Grafting compatibility

Question

I have a fairly small yard, in which I've got a well-established (no idea of the age) mirabelle plum tree, and 3 young trees that I bought last year (malus apple, conference pear, I-forget-exactly-what-but-not-bing cherry).

I'd like to do some grafting, with the goals of providing pollinators and adding variety.

Questions concerning compatibility:

1. The neighbor has a quince and at least one apple tree. This year, my apple was the only one of the new trees that produced fruit. No problem grafting a scion from his apple onto mine, right?
2. Would scions from his quince take on my apple (or pear)?
3. I've seen online that pear, apple, and quince can be grafted together (in fact, putting an apple onto a quince rootstock is supposed to make it a dwarf). Is this true?
4. I've also seen online that plum and cherry (and a few others...) can be grafted together. Is this true? Could I put some cherry pollinators on my plum tree? Could I put some fresh plum branches on my cherry tree (to make a "backup" of the old tree)?

Questions concerning technique:

1. The hot season (i.e., now) is when I should be T-budding, right? Why would whip-and-tongue grafts not take?

Answer 1

1) Apple onto apple usually works, not always. Bear in mind that grafts are weak spots and a grafted branch would have to be supported for years. A apple tree with two varieties grafted is often marketed as a "family tree". Grafting should really be onto the rootstock if you can.

2) I don't think so. Quince is used to provide roots to Pear trees to keep them small, it doesn't graft onto apple or pear itself, it's the other way round. Apple is grafted onto dwarf and crab apple roots. Grow Quince from cuttings, they're not a big tree.

3) Putting a pear onto Quince roots makes it dwarf. I think apples only go onto dwarf variety and crab apple roots.

4) In theory - yes. They're closely related and both are usually grafted onto Mirabelle plum rootstock. It's better to graft onto the rootstock itself and to try and establish a family tree though. There are often compatibility issues between species and even different varieties. You must be careful not to damage the rootstock when grafting though or else the grafted tree could die. You also have to watch out for silverleaf disease with plums, cherries, peaches and a few other related plants. It often infects then via cuts.

1) I'm not sure. It might be because sap in the tree would ve rising and make it bleed, weakening the tree. T budding in theory is less likely to make it bleed a lot. You also have to watch out for diseases with whip and tongue as mentioned earlier. If you use whip and tongue, seal the graft with beeswax.

Answer 2

1. Apple to apple can work and is largely dependent on the relative vigour of the varieties in question and where/how you graft them. If you were to graft Cox's Orange Pippin onto Bramley's Seedling (a very vigorous cultivar) then the Cox would likely fail as an remaining Bramley shoots would outcompete them. With "family trees" of any description, care must be taken to select varieties of similar vigour - if one is more vigorous it will grow faster, assert dominance and the other varieties will fail. In practice, most "family trees" will lose all but one cultivar unless carefully managed.

2. Quince would not take on apple - like pears they are more closely related to Sorbus. Even compatibility was overcome initially, the apple would out-compete the quince long-term.

3. Apple on quince is likely to face similar issues. Quinces are far less vigorous than apples or pears (pears being the most vigorous), so were the graft to work then it would be very dwarfing. Apple rootstocks tend to be based upon old, non-vigorous apple cultivars (most of the Malling series). Crab-apple rootstocks as mentioned in another answer will vary in vigour greatly - some Malus species are very vigorous, others less so. Apple growers want trees of consistent vigour hence the use of non-seedling rootstocks.
4. If you are careful and clean then it is likely to work. Grafting the same cultivar to rejuvenate an old tree is an interesting idea. Certainly in bonsai, grafting and budding are used to establish new branches into old wood. However, if a fruit tree lacks vigour it is likely that the roots are the limiting factor - trees on dwarfing rootstocks place a heavy strain on their roots and tend to be shorter lived than those on their own roots.

Whip & tongue is done during the dormant season for a couple of reasons. Firstly, the tree has pulled most of its reserves away from the periphery and so are available to the graft when growth resumes. Secondly, sap entering the joint of the graft can block the flow of nutrients to the scion and the rootstock will heal behind the union resulting in failure.

T-budding is less invasive and so sap in the union is less important. It tends to be done later for economic reasons - it gives a second chance to work a rootstock if a whip and tongue fails or the opportunity to double-work: grafting an interstem by whip and tongue followed by a budding a cultivar all in the same year.

Answer 3

I've never grafted a cutting onto another tree but it is very possible. You would have to cut the branches at a 60 degree angle and would have to shave an area of the other tree of the same size, and use twine to attach the two tightly. For a higher success rate take multiple cuttings from ANY tree of your choice and conduct this experiment multiple times on a tree and see what stays alive.