[trolan]

Fun fact: all over the world vineyards use an American variant of grapes for their rootstock and graft their preferred European/Peruvian/etc grapes on top. This makes them more disease resistant and in some cases means the cultivar of European grapes can survive at all after disease had almost wiped them out.

All your citrus and apples from the store are like this, and why they don't grow true to seed. The seeds are open pollinated by whatever is around but the fruit was from a single plant hand selected dozens or more years ago and produces that exact fruit over and over again. It would take hundreds of years to 'stabilize' those traits in the seeds and in that time, you'd probably find another great variety and keep that around to graft to other plants.

[adrian_b]

The use of grafting for grapevines has become necessary only after the insect phylloxera has been brought accidentally from USA to Britain and France at the beginning of the second half of the 19th century and then it has devastated most European vineyards.

The American vines are resistant to phylloxera.

Previously, grapevine was one of the few sources of sweet fruits which did not require grafting, because it propagates naturally through clones.

[CSMastermind]

It's worth noting that there are a handful (like less than 10) vineyards in Europe have escaped infestation so far and thus have their original rootstock:

https://www.decanter.com/features/phylloxera-the-great-escap...

This includes 2 Pinot Noirs in France, 1 Tinta Barroca used to make Port in Portugal, 1 Sangiovese from Italy, 1 Monastrell from Spain, and 4 Nerello Mascalese from Sicily.

There used to be 3 Pinot Noirs in France but one succumbed in 2004 and the Monastrell in Spain is verging on succumbing.

There are also vineyards that have been planted with European rootstock since the infestination of the continent. These include vineyards in Portugal, Sicily, California, Chile, and Australia where soil conditions prevent the bugs from getting to the roots.

[galangalalgol]

I read a, possibly mythical, story about a group that surreptitiously grafted various fruit branches onto the shade trees lining some streets in a major city. Several years later the mess on the sidewalk caused the city to cut them off.

[malfist]

Grafting generally only works within families. I.e. you can't graft a chestnut onto an apple tree.

I doubt many (if any) shade trees would support a fruit.

That said, families can be surprisingly large. Most citrus all come from the same four parent plants and you can mix most of them. Apples and plums are also closely related

[13of40]

Where I live there are a lot of non-fruiting cherry and plum trees planted for shade, so I can imagine people grafting on a fruit bearing branch here and there.

[malfist]

I didn't consider that, thank you for your perspective

[pvaldes]

My bet would be on japanese crabapple

[vtbassmatt]

https://weburbanist.com/2015/10/22/guerrilla-grafting-public... maybe?