Growing Aspen Seeds – How And When To Plant Aspen Seeds

Aspen Seeds
aspen seed
(Image credit: np-e07)

Graceful aspen is the most widely distributed tree in North America, growing from Canada, throughout the U.S. and in Mexico. These natives are also cultivated as garden ornamentals, usually with branch or root cuttings. Aspen seed propagation is also possible if you know how to grow aspens from seeds, and you are willing to work at it. For information on getting seeds from aspen trees and when to plant aspen seeds, read on.

Aspen Seed Propagation

Most aspen trees cultivated for ornamentals are grown from cuttings. You can use branch cuttings or, even easier, root cuttings. Aspens in the wild produce new plants from their root suckers making it easy to “find” a new young tree. Aspen seed propagation is also common in nature. You can start growing aspen seeds in your backyard if you follow a few simple guidelines.

When to Plant Aspen Seeds

If you are wondering how to grow aspens from seed, you’ll need to learn what to do and what not to do. The primary reason aspen seed propagation fails in nature is inadequate irrigation. According to scientific studies by the Forest Service, aspen seeds do not age well. If they do not find moist soil rapidly after dispersal, they dry out and lose their ability to germinate. When to plant aspen seeds? As soon as possible after they mature.

How to Grow Aspens from Seed

If you want to know how to grow aspens from seed, you have to understand how the plants grow. In early spring, aspen trees produce tiny flowers on catkins. You’ll find the catkins growing before the trees leaf out. Male catkins bloom and die. Female catkin flowers produce seed pods that, over a few months, mature and split open. When they do, they release hundreds of cottony seeds that blow off in the wind. Germination occurs, if at all, within days of seed dispersal. You’ll only see seedlings though from growing aspen seeds if the seeds reach a moist area to grow. Seeds don’t stay viable very long and most dry out and die in the wild.

Getting Seeds from Aspen

The first step in growing aspen seeds is getting seeds from aspen. Identify female aspen flowers by their time of appearance and their expanding capsules. Male flowers tend to bloom and die before the female flowers become noticeable. As the female flowers mature, the catkins grow longer, and the capsules expand. You want to collect the seed from the capsules when it matures several months after its appearance. Mature seeds turn pink or brown shades. At that point, cut off branches with mature seeds and allow them to open on their own in a garage or area without wind. They will discharge a cottony substance which you should collect by vacuum. Extract the seeds using screens and either air dry them for spring planting or plant immediately into moist soil.

Teo Spengler

Teo Spengler has been gardening for 30 years. She is a docent at the San Francisco Botanical Garden. Her passion is trees, 250 of which she has planted on her land in France.