Our friends at Intervale and the US Fish & Wildlife Service are looking for help collecting poplar seeds for an experiment in streamside restoration methods! If you are familiar with a stand of poplars in your area you can help by keeping a close eye on the stand and by watching the female catkins and collecting the seed pods when they mature.
Annalise Carington, a Conservation Specialist with the US Fish & Wildlife Service, outlines the objective of the study:
The idea with this project is to establish native tree and shrub species from seed on riparian restoration sites [as] an alternative method to translating using nursery-grown stock.
We’ve found on floodplain sites where there is bare earth and little vegetative competition (i.e. old corn fields) native tree and shrub species are able to regenerate naturally, and often much more densely than we can plant! So, we are testing methods to replicate these “bare earth” conditions and direct seed onto that. We’re starting with the quick-germinating, pioneer species like quaking aspen, cottonwood, silver maple, willows, etc.
For seed collection, the first step is to find female clones! And then be careful to track them regularly as the seed pods mature. Check out this website and the photos below for good reference pictures of what the male vs. female flowers look like. Those female flowers, once fertilized, form the seed pods.
Ideally you can catch the seeds when the fluff is just starting to burst out of the seed pods. I’ve been using a pole pruner to clip branches and then harvest the catkins, storing the catkins in brown paper bags to let them dry and fully release the seed fluff. You can also collect the seed pods off the ground once they’ve fallen, but at that point some of the seed will have blown away.
For more information see this PDF on Seed Collecting which gives more background on identification, phenology, and monitoring for seed maturity. “Once clones have been selected, they need to be monitored daily until seeds mature. Seeds should be harvested when seeds are a light straw colour. Seeds harvested before this time will not ripen and greatly reduce the germinability of the seed lot. Although immature seeds are paler and more translucent than mature seed, it isn’t necessary to open up seed capsules to determine seed ripeness. Seeds are mature enough to harvest when the first capsule begins to split open and the white pappus (fluff) begins to break out (Figure 3). In warm weather the harvest window is three to five days.”
So, if you have the ability to cut branches and harvest that way, that is ideal! But if you need to harvest off the ground (as long as it’s within a day or two of when the seed started to emerge) that’s okay, too. Put the collected seed pods in paper bags to continue drying.
(Not sure if you can/know enough to collect correctly? If you are in the NEK, you can also contact Pete Emerson or Fritz Gerhardt with the locations of your promising poplar stands.)