Yes, you should be able to bud your rose on the mini standard trunk, as long as the buds aren't wider than the trunk. They can be significantly smaller to the same size, but trying to force buds too wide for the stock often results in failure. It usually takes three weeks for the bud (scion) to knit to the stock. If after three weeks, the bud is still green, it has probably taken. You MIGHT be able to root the budded mini piece you are thinking of cutting from the top. But, that is a huge "MIGHT". I think it would be safer for you to root cuttings of the mini before severing the budded top so you don't lose the whole mini in the procedure. I doubt putting the budded piece in a bowl of water will be sufficient unless you are VERY lucky.

What I would suggest you do, presuming you don't want to lose the mini budded to your standard, would be to chip bud your rose to the trunk and get some growth from it. By the time there is sufficient material to bud or root from, your multiflora cuttings should be rooted. Then you can bud to them and cut the newly budded rose growth from the mini standard. But, that's up to you. I'm not sure which method you should try to root the budded mini. Where do you live? Knowing that, others should be able to suggest what the best method for you to use would be. Good luck! Kim

Hey Kim! Thank you for your reply!
The buds are normal sized, by that I mean medium, so they're not bigger than the trunk, so no worries there! ^_^
How can I do this without the bud drying out? I got florist tape for the procedure but how do I know that the bud wont dru out before knitting? It is always a fear I have :(

About the mini, there will be some of the root stock with it, the root stock it is attached to for that matter, so I will try getting the rootstock to re-root in some florist foam and I will try my best to keep it alive till then :)
Or I might try layering before cutting off the top to get some roots.. always an option!
I live in Nottingham in England, so I am either a zone 8a or 8b.

You're welcome! Before doing anything, you may want to take some canes you were going to prune off anyway, and use your budding knife or single edged razor blade to practice lifting the bark to expose the cambium layer. You can also practice slicing out the buds so you will have a bit of experience removing them from the rose you wish to replicate. You need cambium tissue on the back of the scion (bud you wish to insert into the stock) and on the surface of the stock for the scion to grow to. Once you see what it takes to have cambium tissue on both pieces, you are ready to move on.

Preventing the bud from drying out is so easy, you'll probably wonder why you didn't think of it. Do you have any jar lids you're about to throw into the trash? How about small, shallow saucers you can put some water in so you have something to keep the buds wet until they are inserted? Yup, that's all it takes. Mel Hulse, who was the Volunteer Coordinator for the San Jose Heritage Rose Garden in San Jose, CA, used to keep them on his tongue until he inserted them. It works, but isn't something I would suggest for a variety of reasons. Not the least of which is, do you really KNOW what chemicals may have been used on the rose you are putting pieces of into your mouth? A jar lid or saucer works just fine and doesn't potentially expose you to any harmful products.

I also like wetting the exposed cambium on the stock before inserting the bud, but I also live in a very hot, arid climate (inland valley, just north of Los Angeles, where it is to be between 100 and 107 F for the next five days). I've found by wetting the exposed cambium and the bud, they stick together quite well while I fumble with the tape I'm wrapping them with.

As long as you have good cambium to cambium contact; you don't let the bud dry out prior to inserting it; it's tied in tightly to prevent movement and water loss before it knits; you don't let the stock dry out while it is knitting, you should see success in the three or so week period. The only caveat I can think of outside of this is, September may be a bit late for budding in your climate and particularly with your stock. I don't know which stock was used to create your standard, nor how long it remains suitable for budding in your climate. If the sap isn't flowing sufficiently in the stock, it may affect how well, how quickly, or even IF the pieces will knit together. Anything you can do to keep the standard actively pushing new growth during this period should help.

If you can get the buds to knit to the stock, you might want to wait until next spring to sever the budded mini. I don't know whether the buds will push between now and winter on the stock you're using, nor whether you will be easily able to root the budded mini this time of year. The buds will successfully hold until next spring as long as they are knitted to the stock. Next spring, you can sever them from each other, the buds should begin pushing as the weather warms and the budded mini may be easier to root in the warming weather. Just some thoughts. Not that it can't work. I'm just not sufficiently familiar with attempting what you want to do in your climate. Good luck with them! It will be an interesting experiment. Kim