Flowers of black walnut: S, Staminate 
(male) flowers; P, pistillate (female) 
flowers. 
is often saturated with water. They 
will not grow well or produce large nut 
crops on eroded hillsides or other land 
that will not support good corn crops. 
Reliable indicators of suitable land are 
good stands of white oak and tulip- 
poplar. 
PLANTING TIMES 
The most favorable time to plant 
black walnut trees in most areas is in 
early spring. New roots will then be 
able to grow quickly to replace those 
lost in transplanting. 
In the South, you can plant young 
trees in the fall or winter. But trees 
planted north of the Ohio and Potomac 
Rivers in fall and winter will not grow 
new roots before the ground freezes 
and may die. 
SPACING 
Black walnut trees planted for either 
ornamental use or nut production 
should be spaced at least 60 feet apart. 
Branches and roots will then have 
enough space in which to spread out. 
4 
SETTING TREES 
For trees up to 7 feet tall, dig a hole 
2 feet deep and 3 feet wide. Place the 
tree at the same depth in the hole as 
it stood in the nursery bed and spread 
the roots out well. Refill the hole with 
topsoil. Tamp the soil down around 
the roots until the ground is firm. Then 
form a basin around the edge of the 
hole with extra soil and soak the soil 
immediately. : 
FERTILIZER AND LIME 
REQUIREMENTS 
Fertilizing 
Black walnut trees need large 
amounts of nitrogen and potassium for 
best growth and nut production. They 
need small amounts of phosphorus. 
Apply mixed fertilizers each year. 
Spread them evenly under the tree 
branches when the buds begin to swell 
in early spring. 
Mixed fertilizers having analyses of 
5-10-5 and 10-10-10 give good re- 
sults. One good rule is to apply 1 
pound of 5-10-5 fertilizer, or one-half 
pound of 10-10-10 fertilizer for each 
year of tree age. Do not use any dur- 
ing the first spring, however, because 
of the danger of injuring roots. 
To fertilize trees in yards, apply a 
little more under the branches than you 
would normally use on your lawn. 
Some trees are grown near barns or 
in stock or poultry yards to provide 
shade. They benefit from the natural 
addition of manures and_ usually 
flourish. 
Liming 
In strongly acid soils, important 
nutrients are often unavailable to black 
walnut trees. If your soil is strongly 
acid, apply enough lime to change the 
pH to 6 or 6.5. Do not overlime; over- 
liming makes zinc in the soil unavail- 
able to the tree. , 
Soils east of the Mississippi River 
are sometimes deficient in magnesium. 
