KATHLEEN’S TAIL

This is the perfect time to collect seeds from trees and shrubs to create your own and add diversity to your landscape. If you think starting trees from seed is a dumb way to incorporate trees into your landscape, think again.

I appreciate the story Justin Evertson of Nebraska Statewide Arboretum likes to share about his 15-foot-tall Bur Oak. Justin started the tree from an acorn he planted just 10 years ago. The tree was quick to establish and grow, disavowing the oaks as slow-growing trees.






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A walk in your neighbor’s yard (with his permission, of course) is an easy way to collect seeds. Choose seeds with an unblemished seed coat and discard seeds that have tiny holes as this indicates insect feeding. Be sure to mark the seeds so you know what they are. Then you can start the process of scarifying and stratifying the seeds.

Scarification, Stratification

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All seeds will have different scarification and stratification requirements before germination can take place. Manuals and online resources provide plenty of information on proper techniques to meet a seed’s germination requirements. These processes are nature’s way of delaying germination until conditions are right and increasing the likelihood that seedlings will survive.

Scarification is the softening of the hard seed coat. Nicking, chipping or sanding the seed coat are just some of the ways that allow water to penetrate through the seed coat to the embryo within, thus accelerating germination.

Stratification is the cold, wet period that seeds must go through to overwinter and germinate successfully when conditions are ideal. A seed of a plant in the tropics often has no stratification requirements, but it is not in a seed’s interest to germinate in December in that region, so winter hardy plants have developed overwintering strategies to help seeds germinate when the time is right for growth and development. . People sometimes think putting seeds in the freezer is good enough to simulate stratification, but that’s just not the case. It is the cold AND wet conditions to which the seeds are exposed that stimulate germination in the spring. Stratification data is listed in the number of days to months needed to accelerate germination. Take, for example, hickory shagbark. The seeds will need 3-5 months of cold stratification before germinating.

Simplified scarification and layering

Winter itself provides the best scarification and stratification for seeds, with the freeze-thaw cycle helping to loosen the seed coats so the seeds can soak up water in the spring. Be sure to mark the spot in the garden so you can identify trees and shrubs once they have sprouted. Keeping squirrels and voles away who will eat the seeds is a good idea. A layer of fabric or fencing with small openings can be placed above and below the seeds to prevent digging. Once the seeds have germinated, they can be carefully dug up and moved to their permanent home.

Kathleen Cue is an ISA & TRAQ Certified Arborist and Nebraska Extension Horticulture Educator for Dodge County. She can be reached at: 1206 West 23rd Street, Fremont, NE 68025-2504; (402) 727-2775; or [email protected]