How do you germinate acorns from willow oak and water oak so that little tree seedlings will sprout?
The Gardener’s Answer
Hello, Kirk: Willow oak (Quercus phellos) and water oak (Quercus nigra) are both readily propagated from seed. These hardwood trees are generally good seed producers. Acorns from these trees will ripen from late October to early November. As a general rule the seed of white oaks (willow oak) matures in one year and the seed of black oaks (water oak) takes two years to ripen. Timing is key for successful propagation. So, this is a perfect time to start collecting your acorns. The acorns on the lower branches will ripen first so go ahead and start removing them from the trees. Choose the larger acorns that have turned brown as opposed to the green ones since these are the ripened ones. Take all the acorns you have collected and soak them in water for 24 hours. Discard the floating ones since this is an indication they have been damaged by insects. With the remaining sinkers you can directly plant them in the ground or in containers outdoors. These seeds require two to three months of cold stratification for improved germination; however, planting them directly in the ground, or in a container for that matter, makes them a likely food source for insects and other critters during the winter months. For this reason you may consider planting more than you would like and hopefully you will have seedlings to share with your friends. So, after you have separated the sinkers from the floaters go ahead and remove the acorn caps and plant the bottom of the acorns 12-18 inches deep. Plant them on their side and water them well. Thin your seedlings the second year. You should not have to water throughout the winter months but spring/summer may require hand watering on your part if Mother Nature does not provide sufficient moisture. A thin layer of mulch will help keep the moisture in. Planting from seed can be very rewarding but it certainly takes a lot of patience so keep this in mind as you begin this process.