This is a post that I wrote a couple months ago, and then forgot about before it got published. Thus, some of the temporal references are dated, but rather than rewrite the post I would like you to pretend that it is September 1. With that awkward introduction out of the way, here’s the post, which I plan to follow with a post delving back into the topic of “locally adapted seed”.

The last post discussed hopes and plans to increase availability of seed for restorations by growing some species for harvest, in effect agricultural fields of native seed. This is obviously dependent upon first gathering native selections to increase. Thus, I have decided to devote a post to a summary of seed gathering and some of the attendant issues, both practical and conceptual.

Over the past four years I have spent a lot of time in my relict prairies, as well as some owned by friends, gathering seed. I’m unable to spend long hours in the field, but an hour or two at a time 2-3 time a week over 15-20 weeks adds up. How much seed do I gather? Well, that becomes a complicated question dependent upon the target, the time of year and the quality of the area I am working in. Early in the year, meaning anytime before now, I often have one or two targets, and can spend my entire gathering session to get only a handful of a desired species. Yesterday I ended up gathering small amounts of six species, four of which are in the picture below. The other two went into a bag that is a catchall for any xeric adapted species, and I didn’t want to try to guess what amount was gathered yesterday to remove for the picture.

Doesn’t look like much for the work of an hour and a half, even if you add what was a big handful of blanket flower (Gaillardia aristata) and hairy goldenaster (Heterotheca villosa), the two species that went directly into the bag, but to me it’s more important than the paltry amount looks. I will return to that thought in my next post, but will backtrack to some bigger issues of seed gathering first.

There are two conjoined conundrums of conservation seed gathering: How to gather enough seed to make an impact on the restoration where the seed will be spread, and how to limit seed gathering to am amount which doesn’t impact long term viability of a species in the relict prairie. A proper balance between these two often competing goals is not always possible, but is rarely a large dilemma. The first goal is usually the larger problem. This spring I had prairie smoke (Geum triflorum) and pasqueflower (Anemone patens) blooming everywhere on both my restoration and the relict prairies. I assumed that I would be able to gather large amounts of both species.

Both these species bloom early and make seeds that stay attached to feathery plumes that waft in the wind. The window for gathering both is perhaps 7-10 days, after which the abscission layer is complete and they blow away. A seed that will blow away in the wind needs to be small and plants tend to make a lot of them, hoping some tiny percentage have an opportunity to continue their lineage. Add in the fact that they will not all mature at the same time and it is almost impossible to gather enough seed to worry about a detrimental impact to the population. The problem, rather, is timing an opportunity to get a useful amount. As it turned out, I had the opportunity to gather the pasque on what may have been the perfect day and have a nice amount of seed, perhaps 4-6 ounces. That is in a refrigerator waiting to be spread on the new restoration this fall. The prairie smoke matures 7-10 days later, and there were three consecutive days of 95-100 degree weather with high winds during that period which abruptly matured and then distributed the seed hither and yon. I may have gathered 10-15% of the pasque seed in my prairies, but doubt I got more than 1% of the prairie smoke, less than an ounce. I will either have to purchase some prairie smoke to supplement what I gathered, or rely upon better luck in gathering next year, no sure thing.

There are several other ways that plants make their seed hard to gather, such as shelling out immediately upon maturity, becoming nondescript brown entities which are almost impossible to find or by being eaten by animals and letting the animals distribute their seed Add in 35 cows with calves eating their way across the pastures to all the other native seed users, and quite a few seeds disappear right before I have the opportunity to pick them. Suffice to say, gathering sufficient seed from the relict prairies to supply the 20 acres of new restoration is a significant problem, and gathering enough seed of most species to impact populations in the relict prairies is less of a concern.

Here is another way to put it: over evolutionary time every species has developed a strategy that allows it to use its resources to maximize its “fitness”, which in short means its ability to send its genetics into another generation. One significant implication of this is that plants don’t really “waste” their resources to produce excess seeds. Over many generations plants of all the prairie species produced enough seed to maximize their chance to continue their genetic line and successfully procreate. Thus, even for species which make a great deal of seed I must assume some might find a new home and become new plants. Gathering a small fraction of their available seed of a species such as pasqueflower seems harmless, but it might mean a few less plants grow the next year. I can balance that fact out, however, with the high population that exists now in the relict prairie and the reasonable hope that I can turn that seed into a significant increase in population and range in the restoration. I have reason to hope that 10,000 seeds gathered that might have become 10 or 20 additional plants in the relict prairie can become 100 or 200 new plants in the restoration. The numbers are cheap speculation, but I think it is fair to assume that many more of the seeds will germinate and grow in a new area with a great deal of biotic space than in an existing prairie with very little. Thus, even though I am assuming I am impacting their natural reproduction in a small way, the more significant problem is not gathering too much seed, but how to access enough adapted seed of those species to augment my restorations.

There are a few species for which this is not true, however. They are more visible, they hold on to their seeds for a longer period of time, and populations in my prairies may be lower, scattered rather than ubiquitous. I will give two examples (out of perhaps 8-10 species where I face this dilemma) and describe how I view them.

The first is what to me is the flagship species of relict dry prairies in this area, black samson, aka narrow-leaved coneflower (Echinacea angustifolia).

If I see black samson in a pasture I know not just that it is a native prairie remnant, but that it has had very little herbicide. Depending upon the herbicide, one treatment is unlikely to eliminate black samson, but two or three treatments will. I have a large population in my prairies and have been fortunate enough to have gathered and spread enough seed upon my restoration that all the xeric to dry mesic areas have developed large populations as well. So where lies my dilemma, you may ask.

My assumption, based upon a few years of observation, is that black samson is a long lived species, and that gathering seed will not visibly affect the population for a long time. The hill above was in spectacular bloom in 2019 because of the combination of a spring burn and excellent summer rain.

After maturity the heads stay upright, holding on to their seeds for weeks, even months, before letting them fall in November or over winter. They are also extremely easy to see, even from a distance. It would be possible to harvest every seedhead. One of the goals of my restoration was to potentially expand habitat for the Dakota skipper butterfly (Hesperia dacotae), and black samson has been well documented as a preferred nectar source of the Dakota skipper. Thus, I have been determined to gather and spread as much as possible, and have exceeded 50% removal in many areas. Once again, it is ubiquitous across the prairie hills, and the literature mentions apocryphal stories about its longevity, leading one to believe that the population in my prairies can manage my theft in a good cause. I now have perhaps 70-80 acres in two different restorations with good populations of black samson, almost entirely from gathered seed.

My question now is whether I dare go to the well again to supply seed for my new 20 acre restoration project. I have found a source in the literature that found germinable seed, likely two or three years old, in the soil of a Kansas prairie. The authors speculated that black samson is a species which “seed banks”, storing up seed in the soil for germination after a disturbance event. In other words, the seed that I have gathered might not be important now, but could be in the future. The seed is maturing now, and I will begin gathering this week. I have not yet made a decision on how aggresive I will be gathering seed this year, but will do so soon. I am leaning towards holding gathering down around a third of the seedheads to allow the seedbank to build, and certainly gather no more than half. Then, next year, when I am not planning to do a new restoration, but may gather seed to topdress some areas of my existing restorations, I will only gather the heads that I find in the restored prairies and give the relict prairies a total rest.

The other example resides on the other end of the spectrum from black samson, being far less common. Standing milkvetch, or prairie milkvetch (Astragalus adsurgens) is an uncommon plant in my prairies, to the point where I know where most of the plants are, primarily on four or five hills on two of the prairies. I found the reason for this when the renters cattle broke through the crossfence in a pasture and grazed the hayland that I was planning to rest. The milkvetch is obviously “cow candy” and almost every plant was grazed right down into the dirt.

My assumption is that one year of premature grazing won’t be a serious problem for the plants which still likely have plenty of root reserves to grow next spring. Otherwise they would never have withstood the grazing of a herd of bison. I will have to be careful, however, not to allow this to happen repeatedly. The grazing, which occurred about a week before seed maturity, presented a dilemma regarding collection. I lost the plants which I had assumed would supply 80% of the seed I would gather. The adjacent pasture, ungrazed so far, has far fewer plants, only 12-15, and I needed to decide my collection strategy.

My strategy, perhaps a bit aggressive, was to gather 80 % of the seed on the plants that I had left. The goal was not to spread the seed this fall, as that method of seeding has so far only netted me one lonely plant in the 100 acre restoration. However, my new best friend, Dr. Lora Perkins at South Dakota State University (SDSU) will likely be able to turn that seed into a lot of seedlings which I can then replant in the new restoration as well as in the old restoration. Standing milkvetch is a a plant for which it is impossible to purchase seed from any vendors within 300 miles. Thus, I hope to begin a seed increase plot to provide seed for myself and hopefully other restorations that may occur in this area. The simple fact that it is unavailable means that there is likely to be difficulties in growing the seed. Otherwise I could probably find a vendor trying to make money on it. My other ace in the hole, besides Dr. Perkins, is another professor at SDSU, Dr. Arvid Boe, who has broad experience in working with native plants, and can hopefully educate me past some of the most obvious pitfalls. Then, if I have any success with the seedling plugs, and if I am successful in increasing seed production I can pay back my seed withdrawals with interest, planting seedlings and spreading seed back on my native prairie remnants.

That’s the plan, anyway, though it was also the plan this year. Several factors came together which interfered with the plan’s implementation and I hope to have better luck in 2023. One advantage I will have is starting early in building a team of people who are invested in making this work. Because of my health issues I am clearly the weak link in this plan and I hope to build in significant redundancy over the winter so it could move forward without my active participation.

As I stated earlier, standing milkvetch is only one of several species which are difficult to gather and also difficult to buy. I end with a picture of another, prairie larkspur (Delphinium virescens), which I discussed in a recent post. I didn’t get a lot of seed, but I hope to turn a small amount of seed into something significant in much the same manner as the standing milkvetch. Big hopes and dreams, but one has to start somewhere. As I also stated earlier, the value of my gathered native seed is, at least in my eyes, greater than what it seems; it is greater than an equivalent amount of purchased seed. That is the topic of the next post which will hopefully be published soon.