So, there is a flowering quince bush at my parent's house that I plan to take scions from next month to graft them onto rootstocks that I will purchase. My question is: would it be fairly easy to graft a scion onto an apple rootstock, such as an M-26?

I'm not sure about flowering quinces, but fruiting quinces are usually grafted on to Quince rootstocks (e.g. Quince A or Quince C). I would be surprised if you could graft on to a Malus rootstock.

That then brings me to my next question: where can I order flowering quince rootstock online from? You'd think it wouldn't be too hard, but Raintree only has cydonia rootstock, One Green World doesn't have any quince and a general Google search turns up more results for pear rootstocks and barely mentions that quince rootstocks exist. I may just have to purchase a couple trees instead, but I really want to try my hand at grafting them.

I think the reason for the confusion is that pears are commonly grafted on to Quince rootstocks. Do you know if flowering quinces need different rootstocks from fruiting ones? I notice Raintree have the Quince "Province" rootstock (I think that should be "Provence") which might be compatible with your flowering quince.

You might save a step here -- most flowering quince are incredibly easy to root directly from cuttings.

Cut some branches 16-24" and stick them into the soil 8" or so and give them a little water in summer -- your take rate will probably be over 50%

I did also notice that Raintree has a quince rootstock available but I'm not 100% sure that flowering quince can be grafted onto fruiting quince stock. If it's fairly easy to get flowering quince to root from cuttings I may just do that. Should a rooting hormone be used, or can they be rooted easily without it?

Also, Eric, when would you recommend taking the cuttings and planting them. My March and April are probably like your February and March, respectively. Thanks for the advice.

I have taken these cuttings in the Jan-Feb dormant season in the Seattle area with about 80% success just cutting and sticking in the ground - no preparation, rooting hormone, or anything..

Wow, those are impressive results. I'd be happy to get 40%. That's very encouraging though, especially since you didn't even use a rooting hormone. I'm definitely going to give that a shot, thanks for the help. I'll probably do it in February or March and I'll make a follow up post in April or May, depending on the progress.

I have also rooted many flowering quinces. By the way, I have grafted crabapples onto flowering quince. They continued to fruit crabapples, but suckered badly. I would just root them. You could try root hormone, but I never did. I used mostly 8" sections, planted mostly in the ground.
John S
PDX OR

I'm really glad that they're pretty easy to root without rooting hormone. Did you also take the cutting and plant them during dormancy?

Yes. Usually in November, our soil is consistently moist enough for roots to form. I always make a slice down both sides of the cutting so that roots can come OUT. Our ground never freezes hard, so you can pretty much always "plant" a cutting other than maybe, 10 days of the winter. So yes, it's always in the dormant season.
John S
PDX OR

That's excellent. I'll have to wait until about late February or early March. Maybe earlier, but it's been a weird winter. We've had days with single digit temperatures and plenty of snow, but then we'll have days like today where it's in the 40's.