Create art in your garden with multigraft fruit trees

Multigrafts, double-grafts, ‘family’ trees, fruit salad trees, cocktail trees – there’s lots of different names for them, but they’re essentially all the same thing. Fruit trees with different varieties or cultivars grafted onto the same rootstock.

A multigraft plum tree: the different varieties are showing their autumn colours at different times, making a beautiful display in the garden
A multigraft plum tree: the different varieties are showing their autumn colours at different times, making a beautiful display in the garden

If the different grafts are all the same variety (e.g., all apples), they will normally be sold as multigrafts, whereas a ‘fruit salad tree’ describes a tree that has different types of fruit from the same family, e.g., apricots and plums.

Generally speaking, fruits from the same family can be grafted onto the same rootstock, e.g., plums and apricots are compatible, peaches and nectarines, and pears and quinces. However, due to the magic of grafting, other combinations may also be compatible, e.g., some varieties of peaches and nectarines are compatible with plum rootstocks, allowing for glorious combinations of 4 fruit types on the same tree. While it’s safer to stick to known compatibilities, it’s always worth experimenting with odd and unusual combinations, because apart from your time, there’s absolutely minimal cost involved.

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The artist’s rendition of a tree from the ‘Tree of 40 Fruit’ series by Sam Aken (from www.treeof40fruit.com”

One of the best ways to think about a multigraft is as a work of art that you are constantly reviewing and improving.  A famous examples of this is the ‘Tree of 40 Fruits’ Series by New York artist Sam Aken.

Many of the problems that can happen with multigrafts (see the list below) are avoidable or fixable by paying careful attention to graft placement and detailed pruning, and then by reviewing and responding to how the tree has actually grown and performed each season.

clare-win-multigraft-353x628If you think of your tree as a living work of art (rather than the ‘plant and forget’ model that most gardeners use), and have high expectations of what you want to achieve with the tree, it’s possible to make them incredibly productive.

Benefits (Pros)

If you’re prepared to put the work into them, there are lots of benefits of having these trees in your garden, one of the most important being that they allow you to increase your food security in a small space.

How does that work? The more biodiversity that you can stack into your garden, the more you’ll be protecting your food supply from the many disasters and natural events that can ruin a crop. If you’re growing 10 varieties of apple, rather than just one, then if a hail storm comes along or you get a particular disease outbreak, chances are that some varieties will fare better than others, which reduces your chances of total wipeout.

The more varieties you can play with in the garden, the more you can work towards a consistent, even harvest throughout the entire growing season, rather than the normal cycle of glut and scarcity that most home fruit growers have to deal with.

Other benefits of growing multigrafts include

  • pollination
  • increasing food production in a small space
  • practising your grafting skills
  • making the most of an existing tree with an established root system, rather than having to get a new tree established

Problems (Cons):

  • Inappropriate varieties – not all varieties grow as well as each other in a given locations, so there’s a risk that some varieties you choose to graft won’t thrive, but, so what? Just regraft with another variety.
  • Pruning. It’s a very common scenario that some varieties will be more dominant than others, either because they are more compatible with the rootstock, the graft was better quality, or the variety is happier in the location.  This can make it more difficult to train the tree into a balanced shape and the dominant branches can end up being bigger and more vigorous. This needs careful management with pruning to prevent the problem becoming worse by allowing the dominant side to crowd out or shade the slower-growing varieties.
  • Branch positioning. It is important that the grafted branches are evenly spaced along the main trunk to produce a balanced form in the mature tree and to avoid undesirable crowding. On a single-variety tree, a misplaced branch can simply be pruned off to allow well-placed branches to grow. However, pruning off any of the first branches of a multigraft tree means sacrificing one of the varieties.
  • Providing pollination partners is one of the main reasons for creating multigrafts, but unless varieties are carefully chosen with this goal specifically in mind, it doesn’t always work. The varieties need to not only be compatible, but also flower simultaneously. In order for all varieties on a multigrafted tree to be pollinated, they must be carefully selected for flowering times to overlap sufficiently. Again, this problem, should it occur, is very fixable by regrafting with a more suitable variety.
  • Different varieties can be vulnerable to different pests and diseases. In the worst-case scenario, the introduction of disease by one variety on a multigrafted tree can compromise the health of the entire tree, particularly if you accidentally introduce a virus to the tree by using infected grafting wood. This is offset to a large degree by the advantages of increasing biodiversity (see above), but it’s good practise to only ever use grafting wood from trees with no visible signs of ill-health, and ideally a good record of productivity as well.
  • Labelling. This almost seems too frivolous to include in this list, but it’s probably one of the problems we hear about most regularly, for all fruit trees, not just multigrafts. It is hard to find a good labelling system that can easily withstand the ravages of time and the weather and remain not only in place but also readable! Our solution is to take a four-pronged approach:
    • make effective, permanent, low-cost labels by cutting up aluminium cans into labels, and using a nail to etch the name into the metal. Punch a hole in the label and use a piece of wire to attach it to the tree. Don’t attach it too tightly around the branch or it’s easy to strangle the branch as it grows.
    • Check the labels at least once a year. Make sure they’re still in place and still readable, and loosen the wire if necessary.
    • Keep a paper (or computerised) record of the location of each tree, its variety, and any varieties you add by grafting.
    • Take photos to back up the computerised record.

Multigraft fruit trees take a bit more work and diligence than single-variety trees, but the benefits are huge, not just in terms of increased production, but through providing other environmental services to your garden, providing beautiful sculptural trees, and providing a life-long interest and passion.

But be warned – it’s addictive!

How to grow apples – the wrong way!

Pretty much everything about our new heritage apple orchard is “wrong”— at least in the world of large-scale commercial apple growing.

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Katie and Merv planting the new heritage apple orchard

As usual, we’re straddling two worlds—the modern world of commercial horticulture that tends to be focused on high production, export, and monoculture; and the slower, more old-fashioned world of small-scale organic farming that aims to meet the needs of the people and the community who support our farm, is responsive to the climate, and empowers other people to become self-sufficient in food production.

So, what are we doing wrong?

  1. Planting more than 60 varieties, including lots of heirloom and heritage varieties you’ve never heard of…

How many varieties of apples can you name? Most people know Pink Ladies, Fuji, maybe Gala or Granny Smith, but for many, that’s as far as it goes—after that it’s “red apples” or “green apples”. If you can name 10 varieties you’re doing really well.

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Katie selling organic apples at market

That’s largely because the number of varieties grown commercially (and therefore sold in supermarkets) has been steadily shrinking over the last few generations. And while there’s lots of research being done into new varieties, most will not end up in large-scale production, and it’s likely you’ll never hear of them.

Why has the number of varieties shrunk? As with every other area of food production, it’s a response to the commercialisation and globalisation of our food systems. For a variety to maintain its position on a supermarket shelf (and therefore on a modern farm) it has to meet certain criteria: it must be increasingly productive, withstand many months of cold storage with no loss of quality, have a long shelf life, be able to travel well, and be very consistent in appearance. And as farms get bigger and bigger, it’s just a lot more practical and cost-effective to grow 100 (or 1,000) hectares of the same variety.

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Sorting different varieties in the nursery

So, you might be surprised to hear that there are literally hundreds—and in fact thousands—of different apple varieties. When we were gathering the grafting wood to grow the trees for our new orchard, we had to make ourselves stop at 60 (it was VERY tempting to keep going). And we must admit, some of them were only included because they have such fantastic names—who could resist growing Geeveston Fanny or Peasgood Nonesuch? You can read the whole list here.

So, why are we swimming against the tide and planting exactly the opposite of a monoculture?

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A huge diversity of different varieties in the tree nursery

If the wild weather conditions (drought, flood, hail…) we’ve experienced over the last 12–15 years have taught us anything, it’s that diversity is our best bet of bringing home a crop every single year, regardless of the weather conditions. The variability between different varieties in things such as timing of flowering, harvest times, and resistance to diseases all increase the chance that when something bad happens it won’t affect all varieties to the same degree, and therefore we have a bigger chance that at least some of our varieties will safely reach maturity each year.

2. Planting on seedling rootstock 

You’ve probably heard of dwarfing rootstocks, right? Well, all modern apple orchards are planted on some type of dwarfing rootstock, from the MM111, which grows to about 80% the size of a seedling tree, down to the M26, which is only about 40% the size of a seedling tree.

 

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Merv (Katie’s dad) planting apple seeds

But not us! Nope, we’re planting our trees on seedling rootstock, which are trees grown straight from an apple seed, and are the biggest possible size an apple tree can become (in fact, this is what sets the benchmark standard of 100% that other rootstocks are measured against). In a modern orchard, this is crazy behaviour!

Seedling trees can get huge, which means they can be harder to prune, harder to thin, harder to pick, and pretty much everything has to be done up a ladder.

So, why are we apparently making life so much harder for ourselves? Well firstly, we’re pretty sure that by diligent pruning and careful management we can stop the trees from becoming too huge.

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Seedling apple rootstocks being transplanted in the nursery, ready to graft

But the main reason is that we’ve just been through the worst drought in living memory, and with the climate variability that has so quickly become a way of life for farmers, we’re anticipating the next drought any time soon. And what we observed was that while trees on dwarfing rootstocks really struggled, most of the remaining few trees in our district that are on seedling rootstock—even the ones that had no irrigation—survived the drought. Wow, they are one tough tree, which makes them the perfect tree for the future climate we should be preparing ourselves for if we want to maintain food security.

3. Not fumigating our soil or killing the weeds

Standard practice in commercial orchards is to fumigate the soil before planting new trees. This is a process where chemicals are pumped into the soil to sterilise it, particularly to kill any root-eating nematodes or other pathogens that might have built up in the soil which would cause replant disease in the new trees. New trees are normally also “supported” by killing any weeds growing under them with herbicides to reduce competition for water and nutrients, and by the addition of various artificial fertilisers.

 

Nuh. Not us. We’re not doing any of those things.

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Clover is a great plant to include in the green manure crop because it’s a nitrogen fixer

Don’t get us wrong, we also want to support our new trees as much as possible, reduce competition, and make sure we don’t get replant disease. We’re just going about it a completely different way, which inevitably is slower, more expensive, and more time consuming to put in place.

For a start, we’re relying on building healthy soil to make sure we don’t get replant disease. The best defense against root-eating nematodes is nematode-eating nematodes, so we inoculate the soil with them and make sure we provide the right soil conditions to keep them happy.

Second, we work consistently to build a strong natural fertility system to make sure the soil contains all the macro and micro nutrients that the trees will need, and that we have plenty of bacteria and fungi present to transform them into a plant-available form.

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Using organic oaten straw as mulch

Third, we reduce competition from weeds by mulching our trees for the first couple of years and, as the mulch breaks down, encouraging a wide biodiversity of plants to grow under the trees, thereby providing a multitude of benefits, from taking nitrogen from the air and putting it into the soil to providing habitat for beneficial predator insects.

Just because we lean towards the “old” way of doing things doesn’t mean we’re not interested in being as modern, efficient, and productive as possible. In our new block we’ll be participating in some ground-breaking research to test different types of mulch and different types of groundcover to see which system can achieve the best results as quickly and cheaply as possible.

We actually believe that by doing all these things “wrong” we’ll be able to demonstrate in the long run how much more sustainable, ecologically viable, and less reliant on artificial inputs our organic orchard will be.

Wish us luck!

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The new heritage apple block taking shape

 

 

 

 

 

 

 

Are multigraft fruit trees a good idea?

Have you heard of the “Tree of 40 Fruit” project? It’s an art project created by American artist Sam Van Aken, where he creates beautiful mega-multigrafted trees, for example a peach tree with more than 40 different varieties of peach and nectarine, for their aesthetic value. They are absolutely stunning (we can’t show you one here because we didn’t get permission to use his photos, but here’s the link to his website if you want to have a look).

multiple-trunk-different-colours-helena-smallInstead, here’s a photo of a multigraft tree from a recent garden consultation we did, showing the different coloured leaves of the two different varieties on the same tree.

 

Not as spectacular as having 40 different varieties putting on their various autumn colours, but you get the idea! Here’s another one of a multigrafted cherry showing the different coloured blossoms in spring (this photo is from Wikimedia Commons).

A multigraft is, as the name suggests, a tree that has multiple varieties grafted onto a single rootstock. So for example an apple tree with Pink Lady, Granny Smith and Fuji all on the same tree (which coincidentally, is one of the trees we have for sale this year). Multigrafts are always the same type of fruit (e.g., all apples), whereas a tree with different types of fruit on the same rootstock –  say a plum, an apricot and a peach – is called a “fruit salad” tree and is quite a different animal.

The idea of a many-grafted fruit tree is not new – there are a couple of very famous examples around the world, such as this ‘family tree’ that has been grown by Paul Barnett in West Sussex, England, on which he’s grafted 250 different apple varieties (photo from the Daily Mail).

Paul Barnett with apple tree

Multigrafting has been used not only as a repository of genetic material of lots of different varieties, but also as a mark of the skill of the master grafter, proving not only their grafting skills, but also their superior pruning and management skills in keeping each separate variety alive and growing, and keeping the whole tree in balance.

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A multigraft plum tree in the garden of one of our Grow Great Fruit program members

Which  brings us neatly to the question of, should you bother?, because while multigrafts have lots of advantages, they are almost always a harder tree to manage in the garden, if you’re trying to keep the different varieties in balance with each other, and they can be daunting for a new gardener in particular.

Sometimes keeping the tree in balance doesn’t matter, for example if you’ve grafted a piece of wood of the same fruit but a different variety to act as a cross-polliniser on to your tree because it wasn’t setting a good crop of fruit. In trees like that, you’re not aiming to grow both varieties in equal proportion.

But if you’ve planted a multigraft because (for example) you have limited space but still want roughly equal amounts of an early and a late apple, then for sure it matters – there’s not a lot of point of having a multigraft Gala and Pink Lady if you get 10 boxes of Gala early in the season (when you already have plenty of plums and peaches), and then have to wait until the end of the season when you pick 2 Pink Ladys from one weakling branch!

So, how do you manage them?

The trick is to pay a lot of attention to your pruning in the first few years of the tree’s life (which we call the ‘establishment phase’). Monitor closely how well the different varieties are growing, and you may need to prune the more dominant variety back quite hard at the beginning to let the weaker side get equally established.

Of course, one of the pruning principles is that the harder you prune, the harder your tree is likely to grow, so the tree’s most likely response to hard pruning is that the dominant side will respond with even more gusto. You can minimse this bounce-back effect by pruning the tree in late summer, rather than winter.

Another trick that might help if you don’t want to continually prune is to weigh the dominant limbs down more horizontally (e.g., with a brick) so the height of the growth tip is lower than the height of the weaker side of the tree. This physical height confers an advantage onto the weaker side, and the tree is more likely to direct more energy and resources to the weaker (higher tip) limb, allowing it to catch up.

So is it worth it? Absolutely! If you’re interested in gardening and growing fruit, all of this is tremendous fun, both the grafting and pruning management. It can be a quick way to experience the age-old relationship between farmer and nature (“who’s in charge here?”), that often starts as a battle for new growers but can end with a much deeper understanding and respect for how nature works. And remember, the tussle goes on mostly in your mind – the tree will just keep being a tree.