First of all, I highly suggest that you buy Stephan Sobkowiak's video. The Permaculture Orchard : Beyond Organic http://www.permacultureorchard.com, plus listen to the free followup video. This will give you a strong foundation about planting an orchard. Also do a search on this forum about Stephan Sobkowiak. His method allows you to plant your trees closer since you then train your branches to maximize a smaller space.
I purchased the video when it first came out and throughly enjoyed it and definitely learnt a lot. Plus he understands your climate & growing conditions in Ontario since he is not far in southern Québec. He gives tours of his orchard so you might like to make a visit to him. Since you will be planting 60 trees, it might be worth to hire him for some consulting, if he offers this service. An hour of his time could be money well spent since you are planting to grow lots of fruit trees.
What I am confused about is the spacing. Most of the trees I am interested in recommend different spacing between trees and rows. ie Apples and plums. Do you default to the larger distance of the 2 species?
"Recommended" spacing will differ if you plan to let your trees grow full size or prune them to 8' for example.
Do you keep a consistent distance between rows?
Often spacing between rows dépends on what size of equipment you use. You need more space if you use a farm tractor compared to a wheel barrel. Are you wanting your rows on contour or parallel to the fence line for example? Is your land flat or has a slop? How will you harvest the water to benefit the trees? These are some factors which determine layout and spacing .
How much space overall you have for will have an impact on spacing. Ex. if you have a one acre field to plant your 60 trees, your spacing will likely be different than if you have 1/4 acre.
If you are using guilds with lupine, yarrow, daffodils, etc do you increase the space between trees?
I think that the trees are foundational, so choose your spacing and then you plant your other plants around them as space allows.
One does not have to have classic rows. You could do plan a curvy pathway system or follow that natural layout of the land. I have one area on our GoPermaculture Food Forest which we cleared some trees in the back forest. The land is naturally very lumpy, so we planted our fruit trees on these lumps. These lumps were were where the cut down or fallen trees used to grow. The low ground between the lumps were too saturated in the the spring time. Fruit trees usually do not like wet feet for long periods. We really followed the pattern the forest was growing before. We have no rows. Just some pathways between the trees. So far they look happy....
I am not sure that there is the perfect "Right way"
I am pretty new at this and want to get it right.
So many décisions will be made because of your goals & desires. Two people can have the same piece of land, same plants & trees but both orchards can look total different and in both cases the trees & plants are happy as well as the orchard growers. And often even if things are not "perfect" plants can thrive just fine.
If you are looking to mimic Stephan Sobkowiak's orchard, then even if your trees are too generous spaced, you can interplant with fruit bearing bushes, and even annuals. I interplant tomatoes, peppers, vining crops like watermelon and cucumbers, as well as goji berries, blue berries, boysen berries . . . all sorts of food sources (nettles, chaya, sweet potatoes).
In some respects, its like thinning small fruit on a tree. It feels so counter-intuitive to be plucking fruit off, but if you want big healthy fruit, you've got to thin aggressively. The same goes for tree spacing. If your orchard is too crowded, you'll be frustrated with the need to constantly prune things to assure that light gets in. So wider spacing is better ---- better for air flow, for access, for light penetration to the understory plants, etc.
Suppose I should point out that with STUN work here I had an 80% fatality rate on those tree lines. The Kraters have had a better success rate and then the spacing there is a bit hard to quantify.
Lots of farming assumes that any land not explicitly devoted to crop is wasted. If you are to plant trees on a square grid, and all trees are the same "size", there will be a regular pattern of "holes" in the plan, which will be wasted space (by this idea). It will also be on a square grid (just offset). Any given tree on a square grid, has 4 nearest neighbours.
If instead of a square grid, we go to a hexagonal grid (with a location in the centre of each hexagon), what we really have is an equilateral triangle grid. Each tree has 6 nearest neighours. There should be less wasted space, or at least each place which is wasted should be smaller.
How much space is between trees does influence how much snow the pattern builds up in winter. If the spacing is too tight, little snow builds up. I suspect that if your planting involves mixtures of trees of different heights, that it will trap more snow than if all the trees are the same size. I think trees which are more "conic" (like spruce trees) will likely trap more snow than trees which are more cylindrical.
For regular grids of any kind, if the spacing is large, there can be favorable directions where wind easily flows through the array of trees. I've never heard of anyone doing it, but if you went to a Penrose tiling (the two rhombuses), you can produce patterns which have no "alleys" over "long" distances. I've never worked with any other quasi-periodic tiling, but they may work as well.
I was interested in a "circular" planting. The idea being to have 3 radial "spokes" at 120 degrees apart and the circumference, all consisting of legume family trees, and then the three "sectors" being the tree I was interested in. I was interested in seedlings only, and assumed that trees had a radius of 4 feet (drip line), and that the circle had a radius of 100 feet (for the trees of interest). The circumference trees were planted every 6 degrees at a distance of 108 feet from the centre. Each sector is an 8x8 array of trees (spaced on 12 foot centres), but instead of a 90 degree angle in the centre, it was "sheared" to 120 degrees. The one location opposite the 120 degree corner which goes next to the centre of the circle falls outside the 100 foot radius, so you only have 63 trees in each sector. Anyway, the leaves about 4 feet between trees for passage.