I've always felt that I needed the good mechanical pull that a budding rubber provides, and to keep it from drying out I think it needs to be sealed with parafilm or wax. Parafilm is my first choice because it breathes a little. But it's not enough by itself to make me feel secure! I used the Ace rubber tape this year on clefts and felt like it worked really well. Rubber tape or bands or rubbers all seem good to me. I think that if you use the wide budding rubbers or tape and overlap thoroughly then the parafilm/wax precaution is probably redundant, but it's cheap redundancy and I do it. I use wide and long rubbers also because it's easier to wrap them off- you have so much to work with, and they're cheap enough that you can afford to cut off excess. Like MiHiGirl I'm in the Rockies, but not at a mile high! We're at 3200 ft, give or take a couple of feet. But it's definitely an arid environment: we get about 12-13 inches total precip per year.

Sounds like you do have a plant that is a rootstock-- does it have a lot of thorns on it?? a lot of rootstock varieties do-but not all. You don't need to leave a branch on, witch is called a "nurse branch" since its probably planted in the ground I assume, that is used mostly but not exclusively for container stock. Grafting is an acquired skill that takes a small bit of learning, best done by hands on experience learning from a person who is already accomplished in the skill especially on mature in ground trees, you can learn on your own by watching grafting tutorials on other web sites and starting on small seedlings or branches of the mature tree. Its not rocket science-- but to be successful you better know what you are doing before you whack down a 20 year old mature tree

Good thinking. First, it would be good to clip healthy stems (pencil thick to 3/8" thick work well) with fat buds from the fruiting tree while the tree is still dormant, cut them to 8" lengths, dip the cut ends into melted candle wax from a wide, lit candle's puddle, lay them in a 1 gallon freezer bag with a moist pc. of paper towel, and put the bag in the fridge where it won't get bumped and crushed. You won't need to keep all the branches on the fruitless trees, so it would be good to prune away excess/unimpressive/less valuable branches before grafting time. Such as twigs and branches that grow downwards, or branches that are jammed too close together, all side growth on the bottom 4 feet of trunk (so a slit pc. of metal duct can encircle the lower trunk to keep out climbing rodents), etc. When choosing which branches to leave for grafting to, be on the lookout for vertical, fast-growing suckers from 3/8" to 1/2" thick for doing cleft grafts, as well as thicker suckers from maybe 5/8" to 1" for doing bark grafts. There is no need to whack off every branch that will not get grafted to, and leaving some of the leafy ungrafted branches will help the tree to keep growing while the young scions begin growing. Try to graft to suckers that are lower for convenience sake, and figure out which suckers are possible contenders to become the new central leader(s). It would be great to eventually have the new central leader(s) to be fruiting branches. One way to try to get that to happen is to graft some suckers near the center of the tree and graft them higher up than other grafts. Once the fruitless trees begin growing out new leaves after the last expected freeze, it is a good time to graft. If the weather has been very dry, it would be good to water the tree real well a week before the grafting. After a year of good growth for the grafted branches, more ungrafted branches could be pruned away. If you choose to, you can graft lots of extra suckers and later prune away those that do not grow as well. Over a few years of growth grafted suckers that are only a foot apart will crowd each other, so they can be pruned later. Try to graft branches over a wide area and spaced apart so as to take over the same tree circle over time. I would not graft horizontal branches at all. There are many youtube videos illustrating cleft and bark grafts. Although you may be content with the fruit from the other tree, it would be worthwhile learning from your local county agricultural extension agent which pear trees are recommended for your area, and then try to acquire dormant scions from those varieties also for grafting to such big trees that have room for lots of grafts. Fire blight resistance is a huge preference. Good luck on your worthwhile project.

I too am interested in grafting a "friendship" tree. I understand citrus overload, I was absent from this thread for a while because the bugs, leaf drop, etc. made me rethink how easy it is to grow citrus in pots up here. Now that it is under control and my citrus collection has been parred down to include only what I like, I am selective in my citrus choices. To that end I want to graft over my Cocktail grapefruit, I have harvested 4 this month and the flavour is not good. I am assuming it is the soil, light, and temperature conditions, but, there is no point in growing what doesn't do well. I looked at the compatibility chart jonmerr posted, my question is, it shows that grapefruit is compatible with mandarine as a rootstock, can mandarine be compatible as a graft on my grapefruit. Or am I tilting at windmills?