"Heavy" (?) frenching, what are my options?

[Skafidr]

Not sure how to organize this post, but here goes.

Sooo... I harvested my leaves after the hail shredded them, and I decided to go for a sucker crop (see the post in the blog here). I removed all the stalks and decided to let new suckers grow from the base.

However, a lot of my plants suffered, apparently, from frenching.

After reading around, I decided to buy soil pH test strips to, well, check the pH of the soil. I sampled three of my pots; the results show that the pH is between 6.0 and 6.5. These test strips are not hard to _use_ but are imprecise, you don't get a hard number, you have to interpret the colours on the strip.

So the apparent conclusion here is that the soil is not acid enough.

I'm no longer really interested in having a sucker harvest at this point, given how bad the plants look, I'm more interested in the challenge of getting them "back on track".

Now a few random points:

• plants seemed okay before the hail (2024-08-14); although some displayed signs of slight downward curling
• I harvested all the leaves at once (2024-08-16)
• I cut the stalks at the base (2024-08-18)
• I gave a shot of fertilizer not so long ago (2024-09-19); the plant had a "boost" in growth but still grew funny, I think
• It's fall here, nights are getting cold but we're not that close to freezing yet so I think there is still some time to figure this out
• Whatever I do this season, I'll still have to make sure my soil is decent for next season
• Given that it is fall, water evaporates much less than what we had during the summer, soil is more wet
• I'm thinking, without having any proof (my brain is just trying to fill gaps), that nutrients may have washed away from the soil during the season (and/or have been absorbed by the plants)
• I'm amazed by the fact that they all started frenching at the same time, although this may have been hidden by the fact that the leaves that were there were "started" correctly, and if I had let suckers grow on them, I would have noticed frenching too; that may not be the case, though because on some picutres, the "bottom" leaves that were there when I cut the stalks seem okay, while what grows after I cut the stalks show frenching
• A sucker harvest may not be "a thing" for the varieties I grew; maybe those varieties are just trash once the main stalk is removed?

I'm trying to figure out if it's just soil nutrient deficiency (including "high pH"), or if something else caused it, e.g.: I cut the plants -> [the need in water suddenly drops] + [more rain water gets to the pot because the leaves that protected it are no longer there] -> the soil gets too wet -> it gives more ammo to the Bacillus cereus to be active and produce its toxins.

What would be the recommended next steps (a soil test professionally done by a decent organisation is not an option for now ($$$))? Can the "toxins" be washed away (e.g. if I let water go through for some time)? Can I mix some fertilizer with diluted vinegar and feed this to the plants to 1) adjust the pH and 2) make the nutrients readily available for when the "toxins" stop disabling absorption? Should I see if my soil pH tests actually work by taking two samples from the same pot, and add a bit vinegar to one of the samples before doing the test? (In fact, this should likely be done in any case )

Thanks!

 

[deluxestogie]

Too many variables for my brain to sort out. Pots/bags; end of season; wild, bushy sucker growth; ...

A pH of 6.0 to 6.5 is possibly okay, though the range is large. If you attempt to lower the pH, sulfur may be a more benign choice (used to acidify soil for Azaleas, blueberries, etc.).

Are you attempting to salvage the plants or the soil? Or are you just curious to understand the cause?

Bob

 

[Knucklehead]

Tobacco - Polyphylla (or Frenching)

Tobacco - Polyphylla (or Frenching)

ephytia.inra.fr

Frenching | Burley Tobacco Extension

Although most people think of Frenching as strappy leaves, MH damage can cause the same symptoms. Leaves in the first two pictures have symptoms that are more representative of Frenching. Frenching is more common in poorly drained and high pH soils. (photo courtesy of Eludia Thomas, Green...

burleytobaccoextension.ca.uky.edu

 

[deluxestogie]

Interesting that you posted a mention of "MH", which is malic hydrazide, a chemical used for sucker control. That notion of course raises many other possible impacts from stray chemicals that might affect leaf growth—cleaning sprays, insecticide sprays, insect repellent sprays, etc. A couple of years ago, I noticed that if I sprayed picaridin repellent on my arms, while standing above my lawn, it killed the grass there.

Bob

 

[Juxtaposer-]

It sounds like the rain/hail was acidic. This is just a simple observation and I can’t really help in this matter otherwise.

 

[Skafidr]

As usual, thanks for the reply!

Are you attempting to salvage the plants or the soil? Or are you just curious to understand the cause?

The way I see this, is that all of this is kind of linked. I mean, if I "do things" and the plants get "back to normal", presumably, I'll have fixed the soil, and by knowing what "I did to the soil", I'll know what caused the frenching? Ultimately, I will not be using the plants given their current state, so I'm not hoping to get a crop out of them, but just seeing them grow "normally" again would probably suffice for this season.

sulfur may be a more benign choice

As I understand this, actual sulphur will take a certain amount of time to have its effect on soil acidity due to the need of bacteria acting on it and converting it to sulphuric acid (and this only happens above 13°C/55 F). So this would work in order to lower the pH for next season, but would not be a quick fix for this season?

@Knucklehead Thanks for those links!

That notion of course raises many other possible impacts from stray chemicals

Aside from the fertilizers noted in this post, I did not put anything on those plants/in those pots. The soil was fresh out of bags at the beginning of the season. The ingredients written on the bag: "black earth and peat moss".

It sounds like the rain/hail was acidic.

It seems the issue here is that the soil is not acid enough, acid rain would likely have helped.

Although this makes me curious as to how acid is the rain we have here. And how does this affect soil acidity. I mean, if the soil is 6.5 and the rain is 6.8, will it eventually make the soil more or less acid?

I understand that I may underestimate the possibility to fix all this before the end of the season, though.

And in all honesty, I'm starting to have a hard time seeing value in this project considering that I'm not sure what a "healthy" sucker looks like (in part due to the fact that it seems I have uncommon varieties), and that aphids have invited themselves to the party

 

[PressuredLeaf]

I’m not sure it’s a pH issue. I grow tobacco here in ground, and the plants are always very healthy. Our soil pH is around 8.2-8.5 with free lime over 6%!

Now days, I’m very suspicious of any store bought “soil” that isn’t straight peat moss. A lot of producers make bagged soil regionally from local green waste. Any sort of persistent funky stuff in the green waste can make it into the finished soil. For example, sometimes manure can outright kill plants and not just because it’s “hot”. A lot of hay crops are sprayed with broadleaf herbicides that can persist for sometime after digestion and composting. Even if not at plant fatal level, I suspect small amounts can cause issues with plants.

I used to use cheap local compost a lot in my garden, but don’t anymore. The desert plants used in my local blend tend to be pretty salty, and that is the opposite of what my soil needs.

Anyways, I’m not 100% sure herbicide residues are your problem, but it’s something to think about. As far as pH goes, tobacco is pretty dang resilient.

 

[Skafidr]

@PressuredLeaf Okay, that's good to know, thanks! My "normal" plants grew okay IMHO, given the circumstances, but maybe the (bad) soil quality along with the stalk cut traumatized them too much.

I have some plants (weeds) that have started to grow there and they look like strawberry leaves, but there has not been strawberries planted there, and strawberry seeds don't travel through wind AFAIK, so I suspect there may have been strawberries in this "soil"?

Not sure if in preparation for the next season I should totally soak the pots to help wash away the "bad things" from the soil and then re-fertilize...

 

[deluxestogie]

I always recommend that you wash and sanitize any pots or trays that will be re-used.

Bob

 

[PressuredLeaf]

@PressuredLeaf Okay, that's good to know, thanks! My "normal" plants grew okay IMHO, given the circumstances, but maybe the (bad) soil quality along with the stalk cut traumatized them too much.

I have some plants (weeds) that have started to grow there and they look like strawberry leaves, but there has not been strawberries planted there, and strawberry seeds don't travel through wind AFAIK, so I suspect there may have been strawberries in this "soil"?

Not sure if in preparation for the next season I should totally soak the pots to help wash away the "bad things" from the soil and then re-fertilize...

You may try leaving your soil outside in its pots over winter. I’ve noticed that most soils and compost always seem better the next season or two. I’m not sure if it’s a leaching thing, or just the needed time compost based materials must have to properly mature.

Weeds growing are a good sign IMO. It means your soils isn’t totally toxic, and more plants will condition the soil as the roots do their stuff.

I don’t think strawberry seeds travel by wind either, but I’m not sure. Reminds me of a story. I have a small apple orchard in Oregon. Adjacent to it is my mothers vegetable and flower garden. One day I was doing my daily “did the apple trees do anything overnight?” Orchard inspection and I noticed a few strawberry plants. This was odd to me because the orchard is in a rain shadow and there are no wild strawberries around. Later on, I was reading about the mountain Forrest on the border of Kazakstan where many domesticated fruits are originally from. Specifically, I was ready about malus sieversii, which is the wild apple ancestor, which I had a couple of. I read that most of these fruits are spread by bears after they eat, digest, and leave the “residue” in a new area. The next day I observed my mothers lab doing his daily routine, which involves helping himself to whatever berries were ripe in the garden. Later that day the lab deposited the digested berries in the corner of the orchard where the strawberries were growing. Mystery solved! My parents black lab was acting as the local black bear surrogate.

To Bob’s point, sanitizing seedling starting pots and soil is a good practice. I’ve lost plenty of fragile seedlings to damping off in un sanitized soil. Once they get a few leaves, I’ve never lost any to disease, even in the worst soil I have.

 

[Skafidr]

Good advice, Bob, thanks! These were brand new so I didn't give them any special treatment. However I did not sterilise the soil; I've read some folks sterilise the potting mix they'll use for their house plants (e.g. have it spend some time in the oven), but I have trouble figuring out how I would sterilise 100 gallons of soil this way..!

@PressuredLeaf I used brand new seed starting mix (Miracle Gro) to start the seeds, and I did not think about sterilise it either, so I'll do that next time (even if I did not get any issue with it this season).

As for the strawberry plants, I'll keep on looking at it grow and determine if it's actually strawberries, but in this case, if they are actually strawberries, they're there because either 1) they were in the soil bags when I bought them (and somehow resisted the "composting" phase) or 2) birds, as no other animal can climb up there; although I don't see much bird poo on the rest of the patio.

You may try leaving your soil outside in its pots over winter.

I was starting to wonder what I'd do with that; do you suggest leaving the pots right in the open (so they can receive their share of snow and [freezing] rain), or kind of sheltering them (like put them under a tarp)? My biggest concerns are 1) that water expands when it freezes and I'm wondering if this would make the pots (specially the commercial plastic pails) break and 2) if they get too soaked in water/ice, their mass may cause issues on the patio and underneath ceiling structures.

 

[deluxestogie]

A significant characteristic of every soil is its microbiome. I have never sterilized my soil mix. I don't really know if that choice is good or bad. But the science is fairly clear that soil micro-organisms are full participants in the nutrient uptake mechanisms of plants.

Bob

 

[johnny108]

There is an older thread where seedlings were started in pasteurized soil, and the seedlings that grew were stunted, compared to unpasteurized soil.
But, right now, I can’t find it!

 

[PressuredLeaf]

Good advice, Bob, thanks! These were brand new so I didn't give them any special treatment. However I did not sterilise the soil; I've read some folks sterilise the potting mix they'll use for their house plants (e.g. have it spend some time in the oven), but I have trouble figuring out how I would sterilise 100 gallons of soil this way..!

@PressuredLeaf I used brand new seed starting mix (Miracle Gro) to start the seeds, and I did not think about sterilise it either, so I'll do that next time (even if I did not get any issue with it this season).

As for the strawberry plants, I'll keep on looking at it grow and determine if it's actually strawberries, but in this case, if they are actually strawberries, they're there because either 1) they were in the soil bags when I bought them (and somehow resisted the "composting" phase) or 2) birds, as no other animal can climb up there; although I don't see much bird poo on the rest of the patio.



I was starting to wonder what I'd do with that; do you suggest leaving the pots right in the open (so they can receive their share of snow and [freezing] rain), or kind of sheltering them (like put them under a tarp)? My biggest concerns are 1) that water expands when it freezes and I'm wondering if this would make the pots (specially the commercial plastic pails) break and 2) if they get too soaked in water/ice, their mass may cause issues on the patio and underneath ceiling structures.

I wouldn’t worry about sterilizing but 100lbs of soul. I think what Bob is referring to is making sure seedling trays are clean, and you starting soil is as well. If you go this rout, all you need to do is rinse your seedling trays with some bleach water and toast your dry soil in the oven for 15-20 mins until it reaches around 250F. Once your seedlings are past the infant stage, they can handle potential pathogens much better!

As far as overwintering your pots go. Personally, I’d leave them to the elements. The water, freeze thawing, and thermal cycling will help break it down. It will likely leave some residue where the pots drain that could stain. I don’t think the soil freezing would crack your pots, but if they are in the sun a lot they can get brittle pretty quickly.

When I lived on the east coast and was a balcony gardener I had system that worked pretty well. In fall, I’d dump the soil from my potted plants into a big tub in my outside balcony storage room. In spring I’d use it again. That way you can clean up your pots if you want to tidy up for the winter.

 

[deluxestogie]

Some of the challenges in interpreting studies that compare sterilized vs. unsterilized soil is the complexity of soil itself (su soil no es mi soil), as well as the interaction of that soil with the microbes in its testing environment. If you nuke the soil, then observe its impact in a closed setting, say a laboratory, it ignores the ubiquity of microbes that are floating about in a more natural environment. In real world settings, soil is continuously supplemented with microbes from elsewhere.

Bob

 

[deluxestogie]

"...we found beneficial plant microbes are also receptive to sound. We used high-frequency white noise to stimulate a fungus that promotes plant growth.​

​

These microbes play an essential role in plant health. Some promote nutrient uptake in plants, others protect against disease. But these communities of microorganisms can be diminished and disrupted in degraded soils, hampering plant growth and ecosystem recovery."​

The biodiversity jukebox: How sound can boost beneficial soil microbes to heal nature

In a race against time, scientists are exploring new ways to restore natural systems. Alongside traditional methods such as planting trees, reducing pollution and reintroducing native species, a surprising new tool is emerging: sound. Ecologists can harness sound to bring life back to degraded...

phys.org

Bob