With that width restriction, and with you wanting access through the "Alley", it's NOT going to be easy to plant trees. Since that's a property line, are you aware that any part of a tree with roots on your side of the line that extends over the line then belongs to your neighbor? He can cut it off at the property line and dispose of it - he just can't toss it back over the line to you. So it sounds as though your "shade" trees need to be tall, thickly leaved, and about four feet wide, and I am not sure that such a plant exists! I think you are looking at evergreen trees. Just to list the requirements - you want to move wheelbarrows, etc., through the passage, which needs a minimum of 3' for a path next to the house wall. But you need to be able to walk freely, and not worry about bumping into the wall of the house, so let's make it 3'6" at a minimum, 4' if feeling generous, for the pathway. That leaves 3' or 3'6" for planting space. You can trim up the trunks of trees, removing the branches, to a height of 6-8', so you can walk under the limbs of the trees, and have only the trunks to contend with next to the path. However, for this to be done with regard to the health of the tree, the tree needs to be somewhere around 15' tall. If you aren't going to look for permission from your neighbor to annually go on his property and trim your trees, you are looking at very narrow, columnar trees, that will grow no more than 4-5' wide - the width of the planting space plus the width of the block wall. You might, if you planted the trees right at the edge of the pathway, get away with a 6' width. To fill a 40' length, you will need 8 trees, maybe 9. This project is NOT going to be cheap! And I am not familiar with trees that grow in a columnar fashion, so I can't make any recommendations for especially narrow ones - all the ones I can think of would be at least 10-12' wide. I am not saying you can't do it, but I am saying it will NOT be easy. You might do better to plant a tree near the SW corner of the house, in the back yard - I am assuming there is one there? - and get shade from a tree that way, which would give partial shade to the "Alley". To shade the entire wall, you might, indeed, do better with a large trellis, but put it up on the house, and not on the wall. If you position it a foot or so away from the wall of the house, you will get shade, and be able to have some air circulation there too. Your passageway then would run next to the block wall, and you would be able to make it 4-5' wide, not 3-4'. You could plant vines, both evergreen and perennial, and also trees like pyracantha, that lend themselves to espalliering. Roses might work, also. Any work that needed to be done, in terms of trimming back wayward shoots, tieing in to fill up the trellis, and trimming to keep windows clear, could be done, and cleaned up, from the passageway, so your neighbor wouldn't be involved. This might not give as much shade as you wanted, but would be MUCH more do-able.

Terry Duchess of Albany is planted directly on the northern side of the house here and it does terrifically well. The north side of my house still gets some direct and quite a lot of bright indirect sun even in the summer. The further north you go however, the lower the sun is in the sky even in the dead of summer so that is something someone in the far north needs to concern themselves with. Now the westerly side of my house is the one area that bakes in the summer sun and that I would avoid planting any clematis directly on. I do have clematis on the west side of the house but they are shaded somewhat by various trees of the neighbors and they are not growing directly on the brick wall itself. If they were growing on the wall, they would fry since the brick absorbs heat and radiates it even after the sun has set, creating a superheated microclimate.

Dovetonsils, yes those are valid concerns. I am considering this solution only during the peak summer months (I'm in Alabama) perhaps June through September. Therefore, I would have this shield up during those times with a series of anchor hooks for easy removal. The shield material would ideally be semi-air permeable to reduce wind loads during summer storms. If I could get an 80% or better reduction in solar radiant load, I would consider it a smashing success.

There are quite a number of wonderful perennial vines that grow in NH. (I am assuming that the NH in your user name indicates location, but if not these may not be good suggestions.) Some of the non-invasive honeysuckles include Trumpet honeysuckle (Lonicera sempervirens), European honeysuckle (L. periclymenum) and a couple of hybrids, Goldflame and Mandarin. Lonicera sempervirens 'Major Wheeler' last week There's a wide range of clematis available in sizes ranging from just a few feet to 15 feet or more, and they come in shades of purple, pink, reddish, and white. Clematis Mikelite late June Clematis Gravetye Beauty early July Clematis Prince Charles early July Clematis Venosa Violacea early July Clematis HF Young early June Clematis Ville de Lyon mid June The native pipevine (Aristolochia macrophylla) is mostly a foliage plant, with large heart-shaped leaves and pipe-shaped flowers tucked into the foliage. It provides food for one of the types of swallowtail butterflies. Another vine that can be grown for foliage is hops, Humulus lupulus, which is another really large plant. Besides the various green forms that provide the hops for brewing and their ornamental value, there is a gold-leafed form. There's a great photo of mature hops vines in this thread. Climbing Hydrangea will grow in part to full shade and has white flowers in June. It gets to 20' or more if untrimmed and needs a surface to climb such as a masonry wall or tree trunk so I don't think would work for your chain link. Virginia creeper (Parthenocissus quinquefolia) isn't great for a small garden as it is a large, vigorous plant, but is good for a woodland edge where it produces fruit for birds and has crimson fall foliage. It can be grown successfully on chain link fencing also. If you are interested in edible fruit, in addition to grapes, hardy kiwi vines produce clusters of grape-sized smooth fruit that taste just like tropical kiwis, but without the fuzzy coat. Both Kiwi and grapes will produce best with proper training. There are also various annual vines such as scarlet runner beans, sweet peas, and black-eyed Susan vines (Thunbergia) that you can plant between the perennial vines for a season or two while you wait for the perennial vines to get some size. Unless you have a really narrow area, you might also want to consider shrubs planted close enough to the fence so that some of the branches grow through the fence to help hide it. Hydrangea paniculata such as Limelight, Quickfire, or Vanilla Strawberry might work for this if the area is at least 7' wide.