Thoughts on grafting over a food forest

 This spring has been long anticipated, a large grafting project was planned in the fall and everything needed to fall into place.   Our backyard orchard is about an acre in size and coming into it's third leaf for the oldest trees (the third year the trees have leafed out).  Probably an unconventional orchard as far the you might expect, because it's cut right into the forest.  It's a food forest, it's an orchard, it's a retreat with a wildlife pond by a hammock and a bench, dotted with small conifers and wood chipped lined paths.  It's just better than what started out as scrubby bush with a small path through it.   The first year entailed planting trees spaced along that one path.  The next year more paths were cut to the north through the underbrush winding and looping around the existing trees creating access to unexplored corners full of hazel, wild raspberries, Choke Cherry and Saskatoon bushes spotted by the occasional Bur Oak. The whole area is thinly overcast by Aspen trees, many of which were old and falling over opening up the canopy to plenty of light.  The truth about older Aspens (Populus tremuloides) is that they often just don't cast a lot of shade, as the crowded trees reach their end of life, the canopy opens readily giving room for succession.  Planting the orchard is the bush has been a great experience, indeed it was already a food forest - nearly all the native vegetation was edible, it just lacked in biodiversity - so many species that could grow in our cold zone 3 climate were missing. 

Project Biodiversity

This was the spark that started it, and it's a very deep rabbit hole to head down.  What are all the types of fruit trees that could grow here?  What about other fruit like berry bushes, are there some crazy kinds out there that excellent but just rarely planted?  A few months of looking around at what felt like every Canadian nursery's catalog, every permaculture website, every permaculture youtube video and the scope of what could be started to fill in. A surprising world of possibility, and if you looked closely at the edges there always seems to be more out there to discover.   Quickly you'll find that our map is divided into USDA climate zones, and those are an important filter to consider.  The main factor is the coldest temperature you'll experience in an average winter, and here you hit a wall up against plant biology.  Here on the Canadian Prairies most of us are in zone 3, which means at the height of every winter some nights can dip to -40C.   So when someone living here examines a list of apple varieties, the very first question should be "Can it survive in my zone?"  Out of the reported 2500 varieties of apples cultivars to be found in North America, many of the great ones can grow here. In fact some grow better here, where we have surplus chill hours and reduced insect pressure.  The same question when directed at every other category of fruit turns up an impressive list that can survive our cold climate.   There doesn't seem to be just one list, it's very scattered.. between nurseries, seed suppliers, universities, research stations and other backyard orchards.   Many new varieties stumbled across and "discovered" are later found to be 50 or 100 years old.. why haven't I heard of chums before?  In fact some of the best resources can be scans of old news articles or type written pages from years ago, offering prospective and relevant information on the varieties commonly planted to this day.  Take head that "cold hardy" is relative, for example the most hardy European varieties may not survive a Canadian winter. 

So the when the project is to add as much biodiversity as possible to the food forest, the solution gets interesting at a certain point.  Quickly every local store offering plants begins to look another vendor selling stock offloaded from the same truck. For our orchard going into this year, we ordered some trees and other plants from a selection of nurseries across Canada.  It was exciting receiving them in the mail this spring. By this point we had planted nearly all the trees we could fit, but there were so many more types of fruit.  It had became clear in the fall that the only way to add as diversify as we wanted would be to create an orchard of multi-grafted trees. 

100 trees and 500 grafts

So I did my first grafts in 2004, at our last property in a 120 year old farm yard. This is where I planned my first orchard.  There were logistical challenges to say the least, the garden area was far from, and even that water supply was on shaky ground.  If I knew then what I know now about mulch and compost, that orchard space would look much different.  I did some cleft grafts, and some chip budding on trees around the yard and i t was exciting when it worked.  I went on to other projects and came back to grafting in recent years.   With some luck I was able to find scion wood from a few sources in total about 100 varieties of apples, pears, plums and apricots. This would be good enough for the first year of grafting.   Tags to label the varieties used were are basic plastic tree tags with a UV resistant garden marker to avoid fading (sharpie will reliably fade from the elements). Labelling is essential for this task - and ok plastic tags aren't going to last forever, and I've used metal tags in the past - but for this number of grafts I went with what was quick and easy.   With a razor sharp grafting knife, scion, labels, a roll of Parafilm and a travel mug of coffee I set out.  With covid the little hand sanitizer spray bottles are everywhere, and those are handy to sterilize tools between trees, always a good practice.     

Grafting Technique

Most of my grafts were whip and tongue, which surprised me. There are several types of grafts you could use, and for each a special situation you might prefer one over the other - but when you're looking at a bag of scions and then at the tree, it's pretty easy plan your cuts and match up the diameter.  Anywhere I needed to used a scion that was smaller than the stock I preferred the modified cleft graft.   What I was doing is called Frameworking - as opposed to Topworking, here the goal was to add to the existing variety and grafting over the tree while keeping the frame of the tree intact, the scaffold branches and overall structure of the tree remains.  In fact I liked the existing variety so the goal wasn't to completely replace every trace of it, I just didn't need the whole tree to be Honeycrisp.  Any fruiting spurs or sections of the branches left alone would continue be the same variety as the frame of the tree, which was great.  From those main structural branches, of which often there are three or four after the tree's initial pruning and training - every secondary side branch is the fruiting wood, and this is where we're grafting. Giving enough space between branches and consideration to balance, size, shape and aesthetics - you can graft many varieties onto one branch.   The trees were just the right size to do this, a couple years from planting and just starting to establish those fruiting branches.   

Wrapping the grafts can be done in several ways, in fact a surprising number of ways.  Everything is used from rubber strips to plastic nursery tape, string, to nothing at all.  Sealing the grafts done with everything from wax to paint, grafting sealants that are like thick paint to ones that contain asphalt.  For this project I tried a minimal approach and just used Parafilm - a stretchy very waxy material used as a laboratory film that has great properties for grafting. It sticks to itself but not the bark, it breaks down just slowly enough that the graft can heal and then eventually it falls off and biodegrades, meaning it doesn't need to be cut removed like a plastic tape, it also seals moisture so well that a liquid grafting sealer like Doc Farwell's isn't necessary.  Parafilm requires one extra technique to stretch it tight and squeeze the graft together, which is essential. Just pinching or twisting it that it wraps a bit like twine allows you to pull it much tighter.  A couple layers and maybe a dozen wraps around the scion can be necessary to get it tight, and from experience I can tell you wrapping just one thin layer often leads to the film splitting before you want it to. I usually wrapped the scions all the way to the end  (probably not needed) and pinched the film over the tip.  Sealing the tip of a cut scion is needed - the scion losses almost all of it's moisture through the end grain.  After this round of grafts at every corner of the orchard, up high and down low, on every shape and size of tree and branch - I think it was a good fit.  I think for next grafting season if I have them on hand I might prefer to use rubber grafting strips and wax. By next spring we'll bench grafting fruit trees that for spring of 2022. 

So the orchard is a test bed of sorts, an ongoing experiment to try growing new plant varieties, grafting methods, training and pruning methods, all to see what works what is possible.   This spring was all about grafting onto a wide array of tree sizes, shapes and species. Many conventional, but some less conventional - results for our trials to graft plums , pears and apples onto wild rootstocks will follow.  Tree forms ranging from the more usual modified central leader and delayed open center, to step over and informal espalier, to less well known Russian creeping forms like the Arctic and Melon stanza - which could allow us to zone push new varieties.   




Back to blog