Growing Walnut trees is a bit of a niche pursuit in the UK these days. They take a long time to grow, their crops aren’t a huge part of our everyday diet and you’ll have to battle the squirrels to see any of that precious harvest.
On the other hand – They’re beautiful trees, produce large, valuable crops and once established will produce for decades to come.
Perhaps there’s something to this growing Walnuts business?
It’s thought that the Walnut tree arrived on British shores some time around the 16th century. Originating from the Western region of Asia, Walnuts have been used sporadically for food & timber production all across the country ever since taking those first steps ashore in the 1500’s.
As we’ve mentioned, commercial production has never quite taken off here in the UK to the same extent as our continental neighbours, with our scarce Walnut orchards based primarily in warmer, drier pockets of the country such as Kent and Somerset.
Fancy diving deeper into the wonderful world of Nut Trees? Check out our Comprehensive Sweet Chestnut Growing Guide here for more.
In recent years however a few fledgling operations have begun to spring up around the country, trialling selections of hardier cultivars within their specific micro-climates in a trailblazing attempt to bring home growing walnuts onto the British farming scene at long last.
We ourselves have recently planted out a four-acre trial orchard containing a mixture of Walnut & Sweet Chestnut varieties. We will be certain to keep the site updated as to which of our contenders cope best with the South Walian weather as the years tick over.
As an everyday grower however, commercial levels of success aren’t an issue you’ll need to worry about. Growing walnut trees after all isn’t all about the pounds & pence.
A Walnut tree will generally do fine in all but the coldest, windiest areas of our country. And what’s more, once established it will provide huge yields of delicious kernels, along with being a stunning ornamental addition to the garden in its own right.
How to Care for your Walnut Tree
Growing Walnut trees is a long-term endeavour. So, to give your new nutty friend the best chance at a long and healthy life – and you the best chance of seeing buckets of healthy, delicious nuts – You’d be well served to do a little research before diving in.
Below we’ve put together a brief overview of the basics which you should bear in mind.
Let’s take a look.
Planting Your Walnut Tree
Growing walnuts is a nutrient demanding endeavour. They’re by nature hungry trees. As such they should be planted on free-draining, fertile soils, in as sunny a position as you can afford them.
While you can technically plant your Walnut tree at any point during its dormant period, ideally this should be carried out during Autumn if possible. Those extra few precious months generally lead to healthier root development, and in turn, a healthier tree.
Heavy soils will not provide optimal conditions for growth, while soil pH of 5.5 – 8.5 is generally tolerated with 6.5 – 7.5 being optimum. It’ll serve your Walnut tree well to test your soil’s pH beforehand using a Soil pH Testing Tool allowing you to amend as needed prior to planting.
Once your soil is prepped, dig a hole twice the depth and width of your root-ball before planting and backfilling with soil. Removing this excess earth provides a more aerated environment immediately surrounding the root ball of your Walnut, allowing for easier early-stage root growth.
With regards to backfilling, we generally like to save our amendments for top-dressing (placing around the trunk of your tree), however there are different schools of thought on this one. Some people like to add their amendments to the backfill, others don’t. In truth, either way is fine.
One thing you absolutely should amend your backfill with however is a powdered addition of Mycorrhizal Fungi. This magical powder is made up of microbial life forms which naturally inhabit all soils, and play a key role in a tree’s ability to collect and process nutrients.
Some would class this as a non-essential. In our experience however, the addition of this one amendment leads to huge increases in the overall wellbeing of the tree over those all important early months & years.
After all, growing Walnuts is a long-term endeavour. For the sake of a couple of quid and 10 seconds mixing-work – why not give your Walnut tree every chance at a long and healthy life that you can?
Pruning Your Walnut Tree
Pruning should be carried out during the Walnut trees dormancy period, ideally between late autumn and early winter. Carrying this work out at any other time of the year can lead to bleeding, stunting growth and potentially introducing disease to your Walnut tree.
This is a key skill to get the hang of when growing walnut trees, so take some time to have a look around at various online guides before jumping in.
All tools should be sterilised before beginning your pruning session, as well as between individual trees. This minimises the risk of inadvertently spreading any unnoticed disease throughout your garden or orchard.
You should also ensure your tools are sharp before getting started. This minimises the risk of ripping or tearing while making your cuts, in turn reducing your Walnut trees chance of contracting diseases through the resulting open wound.
As with any productive tree, proper pruning is as much an art-form as it is a science. You should begin by removing any dead, diseased or crossing branches, pruning for health rather than yield.
Next, prune for your desired shape, aiming to achieve sufficient light penetration across your canopy along with an even spread of fruiting branches, and always keeping in mind the future growth habit you are encouraging. Growing Walnuts is a marathon not a sprint, so it’s important to look ahead when pruning to shape.
With fruiting Walnuts, you should aim to keep a strong central leader, with offshooting ‘Scaffold’ branches there to contain the majority of your fruiting buds. Any branches looking to curve inwards toward your central leader should be removed, as well as any particularly crowded areas of your tree.
For me this is one of the most interesting aspects of growing any kind of fruiting tree, and is only amplified when growing Walnut trees due to their long lifespans. The cuts you make during those first early years will impact the tree’s shape in 10, 20, even 100 years. Maybe I’m just a tree nerd but, I think that’s pretty cool.
Feeding & Watering Your Walnut Tree
Lay a thick layer of organic mulch in early spring to encourage healthy growth across the season. We like to use wood chips sourced from around the farm mixed with some well rotted manure, though just about any organic material will do just fine.
This serves to both provide the necessary nutrients as well as suppressing competition from weeds. A well-balanced fertiliser is also suitable if you prefer.
I’d caution against using Walnut leaves for this due to some pests & diseases which like to overwinter on them.
Once established Walnut trees require little in the way of watering in our climate, except in particularly harsh drought conditions. During the first two-three years of growing your Walnut tree however, ensure that it gets a heavy watering to sustain it through any dry periods. Heavy and often is better if you’re having to manually water.
Harvesting Your Walnuts
That day that we’ve all been waiting for. Harvest day! What a time to be alive.
Yield sizes will of course differ from one cultivar to the next, however as a rough guide you can expect around 3-5kg per five year old tree, increasing to as much as 75kg at full maturity. Most Walnut trees are only self-fertile at best, so a pollinator partner will increase this yield significantly if you can find the space.
Nuts ripen in Autumn, falling from the tree once fully-ripe. If grey squirrels are common in your area then you’ll have to be vigilant, as once they find your tree they’ll be sure to try and strip it bare before they get anywhere near ripening.
Setting up a tarp or net below and shaking your tree can speed up this process some, as well as using a tool such as a Nut Wizard to pick them directly from their branches.
Common Walnut Tree Pests & Diseases
Interested in effective, organic methods to reduce pests and disease throughout your garden? Check out our posts on both Companion Planting & Attracting Ladybirds to kick your pest-control into overdrive.
Walnuts are generally quite pest and disease resistant, with damage usually being superficial rather than truly life-threatening. The main things to watch out for when growing Walnut trees in the UK however would include:
- Codling Moth – Can damage nut kernels. Control with pheromone traps.
- Leaf Gall Mite – Tiny mites which cause superficial damage to leaves. Not a huge problem unless infestation is very high in numbers. Can be controlled using organic gardening principles.
- Walnut Blight – Can be a quite serious disease, damaging crops, leaves and catkins. Control through proper pruning techniques, soil pH control and avoiding daily watering.
- Walnut Leaf Blotch – Causes brown blotches on both leaves and fruits, which in severe cases can adversely affect harvest. Control by clearing away fallen leaves.
Walnut Juglone & Allelopathy
Allelopathy is the process of one organism producing biochemicals which inhibit the growth of other, surrounding organisms.
This applies to the Walnut tree due to its secretion of the chemical ‘Juglone’, a chemical which is poisonous to many types of plant, insect and even mammalian lifeforms.
In practice, this means that you should carefully plan your planting arrangements when choosing to grow Walnuts. Certain plants (Such as Tomatoes) are particularly sensitive, while others (Such as Honey Locust) are considered tolerant.
Thankfully, the Walnut rootstocks used for fruiting varieties generally recommended for use are almost exclusively grown on English Walnut stock. English Walnut (Julans Regia) is considerably less harmful than its Black Walnut (Julans Negra) cousin, so don’t worry about killing your garden off on account of growing Walnuts this year.
Having said this, it’s always good to be prepared. We find that interplanting ‘Buffer’ plants has worked well for us. Plants such as Black Mulberry, Hazel and Autumn Olive are well known tolerators of Juglone, as well as being productive additions in their own right.
A pretty comprehensive list of juglone tolerant plants can be found at this cracking site, which was a great help to us when laying out our initial Walnut growing plans.
So plan ahead – Utilise buffers. Isolate your Walnut from particularly susceptible plants – and you should be a-okay.
Best UK Walnut Tree Cultivars
When growing walnut trees it’s hugely important that you tailor your cultivar selection to your specific region, land-size and needs. Below we’ve listed out some of the best varieties for our often unpredictable climate, all of which have been tested and recommended for use by research centres spread across the UK.
Highly productive new French variety. Late-leafing, late-fruiting variety with very good blight tolerance. Begins producing especially quickly. Fruits are large, store well with a very good flavour profile. Lateral bearing.
A new French variety particularly useful as a pollinator for Fernor. Begins producing large, good quality nuts very quickly. Lateral bearing.
Highly productive traditional French variety, a popular mainstay Walnut among many French orchards. Produces large, great tasting nuts.
Corne Du Perigord
Traditional French Walnut variety. Decently productive with great tasting, medium sized nuts. Shows very good disease resistance in our climate and works very well as a pollinator partner to various maincrop cultivars.
Ronde De Montignac
Traditional French variety which shows very good disease resistance in the UK climate. Produces heavy crops of small, great tasting nuts. Works well as a pollinator.
Highly productive new French variety. Shows good disease resistance in the UK climate. Late leafing and quick to come into production.
Partially self-fertile traditional French variety which is late to leaf out. Medium sized nuts have a very good flavour profile.
Heavy cropping traditional French Walnut variety which shows very good disease resistance in the UK climate.
Canadian variety which is widely used across the UK. Heavy cropping and quick to come into production, Broadview is a tried-and-tested Walnut cultivar for the British climate.
Heavy cropping Czech variety which shows very good disease resistance in the UK climate. Produces exceptionally sweet nuts.
UK Walnut Tree Suppliers
- How to Grow Your Own Nuts: Choosing, Cultivating and Harvesting Nuts in Your Garden
- The Fruit Gardener’s Bible: A Complete Guide to Growing Fruits and Nuts in the Home Garden
- Creating a Forest Garden: Working with Nature to Grow Edible Crops
And there we have it, a comprehensive overview of what you need to know before diving head first into growing Walnut trees of your own.
As always I hope this guide has been useful. If you’d like to be kept in the loop of whatever comes next from us here at the EcoGeeks then please feel free to subscribe below.
Have a great day.