A lot of people don’t realise you can grow most British native trees from seed. It is so easy, you or I could grow a whole forest. Being the Tree Warden in my village of Weybread, that is just what I have been starting to do. Anyone can take part in germinating new trees, even if you have a north facing balcony! On this tree seed gather expedition, Nigel Utton, founder of the 10,000 Trees Norwich campaign accompanied me on a walk along the Angles Way on the northern boundary of my village. We set out to gather the first seeds for both his project, to make Norwich an urban forest and for our Weybread village planting schemes. This blog takes you through the whole process from tree seed gathering to growing on and rehoming your new trees.
Having grown trees for a few years, I don’t think I can convey my happiness, when in the spring, little miniature trees start emerging from the flower pots with their tiny leaves and the joy I have in rehoming my tree seedlings. I’d love to share that pleasure with you and inspire you all to grow trees for your garden and your community!
The Basics of Growing Trees from Seed
- Identify healthy native or naturalized trees to collect from
- Collect and prepare the seeds
- Grow and care for the seedling in pots, in an outdoor shaded sheltered place
- Transfer the trees to larger pots or a bed when they need more room
- Protect the trees from foraging animals and weeds and don’t let them dry out
- Give the tree a new and suitable home – the right tree in the right place.
The Right Tree in The Right Place
Do think hard about find the best location so that the tree has a chance to grow to maturity and old age and that it never becomes a nuisance. Do obtain permission if necessary. Don’t plant next to houses, drains etc. Some species such as beech, hornbeam, blackthorn (sloe) yew and hawthorn can be trained as hedging trees and some do best when allowed to grow up as full trees.
If you can’t find suitable locations, get in touch with your local Tree Warden or Parish Council and ask how they can help find homes for your little trees. Tree wardens are often very keen to get new volunteers so you might be able to help each other out.
When to Start Collecting Tree Seeds
The collection of seeds can begin as early as August with hazelnuts. However other types of seed such as cones, winged seeds and fleshy fruits achieve the right state of maturity mainly between September and December. Where possible, collect the mature seeds straight from the tree.
With just a quick glance around you will find chestnuts, crab apples, acorns, alders, ash and berries such as spindle, rowan and yew etc. Only pick healthy looking mature fruit and be sure to leave plenty for the birds.
Stratification, the Key to Tree Seed Germination
Unlike the seeds of annual plants, tree seeds are more resistant to germination and need to be exposed to cold weather and moisture before they will begin to sprout. It just means leaving them outside in their potting medium over the winter and looking out for seeds which are germinating. Some seeds can take 2 years to come through, most will appear in the spring and summer.
How to Grow Trees from Seed
Go seed collecting. Take a book with you if you are unsure of all of the species you might encounter. A crook can come in useful for lowering branches to picking height. Take paper bags to keep different seed species separate as you collect them. I should have taken a footpath map aswell…
How to Prepare Tree Seeds for Planting
Try to plant your seeds the same day they are collected, particularly acorns, chestnuts and nuts so that they don’t dry out.
Remove the outer part of the fruit:
Take the spiky fruit caspule off chestnuts and walnuts
Cut the fruit away from crab apples, damsons, and fleshy fruits to expose the pips or stones
Rub berries to expose the seed
Separate winged seeds
Organising your Potting Medium
Tree seedlings establish best in well draining, fairy poor soil – don’t spoil them with expensive compost! For potting soil, I use garden loam mixed with sand/grit/silt which I gathered from a lane nearby where the sediments get washed downhill. I will get lots of weeds coming through, but the soil, just like the seeds, is local. With making my own potting mix, reusing old plant pots and getting the seeds for free, there was no financial outlay and yet after a few hours foraging for tree seeds, we have potentially hundreds of new trees.
Potting the Tree Seeds
Put all the seed or pips you have gathered in its own pot by species mixed in with your soil. For example get all the hazels in one pot, the maple seeds in another, acorns in another. It can help to label the pot. I wrote on old wooden clothes pegs and pegged them to the pot.
By reducing the bulky fruit down to just the seeds, mixing them with soil and growing them in pots, we have a very efficient way in terms of space and time for creating new trees. With just a few pots, you can grow hundreds of tree seedlings.
Finding the Best Location to Stratify or Germinate the Seeds
The potted seeds do need to be exposed to the weather over the winter so that the natural elements can break down the hard outer seed coating, allow water into the ‘germ’ of the seed and allow the seed to sprout. (Stratification) It doesn’t matter whether the pots are in the shade or light.
However, once the seeds begin germinating, it is much kinder to keep them in a more sheltered location so they can be damaged by frost and in a shaded place. When germination occurs in the wild, it will often be under the mother tree. The wild saplings are under constant shade of the adult tree during the summer and they grow slowly and steadily, waiting for their big break when a bough might drop off the mother tree letting in more light or until trees nearby die. Then the sapling speeds up its growth rate to raise its leaves into the canopy, obtaining as much light as it can.
What I am saying, a tiny north facing balcony is ideal for germinating and growing one or two year old trees and a terraced house back garden could over the years create enough young trees to form a forest. You really only need access to a few meters of outdoor space to grow native trees. Just be sure to pass them on before they outgrow the pots and get root bound.
Imagine as well if you nurtured a spindle tree to adulthood in your tiny front garden? Spindle trees grow to about 3 meters, have quite a light leaf cover and they can thrive in semi shade. In the autumn they are covered in carmine red berries exposing orange seeds. I’m trying to imagine what a street lined with terraces houses would look like in the autumn! Very cheerful indeed!
In fact terraced house lined streets would look great with any berry bearing trees which are generally small or medium sized trees. There is a list of berry trees and bushes which will grow in the UK on the British Trust for Ornithology website, and most of these species can be kept to managable sizes.
Check Regularly for Germination
Just leave the pots outdoors over winter in a shady, sheltered place and in the spring little trees will appear. First you get a pair of leaves, then you will get tiny leaves which are miniature forms of the adult leaves. At this point you can confirm which species are coming through. Some species take longer to germinate than others, some, two years, so keep caring for them even if nothing appears at first.
From April, you can tip the soil out of a pot, search for germinating seeds and plant these in new pots to give them a good start. Put the remaining soil and ungerminated seeds back in the pot and check it again in a month or two.
Once you do get seedlings coming through, give them their individual pots and grown them on. Never let the seeds or tiny trees dry out, so you will need to check them through the winter and more regularly through next spring and summer!
Repot as Required
The miniature trees might again need potting on into larger pots so that the roots can grow into a healthy shape.
When the seedlings begin to fill their pots, if possible place them in a nursery bed, or find new homes for them if you don’t have the space.
I highly recommend reading the https://www.treecouncil.org.uk/Take-Part/Seed-Gathering-Season Tree Council Website which gives more detail.
Whether you would like to just have a little tree nursery on your balcony for your seedlings, or if you would like to grow them on a bit, find permanent homes or plant them out on your own land, trees give not just many forms of pleasure and they can really help, over our lifetimes, to mitigate climate change and to leave a legacy of resources for wildlife and people.
We need to plant billions of trees to help avert the climate emergency, reduce city airborne pollutants and give refuge to wildlife. By collecting and nurturing tree seeds, we can all be part of this global revolution.
How was our walk? Long! For some unknown reason, after taking Nigel down the steep valley’s side towards the River Waveney I turned left instead of right and we wandered along for sometime following the footpath as well as we could guess it. We ended up somehow on the wrong side of the river in Brockdish, no where near the trees I had intended to visit.
On route, however we did find these lovely orange/red berries, but I don’t know which species they are. The leaves look like the wild service tree, but the berries are bright orange and very soft. If you can help with the identification, I would appreciate it because the seeds are in now in a pot and I expect them to grow. I won’t be able to give them away if I don’t know what they are.
Having been set right again by a local, we returned over the bridge, retracted our steps and headed off towards Lucksmill Bridge between Weybread and Needham, where I had previously identified tree seed donors of merit.
Along here we found the gorgeous spindle trees, a tree covered with little sloes with one giant sloe berry, alder cones, a gorgeous hornbeam tree with a trunk which looked like a fantasy tree – with some keys hanging in reach.
As the evening set in Nigel left with bags of freshly collected seeds, some spare pots, a sack of lane sediment, a sack of garden soil and a few boxes or one and two year trees – maple, walnut, chestnut, hazel and hawthorn.
It is great to play a part in the 10,000 Trees Norwich project and I can’t wait to hear report about these young trees and to see what comes through in the spring. In the meantime I hope that you will take up any opportunities to grow native trees from seed and that the 10,000 Tree Norwich project will meet its goals soon and gone on to plant thousand more.
There are plenty of opportunities to link the surrounding countryside into Norwich and to build wildlife corridors right into the centre of Norwich and having lived in Norwich and now living in the countryside, I think that every one should have the privilege of listening to sparrow chatter in the winter, of breathing pure air and being able to admire our wild heritage.
If you’d like to do something to get Nigels’s Norwich project started without getting lost and walking in the wrong direction, you can simply donate something here.