Grass instead of acid for blueberries

I’ve read a couple articles that talk about how your blueberries don’t need acidic soil if they’re planted by grass. They say blueberries need acidic soil to break down the iron so blueberries can absorb it but apparently grass also breaks down the iron into a useable source for blueberries. Has anyone tried this? I hate the idea of having to continuously amend soil.

I'm not sure where you got your info, but in my experience, grass is the number one enemy of blueberries. Blueberries do not have a tap root, and their fibrous root systems cannot compete with grass. Grass sucks up nutrients and water, leading to tiny blueberry crops. Instead of grass, I like to use lots of wood chip mulch, bark and rotten logs. The mycorrhizal fungi that blueberries require thrive in a wood based soil, and donot live in grass based soils. My blueberries love wood chip mulch- the more, the better. I also use Acid Mix organic fertilizer- it's got cottonseed meal, langbeinite, fish bone meal, rock phosphate and seaweed meal. It's pricey, but it makes the difference between a small crop and a huge crop. And if you use softwood chips, they will keep the root zone moist, supply nutrients and keep the soil acidic, although hardwood chips are great, too.

If you don't have acidic soil and want to plant blueberries, you might try amending your planting holes with conifer bark dust and/or compost made from conifer sawdust and manure. In the old days, people used peat moss. Blueberries also really  thrive in hugelkultur beds made with lots of rotten logs and conifer debris. There's also a great thread on this site about plants for blueberry guilds.

https://permies.com/t/147945/Blueberry-guild-companion-plant-chart

As you can see, there are lots of good plants to have near blueberries, but grass is not one of them. And some of these companion plants can also amend the soil when they drop their leaves. Good luck!

M.K. Dorje Sr. wrote:I'm not sure where you got your info, but in my experience, grass is the number one enemy of blueberries. Blueberries do not have a tap root, and their fibrous root systems cannot compete with grass. Grass sucks up nutrients and water, leading to tiny blueberry crops. Instead of grass, I like to use lots of wood chip mulch, bark and rotten logs. The mycorrhizal fungi that blueberries require thrive in a wood based soil, and donot live in grass based soils. My blueberries love wood chip mulch- the more, the better. I also use Acid Mix organic fertilizer- it's got cottonseed meal, langbeinite, fish bone meal, rock phosphate and seaweed meal. It's pricey, but it makes the difference between a small crop and a huge crop. And if you use softwood chips, they will keep the root zone moist, supply nutrients and keep the soil acidic, although hardwood chips are great, too.

If you don't have acidic soil and want to plant blueberries, you might try amending your planting holes with conifer bark dust and/or compost made from conifer sawdust and manure. In the old days, people used peat moss. Blueberries also really  thrive in hugelkultur beds made with lots of rotten logs and conifer debris. There's also a great thread on this site about plants for blueberry guilds.

https://permies.com/t/147945/Blueberry-guild-companion-plant-chart

As you can see, there are lots of good plants to have near blueberries, but grass is not one of them. And some of these companion plants can also amend the soil when they drop their leaves. Good luck!

This is the article. There are several; I think they’re all talking about the same study though. I do plan on doing hugelkultur eventually so it’s good to know that they like that environment!

https://www.sciencedaily.com/releases/2019/03/190312075912.htm#:~:text=Intercropping%20with%20grass%20species%20has,most%20recently%2C%20in%20blueberries.%22

Using grass as a compost tea might be a great way to give nutrients to blueberry plants.

Take your grass clipping and put them in some water overnight.  Then water the blueberry plants with this compost tea.

Also you can use grass clipping as mulch on the blueberry plants.

Compost with coffee grounds, fruit scraps, and pine needles can lower pH like you want.

Peat is also a fairly cheap thing to work into your soil for long term acid.  If you can get wood chips or sawdust from pine or oak you could put it into your soil.

OH, chat gpt had a nice suggestion of pine bark.  This might be simple to harvest in some areas from down trees (where chips and sawdust needs processing).  If you find the right carpenter or sawmill, you might have a free source.  This source is a bit more sparce since people started creating all of the burn bricks from sawdust and paper.  

The product EM1 has helped me, but I don't grow berries.  I enjoy that I can stretch out the EM1 almost indefinitely by brewing it with molasses.  I use a tiny submersible aquarium heater and a stock pot from Walmart.  Then the effective microbes mix that I am culturing goes into a half gallon milk jug.  Instead of burping this often, I only fill the milk jug halfway, and then collapse all of the extra air out of the mill jug.  I squish the liquid all the way to the top.  This provides a huge amount of expansion, taking much less tending to.

I love the squished milk jug trick for culturing effective microorganisms.  The last concern is juts a weight to hold the jug so that it's not floating.

This process sounds like a pain, but I enjoy the thought of being able to make more and more of the stuff, similar to how people culture their own yogurt from the last batch.  HOWEVER, the guy with the most knowledge about this stuff says that the product from the store is better than he can make, because it's a known quantity.  Cultures are going to mutate in ways that we don't know, as it is influenced by many things local to the environment.  He suggests not going past a few generations of brewed cultures before starting off again.

The culture you brew is called EM-2, once it has matured.  Going to 5 and beyond you start to see slight variences.

But yeah, thanks for joining my mini Ted talk today

Edit to add:  it's called Stretching, but the process is also how they suggest you activate the em1 before use.  You can use it straight out of the bottle, but this way gives a nice boost.

Ariel Bate wrote:

M.K. Dorje Sr. wrote:I'm not sure where you got your info, but in my experience, grass is the number one enemy of blueberries. Blueberries do not have a tap root, and their fibrous root systems cannot compete with grass. Grass sucks up nutrients and water, leading to tiny blueberry crops. Instead of grass, I like to use lots of wood chip mulch, bark and rotten logs. The mycorrhizal fungi that blueberries require thrive in a wood based soil, and donot live in grass based soils. My blueberries love wood chip mulch- the more, the better. I also use Acid Mix organic fertilizer- it's got cottonseed meal, langbeinite, fish bone meal, rock phosphate and seaweed meal. It's pricey, but it makes the difference between a small crop and a huge crop. And if you use softwood chips, they will keep the root zone moist, supply nutrients and keep the soil acidic, although hardwood chips are great, too.

If you don't have acidic soil and want to plant blueberries, you might try amending your planting holes with conifer bark dust and/or compost made from conifer sawdust and manure. In the old days, people used peat moss. Blueberries also really  thrive in hugelkultur beds made with lots of rotten logs and conifer debris. There's also a great thread on this site about plants for blueberry guilds.

https://permies.com/t/147945/Blueberry-guild-companion-plant-chart

As you can see, there are lots of good plants to have near blueberries, but grass is not one of them. And some of these companion plants can also amend the soil when they drop their leaves. Good luck!

This is the article. There are several; I think they’re all talking about the same study though. I do plan on doing hugelkultur eventually so it’s good to know that they like that environment!

https://www.sciencedaily.com/releases/2019/03/190312075912.htm#:~:text=Intercropping%20with%20grass%20species%20has,most%20recently%2C%20in%20blueberries.%22

Thank you for posting the article Ariel, I always find out new stuff on here! I'm guessing that my naturally acidic, iron rich red clay soil is probably different than the more alkaline soils in the study.

That's good that you are planning on trying hugelkultur since that growing technique is perfect for berries in the Heath family- such as blueberries, huckleberries and lingonberries. Around here, I see native red huckleberries, a close relative of blueberries,  growing directly out of rotten logs and stumps. I always try to plant rotten logs underneath my blueberries when I transplant- sort of like a mini hugelkultur.

Anyway, welcome to permies and please keep us posted.

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.

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!

Try pine needles. And mix water w a bit of vinegar or lemon juice when you water them. That will drive the pH down the pine needles will remind them of home. Maybe try some iron nails or pieces of metal in the soil. Crush up some iron tablets. Companion plant with plants that love to be with blueberries.

Ian Young wrote: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!

My goodness thank you! I couldn’t find the study and had the same exact questions! I think I’m gonna try it out with a couple bushes and then if it doesn’t work out I’ll try something else! If you try it out you should definitely let me know how it works out for you. I also wish there was more than one study and am surprised there isn’t because it kinda feels like a big deal.

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!