Shield Budding Fruit Trees (epic post)

21:45:00

Finally, a comprehensive guide with piccys! Also includes some answers on the 'how to' and 'why's of the business, plus a few additional links and places to buy the rootstocks and supplies.

This year is whizzing by obscenely fast. Thus far, I've  more-or-less tackled the larger garden jobs and have managed to start propagating a fair number of things. Large black pots of compost are dotted about the greenhouse with little plastic labels identifying each ring of rather unexciting looking twigs and leaves: strawberries, tayberries, figs, gooseberries, grape vines etc. jostle for space (we'll deal with what to do with these later, when I've stopped being giddy on free plants). 

How many grape vines is too many? Six?
Perhaps my favourite activity thus far is budding. Imagine- you're a bit mad, like me, and you may have been compiling a loooong list of every kind of tree and shrub you'd like to have, ever. There are many things, and you are not as your secret fantasy describes, the unacknowledged ruler of a wealthy but little known country, but a post-grad 20-something without the funds to indulge in a casual orchard of 1000 or so fruit trees. Stepping back to reality, propagating your own trees is not only fairly cheap, it's easy. Okay, it's easy like people say bread making is easy;  there is a bit of a learning curve and the occasional bout of just plain bad luck, but unlike bread making, you can do lots of buds in one session and should you succeed you have something which will keep on giving for up to 200+ years. So there. 

Next year, this home-grown seedling apple might be budded or grafted with one of the named varieties on my list if I can get my mitts on them; Pitmaston Pineapple, Rosemary Russet, Doddin,  or Slack Ma Girdle (possibly the best name ever. Will feature in my avenue of funnily named fruit trees).
What is budding? -It's essentially taking a single bud from one tree, and putting it onto another, so that from that single bud a branch or even a whole tree will grow which is an exact genetic copy of the original. A lot of trees are started and grown this way. 

What you need ...
  • Very very sharp thin bladed knife - This is the one I've got. This is a slightly jazzier and more pricey model, with a bit on the back of the blade specifically for budding, this is it's cheaper cousin. What ever you use, the sharper the knife, the smoother the sides of each cut are and the better the chance they'll join together. Do make sure it's disinfected, as you'd be surprised how easy it is to spread diseases you hadn't even known were around. 
  • Something to tie the bud in place -  This can be raffia, parafilm grafting tape, wide rubber bands or clingfilm. The parafilm is something few of us are likely to happen to have on hand but it is very easy to use and makes the surprisingly fiddly job of tying everything in place much, much easier.
  • Bud stick or scion - this is a stick of this years growth from which you will take off individual buds to graft onto the rootstock. You only want to use the mature buds from the lower end of the scion. In the photo, I'd removed the leaves from the stick, leaving the leaf stalks (petioles) behind as convenient little handles for when it comes to touching the buds once I've removed them. Try not to touch the cut surfaces as much as possible.
  • Rootstock- this is the tree onto which you are grafting the buds.

How to...

First you have everything to hand and within easy reach. Speed is pretty important for success and the longer the scion is in the open air off its parent tree, the more water its losing and the less resources the buds on the scions have - making it more likely that your buds might not take.


The top of the 'T' should be towards the tip of the scion. The edges of this cut are slightly ragged, due to my having used a new and un-sharpened knife.
1. Prepare the rootstock for the bud.  Carefully make a T-shaped cut in the bark of the rootstock, and using the tip of the knife, gently lift the flaps of bark.

2. Hold the scion in one hand with the tip (newest growth) pointing away from you and make two cuts, the first being long cut starting below the bud (about 2-3 cm) and starting at about a 30 degree angle, then levelling off, slice into the scion going through the wood underneath the bud stopping about 1-2 cm above the bud. Then move the knife above where your first cut ended and slice (carefully) down and across till the two cuts meet, making a pointy little 'chip' of wood Detach the bud chip from the scion.


Be careful with your fingers. If your knife is sharp enough to do the job properly, it's sharp enough to seriously slash you if you slip. There is a real risk of cutting too deeply and slicing the whole scion in half while making the first cut upwards.  Practise the whole process with different methods on other twigs and wood and find one which you feel works for you.

3. Next, you carefully remove the thin layer of wood which is attached to the bark of the bud, leafing you with just a layer of bark and the bud. To remove the wood, gently slip the tip of the knife in between the wood and the cambium layer at one of the ends and carefully bend the wood (not the bark) away. While being a bit fiddly, this should come cleanly away.


Thin layer of bark containing a bud on the left, wood on the right.
4. Now, keeping the bud pointing upwards, use the knife in one hand to gently open the flaps a little, then slide the bud underneath till it fits snugly with it's top meeting the straight edge of the T-cut (see picture). Close the flaps over the bud, leaving the petiole poking out and tie everything in place. It's important to do this snugly, but not too tight or with thin string or bands which will cut into the bark.
Everything fitting snugly together

Securely tied bud on my Concorde pear. If this bud takes I will have two types of pear growing in one tree.
5. Now you just have to wait. Keep checking the ties (resist the urge to fiddle) to make sure they're not cutting into the tree. You should be able to remove them in a month or two, depending on what you use and how elastic the material is. If it's taken, the bud will remain dormant all winter but next spring things will finally start to happen. When the bud produces a shoot, cut back the rootstock to about 4-5 inches above the bud, then tie the bud shoot to the little nub of rootstock to help it grow straight, after about a year, or when the bud shoot is around half a metre or so tall, remove the rootstock nub and tie the shoot to a stake if needed to keep it straight.
This is a Dennistons Superb (aka 'Imperial') gage tree which was propagated by the nursery using a shield bud. The rootstock is the darker coloured stem which is cut off just above where the bud (now grown out with the lighter coloured stem) was grafted on.
Questions:

Why do I have to use buds from this years growth?
It has to be this years growth from the lower portion of the scion because above these, the buds are too young. Using immature buds (I'm told) might work but will more likely result in a weak join which will likely die over winter, so why bother when a good piece of scion wood will give you enough buds for several trees? Using a bud from last years growth will probably produce a fruiting bud, which might survive to flower but will die afterwards.

What is shield budding? Are shield budding and t-budding the same thing?
 Basically, yes. Very occasionally, t-budding seems to get confused with chip budding. Chip budding is another means of budding trees and is also carried out at the same time of  year (end of July/August). It's a fairly similar technique, and faster, as the 'chip' cut from the scion wood remains intact and a corresponding chip-shaped space is cut into the rootstock. No fiddling with bits of wood, no flappy bits in the bark to fight with. In chip budding, the flat edge of the chip is usually made on the bottom end, rather than the top as in shield or t-budding. There is the issue of matching up cambium layers with chip budding, whereas in shield budding, there is a pretty large surface area almost guaranteed to meet, so long as they're prepared and tied properly.Try both and see which one works for you.


What trees can you graft using this technique?
Fruit trees in the rose family, (apples, pears, crab apples etc.) do tend to take especially well to shield budding. Other plants are also propagated using this technique and include everything from figs and roses to peaches and dogwoods. In any case of budding or grafting, you can graft the same species onto the same species, like apples on apples, and sometimes you can graft within the same family, like the stone fruits; peaches and cherries on plums (St. Julian A rootstock). These can be different varieties - some are more compatible than others- but at the end of the day a good rule is to graft pear onto pear (or quince), apple onto apple (or crab apple), plum onto plum, cherry onto cherry (or plum) and peach onto peach (or plum again). There are exceptions and some are more common than others, like the pears on quinces and cherries on some plum root stocks. Once you start looking into what root stocks you want to use, you'll often find that the supplier has helpfully listed the species which they're suitable for. Once you've done a few successful grafts using the advice given by suppliers of root stocks, then start to get more adventurous. Go safe and steady as opposed to getting a little overexcited (says the world's most impulsive gardener) and starting out with something that's a long shot and knocking your confidence. Peaches, for example are notoriously fiddly because their wounds only heal in warmer temperatures (erg, meant to be more specific but can't find the exact nth degree). 

Slipping bark lifted, showing the wood underneath.
When can you shield bud?
When the bark is slipping. This usually happens around late July, August and early September and varies between fruit species, the weather and location. The best way to know if your trees bark is slipping is to go out and try it.

See how cleanly the bark separates from the light white/green wood underneath? This means the cambium, that all important layer, is super-active, so much so that it is more likely to be able to tolerate the trauma of being cut and fiddled with when you add the new bud from the scion. Trying to peel back the bark enough to shield bud is sometimes possible out of season, and sometimes it's worth seeing for yourself what is and isn't possible by trying to graft or bud out of the recommended time. If you want to maybe just do it with spare stock and save the good stuff for when the graft or bud is really most likely to take.


Really excellent further reading:
The Grafters Handbook - Revised - Sadly, not out just yet but it is available for pre-order and the anticipated print date is in February 2013.
Grafting for Fruit Trees - Cheap, short and to the point, this less formal booklet is aimed at a US audience but is readily available and is fairly comprehensive. Most of what is recommended is still perfectly relevant to the UK.
Orangepippin.com Has lots of info on root stocks and tree varieties. They also sell trees and have a very useful tree size calculator.

Where to buy root stocks and scions (UK):
No doubt we all know this, but there are of course other suppliers out there. These are just the ones I know of and have either used or have had recommended to me. If you can think of anyone else I'm missing please let me know!

Ashridge Nurseries - Haven't used them personally, and at the moment, their stock is pretty limited. This might improve around September.
Blackmoor Nursery -Out of stock at the moment, but will have them available to order September-ish.
GB Online - Also supplies scion wood and can do some bud sticks on reques.
Grow your own: a very helpful series of videos which coveres growing your own rootstocks, grafting, budding and pruning by Stephen Hayes 
 
Most places will ship the root stocks once dormant between January and March. For twitchy people like me, this is a long wait and it can be a bit disappointing when a bundle of wet, twiggy sticks finally does arrive. Have faith, poke them in the ground, (or heel them in the shadow of a north wall if you're not sure where to put them) and they'll romp into life come spring.


Orchard Groups
 Check out The Orchard Network to find an Orchard Group near you.

Totally un-biased coverage of my local group: Suffolk - The Suffolk Traditional Orchard Group has seasonal classes on grafting and sometimes budding. Check out their newsletters: January 2012, April 2012 for more information and on who to contact.

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1 comments

  1. Great post - when I have some time to think about attacking my citrus I'll come back to it and have a go. Grafting different citrus varieties onto the one tree is really popular with gardeners here but I've yet to attempt it.

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