This info is from a previous thread:

Propagating Japanese Maples

Japanese Maple seeds are ready to be picked when they turn brown and start falling from the tree (around Sept through Nov - depending on your zone). Collect the seeds and clean them by breaking off the wing attached to the seeds. Place the cleaned seeds in a cup, and fill the cup with hot tap water and let them soak for 24 hours. This will soften the outer coating of the seed so moisture can penetrate and germination can begin.

After soaking the seeds place them in a plastic bag in a mixture of moist peat moss. Make sure the peat is moist but not too wet, you donÂt want the seeds to rot. The bag should be closed but not completely air tight. Poke a few holes in the bag.

Store them at room temperature, but not in direct sunlight for a period of 90 days, and then move them to the refrigerator for a period of 70 days. During the cold stratification period check your seeds once a week to see if any of them have begun to sprout. Once they sprouted, plant them in soil at 1/8" deep. Make sure you donÂt plant them too deep, and keep them watered but not too wet. Once they begin to grow provide them with about 50% shade. That's all there is to it.

Yeah, I got them to sprout OK, it's the care during their first year that is turning out to be a problem. And all I get from that post above is they should have 50% shade.

Anyone else out there actually have experience growing some JM seedlings? What do you do? Where do you put them, how much do you water them, how do you fertilize them, etc?

Karen -- thank you! I've been wondering if maybe too much water has given them some kind of rot. I'll try a more porous soil mixture and more sun, and I'll get a different fertilizer. There used to be a version called Miracid that was for acid-loving plants. I think it's now just called Miracle-Gro for Azaleas or something like that. Maybe I can find that or some other fertilizer meant for the acid-loving plants.

Thanks again.

You might try some of the Osmocote type fertilizers as well. I buy JM grafts all the time and the pots are full of it. Also, there are some systemic fungicides that should help with root rot and other curses.

Karen, have you tried copper wire for the slugs? Wrap a piece of bare (not coated) copper wire around the middle of each pot. Evidently the electrical properties of the copper don't set well with slugs! When they touch it, they backoff!

Regards,

According to "Kaitain7"
"After soaking the seeds place them in a plastic bag in a mixture of moist peat moss. Make sure the peat is moist but not too wet, you donâÂÂt want the seeds to rot. The bag should be closed but not completely air tight. Poke a few holes in the bag. Store them at room temperature, but not in direct sunlight for a period of 90 days, and then move them to the refrigerator for a period of 70 days. During the cold stratification period check your seeds once a week to see if any of them have begun to sprout."

Here is my question:
I just gathered the seeds from a local botanic garden grounds.
quest#1: how many seedlings should I put/plastic baggie?
quest#2: how much peat moss/baggie
quest#3: if I bag the seed(s) at room temp. for 90 days, that brings me to March 1st '09. To then stratify them in the refrig. for another 70 days brings me to about the 1st week in May '09. Is that too late to be bringing the seedlings out of "cold storage?" Should I just place them in the refrigerator now for 90 days then transplant any that germinate to small pots indoors?
Please advise. Thanks

The easiest way to germinate JM seeds that I've found is to soak the seeds for 24 hours then place them on moist paper towel in a sandwich plastic container with the lid on. Put the container in the fridge. Depending on the species, the period of time varies in the fridge before they start to germinate then you can simply place seeds in 50/50 perlite and peat moss mix at room temperature till they are a couple inches then place them outside (that's what I use in Rootmaker starter tray) then 3 parts pine bark fines, one part expanded shale and 1 part peat moss for 1g or larger when they are ready to be potted up. Green JM seeds took a few weeks to germinate in the fridge. Shantung maple seeds took the least amount of time to germinate. Red JM takes 2-3 months. Trident maple takes around 2 months. This is based on Deno's work. I much prefer this. A lot less messy and reduce space as well.

If you somehow get your hands on Micromax and Osmocote 18-6-12 (9 months) and 17-7-12 (12 months), you get better growth. It's tough to get them because I'm not "commerical" grower. I use Dynamite 18-6-8 (9 months) from Lowes or Home Depot which seemed to do decent job.

I transplant my JM seedlings outside in early to mid-summer in a nursery bed, placing the seedlings about 6" apart. In late fall, I mulch the bed heavily with oak leaves (several inches) which I hold down with plastic netting, and uncover them in early April the following spring. Depending on their parentage, I get anywhere from 50-90% survival. I live in zone 4 Minnesota so am pretty happy even with a 50% rate. I transplant the survivors later on that year if they are 1' or more in height, those that are shorter get mulched for a second winter and then are transplanted to their permanent location the following spring/summer.

Thanks for the tips, kms4me. How much water are they getting in that bed -- how frequent? And are you applying any fertilizer?

I think this sounds like a good idea for me, too. I did have two other tree seedlings in pots, plus two clematis I grew from cuttings, that I decided to put in a section of my veggie garden this year. That gave them better watering and protection from the heat drying them out in the little pots. With the clematis, I just buried their pots, since I read that their roots like to get a bit crowded, but with the trees, I planted them in the bed.

Do you do any root pruning before you dig them up? If so, how long before you dig them up?

Stevation,

I water them in with a low dose of water-soluble fertilizer or fish emulsion when I plant them. I don't feed them after that as I don't want to encourage too much growth later in the season that won't have any chance of hardening off.

Rainfall is usually pretty regular here so I water them only if there is extreme drought. As long as there is no leaf scorch or drop, I leave them alone. I think it results in less but stronger growth.

I don't root prune my JMs. I try to move them during a cloudy day---just before a rain if possible. If I can't wait for that, I water them a couple of hours before I move them--it seems to help the soil stay on the root ball better.

I am a big fan of nursery beds--it makes tending young plants easier (they are all together, can be mulched, watered, fed, protected from critters), and it is easy to compare the characteristics and growth rate of the seedlings.

Kate

if i put the seeds on a paper towel in fridg. do i cover the seeds with the paper towel or just lay them on top in side bag. i am very new to this. thanks mary

I have about 50 JRM and 20 Green that had been in peat, and when they started to sprout, the person that had them didn't know what to do with them...so I took them. I don't know what she did, but it's apparent the poor things think it's spring! I want to "pretend" it's spring until they get a root system of some sort, then they can go dormant until spring.

I put them in a 72ct cell liner. They have all popped their little heads up out of the soil, but between now and when they put on their their first "real leaves" is a mystery. Usually when I get things to grow from seed like this, they get spindly and wind up falling over and dying. I have a mister bottle that I mist them with....I don't want to drown the poor things or cause them to rot off at ground level. I am trying to avoid this since I love JRM!

Once they are above ground.....how to do I care for them until they get their first leaves? Thanks.

I have seeds that pop up everywhere from my 55 yr old tree. I let them grow where they start and if they survive after a year or so I put them in pots. Works well for me. I have 3 in pots and have given away to many to count.

Don't be afraid to try planting JM seed. Take seed from tree in Oct/Nov depending on Zone (I am 7/8) place in a cool dry place until Jan. Then place in crisper in fridge for 100 days. Take out and sew/broadcast in fertile soil with morning sun. The following Spring you will have more than you can process.
The picture is less than half of the seedlings from one tree.

This is my 2nd year of trying to get my baby Dwarf Red Japanese seedlings to grow. I picked the babies out from under the tree and transplanted in 4" pots, left them outside for the winter. The first year I placed them in a sheltered area for snow and wind and covered them with straw but it was a very harsh winter. Out of 80 plants, only 5 came back with leaves and buds. The rest were just a red twig - not dead, but no buds so thought the buds froze. This past year I moved them against a shed wall, morning sunlight, facing south, but sheltered from wind and snow. I did not cover them and it was a very mild winter, no snow. Still only have 8 with buds/leaves, rest are reddish twigs. Why no leaves, branches? Is there something else I should be doing?

You are all nuts. Don't do this always do that... Mother nature herself never has as many issues as you all seem to have. I don't refrigerate, bag up, or alter seeds or anything for my maples to grow here is a photo I treat them naturally and in years I may have only lost a few. The only thing I do differently than nature herself is allow them to germinate and grow to about 6inches in a homemade hothouse in my basement in fact even during the cold seasons. I live in central pa where the weather is almost unpredictable and lately a bit nuts. I have also been 90% successful in rooting cuttings, branches even. With this method you can have lots of maples in larger sizes without the wait for your nursery. Cut a nice looking branch on a good angle to allow a large enough area for rooting lay them on your table counter workbench basement floor whatever you may prefer for a few days to allow the cut area to form a calas. Then simply stake them up in a container of water of about 1-2 inches over your cut area for roughly thirty days changing out the water every couple days so it doesnt rot the branch dirty water is no good so when the water starts to color change it so let that be your guide to clean rooting. It's all simple nature has things for centuries on her own without our help although you can alter some of it for faster starts. Once your branch has developed about 2 inches of root transfer it to a pot of 3part peat 2part sand and two part coconut soil no direct sun for up to 3months and should semi-moist to not rot the roots as this will be a crucial time for root development and a good strong successful clone.

No picture came with that last post....did you mean to attach one? And I'd be very interested to see the results of your cutting propagation as Japanese maples are notoriously difficult to strike from cuttings. That's why 99% of the trees for sale in nurseries are grafted and not cutting grown.

I assume you ARE talking about JM's as that's what this thread is focusing on. And is it really appropriate to call previous posters nuts because they choose to do things differently?

Firstly - this post is from July 2008, If the OP hasn't figured it out by now, he has long since stopped trying.

Secondly - Terry, I am nuts, but that is not relevant to this thread.

Thirdly - 1msr, there is vast mortality rate in seedlings. If all of the hunderds of thousands of seeds became trees, we'd be up to our eyeballs in JMs. Digging them up is extremely stressful to them, and the soil is too water retentive in a pot. You'd be better of gathering the seeds and putting them in a fast draining potting mix and letting them be for a few years.

Thanks, have about 10 little trees out of the 80 or so, rest are twigs, but didn't cost me anything, waiting to see how the little ones make out.

I ordered some fancy japanese Maple small rooted trees in March. When they came they had already leafed out. I had to keep them in the house and I have lost almost every one. Our last freeze should be tonight and then I will start taking the survivors outside and putting them in the ground. But I don't know what I did wrong and what I should have done differently. I am very disappointed. They were such good looking trees when I received them and I have killed them!

Sad to hear that, Sheila. It's hard to say what happened, but it is possible they dropped leaves but are still alive. If they're not brittle, they may produce new leaves. Look for tiny leaf buds on the branches. They like shade, and they should be watered when they've just gotten dry but not parched. Don't keep them too wet. If they are very small, you might want to keep them in pots somewhere in the shade until they've grown a bit to be sure they survive.

Thank you. I am hoping they might come back. I repotted one today and will start vernalizing it tomorrow. Will repot the others tomorrow too. Thank you for your tops about caring for them.

wow, this is a 10 year old thread.. anyway, I am currently facing similar difficulties. Stratification and germination went well, but they are having trouble flourishing in a humid zone 7/8. Some of them are starting to brown. I've got some interesting variation in the seedlings and there are a few that I would hate to lose. I water them at least every other day in very well draining soil. Maybe I should test ph?

I have 2 seedlings. One from a local nursery that I took from a tree that was next to the one I bought and the other I dug up from my friends tree. The first one has tripled in size in 3 months and the other one from my friend is much slower and looks like a second set of leaves are on there way soon. The first one had only 1 set of leaves and now has 7. I will post some pics

I pulled a couple of seedlings along with their root balls from a Japanese maple in my front yard. They have done well so far in the pots on my back deck. I live in the north east, what should I do with them this winter?

HU, if still in their pots, then you will need to provide them with some sort of winter protection. Once the leaves drop off, bring them into someplace that stays quite cold but above freezing....unheated garage or basement, etc.. They don't need any light during dormancy but they do need just a bit of soil moisture and temperatures that stay somewhere around 35-40F until it's time for them to emerge from dormancy in spring.

A friend of ours gave us a seedling a few years ago and said it needs sun. We planted it in direct sun and it took off. We haven’t touched it or watered it except initially when planted. We live in New England seasons change so it. Plus be the dry air you’re talking about that it can’t withstand.

HU #2, I don't understand the relevance of your comments. There is a big difference with how one handles potted or containerized seedlings in winter compared to those that are planted in the ground :-)

And to both the HU's.........if you plan to continue on these forums, please get a proper, individualized screenname rather than the quick and dirty Houzz User and number designation. It is very confusing trying to communicate with multiples of HU postings from very different sources.

Mike Kincaid has a You tube Chanel which I saw on growing Japanese maple seeds. Right now I have about 80 JPM seeds growing like mad. Recommend everyone watch his videos, I cannot be happier with the results.

I have a lovely Bloodgood that I've had for 8 years and it has grown quite a bit. This past winter in Northern California has been quite wet (the drought has been officially called off) and I have a couple of tiny seedlings under my tree, only an inch or so tall but with deep red leaves. Should I leave them alone for now, making sure they stay well watered? They will be sheltered from the hottest sun in the summer under the parent tree. Or should I carefully dig them up and plant in pots?

Let them grow on a bit before digging them up. Seedlings sprouting under mature JM's are very common here. I just visited a client this morning that had an entire forest of baby JM's gowing under one of his trees!

I would probably wait until late summer or early fall before digging...somewhere around 6" and with a decent compliment of leaves. You can transplant elsewhere at that time or pot up

Thank you gardengal. That’s exactly what I needed to hear. I’ll check back in September or so.

I grow Japanese maples in containers for a living, The biggest mistake I made in my first year of business was choosing the wrong containers. By "wrong", I mean they were TOO SHALLOW. Imagine a pot of well draining mix without a JM in it. If you water the pot completely, most of the water will drain out in a minute or so., but a perched water table remains in the bottom of the container. My mistake was transplanting my baby JM's into containers that were 7 inches deep. Over 200 baby 12 month old grafted JM's arrived on May 1. We up-potted them in from the 4 inch deep propagation cells. . We are in zone 7B. Even though Ive used the best soil and air pruning perforated pots, our plants started dying one after another. The root balls of these 12 month old JM's were 4 Inches Deep. The perched water table in the containers we used for up-potting was at 3 inches above the bottom of the container. So we were drowning our JM's because the pots we chose for up-potting were too shallow. You should assume that the perched water table never drops an never goes away. We saved nearly all of our waterlogged JM's by repotting them again, but this time, we used 12 Inch Deep by 5 Inch Wide air pruning pots from Prop-Tek. We had to trump away all roots that were soft and spongy and blackened before repotting. We also learned that the potting mix the JM's arrived in was heavy on the bark side. This is commonplace with all growers and grafters of JM's. It ROTS within 6-12 months, so the bark must be removed from the JM's whenever you up-pot. Use at least 70% perlite in your potting mix. Use very little peat moss and very little choir. It breaks down compacts, and won't drain well after 6 months. Use a hose to wash the organic material (Bark and Peat) from the root balls before up-potting. Remember this: Growers don't ship plants with sustainable soil. It only lasts 6 months. And test you mix for the height of the perched water table. It's typically 3 inches-5 high from the bottom of any container with any soil. Don't let your JM's get wet feet.

"We also learned that the potting mix the JM's arrived in was heavy on the bark side.This is commonplace with all growers and grafters of JM's. It ROTS within 6-12 months, so the bark must be removed from the JM's whenever you up-pot...... Remember this: Growers don't ship plants with sustainable soil. It only lasts 6 months."

I am going to disagree with this :-) While I don't do it commercially, I grow all my JM's in containers and have for many years.......my oldest is approaching 30 y.o. And my potting mix is and has always been heavily barked-based as it produces a very freely draining, textural and extremely durable media. With this barked based mix (the 5-1-1 discussed intensively on the Container Gardening forum), I do not need to repot or refresh the soil for 3-5 years depending on the container and the size of the tree. Even at that point the soil is still in reasonably good condition.

The location and depth of the perched water table is entirely dependent on the soil media being used, not the size/depth of the container. It is quite possible to maintain a small seedling or 1 year graft in a 4" pot or a larger, 7" deep trade gallon for as long as necessary before up-potting provided you are using a highly textural soil that allows for fast drainage. Due to the vagaries of soil physics and water movement, there will always be a PWT in the base of the container but the better the potting mix, the lower/thinner the PWT will be.

The reason growers focus on bark-based mixes is for this very reason. They hold up well long term yet provide the aeration and very necessary fast drainage but the degree of moisture retention JM's are happiest in. And also maintain a low PWT.

Although it would not be my first choice, your perlite based mix should offer a similar situation. However, I would encourage you to disavow yourself of the notion that a barked based potting mix deteriorates rapidly. 30+ years of using it and growing a large collection of containerized trees (a variety but primarily JM's) has adequately proven that to be inaccurate :-)

I would also encourage you to read this thread on container soils and water movement thoroughly to educate yourself on the many qualities of a bark-based mix.