Growing Dogwoods (Cornus kousa) from Seed in the Fall

A week ago we found ourselves at the doctors office for one of my children.  Nothing major (this time), just a regular check up and physical so she could run cross country (Very cool that a 7 year old wants to run cross country!).  After her appointment we left the doctor’s office and found a dogwood tree, Cornus kousa, that was loaded with fruit.  To make a long story short (actually the rest of the story is below – otherwise there wouldn’t be a post) we gathered a small bunch of berries(drupes) that had already fallen to the ground and brought them home to try and grow.

Starting Cornus kousa Dogwood from Seeds

Dogwood seeds can be started in the fall by soaking and removing the fleshy outer coating and sowing directly in pots to overwinter outdoors. This allows them time for the natural changing seasons and cold fluctuations – stratification.

Cornus kousa is a dogwood that is native to Asia.  It’s becoming more and more popular here in the U.S. due to its resistance to diseases like anthracnose which is brutal to our native dogwoods.  In fact a number of cultivars are now on the market which are a cross between the native dogwood (Cornus florida) and the Kousa dogwood including one called ‘Appalachian Spring’ which was introduced by the University of Tennessee.  

If you compare the drupes of the two types of dogwood (native and Asian) you will notice some big differences.  Size is the most obvious with the Cornus kousa dogwood reaching about 3/4 of an inch in diameter where the C. florida dogwood drupes are about 1/4 to 1/2 inch.  (You can see a picture of the cleaned C. florida seeds here) Our native dogwood has drupes that are elongated where the Kousa is spherical.  

The native dogwoods bloom earlier than the Kousa dogwoods by several weeks.  This gives the landscaper or gardener a nice option when planning spring flowering trees to ensure a succession of dogwood blooms.  Plan for the natives first, hybrids second, then the Kousa dogwoods for about 4-6 weeks of dogwood blooms.

Planting the Dogwood Seeds

When we got the drupes home I dropped them into a cup of water and let them soak.  I didn’t keep track of how long I left them in the water but it wasn’t more than a week.  Then I separated the seeds from the flesh of the fruit.  Here is where I was very disappointed.  Out of ten drupes only two had seeds.  That’s the way it goes sometimes!  The two seeds were already beginning to put out roots so rather than stratifying them in a moist bag of sand in the fridge I planted them directly into a pot.  Dogwood seeds normally need a cold period to trigger germination so putting them in a cold refrigerator over the winter months is often a good idea.  Dogwood seeds are great candidates to try winter sowing too.

Assuming my two little dogwood seedlings spring up from the soil before cold weather hits I may have to bring them indoors to overwinter.  Otherwise I’ll store the pot in the shed for some natural stratification!