Guest blog: Conserving Camellias

My immense thanks to plantsman Jim Stephens for writing this piece; be sure to check out Jim's website to see a huge and diverse range of Camellia flowers (link at the bottom of the page).

Last year I 'retired' from my job at one of Cornwall's more highly regarded nurseries. Over a considerable number of years we had built up a range of Camellias that was at least the equal of any of the rather small number of nurseries that carry this plant group as a specialism. It is highly unlikely that the Camellia range will survive my departure.

Camellia 'Dewatairin'

One of the things I have done since is to sign up to Plant Heritage, fueled by the conviction that its mission of "Conservation through Cultivation" is a worthy one. I would go further. The number of threats to our garden plants has increased steadily over the 40 odd years that I have followed horticulture as a career. There has been a steady trickle of pests and diseases added to the existing roll call; some very serious, some quite trivial. But the important point is that they are additions, not replacements. None of the old threats have gone away. There is no horticultural equivalent of smallpox, eradicated from the world.

While the predatory list has lengthened, the list of weapons to tackle it has shrunk almost to vanishing point. Whatever one’s view on chemicals may be, it seems likely that within a decade or so there will be no chemical armoury available to gardeners.

In parallel with this, the climate is going to hell in a handcart. The incidence of weather that is stressful to plants seems to me to be increasing alarmingly, be it high temperatures, storms, high rainfall or whatever. Stressed plants are plants that are more susceptible to pests and diseases.

Going back to Camellias, I was reading an article on the International Camellia Society’s website about Camellia flower blight and the prospects of tackling it either with fungicides or with biological agents. The conclusion was that in a garden situation, those prospects are bleak. The best hope for disease free camellias lies with resistant species and varieties.

Camellia 'Goshozakura', a gorgeous old cultivar!

I am not a scientist, but I think I see an important distinction between the majority of garden plants and both the wild flora of a country and the vast majority of its food crops. That difference is that most garden plants are clones whereas very few food crops and almost no wild plants are. So the potential for a new pest or disease, or perhaps a climatically rejuvenated old one, playing havoc, is greater with garden plants than with the others. Thus Chalara in Ash may wipe out 90% plus of Ash trees, but there is likely to be a surviving rump with genetic resistance to the disease. On the other hand, if my Camellia ‘Debbie’ were to be crippled by a newly introduced pest, all plants of it are likely to be equally susceptible. It then becomes very important that we grow in gardens the widest possible range of Camellias, raised from as diverse a background of species and varieties as can be found, to ensure that a good proportion survive.

A cultivated plant doesn’t have to be killed by a pathogen for us to stop growing it. Black spot susceptible Roses and Scab prone apples will get a nursery a bad name and will soon disappear from the catalogues. Some gardeners will persevere with them, but  if a variety is not being propagated and disseminated, its days are surely numbered.

So back to Camellias again. What is the situation? There are many tens of thousands of varieties in existence in the world, some grown very widely, some much more locally. As far as the UK is concerned, there are a few National Collections and a handful of specialist nurseries.  Unless National Collections are held by nurseries their role in making varieties widely available is limited. When you search on “Camellia” in the Plant Finder section of the RHS website you get 1641 results. It  would not surprise me if there were as many again that are grown but do not appear in the list.

Camellia 'Charlotte Petherick' has disappeared!

It takes years for a nursery to build up stock of a wide range of Camellias. It may take five or more years from getting a cutting of a new variety to being able to propagate from the resultant plant. It will then take two to four years to get that first batch of plants out for sale. By contrast it takes only a few seconds to decide that you won’t carry on with a specialism, probably for commercial reasons.

It all seems so tenuous. The National Collection holders struggle to maintain their collections, let alone to add to them. The nurseries struggle to justify maintaining a wide range when the 80:20 rule* is screaming, via the accountants, to drop all but the most popular. Do that and the one time specialist nursery finds itself competing with every garden centre chain up and down the country.

In private gardens, how many plants more than five years old can be identified with any degree of certainty? When a house and garden changes hands, what chance is there of the new owner being told the names of the plants, even supposing they are interested. In many cases they will rip them out and start afresh. Unlike herbaceous plants, or Fuchsias, for example, you can’t easily take a cutting of a camellia from your friend or neighbour and grow it on.

A mystery Camellia sent for identification- good luck!

I suspect the situation is similar with other groups of plants. We don’t seem to have a firm grip on the potential for losing a large proportion of our garden plants. Plant Heritage and the National Collections were an important step but I think much more is needed. In particular there is a need to get more people involved.

Jim Stephens is a Camellia expert based in Cornwall, UK. In addition to Camellias he has a great deal of knowledge of, and experience with, a wide range of other plants. You can visit Jim's excellent  website at www.jimscamellias.co.uk, and you can follow him on Twitter, @JamesLStephens.

*The '80:20 rule' is the theory that 80% of a retail business' income comes from 20% of its range. I'm not convinced that it's necessarily a hard and fast rule for horticultural businesses, but there are enough accountants that disagree!