I know that I’ve mentioned before that the National Trust at Wimpole Estate looks after a National Collection of Juglans. One of the reasons that Plant Heritage encourages the creation of national collections is to future-proof the incredible stock of cultivated plants that exists in the UK. So collection holders undertake to conserve, grow, propagate, document their charges. It is a labour of obsession and love.
I would be interested to know how often other collections get called upon to provide material for propagation, but I know that it is fairly rare request for the walnut trees at Wimpole. However, a few weeks back we were hosts to some visitors who wished to take cuttings of some of the Juglans regia cultivars for grafting and I have to say that it was a great feeling to have the trees serve this purpose.
In fact our visitors, John Bilton and Nick Dunn, are on a tree hunt following a call from the Royal Horticultural Society for information on heritage walnut varieties in southern England. They hope to be able to track down and reproduce varieties trialled in collaboration with the East Malling Research Station between 1929 and 1935. John Bilton explains what they have previously been up to in this Veteran Tree Association newsletter (from page 6).
Back at Wimpole, armed with pruning tools and collection bags, we worked our way around the Pleasure Grounds visiting a list of ~ 10 specimens of interest.
After a busy morning, Nick and John had collected a decent amount of material from each target tree. The plan is that these scions will be grafted on to prepared Juglans nigra stock. Apparently the chance of a successful graft is higher with this combination. The grafting process will use the hot-pipe technique, which again increases graft success rate.
Hopefully, the end results will be healthy clean grafts, like this example below.
We should know more later in the year …