Can you graft a pear onto an apple tree?

Technically you can, but the graft survival rate is poor and the scion often falls off after 2-3 years. It's better to graft a pear onto wild pear, quince, or rowan.

Tried it a few times - out of five grafts, only one took, and even that one turned out weak. Don't bother wasting your time.

Pear grafts better onto irga and hawthorn than onto an apple tree, if you're gonna experiment anyway)

I won't lie, in 15 years working in the service I didn't really do much with grafting, but I know the problem. Grafting a pear onto an apple tree is like trying to make a dog and cat friends. Theoretically possible, but they're too different physiologically. Apple and pear trees are different species, even though both are in the Rosaceae family. The incompatibility doesn't show up right away - the scion can take in the first year, creating the illusion of success, and then the system just rejects the foreign object. I saw exactly this happen with my neighbors: they grafted a pear onto an apple tree, everything seemed fine for two years, and then the branch started withering and fell off. Time wasted.

If you really want to experiment with grafting on an old apple tree, better graft an apple tree onto it, that's like 80-90% success rate. And if you really want pears, then either plant a separate pear tree, or use quince, serviceberry, or hawthorn as rootstock - they're way more compatible with pear. In practice, pear on these rootstocks holds up for years and develops normally.

Do you have a chance to find a wild pear or at least a quince? Because I wouldn't recommend struggling with an apple tree. The difference in tissue structure and sap flow rate between them is too big - this isn't just "different species," these are genuinely incompatible systems. Yeah, theoretically the scion might take, but it'll be a long-lived conflict, not a normal symbiosis. After a couple of years you usually get problems with thickening at the graft site or the opposite - thinning, and then the scion either falls off or becomes weak and's always sick.

Here's what everyone forgets to mention: even if you somehow manage and the scion takes - pear on apple doesn't winter well. The graft site becomes a weak spot where frost just breaks through. My neighbor on the dacha tried this, the scion survived the first winter, but then every winter after the frosts everything would fall apart, and he eventually just cut off that branch.

If you want to experiment - try grafting onto serviceberry or hawthorn, those work way better. But if the goal is just to get a pear that'll actually fruit normally, it's simpler to just plant a separate wild pear seedling or go straight for pear on quince. You'll get results in a couple years, whereas here you'll spend two years on an experiment that'll probably fail anyway 😕

The question is phrased like it's just a technical task, but in practice it's more like playing the lottery. A pear and an apple tree are different species with incompatibility at the cellular level, so even if the graft takes, it won't last long. People who got lucky were probably just observing temporary tissue fusion that would later fall apart. And here's what nobody mentioned - even if some branch does grow, it'll be weakened and way more susceptible to disease than normal branches. Infections easily penetrate the fusion sites, and the whole apple tree can end up suffering.

If you really want to experiment, it's better to use a wild pear or quince - those are proven, stable rootstocks. And if you can't get those saplings, it's easier to grow a pear separately from a pit or cutting, even if it takes more time. I've also seen attempts to graft a pear onto medlar or hawthorn - the results there are better than on an apple tree, but it's still no guarantee. But if the tree does take on the right rootstock, it'll be healthy and productive for years, instead of slowly withering away.