SHOP BY DEPARTMENT
Houzz Logo Print
pbaz

Re-potting Japanese Maple - Looking for Advice

Pat
5 years ago

At the end of fall last year, I purchased a small Japanese Maple (Peaches and Cream) that was on clearance for $10. It was pretty much dormant when I got it. I stored it outside, in a sheltered corner, behind my shed. We had a relatively mild winter, though there definitely were some cold nights in the high teens.

I have no idea how to tell if it survived the winter, but assuming that it has I’m trying to make plans, since I feel like spring is just around the corner. Although I’ve grown several house plants with some success, I’m essentially a noob. Last year, I discovered this forum and learnt a tremendous amount with regards to soil, watering, fertilizing, root pruning, etc…. Most of this came from reading many threads maintained by Al. I have yet to put any of this newly acquired information to use yet, but it is now time!

My long term plans for this tree (assuming it is alive) is to grow it as a bonsai. I’ve never grown or taken care of a bonsai, so all I have is some basic knowledge from reading forums and watching videos. That being said, I’m not in a hurry. At this point, all I want to do is get it on the right path. This is what I plan to do this year, please provide any advice or guidance as you see fit:

  1. Wait to see some signs of budding (I want to know if it’s alive).
  2. Re-pot into Gritty Mix, including some root pruning.
  3. Prune the very top of the tree to promote growth on the lower branches.


I have a few small questions I’d like to pose.

  1. How long is my window of opportunity for repotting? When is it too late?
  2. What size of pot should I use? Is shape important?
  3. I will be using Dyna-Gro FP, do I need gypsum in the Gritty Mix? (I think the answer is no)
  4. How aggressive should I be when pruning?


Any advice you would like to share about what to do in the next couple years?

Thanks in advance,

Pat


Comments (20)

  • gardengal48 (PNW Z8/9)
    5 years ago

    The evidence of budding is a critical factor. Japanese maples produce buds in fall that winter over - these should be present now although still dormant. Examine them closely to see if they are still viable......they should be somewhat succulent looking, not dried or dark colored. The roots of containerized JM's are quite sensitive to cold temperatures and can sustain damage in the mid 20's so we can only hope for the best that yours survived the cold.

    I have repotted my JM's at all times of the year without issue. Root pruning is a bit different and is typically suggested to be done while the tree is still dormant. But these little trees are quite a bit more resilient to rough handling than you would imagine so I would go ahead and do what you need to when you have confirmed it is still alive.

    Pot shape is not important - pot size is but if you are going to be bonsai'ing, you'll address the size container by the size of the root system (and therefore the size of the tree) you are trying to maintain.

    I don't use gritty mix with my JM's - I prefer the 5-1-1 (or a very close facsimile) as it is more moisture retentive and I don't have to water daily in summer. I omit any gypsum but I do use a CRF when potting and again each spring. I also use a Dyna Gro product (GROW, not FP) infrequently a few times during the growing season to supplement the trace elements.

    Although I have a large collection of JM's in containers, I do not bonsai them but let them grow naturally. So my pruning is negligible :-) I will leave any pruning suggestions to those who practice bonsai more intently!

    Your biggest issue going forward will be addressing the watering needs during the growing season. These are not very drought tolerant plants and the heat of summer coupled with a small bonsai pot and the very fast draining gritty mix could require daily - or more often - attention. And winter protection - ideally these containerized plants should be stored somewhere where the temps stay between 30-40F - not any colder nor much warmer.

  • Pat
    Original Author
    5 years ago

    Gardengal, thanks so much for your response. I've taken another look at the tree, and based on your description of what the buds should look like, I'm not super hopeful. I don't really want to go through the whole re-pot procedure for nothing. So, I wait to see signs of life. For next winter, I'll have to come up with a solution. Maybe build an insulated box over the container to protect the roots.

    Your point about moisture retention is a good one. New England is a couple zone cooler than yours. But, it definitely gets hot in the summer. I will be using Gritty Mix for a houseplant, so I figured I'd just use the same mix for the JM.

    If you don't do much pruning, I have to assume that your JM trees get pretty tall.



  • Related Discussions

    Need advice on Japanese Maple grown in pot *HELP*!

    Q

    Comments (21)
    Just to add to Al's always excellent advice - I too grow a great number of trees in containers, most of which are JM's - I use a controlled release fertilizer (CRF) - Osmocote - when I first pot up and again at the beginning of each new growing season. I then supplement during the summer with a liquid now and again. For that I also use a Dyna Gro product (Liquid Grow rather than Foliage Pro) as it addresses the needs of ALL my plants, including the flowering and fruiting ones as well as the trees and shrubs. I may use only 3-4 times a season on the permanent tree plantings to supplement trace minerals - the Osmocote takes care of the primary nutrient needs for the entire season.
    ...See More

    Japanese maples, potted, & crocus bulbs

    Q

    Comments (1)
    It should look very good. I would say that as long as you aren't cutting or otherwise damaging roots of the trees, it should be fine. Just go into the soil very gently.
    ...See More

    Pots Pots Pots! (Some local Japanese maple learnings)

    Q

    Comments (1)
    Continued... (He whispered, "This is for pot growers.") Always buying concentrates, diluting them properly. But he did tell me my trees were probably starving. All this brings me to my question. (It wouldn't let me cut out that last sentence in the original post. I had no idea we were limitd. and the way I talk?!?) I am way out of big pots. Does anyone have anything that's 5-7 gallons they don't need? I'll pick up anytime. I can't make the swap, so I'd need to come to you. I guess I should put this into the Wanteds, but I admit I haven't looked to see if this board was translated to Houzz. Thanks very much!!
    ...See More

    Pots & Japanese Maple Advice, and a Request

    Q

    Comments (2)
    If you can't locate any donations, nurseries often sell the larger black nursery pots and they are not particularly expensive. I also favor the plastic resin containers sold at places like Walmart and the box stores. They are also inexpensive, come in a range of sizes and are lightweight enough that I can move my planted JM's without assistance. Most of my maples outgrow a 5G container after their first or second season in a container (except for my little bitty guys) so I am continually on the look out for inexpensive, lightweight, large containers. I just finished repotting several of mine into 15-25G containers, all the plastic resin style.
    ...See More
  • gardengal48 (PNW Z8/9)
    5 years ago

    New England is only cooler in the winter - that is ALL the hardiness zones indicate :-) 85F here for more than 2 or 3 days during the summer is considered a major heat wave........we just don't have hot summers.

    Growing any tree in a container is a natural dwarfing process......bonsai training just amplifies it substantially. I do root prune and repot mine so that also tends to keep them smaller without the need for much pruning.

    Pat thanked gardengal48 (PNW Z8/9)
  • greenman28 NorCal 7b/8a
    5 years ago

    Pat, post some close ups of the buds. You can also do a scratch test to see if there's green tissue under the bark.

    I, too, use the 5-1-1 mix for my maples, as it gets very hot here in northern California. The buds are starting to break on a couple of my maples, so I repotted them this afternoon into larger containers.

    Josh

    Pat thanked greenman28 NorCal 7b/8a
  • Pat
    Original Author
    5 years ago

    Thanks to everyone for your thoughts and advice. In particular to Al, who must get many questions and does a masterful job of providing information to this community.

    I've keeping my eye on the tree, and I'm somewhat optimistic that it will wake up. Most of the branches look "dead", but a few are showing what I think are signs of life. I've got my Gritty Mix components all sifted and ready to go.

    I'm posting a few pictures. The first is of what I think are dead buds, and then a few of what I think are buds swelling?. The last picture is of the stem/trunk which shows that Al is once again right in that it looks to be a grafted tree.

    Al, if I interpret your pruning advice, it's to basically encourage back-budding lower on the tree, by pruning the top (ensuring to leave of buds). Then once a lower branch is established, chop the trunk above that point. As a general multi-year plan, I can strive for that.

  • greenman28 NorCal 7b/8a
    5 years ago

    Yep, the tree is alive.

    Josh

  • tapla (mid-Michigan, USDA z5b-6a)
    5 years ago
    last modified: 5 years ago

    Pam and Josh are no slouches when it comes to good advice, either. ;-)

    Tips: Prune every branch back to 1 pair of buds and remove trifurcations. A bifurcation looks like a slingshot. A trifurcation looks like a trident or pitch fork. Acer is programmed to grow in trifurcative form, a central branch with buds/leaves arranged in opposite pairs along the branch.


    In the forth image from the top, you'll see buds emerging from the branch collar. There are already 2 living branches growing from that point, you do not want more. Those buds should be rubbed off with your thumbnail or some other tool that will rub them off w/o damaging tissue.

    In the same image, you'll see a branch wedged into a crotch formed by a little spur. That needs fixing. Prune off the spur, prune the branch back to a point immediately distal to the pair of buds, or farther back if there are more buds behind the pair in the picture.

    If you have branches on the tree that are growing too close to another branch, like in the first picture you posted, cut a piece of wire or a thin brad and wedge it between the branches that need to be separated. In a couple of months, you can remove the wire and the branch will retain its position.

    Finally - Every bud on your tree represents a new branch. When buds start opening, the first set of leaves will be very close to the branch; but then your tree will shoot out a very long internode if you don't take some control over how it grows. AS SOON AS the first set of leaves emerges and you can see the central branch extending, pinch it out immediately.

    What happens if you pinch out the leader the first day it's visible: The 2 leaves you left will mature. From both of the axils (crotches) of the leaves you left, 2 new branches will form. These will push out a short internode with a pair of leaves, then a very long internode. Instead of letting that long internode grow, repeat the pinching process again. That way, you end up with a very compact and full tree with no long internodes. Once the tree gets thousands of growing points instead of a hundred or so like it has now, the internode length will start to decrease on it's own and you won't need to pay as much attention to its development unless you prune very hard and reduce the number of growing points.

    Al

  • Pat
    Original Author
    5 years ago

    Thanks again to everyone for their advice so far. I re-potted the tree this weekend. I'm sure I made some very questionable pruning decisions, but hey, I have to start somewhere. I was fairly timid on pruning the top. I simply tried to remove many of the trifurcations. If it lives and has a good year, then I'll re-pot again next year and take a bigger swing at it.

    My Gritty Mix, pre blending.

  • tapla (mid-Michigan, USDA z5b-6a)
    5 years ago
    last modified: 5 years ago

    Keep it out of sun and wind until the leaves start to open. When you see the next order of branches starting to grow, you can give it some sun and fertilize if you wish. I usually wait to fertilize until the first sets of leaves have matured. That helps to keep internode length shorter. Don't forget to pinch out the center of the extending branch after the first pair of leaves emerges. It makes a very significant difference.

    Al

    Pat thanked tapla (mid-Michigan, USDA z5b-6a)
  • Pat
    Original Author
    5 years ago

    Yes, pinching out the center of the extending branches is my main objective this year. I'm quite looking forward to paying close attention to the tree to observe it's growth habits.

    Thanks for the tips about sun, wind and fertilizing. I shall do as recommended.

    Pat



  • greenman28 NorCal 7b/8a
    5 years ago

    Good work, Pat.

    Josh

    Pat thanked greenman28 NorCal 7b/8a
  • Pat
    Original Author
    5 years ago

    Good news! Looks like the tree is doing well. I am very happy, thanks again to everyone.

    Here are some photos of me pinching out what I believe to be a central branch. I do have a question though. I've been looking at other JM in the "wild" and in these trees it seems like the central branch is generating seed pods. Am I pinching out seed pods, or the branch extension? Just curious.


  • tapla (mid-Michigan, USDA z5b-6a)
    5 years ago

    Great!

    Your plant will tend to get VERY long branches if you don't shorten them every year. Next spring before your tree wakes up, prune all branches in the top 1/3 of the tree back to the first pair (most proximal) of buds on every branch and remove any heavy branches with a flush cut to the lower order branch. You can actually do that now, if you like. The trunk is the first order, branches growing off the trunk are second order, branches off the second order are third order, etc. While flush cuts are to be avoided on trees in the landscape, they are preferred for trees in pots because the wounds heal faster. You'll need to keep the top in check so you don't get heavy branches, which make the top look unnatural. Your tree will automatically want to spend 2/3 of the energy (food) it makes in the top 1/3 of the tree. You must restrain the top if you want the lower branches to develop (thicken). If you don't restrain the top, the lower branches weaken and die and you end up with a lot of bulk in the top where branches should be fine and twiggy.


    Al

    Pat thanked tapla (mid-Michigan, USDA z5b-6a)
  • tapla (mid-Michigan, USDA z5b-6a)
    5 years ago

    Acer p 'Mikawa Yatsubusa' in early stages of development (still in training pot). Image taken yesterday while it was raining. It had it's second styling earlier this spring as buds were swelling.

    Al

  • litterbuggy (z7b, Utah)
    5 years ago

    That's purty!

  • halocline
    5 years ago

    Pat - you should limit your pruning to the cooler months and Winter; when the sap's not flowing. Knowing your Winters, you might want to consider overwintering your tree; in a pot in pot set up. Put your tree as is (with pot) into a larger pot, then fill it in with mulch. This will give the roots enough insulation until you transplant it next year. You also might want to wrap the trunk, and buy or make a tree cover to protect against cold and wind.

    I just now took these pics, and my tree began leafing out about 3 weeks ago. I used the Pepsi can for size comparison. I put my tree into a rather large pot to give the roots insulation; in addition to, Two layers of insulation wrapped around the pot.



    Your tree is probably hardy to zone 5, but above ground in a pot; you have to add 2 zones.


    Rob

  • val rie (7a - NJ)
    3 years ago

    Hi I just acquired a Bloodgood Maple. Seems like it was maltreated at the big box store. It has 1/3 of the leaves it is aupposed to have. The rest are branches that seem to look like in good shape. They have red buds on them, kind of a lot of them. I would like to know if you think they will put out news leaves this fall or if they will stay like this until Spring of next year. My other treea are putting out new leaves now that the high Summer has passed and I'm wondering if mine will do the same. The branches with buds look the same as picturw number 2 of the 4 pictures that Pat posted above. At the top of the tree are are brand new red leaves that have just started coming out and developing, maybe a month ago. The soil is pine bark based and seems to drain very well. The tree has green wide leaves at the center that seem like getting old, do they turn green after they come out red or do they turn red after they come out green? Let me post a picture of it. Thoughts?



  • gardengal48 (PNW Z8/9)
    3 years ago

    First, I doubt you have a Bloodgood - the leaves are far too small/lobes too narrow, even on a young tree, for that cultivar. There are a lot JM's being sold as Bloodgood that are just seedling trees. That could account for the leaf aberration as well as the coloring. Bloogood is a very deep wine red color, although it can bronze up or lose some of its redness in full sun in hotter climates. But it should never have distinctly green leaves like what is showing in your photo.

    And no, it will not produce any more new leaves now. It is fall and the tree will be entering dormancy soon and dropping what remaining leaves it has.

    I hope you didn't pay much for it :-) It is in bad shape, suffered some serious drought stress and looks like it has some tip dieback as a result.....not to mention a good likelihood of labeling issues.

    Just get it planted and hope for the best in spring.

    btw, if you have more questions, it is advisable to start your own thread rather than tacking on to an old, stale one. And there is forum dedicated specifically to maples as well that will give you very precise JM advice.

  • val rie (7a - NJ)
    3 years ago

    That makes sense. Maybe this is a fireglow, or another. I discovered it has powdery mildew. I will post a new thred in Maples to ask for advice on this new tree. Kind of an emergency tree rehab thread. I'm a sucker for fixer-uppers. By the way I'm not planting it I only grow in containers I don't have a garden. Im kind of sad it's not a Bloodgood but it's okay because what I wanted was red leaves so this one is okay. Let's continue in the new thread?