I have an "Olsens Frosted Strawberry" and a "Ben Hoshi" that have been in the ground for less than a year with both making it through this past crazy cold winter. The problem is that both tress were eaten badly by marauding rabbits. They devoured almost all the tender branches; the ones on which leaves appeared last season. (The first picture of a very small OFS shows a red bump of growth at the bottom; there are several of these red bumps appearing on the trunk and side "branch". The second pic is the same OFS but showing all that is left. The last picture is of our small "Ben Hoshi" with almost all branch bearing leaves from last year eaten by the rabbits). Under such current conditions what will one see by the end of this season?
Oh wow, that sucks! I feel your pain to some degree as squirrels and/or rabbits decided to feast on a few of my shrubs up front, nibbling off all the newer, small branches. Thankfully, they left my maples alone or there would have been hell to pay... I think the amount of growth you should anticipate will depend, unfortunately, on a number of factors: Health of the tree, first and foremost, and the robustness of the roots. How much stress the winter cold placed on the tree. Your weather (ie, sun, rain, temps, etc) over the next few months. How 'happy' the tree is in it's location. And so on. Olsen's is a slow-grower from everything I've read, and as I've only had mine a year, I can't really comment too much based on personal experience; I don't have a Beni hoshi, so I can't comment on this cultivar. The good news is you do have buds appearing, but since the trees will be starting out from scratch, as it were (Beni hoshi a little less so), I think you'll probably have to baby them this year since there won't be many leaves to help produce food for the plant and also 'recharge' the roots after all the energy they expend pushing this new growth. A little bit of light fertilizer 2-3 times this growing season might be wise, but nothing too strong I wouldn't think, to help the trees along. Maybe a 'root booster' too, of some sort. Can you get Superthrive up there? Or any of the Fox Farm products? I really like their Japanese Maple Fertilizer http://foxfarmfertilizer.com/index.php/item/happy-frog-japanese-maple-fertilizer.html and their Bush Doctor line, especially the KangaRoots or Microbe Brew, might be a beneficial boost during this season http://foxfarmfertilizer.com/index.php/category/bush-doctor.html Regarding the little buds you have appearing on your OFS. In the first picture, there is a bud right at the very base of the trunk, at the graft union. Personally, I would rub this bud off, and any others that might appear in this same area. You don't want to risk the bud possibly being from the understock, firstly, and secondly, that bud will likely end up sucking a lot of the energy away from the other new buds since it is right at the base of the trunk. You want as much energy going to the bulk of the tree as possible. Another suggestion would be to rig up some sort of cage around both trees, and I would do it now already, leaving it up over winter for at least the next year, possibly two depending on growth. The rabbits know that this was a good source of food, so they may come back and nibble on the new growth. It won't look terribly pretty, but a cage of fine mesh chicken wire around the trees, and I would dig it a few inches into the ground too, would protect them from such scavenging.
I agree with Andrea about the low bud -- which looks like potentially from the understock -- and the chicken wire. It's a drag, but for me is the only way to keep hare and roe deer from this sort of attack in my garden. The other possibility is to fence the whole garden, which can be prohibitively expensive. Not so much on the fertilizer, though. I don't like to give any to stressed maples. In any case the roots haven't been effected by the attack. Although I suppose given that they\re not really established it couldn't hurt. IME these plants will now put out long whips now to try and keep the roots fed with as much foliage as possible. These should be left on until next fall, when you can start to reshape it; the whips will probably die back somewhat over next winter anyway. HTH, and sorry about the troubles. Wildlife attacks really suck. But glad to hear they made it through your hard winter anyway.
Don't feel too bad, my two ofs are a couple of the only small maples that didn't get nibbled by rabbits or deer, but they died back so much from this brutal winter all I have left is buds at the base like yours anyway :-(
