Anja Murray: Plant more saplings — it's fun now and beneficial later
Rowan tree berries are eaten by thrushes, starlings, field fares, and waxwings
Since spring, trees have been harvesting energy from the sun, fusing molecules of carbon dioxide and water in their leaves to concoct energy to grow, bulk up, and produce the flowers and seeds through which they reproduce. Now, in autumn, the culmination of all the year's arboreal activity is on show in woodlands and hedges everywhere, as trees are laden with wild fruits and nuts.Tree fruits are often bright red to make them stand out against the fading leaves, to be seen by the furry and feathered animals who are necessary agents of transportation.
- Rowan berries dangle from branches in bright red clusters amid yellowing leaves.
- Hawthorn trees, now with barely a leaf left in place, are laden with rich, translucent dark red haws, varying from round to oblong, abundant as the white hawthorn flowers were last May.
- Spindle, a native though not well-known small tree, has leaves that turn especially vivid crimson and the most unusual of autumn fruits: star-shaped dark pink berries containing big bright orange seeds within.
- Native evergreen trees, yew and holly, are also bedecked with bright red berries right now.
The outer, tasty red flesh acts as the invitation for birds and mammals to eat them, rich in vitamins that help sustain wide-eyed woodmice, agile pine martens, and squirrels through the colder months. Birds that eat tree fruits include thrushes, blackbirds, starlings, fieldfares, and waxwings. The compact seeds within are generally sturdy enough to remain viable when popped out and deposited at a distance from the parent tree.
Nuts, too, have evolved as protein-rich pellets for good reason: to make them nutritious and thus appealing for animals such as ourselves to eat. This is the strategy of oak, hazel, and other nut-bearing trees to transport their seeds beyond what is possible without help from animal allies. Squirrels and jays are excellent vectors of acorns and hazelnuts, collecting a cache to feed from during winter and inevitably forgetting a few. The trees rely on a proportion of gathered and stored seeds being forgotten or otherwise left in a suitable nook where they might germinate next spring.
There is still time now to collect tree seeds for planting — an excellent way to connect with the bounty of autumn and create a store of saplings for planting up in a year or three. Self-collected and sown native tree saplings make wonderful gifts. A two-year rowan tree sapling, for example, accompanied by the story of where the seeds came from, is a wonderful legacy to give and to receive. A potted sapling, gathered, sown, and nurtured by your own hand, could mark a special birthday, a new baby, an anniversary, a new home, or be sown or gifted without any special excuse at all.
The first thing to consider, if collecting native tree seeds for planting, is the source. If possible, in order to maximise benefit to wildlife, ensure that the tree you are harvesting from is a wild and native tree, rather than a horticultural cultivar or imported nursery stock. Local provenance native trees are best for our native wildlife, as they have evolved alongside each other.
When we act as vectors to save seeds for planting, it can be necessary to find a way to imitate the process of consumption by wild animals so that the tree seeds will sprout come spring, or make sure they are exposed to winter frosts to trigger germination.
Be careful not to damage the trees you are collecting from. For acorns, hazelnuts, or crab apples, you can pick them directly off the ground. Keep them in a cool, dry place — a fridge or unheated shed will do — until you are ready to extract the seeds. For fleshy seeds, the soft outer coating will need to be removed, to mimic what happens when a fruity tree seed is eaten. For rowan berries, spindle, guelder rose and haws for example, processing the seeds involves soaking and mashing to extract clean seed, or if you are only dealing in small quantities, you can remove the flesh and extract the seed by hand.
For hazelnuts, test them in a bucket of water — those that float are empty husks that won’t ever sprout. Full and viable nuts, on the other hand, will sink. To germinate acorns and hazelnuts, ‘chitting’ them first in some leaf compost is a good way to start, then planting them in pots with a mix of leaf compost and mineral soil. Some seeds need two winters' dormancy before they will germinate, so find out which seeds need what special conditions to sprout.
When it comes to planting out the tree in a year or two, take care to consider how that species will develop in future. How tall will it grow? Will the canopy cast light or heavy shade? Where the trees are less likely to cause issues for human neighbours, they are more likely to be allowed to mature.
Gathering tree seeds and nurturing saplings is a special legacy to offer, the possibility that the saplings we nurture now, if protected, and given the right conditions to thrive, will spend decades transforming sunlight into sustenance, flowering, and fruiting each year. Think how, 30 or even 100 years from now, when the world we know will have changed beyond recognition, the rowan, hazel, hawthorn, or oak will shelter and sustain butterflies, bees, moths, mammals, and birds, harvest carbon dioxide and spill out copious quantities of oxygen, and cast a dappled shade for future generations of humans to enjoy.
This autumn, in homage to our dependence on trees, gathering up and nurturing some tree seeds is one of the loveliest things we can do.
