Pruning at the Last Minute

The cherry plum trees have already opened blossoms around here.

I thought, “Oh shit, I better prune my Santa Rosa plum.”

I didn’t prune the tree in early winter because there was a chance of rain, then there was a period of a few weeks with a ton of rain, then after the rain ended I put it off for days… yeah.

Ideally, I would’ve pruned the tree as soon as the rain stopped.

I only got around to pruning it one week later, when the buds are already forming. The wood is green too at the cuts. Yikes.

Well, at least I did it before any flowers opened.

I know little about plum trees in the wild. Even the “wild” plum trees around here are descended from domesticated plum trees. How do wild plum trees live without pruning?

Santa Rosa Plum trees were bred to grow a lot of fruit. They grow a lot, period. My Santa Rosa Plum tree has a rootstock which isn’t Santa Rosa (IIRC, the roots are even plum tree roots) so underground it doesn’t grow to a ridiculous extent. But the aboveground part of the tree, the Santa Rosa, grows and grows and grows.

Each year, I’m surprised by how much more growth the tree has. At some point, it should hit a limit and stop growing bigger. Hasn’t happened yet.

Why prune? First, these branches grow in all directions, including directions which cause them to form traffic jams with other branches. In some tree in my neighborhood, I see this happen and… the trees seem fine? But those are ornamental trees, not tree for growing fruit.

When branches touch each other, and the wind blows, they can rub and injure each other, opening up the tree to fungal infection. Nice. They can also damage fruit (and I have seen this happen, though I only lose a small percentage of fruit to branches rubbing each other the wrong way). The solution is to cut branches so they don’t touch each other, even in windy weather.

Another reason to prune is to keep good airflow around the branches. When the tree has no leaves, airflow is great. But when it leafs out, it can create stagnant pockets of moist air which lead to, you guessed it, fungi. I haven’t had a problem with this, but I prune the tree yearly. I haven’t inspected unpruned or under-pruned trees closely enough to see if they’ve gotten fungal inspections in spots where the leaves are too packed.

Santa Rosas can bear so much fruit that the weight breaks branches. This is why I pick off some unripe fruit. Another way to prevent branches from breaking under the weight of fruit is to prune weaker branches and take weight off stronger branches.

(I have a feeling that wild plum trees don’t overbear fruit to the point of breaking branches, but what do I know?)

Plum trees are tough. That’s why I planted a plum tree rather than a tastier fruit tree (plums are good, but not my favorite). Even with imperfect pruning, even with be pruning when the buds are already out and the wood is already green, the tree should do fine.

Soon, the flowers will be out, and it will be so lovely. Maybe I’ll post pictures to this blog 😀