Through my research, I've decided that creating a black walnut guild may protect our apple trees and allow them to thrive. We have four -- a Spitzenberg, a Granny Smith, a Macfree and a Liberty -- uphill and outside the drip zone from two mature walnuts, but they are in varying stages of happiness.
Since mulberries are key players in black walnut guilds, immune to juglone themselves and able to shield neighbors from its effects, I want to create a buffer zone with them.
But, which to choose? Red, black or white?
Here are the critical factors: shielding ability, berry taste, invasiveness and hardiness. Apparently, no single mulberry can satisfy our needs!
Red mulberries are native to the Northeast -- a big plus in my book. But of the three, red mulberries are actually susceptible to juglone. So, they're out.
Black mulberries are said to be the most flavorful. The white are described as "bland." Plus, there seem to be a wide variety of dwarf black mulberries that are more easily kept pruned to a manageable size. Our yard can't accommodate a 40-foot tall mulberry, which the white can easily reach. So, black it is!
But, wait, black mulberries, dwarf or otherwise, are only hardy to zone 7. Sigh.
That leaves white. Berries that will feed birds, but not us. A tendency to be aggressive and invasive. And way too tall for our space. But, it's tolerant of juglone, which, ultimately is the key factor.
So, I'm on the hunt for a dwarf, or at least manageable-sized white mulberry that's hardy to at least zone 5a.
Round and round I go again!