Posted by Chieftain Trees ● Dec 11, 2019 11:00:12 PM

How to Grow Oak Trees from Acorns

The word for oak in both Irish and Welsh means a chieftain. Oak trees were often found near ancient royal sites across Ireland and influence many place names up until this day. The Gaelic for oak, Duir can be found in names like Kildare and Derry among many others. Sacred to the druids and many other faiths, the oak was associated with longevity, strength and endurance.


Why Plant Oak Trees

Studies have identified several optimal tree species for carbon storage and biodiversity, one of which is the oak. Why should we plant them? 

  • Long-lived trees can keep carbon stored for generations without releasing it in decomposition.
  • Large leaves and wide crowns enable maximum photosynthesis.
  • Native species will thrive in your soil and best support local wildlife.
  • Low-maintenance, disease-resistant species will do better without greenhouse-gas-producing fertilisers and equipment. Which is important when considering a sustainable lifestyle.

How to Grow a Mighty Oak

1. Collect Acorns

Autumn is the best time to collect acorns. 

2. Float test

Place your acorns in water for 48 hours, if they sink they are good to go. If the acorn floats it is bad and won't grow into a sapling. An acorn may float because a worm or grub has burrowed into it, creating an air hole. Similarly, a fungus can make the acorn float. If, at any point, you notice that an acorn is soft to the touch, discard it as well. Soft, mushy acorns are rotten.

3. Stratification

Wrap in wet paper towel and put them in a ziplock bag in the fridge for up to 8 weeks to trick your acorns into thinking they have spent a winter in the earth. This process is known as stratification, which is simply exposing a seed to cold temperatures, mimicking the natural conditions that a seed would experience had it fallen to the ground. This primes the seed for sprouting in the spring.

Periodically check on your acorns. The medium should be just barely moist. Too moist, and the acorns may rot. Too dry, and they may not grow.

4. Transfer 

Once the first signs of growth appear, wait until the length of the roots are 3-4cm and then transfer them to a vessel where the new root can reach water. Leave your fledgling oak in the light and once the first leaves appear you can plant your sapling outdoors.

5. Plant 

When your oak seedling is at least 8 inches tall, it is ready to be planted into its permanent home. Find a spot with enough space for your oak to grow, remember that it can grow up to 45m high and 20m wide! Prepare the site well by clearing away any weeds or grass and make a hole big enough to accommodate the root ball.

6. Wait

It takes 30 years for an oak tree to mature and grow new acorns, so get going. 

If you don't have the space for oaks you can check out our article on how to rewild your garden, or you're interested in other trees check out our guide to native irish trees.





"A society grows great when old men plant trees whose shade they know they shall never sit in." - Greek Proverb


Topics: Rewilding