I am not an expert on the nursery industry. My interest was mainly to photograph the flowers of as many varieties as I could find. I saw lots of varieties that I had never even heard of. One thing that surprised me was the large number of old "iron-clads" that they were raising such as Nova Zembla, Roseum Pink, Roseum Elegans, English Roseum and Lee's Dark Purple. These are old fairly fool-proof plants. But they also raise many yellow rhododendrons and exciting newer hybrids.

Germany, and most of Europe in general, raises most of their rhododendrons on grafted plants. Many of their plants, if grown on cuttings on their own roots, as would be done in the US where grafting of rhododendrons is virtually unheard of, would be 1) too difficult to root to be commercially successful, 2) too tall and leggy, and/or 3) too difficult to raise due to low pH demands, susceptibility to root-born diseases, or poor root structures.

One thing that I found interesting in Germany was that there are basically two different methods of raising grafted plants. One method, the more conventional method, has something like Cunningham's White or Inkarho patented rootstocks that are rooted from cuttings and grown for 2 years. Then the scion is grafted on to the root stock using a side graft. The graft is wrapped with a rubber band type material until the graft takes.

The second and newer method takes cuttings of both the scion and the root stock and grafts them together and roots them at the same time. For about 1.5 to 2 inches each cutting is cut from one side to the center of the base. Then the cut areas of each cutting are mated with green tissue touching green tissue. Then the two cut areas of mated cuttings are wrapped with raw cotton string and dipped in a powdered rooting hormone and stuck in a rooting soil-mix. The raw cotton string will eventually rot in the soil.

The main rhododendron growing region of Germany is in northwest Germany which was once a large peat bog. It was a swamp. Success by the Dutch in reclaiming such land caused the Germans to build a ditch and canal network with windmill powered pumps to drain the swamp. Then the peat bogs turned into ideal areas for growing acid-soil loving plants such as rhododendrons and azaleas. During this process the peat bogs died. The sphagnum moss could no longer grow without the swamp. In some areas peat was harvested. In other areas plants were grown in the peat.

There are more rhododendrons produced here than in the rest of the world combined and the scale is staggering. These family-owned firms are usually 2-3 generations old and are able to pass down the family tradition. They use gantry irrigation, water recycling, computer controlled potting and grading and greenhouses whose rooves lift as the temperatures rise. Most of the garden work is done by Polish laborers and some work such as grafting is sent to be done in Poland.

Today things are done much differently. First, most plants are grown in containers with little or no peat moss. They tend to use more bark dust and less peat. It gives them a much better yield. They are not raising the plants in the peat bog, but in containers placed on water proof fabric on top of the peat bog. The growing areas are sloped in such a manner that they can collect all irrigation and rain water that is not used and drain it into ponds that are used for irrigation. In a normal season they can get by almost entirely on rain water.

The buying habits of both Germans and Americans are shaping the nursery industry. People tend to buy from large box garden centers and home stores rather than the local nurseryman. There are now two very successful types of nurseries, 1) the mega nurseries that supply most of the garden centers and home stores and 2) the specialized nurseries that supply landscape architects with large expensive plants. Some of the nurseries in Germany did both.

I will try to put together a plant list in a future posting.

The blog in the link below is written by author, plantsman and plant explorer Ken Cox of Glendoick, Scotland, and does an excellent job of describing our trip. He neglected to mention that we had a couple that run a large nursery in Brazil and are introducing rhododendrons to Brazil.

Here is a link that might be useful: International Rhododendron Conference in Germany

Thank you for the information as well as the link - I really enjoy Kenneth Cox's blunt honesty as a contrast to the more usual bland diplomacy in garden writing. I look forward to a plant list in the future.

The second, "double" grafting method is interesting, but I'm not at all sure how it works or what the advantages might be. Your description seems to indicate that both the scion and rootstock are producing roots. If the main purpose of grafting is a more adaptable, heat and phytophthora resistant plant, why would you also want or need roots from the scion?

Thanks again and please continue with more information when you can.

You have a good point. They probably are sacrificing some of the advantages of grafting. But if the phytophthora only infected the scions root's, the root stock's roots would still be functional. In any case at least one very major grower finds it speed up his production by 2 years. Another way of looking at it, he doesn't have to have nursery space for rooting Cunningham's White and Inkarho cuttings for 2 years which is what some of his competition is doing and he used to do.

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Here is a photo of a cutting graft, the new simultaneous graft and rooting, after it rooted and grafted together and the Cunningham White cutting was trimmed back leaving the "scion" at Schröder's.

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Here is a photo of a conventional splice graft of a scion onto a rooted rootstock at Hachmann's.

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Here is a photo of conventional side grafts of a scion onto a rooted rootstock at Hachmann's.

Here are the recent introductions we saw at Hachmann's. The photos are from Hachmann's website:

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Candy Striped Pink






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Christian Gehler


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Denise






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Duftwolke


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Fresiane






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Gunter Dinger


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Hans Hachmann (Night & Day)






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Karl Naue


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Konfettiregen






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Maroon Sappho


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Matador






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Metallica


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Midnight Beauty






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Minas Snow


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Papaya Punch






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Orakel


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RhododendronPark Graal-Müritz






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Raphaela


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Rudolph Heinemann






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Sariska


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Saskia






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Silver Jubilee


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Tanaga






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Veronika


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Yak "Blue Leaves"






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Yak "Cup Cake"


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Yak "Mariola"

Here are the recent introductions we saw at Schröder's. The photos are from their catalog.



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Erika Guyens

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Guyens's Fasching






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Guyens's Peking

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Picotee





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Yak 'Dear Barbara'

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Yak 'Herbstzauber'

Thank you for posting the photos - some of the Hachmann hybrids are just spectacular. (Interesting also to see Minas Snow from Nova Scotia and Papya Punch from the PNW included.)

Your explanation for the double grafting technique makes a lot of sense. The scale of annual production in Germany is really mind boggling, so any savings in time and space would be worthwhile. (As long as you have a source of skilled and probably not terribly expensive labor from Poland).And as long as the existence of phytophthora susceptible roots intermingling with resistant ones doesn't lower the overall disease resistance.

In his book, Kenneth Cox argues that grafting could make many more varieties suitable for the eastern US by eliminating the phytophora problem and related lack of heat resistance. 'Capistrano' is a case in point. I know it is very difficult to grow in much of the East. Here in Maine - at least so far (has only been widely available for about 5 years) - it's proving to be an excellent variety. Cooler temperatures, especially at night, is the most likely explanation. Capistrano and any number of other heat sensitive varieties grafted on Cunningham's White or Caroline ought to be growable in many more areas.

Rhodyman, thank you very much for sharing such usefull info. Wish you all the best.