A Gardening Journal
Today in the Garden of a Lifetime: Mulberry Mystery Solved
- Published: October 05 2016
This season, I've been tracking a volunteer gold-leaved mulberry whose foliage is exceptionally lacy. I figured out that, although it's a good fifteen feet from the one I planted, it had to be a sprout directly from the parent. Fifteen feet away! Those surely are far-reaching roots. Is this how the species behaves, or was this far-flung root sprout a fluke?
An excursion to Boston's world-famous Arnold Arboretum was in order; its collection of trees and shrubs is unrivaled east of the Rockies. In the mulberry grove, I found this cut-leaved beauty and, in everything but foliage color, it was a dead ringer for my gold-leaved volunteer.
Was its parent tree nearby? Just a few feet away, actually.
I had to double check because most of this tree's foliage lacks any lobes and, so, is almost unrecognizable as a mulberry. This is regrettably typical for free-range growth of established Broussonetia: The foliage displays little to none of the cut-leaved habits that makes youngsters (whether sprouting from roots of a parent tree or growing independently) distinctive. Regardless, the cut-leaved youngster was sprouting directly from one of the parent tree's thick roots.
This tree is a Korean cousin of my Golden Shadow's parent species, Broussonetia papyrifera. Although Broussonetia kazinoki has produced a variegated cultivar, neither it nor either of these straight species are as ornamentally useful as Golden Shadow. But the root-sprouting prowess is similar to my own tree's, and that's significant: One species' behavior reinforces our understanding of the others.
Thirty feet away, another young mulberry was muscling its way up through a colony of a rare lilac. It also bears desirable deeply cut foliage, and was clearly a volunteer. Is it also a root sprout?
Hard to say. Even at thirty feet, the Broussonetia kazinoki was the closest mulberry. Its roots may well extend that far from its trunk. But the Arnold Arboretum's mulberry collection includes both male and female trees, so volunteers could arise from seeds, too, not just from roots.
Here's the beautiful root sprout of Broussonetia papyrifera 'Golden Shadow'. Its foliage is strikingly similar in shape to that of the root sprout of Broussonetia kazinoki.
Here's the introduction on how to grow Broussonetia papyrifera 'Golden Shadow'. The hardiness and handling of Broussonetia kazinoki 'Variegata' are the same.
Here's a closer look at this tree's shape-shifting foliage. The leaves it produces in Spring have one shape; those produced in Summer, quite another.
Here's how particularly interesting this tree is in Spring, when the ephemeral bronze color of the new foliage matches that of the catkins.
Here's how interesting this tree's bark is in Winter, as well as how to maximize its cool-season display.