Should I prune these apple trees?
We recently purchased a home in Canby. There is one old apple tree and another row of 4 apple trees ( different varieties) on a trellis. You can see how much long, vertical growth has developed over the summer. Should we cut back the long branches, or leave them on over the winter? Not sure if the leaves will drop or not? Thanks much.
Clackamas County Oregon
Generally avoid pruning fruit trees in late autumn before the leaves fall, as pruning before the tree is dormant always prompts new growth, which can be easily damaged by harsh early winter weather.
Technically, it is fine to prune fruit trees any time of the year--generally this is stated in arborcare classes as "any time your tools are sharp". The historical prevalence of winter pruning is not that it is better for the trees, it is that that is the slowest time of the year for the farmer--who therefore has more time to prune. But it is perfectly appropriate to prune fruit trees anytime from when they go dormant (leafless), through spring and summer to midautumn.
And yes, your photo does show a row of espaliered trees that got away. Espaliering is a special method of tree care and pruning that REQUIRES pruning several times in summer to be effective. The recommendation here would be to prune this winter to bring the trees back under control, cutting the vertical growth off down to the gnarly "spur" wood that should be forming close to the main horizontal branches. And then, throughout spring and summer, remove new growth--it will all be whips and shoots--once it has grown to about 11 inches long (at this point the soft new growth will be starting to harden into real wood). Each time you will cut off each whip all the way down to the low rosette of leaves that many apples (and pears) form close to the main branch. Or down to the point that there are only about 4 leaves left, when that variety of tree doesn't form rosettes. This special pruning strategy substantially increases the amount of "fruit spurs" that form close to the main horizontals, and thus the number of blossoms and the amount of fruit.
Espaliering always requires some form of support for the main branches, as horizontal branches will break off if not supported. Thus the posts and wires. You don't need to support the temporary vertical shoots, but you do need to keep an eye on the ties between the permanent branches and the support wires: loosen and re-tie these as necessary so that the ties do not constrict the growing branches.
There are many benefits to espalier: more fruit, efficient use of garden space, and (sometimes) the ability to take advantage of the slightly warmer conditions next to a south-facing wall. But for many of us, their primary advantages are two: they add interest to the garden. And for those of us who are lazy, they bring great homegrown fruit literally withing reach--no ladders!
An excellent resource for all types of pruning, including detailed instructions for starting and maintaining many forms of espalier, is The American Horticultural Society Pruning and Training, by Christopher Brickell and David Joyce (generally available at many libraries).