Become a Seed Harvester… of the Forest!

Have you ever dreamed of planting a small forest of native trees that you have grown from seed? I do! All the time! It’s so satisfying to be able to point to a plant and say “I grew that from seed! Imagine if they were trees!

Sowing trees is actually a wonderful adventure! For some native trees, seeding can be ridiculously easy. Oaks are one example. But there are other species that require a little more knowledge. But once you have unlocked their secrets, your chances of success are greatly increased.

Harvest Seeds at the Right Time

Harvesting tree seeds is a summer and autumn activity. Each species produces seeds that ripen at different times of the year.

It’s also important to know that seed production varies from year to year. It’s quite rare for a tree to produce a lot of seeds for several years in a row. For example, yellow birch (Betula alleghaniensis) has good seed production one year out of two. In the case of the eastern white pine (Pinus strobus), there can be a gap of three to ten years between good seed-producing years. This does not mean that the tree will not produce seeds the rest of the time, but the number and viability of the seeds will be more limited.

Finally, the seeds must be harvested when they have reached full maturity. In general, seeds are ripe when they are dry. This is a good indicator! You can also guess that the fruits are ready to be harvested when they start to fall to the ground. This will be the case with oak acorns, beech nuts or hickory nuts. The third condition for harvesting ripe seeds is to be faster than the squirrels and other animals that love these very nutritious seeds.

These are some generalities that can be applied to a large number of native trees. However, it is useful to know that ash seeds ripen a few weeks after the fruit has fallen. On the other hand, some cones, such as those of the white pine, the white spruce (Picea glauca) and the black spruce (Picea mariana), can be harvested when they are in the process of changing colour from green to brown. These cones are then left to dry and the ripening of the seeds continues at the same time as drying.

Tree Seed Harvesting Calendar

Here, in chronological order, is the sequence of tree seed harvesting. The dates are only indicative and would apply to a forest in the greater Montreal area, in zone 6a, USDA zone 5. These dates will have to be shifted as we move in latitude and altitude. The fact that the forest is on a south-facing or north-facing slope can also influence the harvesting period. But the order in which the seeds ripen remains the same.

From mid-May to mid-June	Red maple, American elm
Late August to mid-September	Late cherry, White spruce, Balsam fir, American basswood
Early September to late September	Tamarack, White Pine
Mid-September to mid-October	Bitternut hickory, swamp oak, bur oak, red oak, butternut, red pine, eastern hemlock
Mid-September to December	Black Spruce
Late September to October	Paper birch, Sugar maple
Mid-October to early November	Yellow birch
At all times	Grey pine

Between Harvesting and Sowing

One of the easiest ways to get started with native tree seedlings is to watch nature at work. Surprisingly, nature is a great source of inspiration for the laidback gardener!

In this famous nature, fruits fall to the ground, hoping not to be eaten by squirrels or chipmunks, and wait for winter to come. In the spring, if the conditions are favourable and the seeds have been lucky enough to fall in the right place, they germinate! In other words, once harvested, the seeds are put straight into the ground, covered with wire mesh to protect them from you know who, and nothing else is done! This is the best way to sow oak acorns!

If it is not possible to sow outdoors, or if you want to sow within a certain time frame, you will need to use different methods of seed storage to ensure the viability of the seeds.

For example, oak acorns and maple seeds should be stored in a cool place, such as a refrigerator. Other seeds, such as elm, poplar or pine seeds, can be dried and stored in a dark, dry place. Seeds in fleshy fruits, such as black cherry (Prunus serotina) or juniper (Juniperus spp.), must be removed and then dried. Finally, my favourite: some seeds are released from the fruit after being burned in a forest fire. This is the case with Jack Pine (Pinus banksiana). Although setting fire to everything is a dubious idea, you can achieve a similar effect with the following trick. The idea is to heat the cones to melt the resin that prevents them from opening. To do this, we place the tightly closed cones in a daisy for a little steam cooking for about 30 seconds! Black spruce cones can be treated in a similar way.

Now you are well prepared to harvest and store most of the tree seeds you collect on your next walks in the woods.