Red Oak Acorns

[B.uneasy]

Has anyone had experience planting acorns on top of a rock to "naturally create a root over rock tree? What are some techniques I could use on my acorns to start a root over rock as early in its life cycle as possible?

 

[leatherback]

You should at least ensure no singular taproot develops. But yeah, the best root over rochs are developed from seedlings. You bareroot a one year old seedling and wrap the roots around the rock, ficing it with natural fibres that will decay. Then wrap with cling film so that only the root ends come out. Plant in the ground and every few years check and adjust the roots.

 

[canoeguide]

The main problem with starting a root-over-rock from seed is that you can't control whether the seed germinates, or whether it will develop any useful or good roots. Consider a scenario where (assuming it germinates) only a few roots grow in an unnatural manner or only over one side of your rock or otherwise in a way you don't like. Using acorns also has the problem of oak trees having rather slow growth. It may take a long time to develop into something that you like. (Don't let that dissuade you from trying it though - I think root-over-rock oaks are rare.)

A better strategy might be to plant a handful of viable acorns (ones that sink in water) in some flats or small pots and after a year or two choose the most promising to place over your rock. This is the highest chance of success and removes a lot of variables.

 

[B.uneasy]

The main problem with starting a root-over-rock from seed is that you can't control whether the seed germinates, or whether it will develop any useful or good roots. Consider a scenario where (assuming it germinates) only a few roots grow in an unnatural manner or only over one side of your rock or otherwise in a way you don't like. Using acorns also has the problem of oak trees having rather slow growth. It may take a long time to develop into something that you like. (Don't let that dissuade you from trying it though - I think root-over-rock oaks are rare.)

A better strategy might be to plant a handful of viable acorns (ones that sink in water) in some flats or small pots and after a year or two choose the most promising to place over your rock. This is the highest chance of success and removes a lot of variables.

Thank you so much, that's a really good idea.

 

[Orion_metalhead]

Oaks in their first year push a verrrry strong tap root. I germinate and clip the taproot when it is still a 2-3" radicle. This forces the acorn to push more roots, similar to the pine seedling cutting.

Once you have several strong roots, it's easier to do a root over rock. In 2 or 3 years, you can wrap over the rock.

 

[Potawatomi13]

Also consider these have big leaves so should plan on large very heavy rock for larger tree

 

[Shibui]

I also do similar to Orion when I grow English oak. Plant plenty of acorns. Prune the first root soon after it starts to grow and plant it . You'll get several roots from near the cut end.
After 1 year bare root them all and pick the one that fits to the rock best taking into account both roots and the young trunk. Root over Rock needs to be a combination of rock shape, size and angle, the roots of the tree flowing down over the rock and the trunk and canopy that will balance the entire scene. Not all root over rock plantings are pleasing so best to start several and ditch the bad ones as you realise that some are better than others.