Here we go round the mulberry bush...er...tree...

Like lots of folks all over the country, we have a fruitless mulberry tree in our yard. When we moved to this house, that tree had beautiful and luxurious foliage. Of course, all those leaves had dropped by Thanksgiving to show me that this tree, like so many other mulberry trees in the world, had had all of it’s annual growth pruned back. I have no idea what the deal is with that drastic and violent pruning that goes on every year with mulberries. I’d noticed it when I lived in Southern California and thought it looked vile. I’d noticed it when I lived in Northern California and thought to myself, “Self, that can’t be good for those trees!”

Apparently, we Americans have adopted this rather European style of pruning. Pollarding, or training the tree from the beginning to a certain height and then removing each year’s new growth, is common in many European cities. With true pollarding – as we see with the fruitless mulberry – the branches are never more than two years old when they are cut. This pruning practice was developed hundreds of years ago in Europe when basket weavers required the long, young branches for their craft.

In my mind, it would be easier – and certainly better for the tree – to simply plant a tree that didn’t get so big that it has to be what I’ve come to view as brutalized every year, to say nothing of the relatively high maintenance aspect of this practice. But I like this tree, unsightly knobs and all, and I’m not going to kill it simply because the previous owner, likely at the instruction of an arborist, whacked it into rather a Quasimodo of trees.

The facts about fruitless mulberry are that it is high-maintenance because of its weak wood, rapid growth and invasive surface root system. It tolerates poor soil and heat, so people plant it as a smaller ornamental shade tree. It then very quickly morphs into a tree with a spread of 20 to 30 feet.

These fruitless mulberries are pruned one of two ways. One is called “crown reduction” involving shortening the extent of the branches by pruning back the leader to shorter, secondary branches that are strong enough to take over as the new leader. I talked to several arborists here in the Rogue Valley and was told that, considering the very rapid growth of this tree and the relatively weak wood, aggressive pruning and control of the fruitless is necessary lest the branches break.

The most common method to manage the fruitless mulberry is, as I said above, pollarding. If you’ve been to California’s Bay Area in the late fall or winter, think about those grotesque looking sycamores with the large knobs on stubby branches. I’ve seen this practice on beech, black locust, catalpa, horse chestnut, linden and London plane in addition to the sycamore and fruitless mulberry.

Pollarding is done only on species that are prolific sprouters – like our fruitless mulberry. I’m told that pollarding should be instituted when the tree is young and the branches small in diameter where they are to be cut. This way, you avoid the invasion of various detrimental funguses. The trees then sprout from buds under the bark below where you’ve made the cuts. These sprouts will grow very rapidly, sometimes as much as six feet in a growing season.

You then prune off the sprouts annually during the tree’s dormant season. The tree will develop large knobs at the pollarding cuts over the years and there will be a large number of spouts from each knob to make a full canopy. If your tree is quite tall, a pole pruner would be the ticket for you do-it-yourselfers; otherwise an arborist who will work on your trees within the conformance parameters of the Tree Care Industry Association standards would be the next choice. If you’re doing this yourself, be very careful no to scar the old knob wood or decay may invade your tree.

So there you have it…Pollarding. I still don’t like it. I think that I would seriously rethink putting a mulberry tree in my yard – or even any of those others the arborists mentioned that would require what equates to – in my mind anyway – tree torture. Still and all, I’m not going to rip out the mulberry tree in my yard and I am going to do my very best to make sure it stays healthy for many years to come. It’s the least we can do.