Cork Oak (Quercus Suber)

The Cork Oak is a tree that has been cultivated for many centuries in Europe and Africa to harvest its bark, which is used to produce wine corks. It can grow up to 25 meters in height.

Cork Oak bonsai cultivation guide

How should I water it?

As a Mediterranean tree, the Cork Oak tolerates drought very well, but we have to bear in mind that a bonsai pot has limited water reserves.

We will water abundantly, letting the water come out through the drainage holes and letting the top layer of substrate dry between waterings.

Should I leave it in full sun?

The cork oak is a Mediterranean tree that is used to receiving many hours of direct light without having other trees to shade it, so we must try to simulate these conditions.

Should I worry about putting it under shelter during the winter?

Although cork oaks can withstand cold temperatures, we must put them under cover if they drop below zero degrees. A greenhouse may be our best option to avoid sources of heat inside the house, such as radiators. If we have no other option than to bring it into the house, we can mount an LED panel if we do not have a sufficiently lit window.

How often do I have to fertilize?

We will fertilize during the growth phase, avoiding the flowering phase, which usually coincides from spring to autumn. We recommend slow-release organic fertilizers.

When and how should you prune?

We can prune before the tree becomes active in late winter, before spring budding begins.

Can I pinch the tree?

Throughout the year we can pinch the tip of the branches leaving a minimum of two leaves, thus preventing the tree from drying out the entire branch.

When and how to wire?

We can do it throughout the year. We must watch that the wire does not bite into the bark because it can take a long time for the marks to heal.

When do I have to repot and how often?

The Cork Oak is a tree that generates few roots, which allows us to space out repotting considerably. We will always wait for the tree itself to show signs that the roots no longer fit in the pot and push the substrate out of it.

What substrate or soil should I use?

The Cork Oak is not a delicate tree in terms of substrate, but it is ideal to use a substrate that drains well to avoid root rot problems.

Our recommendation is 100% akadama or a combination of earthworm humus with gravel or pumice.

How can I propagate it?

The easiest option is the germination of acorns.