About ten years ago I decided to try a few nut grafts in my small
propagating house. The results were so satisfactory that since that time
I have grafted from a few hundred to several thousand each year.
I found by experiment that I could not graft nut trees exactly as I did
ornamental trees and shrubs, due to their extra sap content. Nut trees
bleed excessively and I had to overcome this or my losses were heavy. I
use no wax on grafts. My method is as follows: I take a strong light
string and wax it with beeswax and parafin mixed fifty-fifty. I use a
modified side graft, tying with this waxed string.
Late in December or early in January, I pot the understock, using black
walnut seedlings for four varieties (Persian walnut, butternut, black
walnut and heartnut). I make sure the understock has had its rest period
by not digging and storing them until they have been really hit by frost
and left for a period, to be sure the wood has matured for the season.
The mature understock is then stored in moist sand in a cool cellar.
In late-December, as I have stated, I place the understock in benches
using 3-1/2 to 4 inch pots, wetting them thoroughly after imbedding them
in peat moss. Keep the moss damp and at a temperature of 55 degrees at
night. After two or three weeks examine the roots by knocking several
loose from the pots. If root action has started, the roots will show
white thread-like fibers and are ready for grafting. This is important,
because if grafting is done too soon the loss is heavy. If delayed too
long the top starts growing. So I caution, do grafting when the
understock is ready.
Place newly made grafts on their side, imbedded in moss, and refrain
from watering until the union has formed. Open grafting case after third
day and daily thereafter, until union is complete. Each day wipe glass
off with cloth to prevent moisture from dripping on grafts. Increase
bottom heat after grafts are laid in benches from 68 to 75 degrees. In
about three to four weeks, if union has formed, place grafts in up right
position, then watering is resumed and heat is reduced to around 60
degrees at night. When graft shows two inches or more growth, cut
understock off close above the union, and then give house plenty of
ventilation to avoid soft growth.
I find nut trees very tender subjects and delay planting these
under-glass grown grafts out in nursery rows until every vestige of
frost has passed. Also be sure to sever the waxed string as this is
tougher than the green graft.
If this method sounds like a great deal of work and trouble generally,
remember the reward will be heavy rooted, easy to transplant, healthy,
named varieties of nut trees. Who can say that, at the present, there is
an abundance of such trees in this country.
The Economic, Ecological and Horticultural Aspects of Intercropping Nut
Plantings