The seed pods of a lilac start out green and soft, then they harden and split open as they dry. When you receive the seeds from me, they will be in pods that have dried and some may be split open. Some pods may appear empty, but rest assured the seeds have burst out into the packet and are part of the flake you see in the bottom of the bag. The seeds are thin little wafers that have a faint, almost imperceptible, nucleus in the center.
Because often the seeds are not discernible, my recommendation is to soak the entire contents of the packet, both seeds and pods, in a dish of water for 24 hours. Then add a little soil and keep the lightly moist seed/soil mixture in a zip lock bag in the refrigerator over winter, or about eight weeks. This is a necessary process for cold loving plants, called stratification.
Then after stratification, plant the entire contents of the bag in a 2 gallon pot full of soil. Spread out the seed mix, and lightly cover with soil. Leave indoors or in a 65-70 degree room or garage or somewhere that you will be sure to monitor out of direct sun. Use a spray bottle and spray water frequently to keep the soil evenly moist, not soaking. Once a day should do it.
In about a month, seedlings should emerge. Give each seedling its own 4” pot. Transfer to a bigger pot when roots can be seen coming out of the bottom of the 4” pot.
Carefully tend to the baby plants. You can move them outside making sure they are protected from harsh wind, sun, and ice. Keep in mind that seedlings usually crop up around the base of a lilac bush or tree and are therefore naturally protected from the elements.
The first winter keep them in a sheltered area where temperatures drop low enough to allow the plants to become dormant. Do not bring them in to a warm house, greenhouse, or garage. They still need the sun and monthly waterings even after they have lost their leaves, but they must be allowed to lose their leaves and go dormant for at least 8 weeks. The seedlings will look very sad as they are just one little stick with no leaves the first winter. Some might not make it, but those that do will be more hardy and stronger.
Lilacs require a chill period somewhere around 1000-2000 hours at or below 42 degrees Fahrenheit or they will not bloom. This is their critical rest in winter before they muster all their energy to give us their brilliant show of colossal blooms, vibrant color and marvelous scent in the early Spring.
There are many good resources out there. Of course, John Fiala’s book, Lilacs: The Genus Syringa, is the ultimate source for information about lilacs.
