Updated: May 4, 2021
You might be wondering, why the jump from “acorns” to “brambles”? Well, let’s first look at how the mighty oak gets off the ground, literally.
There are many schools of thought about how to germinate an acorn. Some say you need to collect the acorns before they drop. This can be a problem if the lowest branch of the tree is metres off the ground! However, the Tree Council’s guide states that you can pick the acorns as soon as possible after they have fallen. I will refer to their guide throughout my weekly blogs and show some of their pictures (I thank the Tree Council for their kind permission to do so). Their “Good Seed Guide” explains identifying, collecting and planting tree seeds in an easy-to-follow approach.
So back to the humble acorn. It is worth mentioning that if your oak tree has long stalks attached to the acorn, then it is from an English oak. If the acorns are unstalked, then the tree is likely to be another British native called the Sessile oak.
Acorns illustrated in the Good Seed Guide, by the Tree Council
Once collected, you can test the acorns to see if they have the potential to germinate by placing them in a bucket of water. If they float, they probably are no good. The trick is to keep the acorns moist. The best time to plant out is after the heavy rains have subsided (which is debatable nowadays), so if you harvested the acorns in Autumn, you can store them in a sealed container with some vermiculite or moist potting compost and place in the fridge until the following Spring. The acorns need to be kept moist. If they show signs of mould, you can wash them in water and replace into fresh potting compost.
When you are ready to plant the acorn, prepare the soil so that it is free draining (add grit if the soil is clay based). Place the acorn on its side and bury at least half an inch under the soil. Place the middle of a cardboard carton over the planting area (you can fit 2 acorns in the space). This carton acts as a guard to protect the seedling when it emerges. The acorn produces a long tap root at first, so it will be a couple of months before a shoot appears. The key to success is water, water and water. The acorn is a thirsty nut!
So what part do brambles play? Well, you see, they act as natural tree guards as the seedlings become established. However, they have to be monitored as they can dominate an area and physically smother the seedlings as they compete for light. The best natural method of bramble control is through grazing, but as you may not have access to a pig or goat, you may need to dig it out. Let’s not forget that whilst the mighty oak feeds the larvae of the Purple Hairstreak butterfly, the bramble provides nectar for the Brimstone and Speckled wood butterflies, as well as hiding places for hedgehogs.
Read Alex’s previous A-Z post, here.