One of the biggest blocks to people planting walnuts is the lack of reliable descriptions of cultivars commonly available in the UK. Almost all descriptions of individual cultivars are copies of copies often, of a translation from another language.
I’ve put together a summery of some of these common cultivars with the common descriptions (amalgamated from various sources) and then a brief summary from our experiences. Note that we are in a very cold part of the UK that is fairly dry and is prone to spring frosts, we rarely escape April frosts and mid May frosts are not unknown.
This is not an exhaustive list, we have another 40 cultivars not on it and there are hundreds more worldwide, these are the ones often seen for sale in the UK. Our trees are very young but we see orchards all over the UK so have some experience from other micro-climates.
I get asked a great deal about growing Carya cultivars for nuts in the UK, Pecans mostly but also Hickories and Hicans.
We’re growing them here and others are doing the same but I understand that everyone wants to know if they will fruit regularily here. The answer I give is yes they should (ours are a few years away) and I know of a few people already getting nuts but there is no guarantee that they will grow and fruit everywhere in the UK, we have some extremes of climate.
We grow and supply trees grafted by Ton Friesen in Nunspeet, Netherlands and they fruit successfully for him when they get to 8-10 years on average, these are all grafted named cultivars, below are some picture of the nuts on his trees this October. His climate is very similar to the South Midlands in terms of temperature, although he’s often a little wetter than us surprisingly.
I would say good deep soil with decent drainage (all walnuts hate wet feet), protection in the first few years. All Carya will also spend a few years putting down deep taproots before really growing upwards but once happy will grow a meter a more a year.
The Pecans are all Northern or Ultra Northern cultivars and all the Carya he grafts are on Northern pecan rootstocks grown specially for him.
A great day out at the The Agroforestry Show last Thursday. It took place at Helen Browing’s Eastbrook Farm in Wiltshire and despite being seriously hot was very well attended. Lots to see in the different plots and speakers to listen to and thank you to everyone I chatted to before and after our “Future Nut Production in the UK” event, a similar forum to the one we did at the ORFC in January but obviously with a more Agroforestry flavour. A lot to think about and plenty of new calls and emails to answer in the next few days and weeks I think! (the pic is of one of our fields, I forgot to any pics on site!)
We got hit hard in December with the coldest temperatures for a long time, -15C on the coldest night but quite a few days below -10, new pot grown small trees we’d planted into the orchard were hit badly and we lost about 8 rare cultivars.
Thankfully there were back-up plants for most of them and we can replant in the autumn. February was the driest we’ve ever seen, almost no rain, following by the wettest March on record, a wet start to April and then no rain for weeks.
Thankfully we got the irrigation running by May (late) and June has seen some decent rain the last 10 days, we will have lost some of the newly planted orchard as it was probably too wet but time had run out and we took a chance, replacements this winter I suspect.
On a positive note an early look at nut set seems positive but we won’t be sure until mid July. This winter was 2C colder than average and whilst spring frosts were few and far between and marginal we have noticed that male catkins finished early (wk2 June) and some cultivars like Broadview had virtually none. We have a lot of cultivars with late male pollen but clearly we’d like something later and have sought out some cultivars new to us that have very late pollen, time will tell with us I suspect. Hopefully we’ll get them next year, it’s a long term solution as they won’t produce much pollen for another 6-7 years.
The most exciting part is that many of the cultivars that have never fruited have a few this year, a chance to check they are what they claim (never certain!). It also focuses the mind on squirrel control along with some sort of extra protection for the few nuts on these new trees as well.
Finally we’ve also decided to put many of the newly grafted trees from the Netherlands into the ground instead of pots. Last summer was extreme here, virtually no rain from May to October, very hot (peaked over 40C) with an average temperature of almost 25C in July/August. Black pots act like mini ovens and even in the shade and irrigated they suffered so into the ground they have gone, and mulched with irrigation this year.
We still have some larger trees in pots (mostly Red walnuts) but the rest of the Juglans will be supplied BR when dormant.
All the Carya who really hate root disturbance are in Air-pots with drip irrigation, these pots can withstand the heat much better and all the new root is created away from the outside where it’s hottest. These trees should be available from September we hope.
I’m still not sure how we ended up selling trees, it’s great we can provide what are very hard to find cultivated nuts but it can be time consuming.
When I started looking for walnut cultivars to plant on the farm to trial the sole aim was to find cultivars that would work in our conditions as there was no bank of knowledge in the UK on commercial walnut growing other than the experiences of individual growers. These people had planted what was recommended at the time and I think mostly based on what was actually available in the quantities they wanted.
We were looking for certain cultivars and our ideas of what we should plant was based on their knowledge kindly shared and what we could glean off the internet from articles produced around the world. In reality we couldn’t actually source what we wanted and so we, like many others, took what we could get initially and started looking for others to trial.
That searching led me to a few very helpful growers in the Netherlands and Bulgaria who sent us a good selection of what I thought might work, this was before Brexit so it was a bit easier than today. With the serious plant diseases in the world moving into Europe now having tighter controls has to be much better, I expect the controls intra europe to tighten a lot over the coming years.
As we already had a customer base for the dried walnuts and oil we were selling and as we made more contacts with other growers and people in the horticultural industry we started getting asked if we could supply a few trees to others who were struggling to source them. Initially this just piggybacked onto our existing orders every autumn but when Ton Friesen of De Smallekamp asked if we’d take on UK customers and enquiries we agreed, Ton doesn’t do mail order and shipping 1-2 trees internationally certainly isn’t cost effective nowadays.
At this point we’d already started planting Carya cultivars, Pecans, Hicans and Hickories along with Red Kernelled cultivars and all the other cultivated walnut species like Butternuts, Black Walnuts, Heartnuts etc. We realised that we could meet a demand for these cultivars that no-one else was meeting and hopefully make a bit of profit to help with the machinery and planting costs of our own walnut business.
It was around this time that we started sourcing larger bare-root trees to finish our orchard, these were generally 1.2-1.5m tall and were cultivars we are pretty confident will work well in the UK, most having all proven themselves either here or similar climates in northern Europe. These are generally much cheaper to produce as they’re summer bud grafted rather than winter grafted (and heat callused) and the source material is available in far greater quantities, scion wood for Carya and other species is usually very limited and therefore expensive.
We still view our tree supply as just a part of our walnut business and a service that complements the harvesting, drying and processing business. One of the great benefits is the large array of different people interested in nuts that we meet, a benefit that goes both ways with information flows.
We’ve also learned just how hard it is to graft walnuts successfully which is why we’d never be able to supply everything 100% UK grown and I doubt the UK ever will. We simply don’t have the climate (yet?) to grow the large vigorous rootstocks required and scion wood needed for 1000’s of trees and we’ll always have to winter graft which means warm-callusing. The real experts in this average about 90-95% success I think and some have been doing it all their lives, summer bud grafting gives far more consistent results if you have the climate and the trees are much larger and more vigorous.
We are grafting a small number of our selected seedlings for genetic diversity and heritage reasons and small numbers of some of our cultivars as scion wood is available but success rates aren’t fantastic. Below is a Butternut (Chamberlin) that I grafted this January, the mother tree is still small (2m) but there were a couple of small spurs on the main trunk that needed to be removed, you’ll see this had already started shooting in the heat bench so is now in my greenhouse! Why this woke up when all the others are still fully dormant I’ve no idea, welcome to the weird world of walnut cultivation!