How to Grow Trees and Shrubs from Seed

How to Successfully Grow a Tree from Seed: Discover Our Expert Tips

In natural ecosystems, plants mostly reproduce by producing large quantities of seeds that are dispersed by wind, water, and even animals.

In nurseries, different methods have been developed to propagate specific plants in a more controlled and predictable way. These include cuttings, layering, and even in vitro propagation.

These artificial propagation methods produce clones—exact copies of the parent plants. This is especially useful when working with sterile cultivars or when reproducing a specimen with desirable genetic traits.

Seed propagation is also widely used in nurseries. This method simply involves germinating seeds in a growing medium. It’s our favourite approach—nearly all the species we produce are grown from seed.

In our view, the main advantage of this method is that it promotes strong genetic diversity within cultivated plants, which is essential for resilience and long-term adaptability.

To successfully grow a tree from seed, two key steps are essential: harvesting and preparing seeds for germination. In this article, we focus on both.

Harvesting: Healthy, Mature Seeds Are Key

Seeds from trees and shrubs in Quebec vary widely in their structure and physiology. Some, like those of birches, spireas, or wild blueberries, are extremely small, while others—like walnuts, oaks, or hickories—are much larger.

Some seeds are found in fruits (serviceberries, chokeberries, elderberries) or cones (hemlock, larch, pines, spruces, cedars) and must be extracted. Others can simply be collected directly from the tree or shrub (maples, oaks, birches, lindens).

Seed extraction and cleaning are topics in their own right. They become especially important at a production scale, when large quantities of seeds must be processed and manual extraction is no longer practical. For smaller quantities, however, keep things simple—use your hands and your judgement.

Seeds should be stored in a refrigerator. For long-term storage (from a few weeks to several years), they should be dried before refrigeration.

Timing: A Key Factor You Can’t Ignore

The most important factor when harvesting seeds is timing—collect them when they are fully mature. Seeds harvested too early may not give you the results you’re hoping for.

Some species flower early in spring and reach maturity quickly, by May or June. This is the case for Red Maple, Silver Maple, poplars, willows, and serviceberries.

Other species take more time and should be harvested in fall, between September and November. This includes Sugar Maple, oaks, hickories, and hazelnuts.

There are, of course, some exceptions. For certain species, harvesting slightly before full maturity can actually be beneficial—such as viburnums, lindens, and hop-hornbeam.

The ideal harvest period therefore varies by species. It’s important to identify the right timing for the plant you want to grow. Several resources can help with this—we recommend a few at the end of this article.

At harvest time, a simple cut test can help assess seed viability and confirm that the seed is fully formed and healthy.

Preparing Seeds for Germination (or How to Think Like Mother Nature)

After harvesting, a few steps are needed to get seeds to germinate. Nothing too complicated—you just need to think like Mother Nature!

Dormancy: A Key Adaptation to Quebec’s Climate

In our climate, plants have developed mechanisms to ensure seeds germinate at the right time. For example, it would be risky for an acorn to germinate in fall just before winter sets in.

Instead, the seed must wait until spring. This mechanism is called dormancy.

As long as seeds remain in dormancy, they will not germinate. In nature, dormancy is broken by environmental conditions—but these conditions must be recreated artificially at home.

Breaking Dormancy: Simple Steps

Start by properly hydrating the seeds. Then, apply stratification by exposing them to cold for a specific period. In some cases, a warm phase is required beforehand.

Each species has its own “recipe,” so it’s important to do your research.

Scarification: Sometimes Necessary

Some seeds have a thick, hard, and impermeable outer layer. These seeds must be scarified before they can absorb water.

Scarification simply means creating small openings in the seed coat. This can be done with sandpaper for smaller seeds or a knife for larger ones.

At the nursery, for example, Kentucky coffee tree seeds are so hard they are literally sanded one by one.

Industrial methods exist, but they are not recommended for home use due to safety concerns.

Soaking: Getting Seeds Ready

To hydrate seeds, simply soak them in water for 12 to 24 hours, sometimes longer.

Most viable seeds will sink once fully hydrated. If some remain floating after 24 hours, they may be empty or damaged—confirm with a cut test.

Floating seeds

Some exceptions exist—for example, certain rose seeds float even when viable.

Very small seeds, like those of spirea, can be hydrated directly on moist peat. Spray them with water to ensure they adhere well to the growing medium. 

After soaking, place seeds in a bag or container with a moist medium (sand, soil mix, vermiculite, or paper towel). Make sure there is some air circulation to prevent mould.

Warm Stratification: Mimicking Summer

Some species require a warm phase before cold treatment, similar to what they would experience if dispersed in summer. The warm stratification period ranges from one week to several months, depending on the species.

Room temperature conditions are usually sufficient. Check regularly to maintain proper moisture levels.

Cold Stratification: Mimicking Winter

All seeds that require treatment must go through a cold period (0 to 5°C). A household refrigerator works perfectly.

The duration varies depending on the species, from a few weeks to several months.

From Seed to Seedling: Timing Matters

At the end of the process, seeds are ready to germinate and grow into young seedlings.

Some species will wait for warm conditions, while others may germinate even in cooler environments.

Indoor winter conditions are not ideal for young trees. Start seeds outdoors after the last frost, or indoors no earlier than two weeks before your region’s last frost.

Growing trees from seed is accessible, affordable, and deeply rewarding. It’s also a great way to connect with nature—and a wonderful learning experience for children.

For those of us who dedicate our work to growing trees and shrubs, nothing is more satisfying than watching carefully prepared seeds germinate and thrive.

Of course, some species remain a challenge—but that’s part of what keeps our passion alive.

Article co-written by Audrey Rondeau, Biol., M. Env., Director of Production and Development, Vert Forêt Nursery, and Suzanne Simard, B.Sc., horticultural writer and graduate horticulture technologist.

References:

Flore Laurentienne (digital version available online: https://florelaurentienne.com/

Dirr, A. Michael, and Charles W. Heuser. The Reference Manual of Woody Plant Propagation: From Seed to Tissue Culture. Second Edition. Oregon: Timber Press, 2006.

Kock, Henry. Growing Trees from Seeds: A Practical Guide to Growing Native Trees, Vines and Shrubs. 2nd Edition. Canada: Firefly Books Ltd. 2016.