Have you ever watched those little helicopter seeds whirling through the air in late spring? They are a sure sign that certain trees are ready to spread their next generation. For a gardener, these fascinating fliers are more than just a pretty sight. They are a key to understanding and managing the trees in your landscape.
This guide will help you identify which trees produce them, explain the science behind the spin, and offer practical tips for handling the seedlings that follow. You’ll learn to appreciate this clever bit of natural engineering happening right in your backyard.
Helicopter Seeds – Whirling Through The Air
The technical term for these winged seeds is a “samara.” A samara is a type of dry fruit with a papery wing that helps it travel on the wind. The unique shape causes it to spin as it falls, a motion called autorotation. This spin slows its descent dramatically, allowing the breeze to carry it much farther from the parent tree than a simple seed could fall.
Which Trees Make Helicopter Seeds?
Several common landscape trees produce these distinctive seeds. Knowing which is which can help you make informed planting choices.
- Maple Trees (Acer species): This is the classic helicopter seed producer. Sugar, Red, Silver, and Norway maples all create the familiar paired “keys.”
- Ash Trees (Fraxinus species): Ash seeds are single samaras, looking more like a canoe paddle than a whirligig. They are often seen in dense clusters.
- Elm Trees (Ulmus species): Elm seeds are round and flat, with a papery wing surrounding the central seed. They tend to disperse in large groups.
- Tree of Heaven (Ailanthus altissima): This invasive tree produces single, twisted samaras that hang in large clusters through the winter.
The Brilliant Science of the Spin
Why does it spin? It’s all about aerodynamics and survival. The wing is asymmetrical and heavier at the seed end. As it falls, air pushes up harder on the wider, flatter part of the wing than on the seed end. This difference in force creates torque, which sets the seed into a stable, spinning motion.
This autorotation has two big benefits for the tree:
- It increases air time, letting the wind carry seeds away to reduce competition with the parent.
- It helps the seed land correctly, often with the pointed end ready to dig into the soil.
Managing Seedlings in Your Garden
While beautiful, thousands of helicopter seeds can mean a battle with seedlings in your lawn and flower beds. Here’s how to manage them effectively.
- Catch Them Early: The best time to remove seedlings is right after germination, when they are easy to pull by hand and their roots are shallow.
- Use the Right Tool: For slightly bigger seedlings, a weeding knife or a hoe is effective. For lawns, a dandelion weeder can get the taproot out cleanly.
- Mulch is Your Friend: A 2-3 inch layer of mulch in garden beds smothers many seeds before they can even sprout and makes pulling any that do get through much easier.
- Mow Regularly: In the lawn, frequent mowing will prevent most tree seedlings from ever establishing themselves.
Should You Grow a Tree from a Helicopter Seed?
Absolutely! It’s a rewarding and cost-effective way to add trees to your property. Follow these steps for the best chance of success.
- Collection and Selection: Gather seeds in late spring or early summer when they first fall. Choose plump, undamaged samaras.
- The “Float Test”: Place seeds in a bowl of water. Viable seeds usually sink, while empty or non-viable ones often float. This isn’t perfect, but it helps.
- Cold Stratification: Most maple and ash seeds need a cold period to break dormancy. Mimic winter by placing them in a damp paper towel inside a sealed plastic bag in your refrigerator for 60-90 days.
- Planting: After cold treatment, plant seeds in small pots with potting mix, about 1/2 inch deep. Keep the soil moist but not soggy.
- Patience and Care: Place pots in a bright, indirect light location. Germination can take several weeks. Once the seedling has a few sets of true leaves, you can begin to acclimate it to outdoor conditions.
A Note on Invasive Species
Be a responsible gardener. While growing a native maple from seed is great, avoid propogating known invasive trees like the Tree of Heaven. Their helicopter seeds are a big reason they spread so agressively, outcompeting native plants and causing ecological damage. It’s often best to remove these trees if they appear on your property.
Fun Projects with Helicopter Seeds
Next time you see a blanket of samaras on the ground, try one of these simple activities, especially with kids.
- The Drop Test: Collect seeds from different trees. Drop them from a height and see which designs spin the best or glide the farthest.
- Seed Art: Use the seeds to create nature collages or to make impressions in clay.
- Science Observation: Plant a few in a clear cup against the side to watch the germination process unfold from seed to sprout.
Frequently Asked Questions (FAQ)
What are helicopter seeds called?
They are called samaras. The paired seeds from maples are often specifically called “maple keys.”
When do helicopter seeds fall?
This depends on the tree species and your climate. Most commonly, you’ll see them whirling down in late spring through early summer. Some, like the Tree of Heaven, may hold their seeds into winter.
Are helicopter seeds harmful to my lawn?
The seeds themselves aren’t harmful, but the sheer number of seedlings can be a nuisance. They won’t damage established grass but will compete with it if left to grow. Regular mowing usually solves the problem.
Can you stop a tree from producing helicopter seeds?
There is no safe, practical way for a homeowner to completely prevent seed production. Some growth regulator chemicals exist but are typically applied by arborists for specific reasons and are not a guaranteed solution. The best approach is to manage the seedlings as they appear.
What tree has the biggest helicopter seeds?
Among common trees, the Norway Maple produces some of the largest and most robust paired samaras. The Bigleaf Maple of the Pacific Northwest also has very sizable seeds.
Understanding the life cycle of the trees around you, from those whirling helicopter seeds to the majestic mature tree, makes you a more engaged and effective gardener. With a little knowledge, you can turn a potential nuisance into a learning opportunity or even the start of a new, beloved tree for your garden.