Last year I successfully identified a mystery apple tree on our Plot #79 allotment orchard as an out-grown MM106 rootstock. It was no use whatsoever in that state – its fruit was dry, mealy and tasteless – but as the base for a new ‘family’ tree it had a lot of potential.
A ‘family’ apple tree is simply a tree that produces different varieties, or cultivars, of apples. Of course, they don’t occur naturally1Unless you include bud-sport branches that might have fruit of a slightly different size or colour to the rest of the tree, but are still essentially the same variety. so they have to be artificially created, by grafting different scion varieties onto the parent stock.
Depending on the shape of the tree and the thickness of its stems and branches you might be able to use the ‘whip and tongue’ grafting method normally employed to graft pencil-sized scions onto one-year-old rootstocks. More likely though, you’ll need to make use of the ‘bark’ or ‘rind’ grafting technique2Another option is bud grafting, but that’s an operation for later in the year, usually late summer. If I get chance to give that a go as well, then I’ll write it up and post it., as I did for the first time this week. I was lucky that a dab-hand at rind grafting, my Twitter buddy Steve48088637, just happened to be in the area last Sunday and was happy to swing by the plot and show me the basic technique. Armed with that demonstration, and the info from a couple of explanatory books and YouTube videos, I set to with a will… and of course a sharp knife. These were the results.
Rind Grating, Step-By-Step
To successfully carry out any sort of rind grafting, you’ll need the following bits of kit:
- Pruning saws / secateurs for taking off the old top-growth.
- A clean, sharp grafting knife for making the rind cut(s) and preparing the scion(s).
- Grafting wax / compound to seal the cut(s).
- Polythene tape, string or similar to bind the top of the stock and help keep the scions in place.
- Plant labels, for labelling the scion(s)
- Notebook and pen, camera et. al. for recording the position of the scion(s).
- Finger plasters (just in case…)
And here’s the basic method, with a detailed explanation of each step to follow:
- Cut back top-growth
- Practice the method
- Make the rind cut(s)
- Prepare and Insert the scion(s)
- Wax and tape the graft(s)
- Label everything!
Here we go!
1. Cut Back Top-Growth
The first step was to take off the whole of the top of the MM106 tree, at least down to the main trunk. Here’s what it looked like before I started in with the loppers:
Here’s where I paused the process to allow myself a bit of a practice (see section 2 below). The old tree stake was no longer necessary so that could go as well.
After practising the cuts to my satisfaction, I made the final height adjustments. I chose the final height of the rootstock with a couple of considerations in mind:
- I needed to cut back to stem sections that were thick enough to accommodate the three scions that I wanted to graft onto each limb.
- I didn’t want the new growth to start developing too far towards the ground, potentially resulting in a very bushy tree.
All in all, this seemed like an effective compromise between those two requirements:
2. Practice the Method
As I mentioned, knowing I was going to trim the rootstock further before I began the final grafting process, I used one of the to-be-trimmed sections to make a practice cut or two. Having followed the next three steps and made a pretty decent job of my practice piece, I decided I was happy to go ahead with the actual grafting.
3. Make the Rind Cut(s)
First, I made the vertical incision, using my curve-bladed Felco budding knife3Which is available on Amazon.co.uk, although I don’t remember paying the £31.33 that they’re currently asking for it… if you’re in the market for a new knife, maybe shop around or wait until the price settles down a bit. rather than my standard, straight-bladed Felco garden knife. The budding knife allowed for a rocking cutting motion that felt very natural.
The other end of this particular knife has a brass wedge attachment, which I used to gently prise the bark away from the wood beneath. You could also use the blade of the knife instead, as long as you’re extra careful not to slip and slice through the bark. You can see in the photo below where I slipped on the practice cut and scored the bark. Try not to do that, it will encourage the bark to split more than necessary. Making the cut with the blade point-down should help.
I’m very glad I did pause to practice before making the final cuts, as I learned something important at the next stage.
4. Prepare and Insert the scion(s)
The scion – the section of the variety or cultivar that you want to grow on into a fruiting section of the new tree – should ideally be around pencil length and thickness (as per Wade Muggleton’s The Orchard Book and various other sources) although I’ve also seen rind-grafting done with longer scions (see Stephen Hayes’ video at the end of this post). I opted for the standard pencil size. Four of the scions had been cut a few weeks ago and stored in the fridge to try to stop them drying out and the other two were freshly cut from other trees in the Plot #79 orchard4I have the highest hopes for the two fresh scions. Three of the fridge-stored ones have a good chance, one was a little on the dry side, so could be touch-and-go…).
In each case, I trimmed the top end of the scion5Although Stephen Hayes’ video shows the entire tip, apical bud and all, left on the scion, I’ve read elsewhere that this can sometimes die back, or cause the graft to fail by growing on too quickly, before a graft union has formed. Obviously methods (and results) will vary greatly, so there’s probably no right or wrong scion-form to aim for, as long as the basic principles you’re following are sound. to leave what looked like a healthy, upward-pointing bud.
Then, having measured for length, I trimmed the bottom end and made the slice cut to expose the cambium layer – the layer of bright green cells just beneath the bark, which carries sap around the plant and is therefore essential for the life of the tree – and woody centre of the stem. I made the the slice cut on the opposite side of the scion to the top-most bud. This should mean that because the exposed slice is placed facing inwards, the top bud is facing outwards, so when it starts back into growth it does so in an outward direction, away from the centre of the tree. When you try it yourself you’ll see what I mean.
Now, here’s the important lesson I alluded to earlier: the angle of the slice cut turns out to be very important indeed. If you make a deep, oblique slice then when you insert the scion into the rind cut it will force the bark too wide, leaving large air gaps and potentially splitting the bark much further than necessary:
Instead, you should make a much more shallow, acute slice across the base of the scion, something like this:
This way when the scion is inserted the bark isn’t forced open as far, and it also means there should be more of the scion cambium exposed and ready to fuse with the cambium layer beneath the bark of the stock:
(The pic above is of my practice cut, so the scruffy bit of damage to the bark opposite the scion isn’t an issue.)
On the ‘back’ of the scion, opposite the slice, I also gently scraped away the surface bark to expose the green cambium layer. Again, the aim is to increase the amount of contact between scion and stock cambium and increase the chances of a successful graft union.
5. Wax and tape the graft(s)
Once the scion has been securely inserted, it’s important to seal the area around the graft point. Cutting and prising back the bark causes a wound that then becomes a potential site for infection via dirt-, air-, or water-borne fungus or bacteria, and will definitely lead to moisture loss. By sealing the wound with grafting compound or wax, both problems can hopefully be prevented:
In this case I used a grafting wax stick – a blend of bees’ wax, tallow and resin – which I bought from from Bee Beautiful UK, via eBay. Un-blended bees’ wax is, by several accounts, just a bit too brittle when it re-sets. The blended wax stick I used was easy to soften just with the heat of my hands, moulded nicely around the graft point, and I think should remain semi-malleable, which should allow the scion to flex a little if needed.
Once I’d inserted three scions into each stem, I waxed over the cut end of the stem as well – again, to help prevent excess moisture loss – and then wrapped tightly around the top of the stem with polythene grafting tape6Although I’ve been told that cut-up strips of freezer bag plastic do the job just as well.:
Tight wrapping will hopefully help to hold the scions in place, in case a robin (mostly manageable) or a wood pigeon (potentially problematic) decides to use them as a perch. Once the scions are growing well the plastic will be removed, to avoid damaging the scions or main stem as they continue to grow.
6. Label Everything!
The final part of the job was to label each scion individually, then take up my trusty pen and notebook to sketch a plan of the placement of all six scions in relation to each other. By way of a double belt-and-braces measure, you can’t beat an online note as well, so for the record (moving clockwise around each stem, starting with the scion nearest to the road that runs along the side of Plot #79) they are:
- ‘Tydeman’s Early Worcester’
- ‘Orleans Reinette’
- ‘Wareham Russet’
- ‘Rosemary Russet’
- ‘Worcester Pearmain’
There’s a nice mix there of mostly dessert apples, with one dual-purpose (‘Catshead’). They’re in a range of pollination groups, but I’m not really concerned on that score as there are more than enough compatible apples growing on Plot #79 and across the wider allotment site to ensure that they all have at least one or two pollination partners close by.7If you were planning your own ‘family’ apple tree to grow an area without so many other apple trees around, you might want to do a bit more research to ensure that the varieties you are growing are likely to be compatible with each other.
Now all I have to do is wait to see whether or not the grafts take. If they’re successful then I ought to see new growth from each scion within the next few weeks. By the end of this year’s growing season they’ll hopefully have produced six strong new stems and the graft points will have fused and grown over with strong scar tissue to hold them ion place. I’m definitely planning to keep a very close eye on them through the year, and I’lll post occasional updates here on OrchardNotes.com as they develop.
I’ll also need to keep an eye on the rootstock section, to make sure it doesn’t send up too many ‘suckers’ from the base, or new stems of its own. If this happens it will draw the water and nutrients away from the scions (as per my previous #epicfail attempt at ‘family’ tree grafting). The easiest way to prevent that from happening will be to wait for any dormant rootstock buds to break into growth and snip them off when they do.
More From the Experts
It’s worth repeating that this was my very first attempt at rind grafting, so my method might not be 100% fool-proof just yet. It’s a very old technique though and there are a great many orchardists and pomologists who have described it through the centuries.
For a recent take on the rind grafting method, have a watch of this video by veteran orchardist Stephen Hayes – who has notched up a whole lot more grafting experience over his lifetime than I have in my five or six years as an orchardist and fruit enthusiast – for a slightly different (but essentially similar) take on the process:
Or, if you’d prefer to refer to the printed word, there’s a very good explanation of the method, with plenty of photos, in Wade Muggleton’s The Orchard Book (see my review for more info).
How about you? Are you an experienced rind / bark grafter? Have you spotted something in my method that might cause a problem that it isn’t too late to correct? Or have you been inspired to have a go at creating your own ‘family’ tree? Do please let me know, via the comments, below.
- 1Unless you include bud-sport branches that might have fruit of a slightly different size or colour to the rest of the tree, but are still essentially the same variety.
- 2Another option is bud grafting, but that’s an operation for later in the year, usually late summer. If I get chance to give that a go as well, then I’ll write it up and post it.
- 3Which is available on Amazon.co.uk, although I don’t remember paying the £31.33 that they’re currently asking for it… if you’re in the market for a new knife, maybe shop around or wait until the price settles down a bit.
- 4I have the highest hopes for the two fresh scions. Three of the fridge-stored ones have a good chance, one was a little on the dry side, so could be touch-and-go…)
- 5Although Stephen Hayes’ video shows the entire tip, apical bud and all, left on the scion, I’ve read elsewhere that this can sometimes die back, or cause the graft to fail by growing on too quickly, before a graft union has formed. Obviously methods (and results) will vary greatly, so there’s probably no right or wrong scion-form to aim for, as long as the basic principles you’re following are sound.
- 6Although I’ve been told that cut-up strips of freezer bag plastic do the job just as well.
- 7If you were planning your own ‘family’ apple tree to grow an area without so many other apple trees around, you might want to do a bit more research to ensure that the varieties you are growing are likely to be compatible with each other.