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sfhellwig

Conditions for maple seedlings

sfhellwig
13 years ago

This year I wanted to try maples from seed, so I did quite a few. I'm not sure that they are growing like they should so maybe someone can tell me if I am doing something wrong. I did Amur, Japanese and Trident maples. All locally collected seed. Sewn outdoors for natural stratification. Once germinated they were pricked out into 4x4x5 pots in a mix of 5 parts potting soil to 5 parts pine bark to 1 part small clay granules (Pro's Choice, Turface). I figured this would be a good mix of aeration and moisture retention. I had been moving them in and out of the sun being cautious as I didn't want to burn a whole flat of trees. I now have them under shade structures that are about 50% at noon and less restrictive during other hours. I fertilize every 2 weeks with 10-10-10. The first Amurs are finally stepping up with multiple sets of leaves and growing trunks. Some of the Japanese maples are also gaining speed but there are many that are still at two sets of true leaves. The Tridents seemed to have just stopped and are sitting there. They may have been immature seed stock. I had very low germination on them.

So, do they need more sun? I built the structures as I figure these plants will not survive full sun in the summer. More N in the fertilizer? Should I be using something acidic as I have read maples like? I feel the soil mix and pot size should be fine. Definitely seen big seedlings grown in smaller pots (tubes). I can't complain too much for my first effort of the sort but I did hand transplant over 60 trees and I want the best success rate. They need as much size as possible to survive the winter. Let me know if you see anything glaring that I have missed. Winter suggestions also. I do not have a cold GH but the shade structures were built with wrapping plastic in mind so they won't be entirely "out in the cold."

Comments (4)

  • kaitain4
    13 years ago

    Don't give them too much sun. Its better to let them ease into your climate so you can see if any of them are more/less sensitive to sun. All maples will do well in partial shade.

    The winter protection issue is more about protecting the roots than the tops. Maple roots are killed at 14 degrees, so larger pots mean more soil mass that has to get down to those temperatures. Small pots are prone to freeze damage.

  • schmoo
    13 years ago

    Kick up the N a bit. Look for something with a ratio of 3-1-2 or 4-1-2 (analysis of 15-5-10 or 20-5-10)....may not be easy if you are just using liquid, just depends on what you have access too. How much 10-10-10 are you applying??

    Schmoo

  • sfhellwig
    Original Author
    13 years ago

    I have been using the Vigoro 10-10-10 at recommended strength which is 1/2 a cap to 2 gallons. I then water well with that. Of course I have always wondered then how much do you water them and I am probably under doing it. I have wanted to pick up some fish emulsion and maybe that would be a good compliment as it is supposedly harder to burn with the organics. For the next feeding however I will probably just bust out the high number granular that I mix into the can for the vegetable garden. I had not been using it as I am trying to keep many of my trees from going crazy (future bonsai) and just don't want to mix up several types of fert. Guess it's time to get over that.

    As for winter, I will likely have to mulch these heavy around there base and may be trying slat houses wrapped in plastic over them. In the past I bury my pots in the ground to help but if these aren't big enough to up-pot I can't really bury them. Last winter's plants that were mulched on the ground and covered with a glass lean-to came through with mixed reviews. If I have them a little more enclosed and it doesn't go so cold, they might do alright.

  • schmoo
    13 years ago

    As an example....if 1/2 cap is a teaspoon, your applying about 65 ppn N (full cap would be about 130 ppm N). A rate of 150-200ppm might be better if your applying every two weeks (that is a rate which would be suitable for "constant" feed in a production greenhouse).

    Schmoo