Maple cuttings failing in propagation box, user error?

[Blue Star]

Hi, I'm relatively new to propagating maple cuttings and need some more experienced advice.

My Japanese maple cuttings last summer dried out while under the deck. Even after misting half a dozen times a day, the high heat, humidity, and wind won.

This year I tried a clear tote propagation box, hedging my odds with one tote inside and one tote outside under the deck.

The green cuttings (I believe Arakawa) indoor developed brown spots (not dried out and crispy though) on July 10th and by July 18th they were shriveling up. The same cuttings in the outdoor tote were fine. All collected from same tree on same day, all equipment cleaned and sterilized. The red cuttings (I believe Bloodgood) indoor faired better, but not great. Does anyone have an idea of what went wrong? I'm assuming I misted too much and developed rot in the leaves, but welcome other input.

Inside conditions: 21 - 23*C/ 70 - 74* F, under LED pot lights, misting 2x per day.

Outside conditions: 15 - 32*C/ 60 - 89*F, no direct light, misting 2x per day.

Both have temp/humid sensors, humidity is pretty stable at 95% RH. Lids are closed with no air holes, so I open them up for 20 min per day and re-mist.

Growing media is a mix of perlite, sphagnum moss, and coconut coir, in various ratios.

Attached are photos of the indoor tote on July 10th, July 18th, and the outdoor tote on July 18th.

Thanks!

 

[Rivian]

If your name is not cmeg, dont bring cuttings inside, or any JM for that matter

Cuttings do not need condensation or misting, restricted airflow combined with moist growing medium should supply suficient humidity. But it probably wont harm them either, if the substrate is good.

I prefer bottles. I never mist and I dont have to check on them more than once a month. Place in mostly shade, some morning or evening sun may be fine. Constant, small amount of airflow.

 

[Canada Bonsai]

@Blue Star

You will find some helpful base information here, from which you can choose to improvise according to your materials and set-up: https://canada-bonsai.myshopify.com/pages/japanese-maple-propagation

When did you take your cuttings? In Montreal I take them around May 15 to June 15 (depending on whether the parent plants are getting an early start in my greenhouse or not). In Toronto, May 15 to June 15 is also optimal.

Some cultivars/strains that you are trying to propagate via cutting have a success rate that is very close to 0% if not 0% itself.

Using designated parent plants (fertilized and pruned in preparation for cutting production) can also help with cutting propagation, as opposed to using older/slower landscape or patio trees.

Your substrate particles also look too large, but this is unlikely to be the problem at this stage.

There are many other comments I can make about humidity, etc., but you will find those on my hand out.

 

[Blue Star]

@Rivian lesson learned, I'll keep it all outside from now on.

@Canada Bonsai thanks for sharing this, the pictures are a great touch.

I took my cuttings June 12th, and the lace leaf varieties on June 26th. They are from my trees or neighbors trees, all of which are older and likely not fertilized. . I forgot to mention I used 0.1% IBA powder.

Lots of good suggestions to know for next spring.

For now, should I keep the lids closed and open them up for 20 min per day, or try to prop the lids open 1/4" for air flow, or just drill some holes in the sides?

 

[Wires_Guy_wires]

A lack of air flow combined with high humidity is a recipe for a lack of roots; the plants get all the water they need through their foliage and they will stop developing roots. They'll do nothing until there's some fungus or bacteria that takes hold and destroys them.

The key is to find a balance, make them work for that water. A humid-dry cycle perhaps. Water in the morning, then let them dry throughout the day through some air holes or a slightly lifted lid. Then water again in the evening, or the next morning, depending on how dry the substrate gets. On the second picture I see that you chopped away the tip of the cuttings, which is the most important part for hormone production.
Auxin can be synthesized locally by the roots and other organs that need it, but the apical meristem is the highest producer. Losing that apical meristem is risky; some plants can do fine without it, but I always look at it as a perfect probe. It it starts to droop, there isn't enough water transport and I'll have to either up the humidity or clip off some foliage. If it turns color, the cutting is done for; bacterial or fungal infection.
If the growing tip isn't there.. There is no probe for you to check on. That makes it difficult to tailor to your plants needs and wants.

 

[sorce]

I'm feeling the too humid scenario too.

I'd start em later too, such young foliage is rarely ready to get really stiff and be able to control it's transpiration.

Waiting till the sun fries em tough, maybe early-mid August should offer a more gangster leaf and progressively cooler temps.

Sorce

 

[sorce]

Welcome to Crazy!

Sorce

 

[duke313]

A lack of air flow combined with high humidity is a recipe for a lack of roots; the plants get all the water they need through their foliage and they will stop developing roots. They'll do nothing until there's some fungus or bacteria that takes hold and destroys them.

The key is to find a balance, make them work for that water. A humid-dry cycle perhaps. Water in the morning, then let them dry throughout the day through some air holes or a slightly lifted lid. Then water again in the evening, or the next morning, depending on how dry the substrate gets. On the second picture I see that you chopped away the tip of the cuttings, which is the most important part for hormone production.
Auxin can be synthesized locally by the roots and other organs that need it, but the apical meristem is the highest producer. Losing that apical meristem is risky; some plants can do fine without it, but I always look at it as a perfect probe. It it starts to droop, there isn't enough water transport and I'll have to either up the humidity or clip off some foliage. If it turns color, the cutting is done for; bacterial or fungal infection.
If the growing tip isn't there.. There is no probe for you to check on. That makes it difficult to tailor to your plants needs and wants.

I thought high humidity was essential to prevent loss of water through the leaves while the roots develop?

 

[Wires_Guy_wires]

I thought high humidity was essential to prevent loss of water through the leaves while the roots develop?

It is essential! But combine it with still/stale air and it's a fungal festival.

 

[duke313]

It is essential! But combine it with still/stale air and it's a fungal festival.

How do you maintain airflow while keeping it humid?

I've had success in propagating plants (not maple) in pots sealed in ziplock bags, no airflow whatsoever but plenty of humidity.

 

[Wires_Guy_wires]

Ventilation and a evaporating substrate can do wonders.
Back when I grew mushrooms like reishi, I built fruiting chambers from plastic containers with holes all around except for the bottom. On the bottom was a layer of wet perlite.
Humidity was around 100% even though there was a constant air flow.

 

[Blue Star]

Ventilation does make sense, to be honest I was wondering about that since the first time I closed the lid.

I tried to lift the lid slightly but found the squirrels liked to investigate. I already lost half a dozen seedlings this year to squirrels chomping the stem in half.

I find it interesting that some users here place their cuttings inside a bag and only open up once a week, yet have great results. Makes me wonder if they are more skilled, or if the two approaches work equally?

I could have just drilled some holes in the side of the totes but instead I turned it into a full on mini project. I designed these adjustable sliding vents in CAD and 3D printed them over the weekend. Might not be enough air flow, always room for improvement.



@Wires_Guy_wires interesting info about the leaf tips; a lot of resources recommend this but I'll forego next time. I'm guessing with the propagation box the humidity loss will be less of an issue.

 

[RJG2]

@Wires_Guy_wires interesting info about the leaf tips; a lot of resources recommend this but I'll forego next time. I'm guessing with the propagation box the humidity loss will be less of an issue

I don't think he meant leaf tips, he meant the leading tip of the shoot.

Chopping most of the leaves is okay, to reduce transpiration, but I normally leave the top one or two untouched (they are normally smaller anyway).

 

[BonScience]

I'm feeling the too humid scenario too.

I'd start em later too, such young foliage is rarely ready to get really stiff and be able to control it's transpiration.

Waiting till the sun fries em tough, maybe early-mid August should offer a more gangster leaf and progressively cooler temps.

Sorce

Can you clarify taking cutting in August? I thought for JMaples spring was the time to do it. If ~August, after the new growth hardens off, is an ok time to try cuttings then that just made my day because i was under the impression i would need to wait until next spring.

 

[sorce]

Can you clarify taking cutting in August? I thought for JMaples spring was the time to do it. If ~August, after the new growth hardens off, is an ok time to try cuttings then that just made my day because i was under the impression i would need to wait until next spring.

I assume spring as the best time may be in this same vein of idea as repotting in spring, cuz "that's when roots grow", which is complete BS. Perhaps under perfect conditions which we can't replicate it's true, perhaps because people fear the winter they think they need to start in spring.

Makes no sense to me whatsoever.

The only ticking time bomb for me is....

"Growing roots before the leaves peter out."

With no roots, August leaves will last longer than June leaves is the easiest way to "diffuse the bomb" IMO.

Sorce

 

[Blue Star]

@RJG2 thank you for the clarification, that makes sense. So should the tip cuttings have the 2 leaves at the tip (apical meristem) and also include the the two leaves on the first node below it, or should the 2 leaves on the first node be removed?

@sorce I'm having a hard time following. Do you mean as long as roots can grow before the cold fall/winter conditions set in is the only way to prevent failed cuttings? Or do you mean the leaves on cuttings collected in August have to survive less time than those collected in spring time, prior to fall/winter? Maybe I'm on the wrong track all together...

My descent into the rabbit hole begins.

 

[Srt8madness]

You don't need a node under the soil, nor do you need two nodes per cutting.

If you have a grow light you can do cutting indoors, I've found infinitely more success this way. You can take cuttings pretty late if so. The reason you'd want them early summer or spring if keeping outside, is to establish roots before leaf drop/dormancy.

Frankly I'd listen to Canada Bonsai and ignore the rest, a bunch of conflicting opinions can cause repeated failure.

 

[sorce]

hole

It's about the energy that new growth has to expend to change itself to something that won't wither with no roots.

By the time a June cutting spends the energy it needs to "harden off" it's a hundred degrees, reckon it will succumb to that before deciding to spend an insufficient amount of energy growing new roots. It also has no obligation to live as it knows it's mother is still alive and seeding.

In summer/fall, the cutting will go directly into root making mode. It may even be happy someone found a use for it's "old ratty" leaves. Old thick walled cells building old thick pipes, these things are less susceptible to transpiration and water loss.

There's certainly hundreds of ways to prevent failed seedlings.
This timing seems to offer the least amount of things that need to be prevented.

Truth though.....

The best Bonsai Material comes from haphazardly rooted stuff that needed no babying or attention.
Nurturing any new project is just asking for a lifelong need for this attention. Horticulturally.
The more stuff we do to do this "correctly", the more we set ourselves up for a life of headache.

We prune at least twice a year.

Just stick everything in something and the ones that make it are the ones willing to be with you in your microclimate.

I honestly think this entire idea of "tending" stuff is Highly counterproductive to the end goal, unless the end goal is money, which is worse IMO, cuz then you add sin into what was just one person's own lifelong suffering due to their own stupidity.

#mytreewillbeatupyourtree
#andwhileitdoesI'llbespendingtimewithmykids

Or better, spending time pondering a better design and safer way to get there.

Sorce

 

[AlainK]

Have you tried to use a "lunar calendar" ? Foresters cut their trees according not only to the season, but also to the cycles of the moon for the circulation of sap is different.
For instance, here, in France, it's "dark moon", the best time to take cuttings.
When I do, I don't use expensive material, I just put my cuttings in the shade, and when the temperatures are above 25°C (75 F or so), I put a sort of plasctic bell that I remove from time to time during the day so they can get fresh air, and I spray them one or twice in a day.
The mix should not dry, but mustn't be too damp.
Of course, conditions may vary from one species to another, and some cultivars are easier to propagate than others, but with plain Acer palmatum or Acer buergerianum, the rate of success is very high.

My 2 €cents worth...