I'm sure this topic has been brought up before, but is there a general explanation - and solution to - the problem of maples leafing out in spring (as mine are now), but not producing any new shoots? I have several that used to be decent growers, but now some of them don't seem to be getting any bigger, or growing new branches. I'm talking about 1 and 2 gallon sized maples. I have a hard time believing they are pot bound because many of these I repotted a season or 2 ago, and they are tiny in comparison to the pot. Even having been repotted, these same problem trees are not producing new shoots. Also, on some of these, they seem to leaf out fine, look nice, and hold through the season, but they just aren't getting any larger, overall. Any ideas???
There will be some shoot growth, you can't have leaves without new shoots, just the shoots produced are very short. That can be an indication of poor conditions for roots, such as compacted soil.
I have had a few maples like this (2 and 3g pots, some larger) that seem to do nothing for a year or two, sometimes even three, and then suddenly they will put on massive growth. My Otome zakura that I bought as a 1g in 2012 did nothing the first year, though I did have to up-pot it that fall since the roots grew so much, and same in 2013. Last year, however, it produced 6 branches roughly 5-6 ft long in a matter of three months. Not leggy growth either, very nicely balanced, that thickened up nicely by fall. So, maybe your trees in question are just biding their time, like mine was? lol Other than the issue of poor roots or soil, or some other environmental factor, I don't have an answer for you, sorry!
I've had trees that get stuck, mostly in the ground. I put it down to Michael's explanation: unhappy roots. I've had some luck last year watering with hydrogen peroxide (in solution obviously) to increase root oxygenation, and I now do this periodically with all potted maples. I think you won't do any harm by tipping the pot out and taking a look at the roots and soil. Although I don't suppose filling up the pot would cause the symptoms, I certainly see maples that go from 5 to 10 l pots in a season.
What type of maples do you have that are growing slowly? Many of the "witches brooms" or dwarf maples do grow very slowly.
Emery, I'd like to know your ratio of peroxide to water and how often you use the peroxide. Is this the same peroxide I'd use on a skin abrasion or cut? Also, what type of potting medium do you use with your potted maples? Thanks, Kevin in KC
Hi Kevin, I buy 35% hydrogen peroxide, which is not what you want to get in contact with! But of course after dilution, it's the same stuff. I follow the directions, which for oxygenation is 2.5 ml per 10 liters water. They say you can do this daily, but during the season I probably do it every 2 weeks or so, maybe a little more often for seedlings. (I have a lot of pots that sit on tables and get automatically watered every day for 10 minutes.) When I water during winter, or if I suspect a pot is waterlogged, I always use the peroxide. As for mix, pretty much soil-less. About 50% pine bark in small chips, 20% fertilized coco chunks, the rest pouzolane and coir. Sometimes I vary it a little, and smaller plants always get more coir and less bark. HTH -E
