Rooted Cuttings Failure Question?

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rikuhelin1
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Rooted Cuttings Failure Question?

Post: # 72451Post rikuhelin1
Fri Dec 04, 2020 1:58 pm

A potpourri of observations of general failure characteristics.

Over the years l had many cuttings root well to my eyes but fail (cane blackens and no new leaflets).

From post mortem examination there are a dozen or more fibrous roots 1 to 2 inches long with majority having what l deem a normal blanched colour.

Eventually in most, but not all cases, the cutting dies (blackens) after 1 to 2 months from the dropping of the original cutting leaflet.

Usually chalk it up to too wet.

I occasionally (<1%) get sprouting of small leaflet (multiple leaves) that quickly wilts and cane turns yellow within a day - examination reveals no roots.

The case thats most head scratching is the rooted case. Starting to wonder if should break the technique paradigm and leave two leaflets.

Any science behind observations, or technique change suggestions to up take?

Use standard 1 leaflet left and score underneath bottom leafless node and dip in liquid hormone.

I have let gallicas sit for three or more months but they retain the original leaf and eventually take (rare). I have a Gertie doing that now and on month 4.
Riku

david zlesak
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Re: Rooted Cuttings Failure Question?

Post: # 72452Post david zlesak
Fri Dec 04, 2020 3:58 pm

I notice that too.... I wonder too if I have them too wet. I suspect in some instances the blackening may be due to one of the root rot organisms getting in and disrupting the vascular system and connection between the top of the cutting and roots. Sometimes when I have cuttings I'm potting up and there are some still in the tray under the midst bench and haven't rooted yet or are starting, but don't look so good, it seems to help if I repot them into fresh mix that isn't as waterlogged and is more porous again. I tend to get better success with those cuttings by doing that than putting them back into the same mix. I haven't used fungicides in the media, but if it is root rot of some sort starting, maybe it would help?? It seems like with the different root rot pathogens, not all fungicides control all of the key culprits. Also in the midst bench, I don't want to be leaching the fungicide all over the ground and benches. When I propagate at home under domes, I sometimes see something similar too.

rikuhelin1
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Re: Rooted Cuttings Failure Question?

Post: # 72453Post rikuhelin1
Fri Dec 04, 2020 6:27 pm

Txs, for the suggestions. I am going with change soil for this years slow ones where cane still green. Use potting mix (sterilized on label) and heavy on vermiculite 50%.

Ditto for the couple with still original leaf. One would believe something must be hindering the start of leaf growth or slowing it down too much with what looks like a lot of healthy root (say 60% +\-)

Think l with stick to changing one parameter for this rescue effort - I don’t use fungicide but using heat mats this year and enclosing domes and 18 hours of grow lamps on. Fungus gnats somewhat extreme as sticky tape is caked.

The early cutting successes show new leaf starting within 4 weeks and before original leaf falls.
Riku

david zlesak
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Re: Rooted Cuttings Failure Question?

Post: # 72454Post david zlesak
Fri Dec 04, 2020 7:32 pm

One thing I've tried last year that has really helped with fungus gnats with seedlings is hydrogen peroxide. I've mixed it about 1 part 3% from pharmacy to a few parts water. The media bubbles and kills the larvae and hasn't seemed to impact roots of rose seedlings. It takes a few applications since it only impacts the larval stage. Eventually I see less and less adults. I use the sticky cards too, but when they are getting out of hand the H2O2 really helps. Maybe a H2O2 treatment will help knock back gnats you may have in propagation too and help with some microbes too.

rikuhelin1
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Re: Rooted Cuttings Failure Question?

Post: # 72455Post rikuhelin1
Fri Dec 04, 2020 8:43 pm

Done. Pricked and transplanted as per above.

However because all dropped leaf cuttings are toast for this year - binned last one today - I was restricted to changing out cuttings that have the original leaf after ~3 1/2 months, but no new "leaf growth". Tried a fresh "peat" based potting "soil"and added vermiculite to 50%. Pots, trays and domes sterilized. Misted with distilled water.

I found roots at 2 to 3 times the length of the failed rooted cuttings - easy 3 to 3.5 inches. Not as dense as "root mat" on the failed ones. Don't think this is a differing tip radius optical illusion. All various shades of blanched (healthy to my eyes). Misted.

Should mention all living and deceased rooted cuttings taken at same time, in same domed tray, medium and watering schedule. Also varied "cultivars" e.g. RDxS, Alika, Lillian and Gertie.

Makes me think the deceased "only rooted" are as you think, water logged a good possibility, maybe, but also a factor could be a vascular tissue pathogen proposal since leaf eventually falls after a long time from taking, with black rot setting in a few weeks to days down the road on green cane. Gnats were having a breeding free for all.

On the moderate case example, or to use layman terms, I would guess the healthy long new roots and original only leaf cases are communicating, albeit very slowly compared to my fast out of gate cuttings (a.k.a. feeding each as neither is dead).

I guess it all begins with a quality medium. Or next year I should vet a new rule of thumb for cuttings triage - if late leaf development, cane still green, change medium right away.

Thanks again thanks for suggestion as high confidence will improved situation next year, and because Gertie has been a target for years as been slowly losing my 15 year old ones to climate (50%, down to south wall protected ones) and I use it as a pollen parent for bloom, color and fragrance goals.
Riku

rikuhelin1
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Re: Rooted Cuttings Failure Question?

Post: # 72456Post rikuhelin1
Fri Dec 04, 2020 8:50 pm

I will added that treatment for gnats as nothing l have done - eg buying labelled sterilized soil and javexing (diluted) the support equipment has worked.
Riku

MidAtlas
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Re: Rooted Cuttings Failure Question?

Post: # 72457Post MidAtlas
Sat Dec 05, 2020 12:49 am

For fungus gnat larvae, you should try using mosquito control bits (Bacillus thuringiensis subsp./var. israelensis); they are actually labeled for fungus gnat control as well as mosquitoes, and are perfectly safe to use indoors and quite effective. You can infuse them into the water that you use to moisten the medium prior to sticking cuttings to help prevent them from getting a foothold, and when watering the rooted cuttings later; you can also sprinkle the bits onto the soil surface and mist or water them to release the bacteria into the soil. They do decompose over time, but I try to keep them from sitting right against the base of the plant until it is fairly sturdy, and they never seem to do any harm.

The medium and its wetness level could be another problem. Many commercial mixes have proven to be disastrous in my experience (either due to pathogens or because of added fertilizer), so much so that I tend not to trust them in general. If the medium is actually sterile, then there's a good chance any introduced pathogens will explode if they aren't checked by naturally antagonistic microbes. I read a study once (Canadian, I believe) that found using dilute fish emulsion to pre-moisten peat moss well ahead of use (two weeks, if I remember correctly) promoted the growth of such antagonists and helped to prevent damping-off quite effectively. Personally, I tend to make my own mixes for both cuttings and seed starting; I use milled peat moss as the primary base, then add a smaller fraction of well-composted commercial manure/humus blend, or another deliberately non-sterile enriched humus of that sort, plus maybe a bit of clean sand (if available) or vermiculite (higher vermiculite for cuttings, little or none for seeds or other potting). The peat/decomposed humus core blend makes a more consistently reliable medium than anything I've found in ready-to-use form, and I suspect that the success is due to beneficial microbes that are likely present from the rotted manure/humus fraction.

For cuttings, I tend to opt for two- or three-leaf cuttings (never just one leaf, unless there is no choice), with one additional node at the bottom with its leaf removed and a cut not far below that; I don't do any wounding. If I'm sticking the cuttings directly into medium, then I pre-moisten the medium before putting it into the (hopefully clean) pot, pack the medium in lightly and dibble a hole, and then set into a zipper-seal polyethylene bag. If I'm especially worried about excess moisture, a folded paper towel or two underneath the pot usually helps to keep that from getting out of hand before I can intervene. Then, I dip the cut end into rooting gel (possibly not necessary--easily rooted roses generally can do without, as long as they keep their leaves); I place the cutting into the hole, pack the medium lightly around it, and use a spray bottle set to jet to squirt a bit of water directly at the bottom of the cutting, just enough to set it in place and ensure that it is moist enough (usually a few squirts). I mist the cutting's leaves a bit and seal the bag, blowing some extra air in, and either leave it alone under lights or open the bag to mist occasionally. If extra water builds up in the bottom from condensation, or from my own misting, I carefully remove that if it threatens to wick back into the medium.

However, experience has taught me that for most roses, it often helps to place the cuttings in a glass/cup/jar in shallow water under lights or in a window sill, and let them callus in that prior to sticking as above (the water should be changed out every few days and the cutting's bottom end rinsed). A well-developed callus seems to make for a pretty good initial barrier to pathogens, and the cutting usually survives better for me overall; I never use rooting hormones when opting for this method. Some roses that are particularly resistant to rooting may not callus in water, or will do so only very slowly, but if they do callus, their odds of successfully rooting and surviving are very good.

The most notoriously difficult-to-root types may still do best when stuck directly, though, especially if the medium is kept from being too moist; those might have trouble compartmentalizing wounds, and if they are placed in water to callus, they'll quickly shrivel and die instead. They might also respond better to rooting over winter as dormant hardwood cuttings, the way European nurserymen used to produce them. I haven't really experimented much with that.

Stefan

chuckp
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Re: Rooted Cuttings Failure Question?

Post: # 72458Post chuckp
Sat Dec 05, 2020 9:38 am

Hi Guys,
Very interesting subject. I have evolved a different process for making rooted cuttings.
I built a 4 meters by 2 meters chamber with builders sand and heating cable in the sand floor.
I use peat pellets to root my cuttings, and like Stefan, I use cuttings with 2 to 3 eyes per cutting.
Some varieties Rugosas and Spins, are difficult to root.
When leaves fall off, I remove them before they rot and provide food for Gnats and Pathogens.

I use a "Mist-O-Matic" automatic mister to keep the cutting bed wet.
For some cuttings I get a 100 % rooting.
chuckp

rikuhelin1
Posts: 302
Joined: Sat Jul 16, 2016 7:56 pm

Re: Rooted Cuttings Failure Question?

Post: # 72459Post rikuhelin1
Sat Dec 05, 2020 1:31 pm

Hi Stefan and Charles,

Good cutting growing experience input for others and myself to consider.

Reminded me ran out of gnat bacteriacide l use to use in house - that tamed them down relative to this year. Tools one can forget in the heat of the moment tunnel vision. But your note reminded that l have an old jug in the garden box of mosquito control bacteria for the outdoor fountains.

I am weakening on single parameter change testing to see what has biggest lift for minimum work steps and complexity.

Leaning to change to combo testing of one and two leaflets - and perhaps one and two scorings - always avoided multiple leaves due to caution about dehydration from lack of root system - irony being over watering maybe trigger for failure.

Though l notice from an over-seas 50 year aberration of the norm of “what ever happened to good in depth gardenIng shows” that multiple leave cuttings are used. Put cuttings to the sides of plastic and non-glazed pots based on l believe l heard correctly moisture regime “better”. No hormone added.

Use to dip fresh cuttings in mild very mild bleach solution to be rid of aphids - going back to that as might kill other pathogens.

Also attracted to idea of a dash of well composited non - sterilized organic matter as beneficial population starter since no point for microziohal (sic) catalyst dusting of cutting cane prior to sticking.
Riku

rikuhelin1
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Re: Rooted Cuttings Failure Question?

Post: # 72460Post rikuhelin1
Sat Dec 05, 2020 2:28 pm

The mosquito - cide is bacillius thurgiensis subspecies israelensis serotype H-14 strain BMP-144, 200 ITU per milligram used in fountain
Riku

MidAtlas
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Re: Rooted Cuttings Failure Question?

Post: # 72464Post MidAtlas
Sat Dec 05, 2020 10:56 pm

Yep, the granules I have are listed as Strain 144, but interestingly, the listed potency is a mere 7.0 ITU per mg. It says that it is 2.86% Bti solids, spores, and toxin. Maybe yours is a bit more concentrated in that form, although the label on my product cautions that potency and percentage measurements of active ingredient aren't federally (U.S.) standardized and shouldn't be used to adjust the usage rates from what is indicated. This product label recommends sprinkling the granules onto the soil surface and watering in normally for control, repeating over a three-week period (frequency of repetition is not mentioned), starting again and continuing over a further period of three weeks if the fungus gnats reappear.

david zlesak
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Re: Rooted Cuttings Failure Question?

Post: # 72465Post david zlesak
Sat Dec 05, 2020 11:29 pm

Wow, thank you sooo much Stefan for pointing out Bacillus thuringiensis and this strain labeled for fungus gnats. I'm super excited to get some and think it'll be less expensive and have a longer residual than hydrogen peroxide. It becomes difficult for me with lots of seedling trays of small cells of seedlings to water everything perfectly, so there are always some cells that are a bit overwatered that keep them going. Thank you again!

MidAtlas
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Re: Rooted Cuttings Failure Question?

Post: # 72470Post MidAtlas
Sun Dec 06, 2020 8:10 pm

You're very welcome, David! I know you'll be happy with the results. The residual effect makes it much easier to keep fungus gnat numbers low, and this treatment has made a tremendous difference for me. No one should have to worry about these pests destroying their hard work, you least of all. I remember how big your seedling setup was years ago... I can only imagine what it must look like now!

rikuhelin1
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Re: Rooted Cuttings Failure Question?

Post: # 72539Post rikuhelin1
Mon Dec 21, 2020 2:53 pm

Yes it works - changed soil and laced with mosquito-cide.

16days after, RDxS pushing out healthy leafs - not the ones that wilt, and Alika racing to put out first leaves before last leaf drops.

... gertie still cooling her heels but no rot and leaf still healthy (and good roots). Gnats cooled off as result of new “soil” and probably “cide”.

Total time since cutting taken ~ 4months+. Fast starters shown for comparison - espaliered due to height restrictions. They sort themselves out when planted.
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Riku

david zlesak
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Re: Rooted Cuttings Failure Question?

Post: # 72540Post david zlesak
Tue Dec 22, 2020 11:42 am

That is wonderful rikuhelin1!! I'm so glad they are taking. Thank you so much again Stefan!! I got Bacillus thuringiensis subsp./var. israelensis and it is working. After the first application it really knocked the fungus gnats down and a couple weeks after now I mixed some more and treated again. It is so much better than all the sticky cards and watering with lots of hydrogen peroxide. :0)

roseseek
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Location: Zone 9b Central California, Sunset Zone 15

Re: Rooted Cuttings Failure Question?

Post: # 72541Post roseseek
Tue Dec 22, 2020 2:23 pm

That is great news! I just wondered if Spinosad might also work. According to this, it is very effective against fungus gnats! https://manicbotanix.com/fungus-gnats-in-coco-coir/
Kim
California Central Coast
USDA Zone 9b
Sunset Zone 15
Cooler inland coastal valley with strong marine influence

MidAtlas
Posts: 95
Joined: Mon Jan 28, 2013 8:49 pm

Re: Rooted Cuttings Failure Question?

Post: # 72542Post MidAtlas
Wed Dec 23, 2020 12:12 am

Riku, that's a fantastic result--I'm glad that you were able to save the cuttings! I'm thrilled to hear that you and David are seeing fewer fungus gnats now. It's easy to keep them down using Bti, and hard to imagine ever going back to living in constant fear of them killing something valuable. Some sticky cards might still be a good idea in combination with the treatment, just to take care of some of the adults and to help monitor numbers.

I didn't know that Spinosad might have some use as a drench, too--I thought that I had a bottle around somewhere and was going to see what the label indicates, but couldn't put my hands on it. I'll report later if I do. It could potentially provide an effective and relatively low toxicity quick-kill, although I wonder how long its residual control might last in an even less sterile growing medium than coir, since it is fairly readily metabolized/broken down. The application also sounds a bit more involved than with the Bti (no need to suit up or adjust pH).

Stefan

philip_la
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Re: Rooted Cuttings Failure Question?

Post: # 72562Post philip_la
Sun Dec 27, 2020 5:17 pm

Are folks using the granular Bti, or were you able to get some of the liquid solution? I know that for some applications, liquids are available, but I've never seen such for sale in the states. My experience with the granular in the soil in the past was a little disappointing. Perhaps the viability was low. Perhaps the fact that I stopped watering to reduce gnats at the same time caused it to not dissolve well.

Interesting observations, Stefan. I have come to think of soil microbes in much the same way I do the human biome, and have assumed that beneficial microbes are critical. Historically, I tended to assume failures such as described were attributable to soil that was too moist, or not aerated well enough, but I have begun to think it is a bit more complex. In New Orleans, the humidity was such that I never had to water the soil excessively to prevent wilt, and had phenomenal results. I did, however, notice that recycled potting mix that had been outdoors and exposed to the elements tended to give better results than fresh potting mix. Often, my outdoor potting mix had had heavy organic amendments, which would have been very well aged by the time I used it.

I also, while in New Orleans, had impression that rooting hormones were in fact detrimental when the weather was warm. I have no idea why that might be. I never did any controlled experiments to confirm that observation however. (I would not be able to do so now since my rooting success rate is downright abysmal here in Central Texas.)
Philip F.
Zone 8 / Sunset Zn 30 (Austin, TX -- formerly New Orleans, LA)

roseseek
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Joined: Sun Dec 11, 2011 6:54 pm
Location: Zone 9b Central California, Sunset Zone 15

Re: Rooted Cuttings Failure Question?

Post: # 72563Post roseseek
Sun Dec 27, 2020 5:39 pm

The powdered hormones can work any time of the year but they are very easy to over apply and it's very easy for them to cause cutting rot. You want the slightest hint of powder on the cutting, about the equivalent of a few hours of dust after you've just dusted. I have TREMENDOUSLY better success with liquid Dip'n Gro. And some have spoken very highly of the gel type. The difference is the liquid and gel don't absorb a lot of water as the powder does, so they don't cake and seal the capillaries.
Kim
California Central Coast
USDA Zone 9b
Sunset Zone 15
Cooler inland coastal valley with strong marine influence

david zlesak
Posts: 451
Joined: Tue Nov 26, 2013 12:27 pm

Re: Rooted Cuttings Failure Question?

Post: # 72564Post david zlesak
Sun Dec 27, 2020 6:06 pm

Hi Philip,

I ordered the liquid form of Bti from a Florida pond supply company (123Ponds; I think it was a 6 or 8 ounce bottle, I have to check- it was about $20 I think). Their main customers are using it for mosquito control in ponds and that is what is on the label when it came, but the website said it can also be used for fungus gnats and recommended 6 drops per gallon. It is a thick brown liquid that needs a bit of gentle agitation to disperse and mix into the pail of water.

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