Although it's a little premature to count our two-year-old high-density apple experiment as a success (since frost nipped all of the blooms this spring), I'm feeling very positive about the system. Planting the apple trees close together allows me to try out lots of different varieties, which in turn makes it easy to select varieties that resist cedar apple rust and our other local bugaboos. The high-density row doesn't take up much precious garden space, and the summer pruning (although frequent) is simple and fun. No wonder Mark and I chose to plant two more high-density apple rows this fall!

With this second planting, I'm experimenting in three different directions. Two years ago, I mostly chose trees grafted onto Bud 9, M26, and Geneva 11 rootstock, meaning that the trees are true dwarfs, but I also included two trees on a semi-dwarf (MM111) rootstock. The semidwarf trees grew very well...but they've already gotten quite a bit bigger than their neighbors. So, when I grafted onto MM111 for some of this year's new trees, I expanded the within-row spacing to 6 feet, hoping that the additional elbow room will help our semidwarf apples achieve their full potential while still toeing the high-density line. I also plan to train the MM111 trees' limbs down considerably below the horizontal this time around, which I was a bit more cautious about in previous years but which I've since decided is definitely a good option for high-density apples in the backyard.

I also opted to branch out and try yet another rootstock this year --- M7, which will produce trees midway in size between the true dwarfs on Bud 9 and the semidwarfs on MM111. My M7 trees went into the ground at 53-inch spacing but will otherwise be treated the same as the MM111 trees. I'll be curious to see, over the next few years, which rootstock turns out to be the best fit for high-density plantings on our farm. It's a bit of a tradeoff --- the more dwarfing the rootstock, the more precocious the tree, meaning that we'll get more fruits faster. But, at the same time, truly dwarf rootstocks have a hard time growing if you don't give them constant TLC, and a few of the trees in my original planting (on Geneva-11 or Bud 9 rootstock) did fail to thrive. Hopefully, either the M7 or MM111 trees (or both) will provide a happy middle ground --- apple trees that do pretty well without watering and other bonus attention, but that also produce within a few years after planting.

I've read lots of good and bad about espaliers (my third high-density apple experiment), so I earmarked only one tree for this final endeavor. I settled on an informal design set against the south side of our front porch and began by bending the young tree so the top was nearly horizontal. As watersprouts inevitably pop up from the flattened trunk, I'll probably bend them at a 45-degree angle to create a type of lattice pattern...or whatever seems to make sense from the growth pattern of the tree. Since I'm far from confident that my espalier will thrive, though, I chose our Chestnut Crab for the experiment ---after all, I'm mostly growing this sweet crabapple variety out of sentimental attachment to a similar tree of my youth, so I won't feel too bad if I don't get high yields.

I'll keep you posted on all three new plantings in the years ahead...and hopefully will be able to report in summer 2015 about our first big crop from our older high-density planting. In the meantime, stay tuned for another post about next year's high-density experiment, which will veer off in yet another direction.