Seed Collection: Reaping What You Sow

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by Natalie Helferty

The law of harvest is to reap more than you sow. Sow an act and you reap a habit. Sow a habit and you reap a character. Sow a character and you reap a destiny.
          James Allen

Although James Allen’s quote was directed toward people, it can be adapted to native plant propagation; in fact, it should be, if we are to restore our connection with Nature. Consider this: Sow a seed and you reap a habitat. Sow a habitat and you reap a community. Sow a community and you reap an ecosystem…one teeming with natural wonders and life! That is our salvation for this planet…sowing one small seed at a time.

Before we can sow, we need to know how to collect. Timing the collection of seeds is a skill of observation. We need to ensure the seeds are ripened to be viable, so patience is necessary. Yet also, we cannot wait too long after the ripening or else we will miss the seeds as they get eaten by birds, insects or mammals, or are scattered by the wind or water.

The spring ephemeral flowers in woodlands are the first to produce seeds. They take advantage of the limited sunlight available to the soil that filters through the bare boughs of the trees. They must bloom early and set seed quickly before the sun’s energy dissipates with leaf-out of the forest canopy. For that reason, you need to be quick in order to collect woodland wildflower seeds. You’re also competing with ants that will carry off the seed to eat the fleshy elaiosome (also called aril) when the seed casing first cracks open. This happens in Trillium species, bloodroot (Sanguinaria canadensis) , and twinleaf (Jeffersonia diphylla) . These seeds need to be sown immediately or stored in moist conditions to ensure the seeds don’t dry out.

Vigilance is necessary to spot seeds for some species as they may be inconspicuous. Examples are trout lily (Erythronium americanum) whose leaves die out quickly after flowering and bloodroot, whose fruiting capsule is enveloped by the leaves. These plants should be marked and seed capsules checked about four weeks after flowering and every few days thereafter. Seeds will darken at maturity and are only two to three millimetres (1/8 inch) long, contained in capsules. Seeds may be mature before the capsule cracks open, so if there are lots of capsules, split one open to check the darkness of the seeds in the population. If they are beginning to darken, and you can’t come back to get them, collect the capsules at that time. Keep them intact in a damp setting for the seeds to continue to ripen. Once the seeds are dark, break open the capsule, rake out the seeds and sow them immediately. If you wish to preserve the capsules or seeds for later sowing, keep them in a damp environment in the fridge. A small amount of their native soil collected from the forest floor will help them germinate.

Some woodland species, such as Jack-in-the-pulpit (Arisaema triphyllum) have bright red juicy fruits in the fall that are easier to spot. Be sure that juices from the seed collection do not get onto your hands as they are noxious to people. If ingested, they leave a burning sensation on your lips and tongue. Mice and voles, on the other hand, relish these seeds and bury them in their overwintering larders thus helping to propagate the plants.

Some plants have seeds that can withstand drying and, in some cases, prefer it. Columbine (Aquilegia canadensis) and harebell (Campanula rotundifolia) both have tiny seeds that require desiccation and full sunlight for germination, and can withstand some heat stress. The light, round seeds of these resilient yet delicate-looking plants tend to bounce around on rocky barrens or alvars (flat limestone outcroppings) and find their way into crevices where soil has collected. These plants are ideal for urban areas and could likely be grown in the cracks of sidewalks and in rock gardens, provided you avoid winter salting your sidewalk and use sand or grit, which aids in soil development.

For these hardy species, watch their developing capsules as they turn from moist green to dried brown and collect them just before they burst open. To capture the seed, you can also tie old pantyhose or other light mesh around the seed capsule with some thread or thin elastic band when they are almost dried. In your garden, if you want the plant to self-propagate, be sure to leave some seed in the capsules and they will fall on the surface of the soil as the capsule dries. Most “weedy” species in gardens are those that are most tolerant of hard conditions, so keep them in their ideally adapted conditions and they won’t become a nuisance. Planting them beside open ground will also enable smaller mammals and birds to find the seeds in the fall, which will also keep the plants’ fecundity in check.

Wetland seeds can be collected in late summer when flowers have turned into seed capsules. Watch insect and dragonfly activity from the shoreline and you’ll be able to tell when the small sedges, rushes and grasses are in bloom (lots of insects and dragonflies buzzing around) and when they are in seed (few to no insects and dragonflies). This is helpful since the seed heads are usually nondescript and difficult to tell from the flower heads, especially without a good, close-up, in-the-hand specimen to examine.

Wetland plants may have lots of tiny floating seeds, like cardinal flower (Lobelia cardinalis) . Or they could have larger floating seeds with air pockets such as pickerelweed (Pontederia cordata) . These eventually sink to the bottom as they get waterlogged in late fall (after migrating ducks and geese have had their fill). Floating seeds will be distributed across the surface of the water often in late summer over a long period, so urgency in collection is not needed, unlike with forest plants. A seed capsule that starts drying out from the top down to the stem, like monkeyflower (Mimulus ringens) , can be cut off the plant as soon it is mostly dried. The remaining seeds will mature, i.e. dry out, if kept inside the capsule in a container.

Meadow plants tend to bloom most prolifically late in summer to late fall. Since meadows are open habitats, wind is the preferred method of seed dispersal. Many tiny airborne seeds (goldenrods or Solidago spp., and Aster spp.) are blown off seed heads during fall storms. Many grasses and other fall seed-producing plants like cattails (Typha latifolia, T. angustifolia) , common milkweed (Asclepias syriaca) , and Joe-pye weed (Eupatorium fistulosum) also disperse their seeds this way. Capture the seeds when fluff first appears and before the seeds are all wind-dispersed. Fall-migrating birds searching for food help tremendously in seed dispersal, so seeds from the Compositae (daisy or sunflower) family, including black-eyed Susan (Rudbeckia hirta) are plentifully produced with open faces and stiff stems making them ideal landing pads. The seeds are mature when the seed head dries and the seeds change from dark brown to ashen gray. Vigorous rubbing will pop the square-sided seeds out of their head.

Treat all seeds with care so they don’t go to waste in your fridge or a bag. As well, when seeds are collected, be sure to collect less than 10% of any population and never collect seeds from plants that number fewer than 10 in a population. If the plant is listed as a Species At Risk in your area, do not collect its seed. Qualified propagators for recovery programs will need access to these seeds under the Canadian Species At Risk Act (SARA) as recovery plans are finalized in 2007. In the United States the collection of these seeds is prohibited under the Endangered Species Act. Seeds from cultivated specimens of threatened plants are exempt from these prohibitions provided that a statement of "cultivated origin" appears on their containers.

Many plant species have become endangered due to over-collection by native plant enthusiasts, so always check the origin of any plants or seeds you buy. On the other hand, propagation of a species in captivity can be sufficient to keep a species alive, so don’t feel that you can’t sow a rarity; just be sure that your activities are promoting its recovery.

Be a collector - and disperser - of Mother Nature’s seeds and we’ll all reap the benefits.

Natalie Helferty has collected seed from her “postage stamp” townhouse garden from almost 30 species planted along a wet-to-dry gradient made by her buried rooftop donwspout.