Diversify Your Forest: Gather and plant seeds from your own trees

By Peter Kuitenbrouwer

Hiring people to plant trees is not the only way to expand and diversify your forest. You
can also increase your woodlot’s size and complexity with seeds from your own trees.

When you’re walking through the woods during the spring, keep an eye out for male and female flowers on tree branches. After the trees pollinate and start to develop cones and seeds, you can get an idea of how much seed potential a tree has. This is what the tree seed business calls ‘forecasting.’

In fall, or late spring for certain species, you may see an abundance of cones, maple keys or acorns on the forest floor.  Don’t take them all: the forest needs these seeds to regenerate itself. Acorns, beech nuts, hickory nuts and other tree fruits are also valuable food for wildlife. Still, you can take some to naturalize your property.

Here are some tips to gather seed and check its health.

Maples

Every year, Red Maple and Silver Maple trees (soft maple) produce both flowers and keys (which contain seeds). These maples flower in April and early May. They drop their keys between late May and the third week of June. Sugar Maples (hard maple), on the other hand, flower every year, but only produce seeds every three to five years. Sugar Maples bloom in mid-April to May and produce keys in late September and October.

Collect and verify: There are several ways to collect seed. Spread a tarp under the tree and shake branches to collect keys, collect directly from the tree if seeds are mature, or off of the ground if they have recently fallen from tree and are not dried out. To check seed viability, cut the key open and look for a well-developed, bright green embryo.

Oaks

White Oaks produce a good crop of acorns only every four to 10 years. Their flowers bloom in May, and their acorns are ready in September and early October. Red Oaks, Ontario’s most common oak, produce a good crop every one to three years. They also flower in May, but Red Oak acorns take two years to develop; they are ready in September through November.

Collect and verify: Rake or sweep acorns into piles. After a frost, shake branches to drop acorns onto a tarp. If you see acorns with caps attached, it usually means the seed was aborted by the tree before complete development or there is insect damage (the exception to this is Bur Oak, where the seed caps come down over most of the acorn and even a healthy acorn can have the cap still on). Pin holes indicate an acorn infested with insects. Then do a float test. Fill a bucket or wheelbarrow with water and pour in your acorns. “Acorns that float
usually mean they are not good,” says Mark McDermid, Seed & Stock Coordinator with Forests Ontario. “The ones that sink are solid. Still, good acorns will occasionally float if they have dried out slightly, so it’s important to do the cut test to confirm.” Cut an acorn in half, and look for a well-developed embryo that fills the seed cavity.

Planting

Most hardwood species should be planted as soon as the seed has matured. The seed will be ready to germinate immediately. Plant them first in flower beds or gardens (where you can care for them) and then transplant them when they get big enough. Transplant hardwoods at 20 to 30 cm in height or roughly one to two years old.. One thing is guaranteed: that seed will be perfectly adapted to the conditions on your property because, in many instances, it comes from parentage that has been there for many generations.