Mike spent a couple of hours yesterday doing some fruit tree grafting. Many kinds of fruit trees are self-fruitful, which means they are able to pollinate themselves to create fruit. Some however, like certain apples and pluots (pluots are plum/apricot hybrids ex. dinosaur egg plums are actually dapple dandy pluots), require another tree of a similar species to pollinate them. This usually requires having a second tree in the vicinity. If you have a pluot or non self-fruitful apple tree by itself it will live a long happy life but will never produce fruit. We have 70+ fruit trees in the orchard now and have made sure that all of them have proper pollinators near them but with our ongoing ground squirrel and rabbit problems it is smart to have backup. Luckily, most pluots are able to be pollinated by the Santa Rosa plum tree and we have a SRP planted right smack in the middle of our 8 pluot trees. If by chance a devil squirrel or rabbit were to girdle that SRP we might have a problem getting fruit on our pluot trees. Mike's solution... grow a Santa Rosa plum limb on every pluot tree so it always has a pollinator!
Right about now, when the buds are just starting to swell, is the best time for grafting. Grafting (for these purposes) just means taking a cutting from one tree and attaching it to another so that you have two or more species growing from the same trunk. This is how you see all of the 5/1 fruit salad trees in the nurseries. In fact, just about every tree you see in a nursery has come from a graft as they have a big head start over seeds and nurseries are able to use root stocks (trunks and roots) that are disease resistant/soil and water tolerant/dwarf/semi dwarf, etc. and then just graft whatever kind of fruit they want on top. That's why every fruit tree in the nursery has a bend or knot in the trunk at the bottom where it meets the roots. It's just a branch of an already grown tree grafted onto a better-suited trunk and root system. Ah, science!
Of course, you can't just stick any limb on any tree and expect it to grow, they have to be closely related. You can grow pears and apples together, most citrus can pair and many of the stone fruits can be combined. In theory, you could make one tree that could bear almost every kind of peach or apple or cherry or plum or orange. We just want to make sure we get the most out of our trees so grafting a pollinator limb on each one just makes good sense... any it's pretty darn cool too! Pictured is one Mike did about a month ago and you can see the grafted limb is a bit behind but still budding. This limb will produce its own flowers which will pollinate the rest of the tree with a little help from the wind and insects.