Timing spring pruning on coast live oak – Bonsai Tonight

April is a busy month for oaks in my garden. At the same time that my largest cork oak starts growing, a second flush of growth appears on the coast live oaks.

Coast live oaks can start growing anywhere from December through April in my garden, but usually get going in January. By mid-April, the first flush of growth hardens off and a second flush appears.

New buds starting to elongate

In the photo below, you can see the early spring flush below my finger, and a second flush starting to develop above it.

Early spring growth below and new a shoot above

Some of the branchess on the oak below have grown quite long this year.

Long branches on coast live oak

Knowing that these new shoots are about to get even longer leaves me with the choice of whether to prune now or prune later.

If I want a branch to thicken, I can let it grow. If I want to create branch density, I can prune now. Because the branches on this tree have thickened considerably since fall, I want to focus on improving branch density.

When pruning oaks, I cut right where I want new buds to develop. Because I want to create a relatively small tree, I reduced the branches significantly.

After cutback

If I had waited another month to prune, the tree may not have had the reserves necessary to push a third flush of growth. By pruning right before – or just after, in this case – the second flush appeared, I can encourage the tree to invest in new growth that will improve the branch density.

Closeup after pruning – 10″ tall

I don’t expect I’ll need to prune the tree again before fall, but I’ll be on the lookout for signs that a new flush of growth is on the way and decide whether or not to cut again using the same criteria I used in spring.

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