. It would explain why the mulched plants, getting better and more consistent moisture retention, are doing better than the unmulched plants. I've been blaming my blueberry woes on alkaline soil (which certainly is part of it), but I'm starting to wonder if the greater part of my problem was insufficient water. We had a couple years of extreme drought and I did some supplemental watering but not nearly enough. Last year had plentiful rain and all the bushes are look way happier after that.

You could hold off on the compost for the remaining plants, but I think mulch would be well worth it and can't possibly alter the pH that much.

Glad I could help!

I probably will give it a try this year. I'm going to be seeding some lawn with a fescue mix that likely includes red fescue, so I'll probably go ahead and sow a little of that on the edges of the blueberry bed.

I'll try to check my soil pH a few times this year so that if I see improvement on the bushes I'll be able to guess at whether it's the grass, or that my generous soil amendments have finally started catching up. Still, I'm going to have anecdotal evidence at best, since I don't have anything resembling a control group. If the bushes are happy, I'll just keep doing the same things I'm doing!

Correction: The study is not actually paywalled, yay! Here it is in full: https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2019.00255/full?utm_source=fweb&utm_medium=nblog&utm_campaign=ba-sci-fpls-blueberries-grass

Some interesting excerpts and answers to some of my questions:

The aim of this investigation was to study the effect of sustainable strategies to correct iron deficiency in blueberries, based on Fe-heme applications or intercropping with graminaceous species, on yield, and berry quality variables. The experiment was conducted in a blueberry orchard established in a sub-alkaline soil. The association with grasses increased the crop load and yield (only Festuca rubra), and decreased the skin/flesh ratio. In addition, these treatments increased anthocyanins as well as some hydroxybenzoic acids, hydroxycinnamic acids, flavanols, and flavonol concentrations in skins with a similar effectiveness as Fe-EDDHA, whereas the Fe-heme applications did not influence such parameters. Moreover, data revealed that the association with both grasses decreased the firmness of the berries, whereas none of the treatments assessed changed the soluble solids, pH, acidity, and the soluble solids/acidity rate compared to the control.

The graminaceous species F. rubra L. and P. pratensis L were sown over the rows in autumn 2014 at a density of 20,000 seeds m-2. During the season, the graminaceous species were cut manually to a height of 5 cm every time they reached 15 cm.

It sounds like they grasses were sown to cover all soil, not just the paths. And they were kept mowed fairly short, which is interesting because that's supposed to be what causes grass to compete heavily for water and nutrients. They did add extra irrigation for the rows with grass so the bushes weren't getting shorted.

If I'm reading their results correctly, it looks like Festuca rubra in particular performed very well, with yield comparable to the synthetic chelator (Fe-EDDHA). Fe-EDDHA produced larger fruit, but fewer berries.

All in all, it sounds promising!

I'm glad you posted this, as I had not heard of this study! I'm trying to grow blueberries in our very alkaline soil, something I knew would be difficult to do but I wanted blueberries badly enough to put in some extra work. I've applied a lot of acidifying amendments for years but still am coming up short on soil pH, and this is even with the berries in a raised bed to try to have more control. I'm seriously considering trialing the grass method, because if I could get better results and not have to fuss with inputs, that would be huge.

Those of us with alkaline soil know that you can have as much soil fertility as you like and it's still game over if your blueberries are iron deficient. The interesting thing about the grass study is they believe the grass provides chelators that make the iron more available, and that happens without needing to actually alter the soil pH!

I wish there were more than one study about this, and that the study itself weren't locked behind a paywall. I have a lot of questions. What spacing from the bushes are they using? I'm guessing it's probably the typical row-cropping fruit production layout and maybe they're planting the grass in or along the paths between rows. The grasses used are described as "red fescue and common meadow grass", not very specific names. I wonder if there's anything special about those species, or if any grass species will work? I'd hate to plant a bunch of little bluestem only to discover that it doesn't have the same chelators or something.

I did a bit of googling to try to learn more about this theory. Most of the articles are carbon copies of the same report from the study's author. The one bit of discussion I found was on this forum, which has a couple interested individuals but no results to report yet. One person there claims that blueberries also need special sources of nitrogen that low-pH soil provides, which grass wouldn't solve. Is that a real problem? It didn't stop the study trial from getting great results, so maybe not, but who knows, maybe they were applying enough fertilizer to sidestep the issue or something. We need a lot more data points and more trials in other locations and conditions.

Oops, accidental double post.

Sounds like bacterial spot. I have this on my peach tree. The gummy "exudate" is a good sign and I can see your leaves have the "shot hole" pattern.

I think there might be some organic copper sprays but I haven't tried anything for control yet so I can't speak to that. I think you often have to have very accurate timing with sprays for them to be effective, and I'm just not willing to make that time investment at the moment. As far as I know, the infection doesn't hurt the tree itself much, so how much effort you put into control depends on how much you care about the effect on the fruit.

For me the severity of infection seems to vary a lot from year to year. Last year was terrible. This year, despite being extremely wet, it's looking like it will be pretty mild. When the infection is bad, it doesn't spoil the fruit but it can give the skin a very unattractive and unpleasant rough texture. If you're peeling and preserving, it's not too big a deal. It definitely makes them less appealing for fresh eating, though.

Barbara Kochan wrote:You may find that his exceptional fastidiousness is due to a very keen observation and that, but for lesser fine motor skills even this 2.5 years old person could put each seed back with it's kindred, given a few attention breaks.

It's true, I actually think he would do great at identifying like-with-like seeds. He seems to be pretty dialed in to that sort of detail. He's had a great time looking at the different sizes and shapes, and is already identifying a few types of seeds by name, which is pretty impressive (to me at least). Unfortunately, my seed collection has lots of different varieties within the same type of seed, which is where the parental heartburn set in. Even I am not that good!

At any rate, I'm not really complaining. I'm excited to get to share this with him. We've been talking about how planting works and I'm eager to get out into the garden with him once the weather warms a little more. He has a book about gardens and has been naming the vegetables he thinks we should plant: garlic, sunflowers, carrots, and watermelon. All good choices, except I had finally written off growing watermelon after too many years of poor results with our short growing season. Time to give Blacktail Mountain one more try, I guess.

In a previous thread ceramic tile was suggested as a permanent barrier. It has a lot of appealing properties: it's inert, not going to corrode, (hopefully) not going to leach anything bad into the soil, nice and strong, and can be collected free from surplus material. I made a raspberry bed using 12" tall tiles (pics in the other thread) and it has been working great. It sounds like you're looking for something slightly taller. Bigger tiles might be a little harder to source, but they exist. A lot of modern bathrooms and commercial facilities are going with large (18"x36" or something like that?) tiles, so if you could source some discards from a project like that, you might be in business.

I mentioned in the other thread that something I had been using as a temporary solution was corrugated plastic like what's used in political yard signs. Plenty of that around to be discarded after an election. I've had a piece in the ground for something like 4 years and it is holding up just fine. A little bit of degradation along the top where it's exposed to the sun, but the stuff under the soil surface seems totally intact.

Douglas Alpenstock wrote:For those who prefer to avoid plastic in the garden, I wonder if overlapping 12" ceramic tiles would be deep enough. I've read that the runners tend to be shallower than the roots of the mature plant. Tile can be had very cheap/free if you know where to look.

Douglas, this comment stuck in my head because ceramic tiles seemed to have the ideal properties for this sort of application, plus I love taking stuff out of the waste stream. It took me a little while to find a suitable quantity, but eventually I nabbed two different sets of leftover tile being given away, one of 12x12 and one of 12x24 tiles (even better).

I dug a trench about 8" deep around the border of the new raspberry bed so the tiles would stick up a little bit—I want this bed to be slightly raised but keep most of the tile under the ground for stability and rhizome protection. I laid the tiles in a simple running bond, and tamped down the soil around them to try to keep them in place. It took a little bit of fussing to get all the tiles straight, level, and tight against each other, but it wasn't a terribly hard installation. My greatest concern was that the bed would suffer from frost heave, that would introduce gaps between the two layers of tiles, and then rhizomes would sneak out the gaps. The bed is on its third winter now and is still looking great, so hopefully it's going to stay like this. I'll probably give it another year or two before I declare success on rhizome containment, but we had some established plants this past summer and nothing got out!

I recently made the mistake of leaving my seed storage box on the dining room table. Of course the toddler immediately notices it and wants to know what's in it. Seeds? He knows what seeds are and demands to see them. Well, of course I want to nurture his interest in gardening, but I also want to have seeds left to plant. First I think I can sell him on taking just a few seeds per envelope. This works with some careful coaching, and he's having a good time pushing them around the table and talking about sunflowers and pumpkins. I can sacrifice a few seeds, I have extras. But then, because he's a weirdly fastidious little dude, he wants to put the seeds back. Back in the correct envelopes, though? Good luck on making that happen with a 2.5 year old. I not only want to have some seeds left to plant, I want to have seeds that will grow into what the envelope says they are.

Luckily, after several nights of heartburn at dinner as the kid requests "I want to play with SEEDS" again, I hit upon a solution. It was time to clean out some old seeds of rejected varieties or too old to be viable. Two big handfuls of seed packets I no longer need? I know someone who could use those. So now my seed box is tucked safely back in the basement and the kid has his own seed collection that he is free to use. He's even getting pretty good at sealing the reusable envelopes back up. I'll thank myself for this later!