Advice on an espalier
Thanks all for your advice a week or two back. Based on the feedback I received, I'm now planning on planting a Belgian fence espalier in my back yard. Technically, it would be a losange espalier, where each tree is planted 3' apart and has two branches on each side (vs a Belgian fence planted closer together with only one branch on each side). The branches grow at 45 degree angles, and cross over the branches of its neighbor, and, to a lesser extent, the branches of the tree two places over. Given the layout of my backyard, the espalier will run east-west. I plan on putting the espalier on wires and posts about 12-18" from the existing wooden fence, to keep air circulating when the temperatures get into the nineties for a couple of weeks in the summer.
I've picked out a dozen trees - five plums, a quince, three pears and three apples - and have three additional slots (prob. for next year) in which I'm thinking of putting in a hybrid persimmon, a sour cherry and another apple. Once things get established, I hope to graft a few more varieties into the espalier.
I'm starting to lay out the order of the trees in the espalier, and I'm looking for your thoughts on how to order them. We have fire blight in this area, though not plum curculio. Here are my questions:
1. Should I try to group the different species together (because of watering, fertilizing, spraying needs), or break them up to keep i.e. fire blight from spreading from one to the next? I'd rather separate them for aesthetic reasons.
2. Do I need to have an air space between the wood fence and the espalier, or can I put the espalier on the fence itself? I'm certainly OK with putting up a separate trellis, but don't want to create needless work.
3. As soon as the ground softens (should be in Feb.) I'm planning on digging the holes for the trees and putting a little compost in each in preparation for planting. I'll probably put up the trellis closer to when the trees arrive in March. Any other things I should be thinking about between now and when the trees arrive?
Thanks again for your help and advice.