Thursday, December 22, 2011

Stratifying pecan seeds

    If you have even considered growing pecan trees from seed, the nuts will need to go through a process called stratification before they will germinate properly. Stratification is a simple process that involves soaking dry seed in water then storing that wet seed in a cool moist condition for 90 to 120 days. With stratification we are basically mimicking what happens in nature. A squirrel buries a pecan in the soil during the fall where it remains cool and moist all winter long. The squirrel-planted seed doesn't germinate until the following spring when the danger of frost has past.
   Here's how I stratify pecans for next year's planting.  First, I place new-crop nuts in a plastic container, filling it about 1/2 way. I then fill the box with enough water to cover the seeds and let the seeds soak overnight (photo at right). You will need to stir the nuts around in the water  once in a while so the nuts on top don't dry.
   After soaking. I add a moisture holding media to the nuts and water. In the past I've used peat moss, cedar shavings, potting soil or saw dust. This year I had plenty of saw dust on hand, so I mixed the dry saw dust into the nut and water mix (photo at right).  I used enough sawdust to surround the nuts and soak up much of the free water. I let the saw dust soak up the moisture for a few hours then pored off any excess free water out of the box. I then placed the tight-fitting lid on the box and placed the box in the refrigerator.
    For the stratification process to work effectively, the nuts should be held in cold storage at between 32 and 40 F (typical refrigerator temps). For northern pecan cultivars, germination is more uniform when nuts are held a full 120 days in stratification. By stratifying nuts now, you will have nuts ready for planting by May 1st, a perfect time for planting pecan seeds.