My previous 'Tree seeds and saplings' blog last autumn saw me clearing oak leaves and acorns that had fallen onto the pond (fortunately it was temporarily netted, with space for wildlife underneath). It was a mast year, so the number of acorns was impressive, and a few took root around the pond. One was already a couple of feet tall, with a deep taproot, but eventually it lifted and was heeled in to the vegetable patch as a stopgap. The others were potted up, and as winter came, their few leaves browned and fell. Fortunately, I had remembered to label four of the pots first and had been taught to identify common tree species by their buds at school, so the anonymous-looking green twigs were still identifiable amongst other leafless overwintering plants in pots.

The mighty oak – its strong, durable wood used historically in houses and great ships – is not usually considered suitable for a normal-sized garden. However, we have oak trees growing along the Cornish hedge at the bottom of the garden (unlaid and growing quite large) and one or two in hedges (to be kept trimmed).

Uphill, and homes for seedlings

Having said that oaks are large and mighty, the ones on Kit Hill across the valley from our house are actually small, sculpted by strong winds that sweep the hillside. At nature reserves such as Cabilla and Redrice Woods, oaks were part of a coppice cycle, regrowing with several stems after being cut to a stump or ‘stool’. So oaks are clearly adaptable.

Some self-sown seedlings from our garden have been given to a community woodland planting project in a nearby village, and I was thinking of doing the same with this year’s oak seedlings when I noticed something going on even closer to home.

A few days ago I was heading for Kit Hill’s summit, starting by walking up a lane that passes through the industrial area around the former Callington station, now full of working (lockdown-allowing) garages and businesses. I noticed a couple of men digging there in all weathers. From the lane down below the bank where they worked, I asked what they were doing. It turned out that they were planting a hedge, with a temporary fence behind it. They were generally improving the landscape around a working garage using native trees and shrubs. 

This immediately seemed like an ideal place for my oak seedlings and sapling, so I gathered them up and delivered them the next day. Even though rain was falling and the light was fading early under dark clouds, the men were still there, working on their nature enhancement project, and they happily accepted my little oaks.

The hedge bank leads up the lane to a small beechwood, then on up past grazing land, including some traditional rough pasture, to the partially wooded, mostly heathy higher slopes of Kit Hill (currently being grazed by ponies). The new hedge by the garage and industrial area would extend the wildlife corridor a little further to the bottom of the hill where the station and industry had taken over. Across the lane, gardens with mature trees adjoin industrial land and fields of the lower slopes. These gardens are visited by woodpeckers, long-tailed tits and other bird and mammal delights. If we can all introduce nature into our residential and working areas, there is hope that we can help halt the catastrophic declines created by setting ourselves apart from the rest of the natural world.

Downhill, and an unsolved mystery

On a walk down to the very bottom of the valley, the trees were clearly less wind-molested and could grow larger. The mast season was very obvious last year. Oak trees fringing the stream had dropped a mat of acorns so thick that I struggled to wade through. Two little muddy islands were carpeted, and walking across involved crunching acorns and acorn cups.

As heavy rain caused new rivulets to appear and feed the stream over winter, the water filling the valley bottom spread, helped by some human ‘beavers’ building dams. I began to notice strange jelly-like domes underwater in the quieter shallows, but had no idea what organism was forming them. Some of them reminded me a little of a miniature Eden Project with jelly biomes. Could this be underwater slime mould or some sort of egg capsule? In the interests of science, I waded in and burst one, to find that it was hollow and apparently empty inside. Had I torn apart and injured an amazing colonial freshwater bryozoan?

Eventually someone suggested that acorns might be going mouldy underwater. Was this possible? Mould usually requires enough oxygen to form. Was it a sort of tannin jelly formed from oak sap?  

In strong currents after heavy rain, the jelly bubbles or domes seemed to go. But now they have reappeared and they do seem to have formed on acorns. So I am conducting an experiment with two acorns in a small jar of rainwater to see whether they form jelly or even jelly domes. Watch this space…

Donate a sapling

If you have oak or other tree seedlings sprouting in your garden, please donate them to a woodland creation scheme near you. However, please check that planting is done in places where other existing wildlife-rich habitats won’t be damaged. Near existing woodland, regeneration may do best if it’s allowed to happen naturally, so pick your location with care! Visit the trust's 'Tree Planting' page or watch the video below to find out more about planting the right tree in the right place.

We have so much to learn about the natural world. Best of all, it regenerates itself, and if we can allow ecosystems to function properly, there will be time and wild spaces for us – and our children – to keep on learning about them.

To find out more about Cornwall's two native oak trees, visit the 'English Oak' and 'Sessile Oak' pages on the trust's website. You can also click on the button below to learn more about growing and planting native trees in Cornwall.

Download the 'Grow More Trees: Autumn Seed Search' guide

Blog by Rowena Millar