Re: acer japonicum/walnut
sdunkley@mindspring.com
Sun, 28 Sep 1997 10:27:15 -0500
To my understanding, the chemical that walnut tree roots excrete is toxic to herbaceous plants only. I don't think woody species are affected. However, anything planted within the root zone of a large tree has to establish itself with a lot of competition from the large tree. I suggest you prepare a good sized hole for the maple and eliminate all the walnut trees roots in the area by severing them (plunge a shovel in a ring around outside of the hole). You shouldn't sever large walnut roots though, say 3" (8cm) diameter or larger. Work around them or site maple to avoid them. Plant the maple and keep it well watered its first year and perhaps the second. You may even lightly fertilize it during early summer and again mid-autumn. Walnut roots will quickly invade the area again so you might repeat the severing procedure again in the fall. (Tree roots grow a lot in fall.) After a year or two of special attention, the maple should be better able to compete with the walnut. It will alway
s respond to preferencia
l treatment though, so a watering during dry spells will help a lot..