Even with that distance, in time, they will need to be thinned out to 50 foot spacing. They thrive in full sun and in soil that is fertile and deep. Pecan trees are deep rooted and need fairly large quantities of water during the growing season. Pollination Pecan trees produce separate male and female flowers on the same tree. However, they are usually not in bloom at the same time on the same tree.
Some varieties shed their pollen before the female flowers are receptive.
Therefore they need pollen from another variety that matures its pollen a little later. The male blooms generally appear first each spring as tassel-like growth. The female blooms appear later and consist of the ovules found at the tips of the new spring growth. When choosing your varieties, look for pollination compatibility and disease resistance. Pecans are wind-pollinated, and only need a few hours of clear weather with favorable humidity and winds, to pollinate a crop.