How to do a bark graft

As far as we’re concerned, grafting might as well be called ‘one of the best magic tricks ever’. It’s where you literally transform some crazily vigorous rootstock tree with underwhelming fruit into the most delightful variety of (insert name of fruit tree here) ever.

Even though it’s a bit late in the season, we’ve been playing around with grafting lately. In particular bark grafting as we have a collection of wild cherry plums which are all pip and no flesh. The positive attribute to these rootstock trees is that they’re incredibly vigorous, so grow like crazy with little/no attention. By doing a bark graft we’re aiming to transform this slightly useless tree into a plum tree which produces abundant, tasty fruit for us, our friends and pantry shelves.

Bark grafting involves some drastic methods, first of which is chopping the tree down. I know, it sounds counter-intuitive doesn’t it – but stay with me. Leaving a ‘stump’ of between 20-50cm, the idea is that you can then do multiple grafts directly into the stump. I’ve also seem people leaving much much more of the tree’s shape than just a stump – this can be a good option if your tree has a good healthy structure and is disease free. The down side is that you’ll have more rootstock branches trying to constantly grow back so you’ll have to be rigorous in pruning off their shoots.

But how do you magic a new and better variety onto the rootstock? Good question. You do so by grafting on scion wood which you harvest from a productive, healthy fruit tree.

A bit more about scion wood

The scion wood is the cuttings you take from another tree with the desired fruit on that you can then graft onto your rootstock. For example we took some cuttings from our neighbour’s AMAZING plum tree to graft onto our very un-amazing wild cherry plum tree. The only thing you really need to remember is that the scion wood and rootstock need to be from the same plant family. The best time to take scion cuttings is in Winter when the trees are dormant and have no signs of budding on them. As soon as they start to bud you’re not meant to bother grafting. However (cough, cough), the scion cuttings we took in the dead of Winter and stored in our fridge started to bud ever so slightly as the vegies also stored in the fridge release ethylene gas which inspires the scion wood to bud – woops. Learn something new every day.  But we went for it anyway, because that’s how we roll. You can read a bit more of scion wood storage here.

20-16This little diagram shows the important things you need to be aware of, and match up, between the scion wood and the rootstock. The cambium layer is where the real magic happens – if you can line the two up then you’re onto a good thing. Diagram from here.

As mentioned, we chopped down one of the cherry plum trees on our place to graft – here’s the full process we went through. Step one, chop the tree down, however we’ve left one branch belonging to the root stock to ensure that the tree will still ‘draw sap’. Apparently this increases the chances of the grafts succeeding, eventually we’ll chop this branch off.

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 Our stump (with its temporary rootstock branch) is ready for some grafting

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Next thing to do is get your very sharp grafting knife and make some slices down the side of your stump which match the length of you scion wood graft (see photo below). Also using your knife, gently peel this bark back to allow the scion wood to be slipped inside. 

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 In hind site we should have trimmed the edges of the scion wood as well (down their long side) to increase the contact between cambium layers, but we’re practicing – and practice makes perfect and mistakes are expected to be made along the way. Also, the end of this particular graft is a bit ratty, generally you’re aiming for a super clean finish, but like I said – we’re practicing.

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Next up, gently wriggle your scion wood into the bark until it perfectly matches with the level of the stump. It’s really, really important that you aim to get the two cambium layers to match up, if they don’t, the graft want work. IMG_0682

Some people actually put a nail through the scion wood and into the rootstock trunk to help ensure it doesn’t move. We chose not to do this, as you’ll see below.

IMG_0684Notching in action

Now this is perhaps one of the most exciting things I’ve learned this year – it’s called ‘notching’. Notching means cutting a small notch above the bud you most desire to shoot, this inspires this particular bud to shoot as it thinks it’s under threat of dying. Make sure your knife is SHARP so you can get a clean cut. Notching helps determine how the plant will grow, ensuring that all (if not most) bugs grow away from the centre of the tree. You don’t want the buds growing into the centre as they’ll start to cross with one another and get tangled which increases the chance of disease (due to decreased air flow) and is darn awkward to harvest and maintain.

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Six grafts, all with notches to encourage them to grow out, instead of in. I’m so excited by this simple technique and have also used it in our very young espaliered orchard we’re currently setting up – more on that another time.

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Next up, we painted all exposed cuts with some eco friendly goop called Tree Stac which protects wounds from unhealthy bacteria or disease moving in. Finally, we bind all the grafts with electrical tape (as seen below), this tape was recommended to us instead of grafting tape as it lasts for a bit longer.

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And now we wait and watch to see what happens, despite our lack of perfection we still have high hopes that at least 50% of the grafts will take.

DSC_0016An example of a successful bark graft on a pecan tree. Image from here.

Recently I went to a grafting workshop with Nick Magnus at Woodbridge Fruit Trees – it was humbling as I have so far to go in developing good skills. But I loved it, especially when Nick affirmed my own approach to gardening by saying something along the lines of: “If your graft doesn’t work, just try again next year, gardening is very forgiving, just keeping learning and developing your skills”. And so we do. Graft on!

Interesting things about grafting

  • Guerrila Grafting: Folk who graft fruit bearing branches onto non-fruit bearing, ornamental fruit trees. Over time, delicious, nutritious fruit is made available to urban residents through these grafts. We aim to prove that a culture of care can be cultivated from the ground up.
  • Woodbridge Fruit Trees – Based in Southern Tasmania, this family business is internationally respected for being some of the most knowledgeable people around when it comes to anything to do with fruit trees, look them up!

*Your blogger is Hannah Moloney, co-director of Good Life and lover of all things fun and garden-esk.

 

 

9 Responses to “How to do a bark graft”

  1. James Gielow

    Are you aiming for the cork cambium or the vascular cambium? I’ve always wanted to try grafting, but have been super intimidated to do so. This write up helps me feel more comfortable. Can the same methods be used to say, graft a branch of a Pink Lady apple tree onto an existing granny smith tree so both apples grow? I’ve always wanted some cool Frankenstein trees to confuse and impress folks with. I don’t want to chop down my tree though as it already has a decent root stock.

    Reply
    • Hannah Moloney

      Hi James, I’m not sure about the different types of cambium layers – I just aim for the “green cambium” layer which seems to always work! And yes, you could definitely do this with apple trees. Good luck :-).

      Reply
  2. Dalmatian

    With bark or rind grafting onto an old live olive stump (top just cut off) is it possible to just drill into the bark from the top with a clean hole just slightly small than the scion? Pare back the scion bark just slightly to live growth and insert with a tight push fit.

    Reply
    • Hannah Moloney

      Maybe… I can’t give you a definitive answer as I haven’t done it. Technically it sounds like it might work as long as you line up with cambium layers properly. Worth a try! Good luck 🙂

      Reply

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