From our experimental plots, we get information about Echinacea survival and reproductive fitness. Survival/health info comes from measurements of living plants, as does some information about reproductive success (# of flowering rosettes and # of heads). But achene (fruit) count, one of the most powerful measures of Echinacea reproductive success, requires the collection of heads. This is why, for the past few weeks, we have been harvesting flowering heads in experimental plots 1, 2, and 8.
Harvest requires careful timing. Harvest a head too early, and the achenes may not be fully developed. Harvest too late, and the head may have begun to lose achenes, throwing off our counts. To give ourselves the best chance of harvesting heads at the perfect moment, we check each head in our experimental plots every 6 days.
This is, as you might imagine, a complex operation. Even though there are few flowering plants in the experimental plots this year, relative to previous years, we still have 200+ heads to monitor and harvest across three experimental plots. Fortunately, there is a system in place. For a detailed description of this system, continue to the next paragraph. For a brief summary, feel free to skip to the final paragraph.
DETAILED DESCRIPTION: First, we create a list of all harvestable heads from our measure data. These are heads which were developing normally when measured, and might reasonably be expected to produce achenes this season. Heads in ExPt02 are identified by individual plant row and position, while heads in ExPt01 and ExPt08 are identified by both individual plant location and twist tie color (we added unique twist ties to each head while measuring).
On harvest days, we visit every head that has not yet been harvested. Working in pairs, we independently assess whether each head is ready for harvest, then compare our assessments and discuss. For an Echinacea head to be ready for harvest, it must have 1) dry/sharp receptacular bracts, 2) crisp involucral bracts, 3) a dry/brown peduncle, and 4) a crisp top cauline leaf. If any achenes are missing or appear loose, the head is harvested no matter what, to minimize the loss of achenes.
We use our harvest datasheets to keep track of this process. Each time we visit a head, we make a mark in a new color of pen to record our visit. If we deem the head ready to harvest, we carefully remove it with a hand pruner and place it in an “h-bag” (head bag). We label the h-bag with the LetNo (a unique 6-character identifier) assigned on the harvest datasheet. If harvesting all heads on one plant together (as is protocol in ExPt02), we may choose to use more than one h-bag, or an “l-bag” (lunch bag). The labeled bag(s) are then placed into a “g-bag” (grocery bag), which is given an identifying letter unique to that harvest session. The identity of the g-bag is also marked on the harvest datasheet. As you can see, a wide assortment of bags is crucial to a successful head harvesting operation.
A harvest datasheet for ExPt01Assorted g-bags in the head dryer
When we are finished with a harvest session, we close up our g-bag and add it to the seed dryer. This way, when it’s time to process these heads and count achenes, they will be well-labeled and completely dry. As we continue to harvest this year’s crop of heads, we have also been working to process the heads and achenes harvested last year. Stay tuned for a flog post on head cleaning and scanning!
Our harvest is progressing well! Harvest at ExPt02 and ExPt08 is complete, and fewer than 10 heads remain to be harvested in ExPt01. Other than an unfortunate incident of seed predation in ExPt02, where 49 heads were eaten by some sort of monstrous creature or creatures (deer? ground squirrels? bears?), we have managed to harvest almost every head without losing achenes. If all goes well, next year’s team will have no problem sorting through and collecting data on the heads that we have harvested.
Many of the variables that affect harvest are out of our hands. We can’t control how quickly Echinacea heads mature, nor can we prevent animals from eating or achenes from loosening. This harvest system, developed by Team Echinacea over the years, allows us to obtain high-quality data from a highly unpredictable system. In the end, the natural unpredictability of our study system is what makes this research so exciting!
QUICK SUMMARY: A wide assortment of bags is crucial to a successful head harvesting operation.
Its that time of the year when the grass is drying out and the kids are going back to school, and that includes me! I am off to the University of Minnesota to pursue a degree in Ecology, Evolution, and Behavior. This summer has been so much fun even though it was a short two months. I got to meet three wonderful people along the way, and together we made quite the team. We worked hard, and played even harder–as seen in our victory at trivia night.
Even in my second summer I learned so much. Together we discussed in depth, the experiments that are held in each of the common gardens. Coming out of the discussions left me with a bigger understanding and respect for the project that I didn’t quite have before.
Even though we played hard outside of work, work was still fun. This summer was filled a lot of shenanigans that I didn’t get to experience last summer. We had visitors from St. Olaf that helped us measure ExPt02. Not only were they a great help, we had a fun time making supper for them and going out on Lake Oscar together. I also got to do a lot more common garden maintenance than last summer, which was surprisingly fun.
Overall, I had a great summer working with Maria, Max, Stuart, Wyatt, and Yavonne. I learned more about the project, met cool people, and I have more great stories to tell for college ice breakers. Learning about the prairie has sent me on a path of life that I never expected and I hope someday that this path leads me back to the Echinacea Project once more.
The Underdog Team: The Angry AstersStuarts Self-Proclaimed “Best Work”Our Matching FootwearTeam Echinacea 2026
Prairie once covered the western Minnesota landscape, but due to European settlement and farming practices, only a little over 1% of this remains today, mainly on roadsides, hillsides, and other patches too difficult to farm. The native Minnesota purple coneflower, Echinacea angustifolia, serves as a model organism for studying these remnant prairies and whether they are persisting. Echinacea cannot self-fertilize, and it depends on pollination from another echinacea plant to reproduce. In small, isolated populations, we know that mating between closely related plants can cause inbreeding depression which negatively affects a population’s ability to persist long-term.But we don’t yet know whether the size of a remnant prairie itself directly affects that persistence and whether these smaller populations are still worth holding on to.Therefore, to answer this question and inform how conservation resources are directed, we continue “total demo” which is a census that revisits previously recorded flowering plants across remnant prairies. Guided by stake files loaded onto high-precision GPS units, we locate each plant on our total demo visit list and record its identification tag, flowering status, number of flowering heads, number of rosettes, and nearby neighbors. This data lets us compare mortality and persistence in populations of varying sizes.
Maria, Aaron, and Yavonne in the field doing total demo
So far this season, we’ve completed total demo at 25 small sites, visiting 777 locations where flowering plants had previously been recorded with an average of about 31 locations per site, ranging from as few as 1 to as many as 89. Next, we’re moving on to 18 large sites with an average of 104 locations each. Given the time and effort it would take to revisit every recorded plant at these larger sites, we instead visit a representative subsection. To help fill in the gaps, we pair this with a flowering plant survey, which catches flowering heads that aren’t on this year’s total demo list. Total demo will continue to keep us busy for a while!
So many monarchs this time of year!Hello leopard frog
Now that Team Echinacea 2026 is more than half-way done with our season, were doing some house keeping items to help fill the time, one of which is killing weeds in our experimental plots! Our biggest weed to kill right now is Rhus glabra, or smooth sumac. Although sumac is a native plant to Minnesota, it makes ours, and Echinacea angustifolias, life a whole lot harder out in the common gardens. It spreads very fast when not managed, and makes walking through much more difficult.
We tested two types of application of triclopyr on sumac. In ExPt01, we worked by ourselves and applied triclopyr to the bottom 10cm of each stem. In ExPt02 we worked in pairs, one person would chop the tops off of sumac and the other would apply the herbicide to the top 10cm of the available plant, including the exposed top. We found that our application in ExPt02 went faster and made application easier.
Both applications of herbicide on sumac were not in the plots themselves but were on the borders of the plots. Soon we will work on herbicide application in the common gardens.
The Southwest Border of ExPt02The Southeast Border of ExPt02Myself, Ready to Utterly Demolish Several Box Elder Trees
Team echinacea has completed the survey of flowering plants at our largest remnant and restored prairie sites, collecting data on their geospatial locations, number of normal and other heads (gone, duds, vertical developments, even a few mowed), and the tag number for each plant that assigns its identity. We visited 17 large sites, finding nearly 400 flowering plants!
Seeing new corners of Grant and Douglas counties as we drive to the sites is always a fun time, along with all the creature encounters. Pictured are curious cows along the road and one of many katydids, not pictured are a couple corn spiders and a bird’s nest!
After finishing surveying at these large sites and as we were to begin the process of total demo, we ran into a bit of an issue with our flag situation. Since total demo uses 5 flags (pink, blue, orange, red, and yellow), and white and neon flags also had been designated with a role, we were in need of a flag color for plants demoed and not surved. After much discussion and a unanimous group vote, we are happy to unveil our new flag color combo: red + blue. Here’s a chart that explains the situation (see if you can decipher it):
Now the team continues to visit smaller sites, revisiting past flowering plants and collecting demographic information. More updates to come!
Mooing at cows on the way to rileyMama katydid lounging on Collins (our GPS unit)
One of my favorite daily rituals has been the cultivation of the viola tub. Every morning since the beginning of Week 2 of our field season (6-Jul-2026), we have watered a tub of Viola pedatifida (prairie violet) outside the Hjelm house. Before we water, we also collect all ripe viola pods. Viola pods, as we call them, are the fruit of the prairie violet, and turn from pale green to white when ready to harvest. Interestingly, all the fruit we collect come from cleistogamous flowers, meaning that the flowers self-pollinated without ever opening. Prairie violet also produces chasmogamous (more traditionally pollinated, petaled) flowers, but our violets had stopped producing these flowers by the time we arrived in late June.
Yavonne and Aaron tending to the violetsCan you spot the viola pod?
I think that I enjoy the collection of viola pods because it satisfies my innate human urge to gather fruit. However, like everything else that we do here on Team Echinacea, it also has a greater purpose: the Advancement of Science! Last Monday, we designed an experiment to quantify the effect of seed freshness on V. pedatifida seedling establishment. This was our first time designing an experiment as a group, and it took us all afternoon, but it was a fun exercise in planning and group decision-making. Our experimental design is as follows:
Each morning, we collect all ripe viola pods in envelopes, where they explosively release their seeds. At the start of each week, we compile all Viola seeds collected in the previous week and weigh them out into 0.26 gram envelopes (roughly 200 seeds). Half of these will be planted later that day, while the other half are set aside for future planting. An additional five envelopes of “old” seeds, collected in the month before we designed the experiment, are planted at the same time.
We plant the Viola seeds in experimental plot 08, which is located just south of the Hjelm house. This plot is the site of an ongoing experiment (see Aaron’s recent post for details), and contains many Echinacea plants, as well as a variety of other prairie forbs and grasses, making it a good analog for a natural prairie habitat. Each envelope is planted in a unique, randomly determined 2-meter line segment within the plot, and given a single watering can’s worth of water. And then we wait!
What, you may be be asking, are we hoping to discover with this experiment? Our primary goal is to determine whether the age of Viola seeds (measured from the date of pod collection to the date of planting) affects seedling establishment. By planting “fresh” seeds (collected in the previous week) and “old” seeds (collected 2+ weeks ago) at the same time, we can directly compare their success. Previous research suggests that fresher seeds fare better, but whether this holds true in a natural setting has yet to be determined. Since our planting period spans from early August into September, we will also be testing whether time of year affects germination success. And lastly, since this is our first time conducting this sort of experiment, we will see whether our planting method yields results at all. At the very least, we should learn something about how to conduct future Viola experiments.
So there you have it! In September, myself and maybe Wyatt will return to exPt08 to count new V. pedatifida seedlings. I’m excited to see what we find out! I’m less excited to look for thousands of tiny seedlings in a sea of knee-high grass… but I’m sure I’ll enjoy it nonetheless. Stay tuned for updates!
Team Echinacea established quantitative genetics experiments to quantify additive genetic variance of fitness in Echinacea, with the idea that we can estimate evolutionary potential of study populations. The plants in qGen2 and qGen3 are offspring of the 1996, 1997, and 1999 cohorts. These plants were crossed with pollen from plants in remnants to produce seed for qGen2 and qGen3, which now inhabit exPt08. Originally, 12,813 seeds were sown in the common garden. Seeds from the same cross (shared maternal and paternal plants) were sown in meter-long segments between nails. This year we visited 1388 positions, found 758 basal plants, and 261 flowering plants.
We are one month into our 2026 field season! We have done so much and have shared so much, but right now, we are here to recap.
Big Accomplishments
Finished measuring Experimental Plots 2, 7, 8, 9.
Finished extracting seed from last years harvested flowering head.
Hosted visitors form St. Olaf, who helped us measure Experimental Plot 2.
To-Do List
Finish measuring Experimental Plot 1.
Finish surveying and doing demography our large remnant and restoration sites.
While these lists are short they pack some punch. We are over half way with both objectives in our To-Do List–but that still means we have to visit 1000+ potential plants in Experimental Plot 1. But that is enough about the future, lets talk about right now.
What is Demography and Survey, and why do we do it? We take surveys on each flowering plant, each year, at each of our remnant and restoration sites, to record the reproductive health of purple cone flower (Echinaceaangustifolia) plants. Then, we use our fancy GPS units to take the coordinates of the purple cone flowers to help us understand population densities and the survival of the same plant year-over-year. Doing these in tandem helps us add to a data base that is over 30 years old, which in turn helps us understand how populations of fragmented prairie plants change over time.
2026 Team Echinacea; Max R, Yavonne V, Maria H, and Aaron B
We so excited to attend Horticulture Night at WCROC and to see our wonderful lead researcher, Stuart, talk about tallgrass prairie!
This summer, Team Echinacea will be conducting ACE (Always Counting Echinacea, Achene Chaos Extraordinaire, Awesome Collaborative Experience, etc.) on the flowering echinacea heads collected during the 2025 field season to measure pollination success. For each head, the end goal is to get an accurate count of the number of achenes produced and the seed viability. Click here to learn more about echinacea seedheads.
Currently, we are working on both completing the inventory on 2025 collected heads and have begun cleaning (i.e. removing seeds from) high priority heads for three experiments: exPt08, polLim (pollen limited), and aphids. This has provided the team with a much needed indoor task during recent 90° and/or poor air quality afternoons.
So far, we’ve completed inventory for our 1st and 2nd priority bags of echinacea heads and 45% of our 3rd priority bags. For cleaning, we have completed all of polLim, are halfway through exPt08, and have yet to begin aphids. Still a ways to go!
During the cleaning process, we found a little stowaway in one of the heads. Our visiting lepidopterist Michael LaScaleia put our new friend under the microscope and declared him living! Shortly after, we rehomed the little guy. Since his chance of success is so low, no name has been given out of fear of attachment.
Echinacea angustifolia, the titular study species of the Echinacea Project, is the only species of purple coneflower native to Minnesota. But these days, it’s not alone. Multiple other species of Echinacea, including Echinacea pallida, have been introduced to Minnesota, whether as ornamental plants in horticultural settings or as E. angustifolia substitutes in prairie restorations (pallida seed is significantly cheaper than angustifolia seed). One such restoration is located within Hegg Lake Wildlife Management Area, a key study site for the Echinacea Project.
These two species of Echinacea are visibly different, with E. pallida typically having taller flowering heads and longer, skinnier rays than E. angustifolia. E. pallida also has white pollen, while E. angustifolia has yellow pollen. E. angustifolia is found throughout the western half of Minnesota, while E. pallida is native to Iowa, Illinois, and other more southern states. But why does this matter? Non-native plants like E. pallida can be aesthetically pleasing, and may even provide some of the same ecological benefits as their native counterparts. However, non-native plants can also outcompete native plants, and if hybridization occurs, may dilute locally adapted native gene pools. Experimental plots 7 and 9 (ExPt07 and ExPt09) were designed to determine if E. pallida can produce viable hybrid offspring with E. angustifolia, and to monitor the fitness of these hybrids.
One of our jobs this year was to measure all of the surviving plants in ExPt07 and ExPt09. We used different protocols for the two plots, but both went by mostly without a hitch. Compared to ExPt01, these plots had far more flowering plants: 37 flowering individuals were found in ExPt07 (29% of searched positions) and 106 were found in ExPt09 (44% of searched positions). The plants that were flowering also seemed to have, on average, more flowering heads (one plant had 18!). E. pallida generally produces more flowering heads, so seeing this pattern in its hybrid offspring made sense.
The legendary “tri-butt”Stuart, marking the boundaries of ExPt07
While we observed many healthy flowering heads, we also noticed lots of failed attempts at flowering (i.e. vertical developments), unsuccessful buds, and even “mutant” flowers (see the “tri-butt”, above). Whether this is an effect of hybridization or simply a result of the larger sample size of flower heads is unclear. If hybridization does increase the rate of unsuccessful flowering attempts, reducing fitness, it presents an immediate threat to populations of E. angustifolia within pollination distance of E. pallida restorations. Which brings us back to the restoration at Hegg Lake WMA…
After counting heads and identifying unique tag numbers for all of the flowering E. pallida plants in the Hegg Lake restoration, we took matters into our own hands. To prevent genetic swamping of nearby wild E. angustifolia, we beheaded every E. pallida plant in the restoration. Guillotined them. Total decapitation. If it sounds violent, that’s because it was. Robespierre would have been proud of us.
Say what you will about our methods, but Echinacea pallida won’t be showing it’s face at Hegg Lake WMA for a long, long time.
