Seed Isolation Strategy
One of the biggest challenges in this thousand-year seed project is proving what I hope is true: that any seeds I collect are the result of a deliberate crossing between two old-growth Western Red Cedar (Thuja plicata) clones.
There’s a complication worth considering. Even though I’ll be using fine mesh pollination bags to isolate the female cones — designed to prevent ambient pollen from reaching them — there’s still a chance that stray pollen could sneak in. I live at the edge of the forest, surrounded by mature Western Red Cedars that release pollen every spring, carried on the wind. So even with precautions in place, I can’t say with certainty that any resulting seed came only from the pollen I applied by hand.
Unless I test it.
So in spring 2026, when I bag the female cones, I’ll be introducing a control group.
Here’s the plan: I’ll bag two sets of female cones. One set will be hand-pollinated with pollen I collect from a chosen donor tree. The other set will be bagged the same way but left untouched.
If a Female Cone Is Bagged and Not Pollinated, It Should Not Produce Seeds
Female cones that are completely isolated from pollen — meaning no hand-applied pollen and no exposure to ambient pollen — will not be fertilized.
Without fertilization, the ovules will not develop into viable seeds.
There will still be cone development (especially early on), but the cones will be empty or underdeveloped inside.
By contrast, cones that are hand-pollinated and produce mature seeds would indicate successful fertilization — almost certainly from my applied pollen, especially if the control cones remain sterile and all precautions were followed.
Integrated Isolation Strategy
There’s also the issue of exposure imbalance. When I open a pollination bag to apply hand-collected pollen, I create a brief window during which stray pollen could enter.
If the control cones are never opened, they’ve had zero exposure risk, while the test group has some. So I’ll match the exposure: I’ll briefly open the control group bags for the same amount of time as the hand-pollination group — but without applying any pollen.
I’m also planning to bring the test trees indoors for the pollination itself. That way:
Both groups use the same type of bag
Both are bagged at the same developmental stage
Both remain bagged for the same duration
Both are exposed to ambient air for the same window
Hand-pollination occurs in a more controlled, cleaner, indoor environment
Why bring the trees indoors?
Controlled Air Environment: Indoors, I’m not contending with forest air thick with background pollen. The fewer pollen grains floating around, the lower the chance of contamination.
Still Air: No wind means no turbulence, which allows for more precise application.
Better Visibility: I can position lighting, steady the plant, and take my time.
Cleaner Surfaces: Indoor air — especially if filtered or closed up — will have vastly fewer pollen sources, making it a more reliable environment for this brief, sensitive step.
If seeds develop in the test group and not in the matched controls, it strongly suggests that my hand-applied pollen was the fertilization source and that ambient contamination was successfully avoided.
If all goes according to plan, we’ll have seeds born from the deliberate union of two ancient trees.