A grafting related question.

[GF3]

I have got a few apple scions of "Spartan" and "Kidd's Orange Red". Reading up on the two varieties they both seem to be susceptible to canker. Would grafting these varieties pose a risk to the overall health of the trees that I graft them onto ? Or would it only affect the growth produced by the grafted scions?

[ChingfordHarry]

Apple canker is usually (always?) a result of some other injury to the plant, so it doesn't just appear.

Unless you're grafting onto an existing tree ( e.g. To make a "family tree"), I wouldn't worry one way or the other. Plenty of people grow these varieties and don't worry particularly about canker or other diseases.

Even if your new tree eventually does develop canker, you should be able to propagate from scions taken from an uninfected part. You can also save the main part of the tree below the canker by removing the infected part and everything above it.

HTH

[ChingfordHarry]

What I should have said is that most cankers (including apple canker) are localised around the site of the original injury and can can take years to spread to the rest of the tree. Unless there's another nearby injury, they don't just jump from one bit of the plant to another.

[GF3]

Thanks for the reply.
I would be grafting them onto a "family Tree" which already has 3 other varietes grafted/growing on it - the main/host tree is a Lord Lambourne.

[ChingfordHarry]

The only thing to worry about with a family tree (which I alluded to above) is that if you let the canker run riot (which would probably take several years to happen) is that you could lose all the varieties. Some people think that a family tree is never as vigorous as a single variety, but I really don't know one way or the other.

Normal garden hygiene (e.g. disinfecting secateurs between cuts if you're cutting out diseased wood), checking the tree for disease regularly, etc should be sufficient to keep the whole thing healthy.

[It never rains..it pours]

I did some grafting on a family free last year and one of the grafts has canker so will cut back to well before the graft. So if grafting on a family tree maybe best to allow enough branch length before graft so can cut off easily if becomes infected