We tend of think of garden history being just about the history of gardens but not really much about the history of gardening itself ie how things are done rather than what is actually done. I was reminded of that sharply when someone got in touch about last week’s post.
When, they asked, did people realise that not only might trees fuse naturally but that they can be deliberately grafted.
I admit I was stumped as I don’t know the history of every gardening technique off the top of my head but I went away to find out the history of grafting and I hope this goes some way to providing the answer.
And by way of a diversion what’s this little bug got to do with it?
The short answer is, of course, that nobody knows who discovered grafting or when!
What we do know is that plants, beginning with pulses and cereals, have been domesticated since way back in pre-history. However domesticating and propagating trees and woody plants was more difficult, until it was realised that those that had useful or better qualities could be layered, or that off-shoots could be removed and transplanted. It can’t have been that much longer before it was discovered that many of those plants will also grow readily from cuttings. That meant that those which respond easily to these ways, such as figs, grapes, pomegranates, olives and dates were probably the first to be taken into cultivation by the earliest gardeners/farmers by around 4000BCE. The problem is that most other fruit including apples, plums and pears can’t be propagated like that.
As last week’s post showed Nature might have stepped in here and shown a possible way forward. Did someone notice as they were building a shelter that some trees, such as willow, not only root easily but, also often eventually fuse together, and then function as single plant? Maybe they experimented to try to find ways of replicating that process?
Certainly the horticultural world changed for ever when it was realised it was possible to take a shoot or a bud from one plant [technically known as the scion] , and then insert it into an opening on another plant [technically the stock or sometimes under-stock or rootstock] and that, if done carefully, it would get supported and become part of the host plant and grow away happily.
That had definitely been known about by the time of the great classical Mediterranean civilisations. The first written account of grafting is in the treatise, On the Nature of the Child, thought to have been written in about 424 BCE by followers of Hippocrates.
By the time of Theophrastus [c371-c287BC], often considered the first father of botany, the techniques were well developed, and he describes how to make sure the graft of the scion and stock doesn’t dry out by wrapping it tightly in layers of bark, mud and hair. Theophrastus also comments on the first major horticultural advance which seems to have made by grafting.
In the wake of Alexander the Great’s conquests in Asia Minor, the Caucasus and India, somebody sent some fruit trees back to Greece. They included a low-growing apple, known as the ‘‘Spring Apple,’’ which ended up at Aristotle’s Lyceum, a school later run by Theophrastus. This must have been another big discovery because one of the advantages of grafting is that it allows the gardener to take advantage of the unique properties of the stock plant such as drought tolerance, resistance to disease or in this case a dwarf growth habit.
“Spring Apple” was probably used there as a dwarfing rootstock for grafting other apples, and recent genetic evidence shows that the most common dwarf rootstock used across Europe until recently, known as French Paradise, is genetically very similar to one found in Armenia. It gets its first printed mention in a French text of 1472.
This was the first evidence we have of an understanding that different stocks [the host plant] had different effects on the scion [the inserted cutting] and how it grew and performed. Nor was this a uniquely western discovery, because grafting was definitely known about in China, for example, by the 6thc. Nor was it confined to apples because Romans also used grafting on citrus trees, a practice which remains standard in commercial citrus growing today.
Grafting techniques are mentioned in several key mediaeval horticultural texts, but what becomes clear is that there is little understanding of its limits. For example Albertus Magnus argued in De Vegetabilibus, a 13thc horticultural tract, that grafting was a way of not only bringing about improvement from wild species, but because plant life was mutable it could also produce entirely new species. This strongly suggest that mediaeval authors were relying, as they did for other forms of knowledge, on what other people had said or written rather than their own first-hand experience and knowledge.
If anyone is interested in following up mediaeval notions of grafting there is a fascinating academic paper by Kathleen Kelly about it in literature and poetry, both literally and metaphorically, and often suggestively [think about it!].
The switch from reliance on text to reliance on observation and experience was a very patchy process. For example, in the first major printed text in Britain to cover grafting, A Booke of The Arte and Manner How to Plant and Graffe All Sorts of Trees published in 1572, the author Leonard Mascall seems quite accurate at first. He correctly suggests that grafting cherry onto cherry, and apple onto apple will work and dismissed the claims of his contemporaries who thought the scion could take on the ‘‘nature’’ of the stock. “Many which have written that if ye graft the medlar upon the quince tree, they shall be without stones, which is abusive and mockery. For I have (saith he) proved the contrary myself.’’
Knowledge of grafting was clearly widespread at the time. In Shakespeare’s Richard II, for example, written in c1595, Queen Isabella curses the” Gard’ner, for telling me these news of woe, Pray God the plants thou graf’st may never grow.” Justice Shallow in Henry IV [again late 1590s] invites Sir John Falstaff to his orchard to eat a pippin of his “own grafting.” and perhaps most famously of all in A Winters Tale [c1610/1] shows how grafting in horticulture could be used as a metaphor for potential human improvement:
“You see, sweet maid, we marry
A gentler scion to the wildest stock,
And make conceive a bark of baser kind
By bud of nobler race. This is an art
Which does mend nature, change it rather, but
The art itself is nature.
For a full list of early modern texts on grafting as well as an analysis of the links between grafting and human reproduction/improvement take a look at Claire Duncan’s article“Nature’s Bastards”: Grafted Generation in Early Modern EnglandA pdf of this article is freely available so do a google search for it if you don’t want to open a free JSTOR account.
From Mascall onwards most gardening texts explain the actual mechanics of grafting well enough to be followed today with a fair chance of success.
Grafting was seen as an essential skill for a gardener and even for gentlemen as evidenced by the elegant set of knives above. John Parkinson for example has a chapter on grafting “because many gentlemen are much delighted to bestowe their paines in grafting themselves, and esteeme their owne labours and handle work farr above other mens.” There is even a drawing of an Elizabethan aristocrat showing off his grafting skills. He is holding the stock, with some grafts already in place, with tools in his right hand, and more scions being held by the gardener behind him.
But that doesn’t mean they necessarily understood what is going on. Mascall’s book was for the most part a translation of a French text L’art et Maniere de Semer Pepins et de Faire Pepiniere by David Brossar and it’s clear he didn’t test many of Brossar’s other claims. So while Mascall was accurate for some things he also suggests grafting cherry onto crabapple, fig onto peach, and apricot onto fig which don’t work. Even as late as 1654 in The Expert Gardener the anonymous author was giving some rather strange advice…
This and ‘‘a multitude of monstrous untruths…in both Latin and English old and new writers’’ are exposed by the first properly scientific writer about horticulture, Robert Sharrock. He was an Oxford cleric and don, and friend of the great scientist Robert Boyle who encouraged him to write a treatise about the propagation of plants. Sharrock combined his own ‘‘observations made from experience and practice,’’ with a good deal of scepticism about the work of others: ‘‘I gave myself the trouble to run over with my eye all books I could procure of the subjects, not intending to trust any.’’ The result was The History of the Propagation and Improvement of Vegetables, first published in 1659 and reprinted in 1672, which was not just a practical text but covered anything relating to the propagation and growth of plants including natural history, botany, natural philosophy and even theology.
One chapter – Insitions – outlines the basic principles of the techniques involved in grafting, stressing that ‘‘The cyon or thing implanted be of like nature to the stock.’’ But to prove a point he goes to describe experiments he has made himself: ‘: ‘‘I have tried mulberries on Beech, Quinces, Apples, Pears, Elms, Poplars and by grafting they would not take” using that evidence to dispute the claims of other writer. He even tests the grafts suggested as compatible by others and these ” I have often prov’d false by mine own trial.’’
Sadly there is just one illustration in Sharrock’s book but it is a very informative one, and sums up the extent of grafting knowledge at the end of the 17thc, demonstrating as many as nine different grafting and budding techniques as well as ‘‘circumposition’’ (air layering), all applied to a single tree trunk.
From Sharrock onwards experiment takes precedence over received wisdom, and within just a few decades practical advice on a whole range of grafting tasks and techniques was a common theme in gardening books. By 1775 the latest edition of Philip Miller’s The Gardeners Kalendar has as many as 14 references to grafting tasks throughout the year.
Later gardening manuals show some of the lengths to which grafting could be taken by the gardener who had time on his or her hands!
But grafting really began to show its potential in the later 19thc, when it became a vital way for commercial horticulture in Europe to overcome pests and diseases. It all seems to have started with the arrival of an almost microscopic bug from America, which attacked vines. It didn’t really attract much attention until the late 1860s, but by then several vineyards in the Rhone Valley had died inexplicably. A government scientific commission identified the culprit but few people thought an aphid could be the underlying cause of such wholesale loss, and by the time they did it was almost too late.
By the 1880s it had devastated France’s vineyards, wiped out at least 75% of production and was spreading into Spain and Italy at a rapid rate.
This bug was a relative of one known in Europe for attacks on oak trees, but its effects were so bad that it was named Phylloxera vastatrix, Latin for “the devastator.” The aphid feeds on every part of the vine, but particularly its roots, weakening the plant and encouraging fungal infections. This cuts off the flow of water and nutrients and the plant dies.
All attempts, to deal with it (including hybridisation) were largely unsuccessful. Then some thought of trying grafting.
American vine species are largely resistant to phylloxera and so, even though wine made from them isn’t very good, rootstocks were imported from America and scions from European grape varieties grafted onto them, saving the day for wine lovers the world over.
One result was that grafting techniques became the subject of several serious manuals, like Charles Baltet’s and moved from being practiced on a small scale to an almost industrial one as can be seen from other illustrations in his book.
It’s worth noting that before phylloxera France had been the world’s largest producer/exporter of wine but by the end of the 1880s it had, almost unimaginably, become the world’s largest importer. About 2/3 of French vineyards were never replanted and it led to the establishment of new wine making regions all over the world.
For a very readable full account of the epidemic read Kelli White’s article “The Devastator: Phylloxera Vastatrix & The Remaking of the World of Wine.”
We saw last week designers and architects have begun to look at ways of using grafting – both natural and man-induced – to develop new kinds of structures, but its equally important to know that by the early 20th century the lessons that phylloxera taught had been learned across almost all of commercial horticulture and gardeners and growers looked to see other possibilities in this millennia-old technique.
I’m planning to look at that in a future post.
In the meantime if you want to know more about the history of grafting I should tell you there’s very little out there and the best place to start is an article by Ken Mudge and others and published by Purdue University.