Progress report for FNC24-1433
Project Information
I, Megan Rudroff, am the owner and operator of Rudy Lane Flower Farm. This flower farm that I operate with help from my husband, Layne Rudroff, is only about 1/4 acre in size, however, we currently grow 600 peony plants, 600 dahlias, and thousands of annuals, tulips, and more on that small acreage. Our flowers are sold both direct to consumer as well as wholesale to florists. In addition, we also have 70 head of cattle, 150 acres pasture, native grass hay, as well as traditional corn and soybean fields. We are very familiar with the amount of work, money, and risk management that is required for farm operations to survive and we're constantly looking for ways to improve.
I have a Bachelors Degree in Agriculture with emphasis in Natural Resource Management and a minor in Wildlife Management. In the past, I have been employed as a research technician for many different projects, from abandoned lead mines, to paddlefish migration, to effects of herbicide on native prairies. These projects have given me a strong understanding of the scientific method and the importance of replicated, non-biased studies and detailed recordkeeping.
Currently, I am also employed full time as a Resource Conservationist where I work with and teach people about resource management on a daily basis. This has given me an immense amount of opportunity to do outreach and education and that is a skill I plan to bring to this study, by sharing the results with other flower farmers within my region and, in fact, throughout the country, as applicable. I enjoy speaking to large groups and have given presentations at multiple conferences to groups from 20 to 200 people, as well as via ZOOM when the group is beyond the local area. Additionally, I have an active social media following where I am posting nearly five times per week - whether it's gardening tips, behind the scenes on the farm, or other topics of interest to flower farmers and flower enthusiasts, alike. Sharing knowledge and helping fellow farmers, especially women entrepreneurs, is one of my passions.
Digging and planting dahlias
tubers represents a huge labor expense for dahlia growers.
Though some have successfully overwintered dahlias in warmer
climates, little information is available for our growing
zone. The vast majority of flower farms in the US employ
just one person. This makes dahlia digging, washing,
storing, and replanting a huge portion of their available time
and labor. Alternatively, leaving dahlia tubers in the
ground over winter can be an enormous financial risk as dahlia
tubers are relatively expensive.
In addition, flowers that bloom
earlier than their traditional season command a higher price due
to their rarity, specifically dahlias which do not ship well and
are highly sought after in the wedding flower sector.
However, there is very little specific data on how much
difference can be seen in overwintered dahlias, especially
between various methods and planting locations.
Solution:
By evaluating the success of
various techniques for over-wintering dahlias, I seek to give a
more definitive answer to whether it can be successful and which
methods work best in zone 6.
Furthermore, in warmer climates,
it is generally accepted that successfully overwintered dahlias
bloom earlier than their spring-planted counterparts.
Additionally, those overwintered in a high tunnel bloom earlier
than their field grown counterparts. This study will record
whether that is true for our growing zone and, if so, is that
difference statistically significant.
In this study, I will have 5 test
plots, each with 50 dahlia plants:
-
control/traditional method:
dahlias are not overwintered and spring-planted instead -
high tunnel covered with leaves
or straw mulch and then topped with reusable weed barrier as a
tarp -
high tunnel with no mulch, only
weed barrier fabric as a tarp -
field grown (outside high
tunnel) with mulch layer and weed barrier as a tarp -
field grown no mulch, only weed
barrier fabric as a tarp
I intend to plant two varieties
of 25 dahlias per test plot for a total of 50 dahlias per plot.
Different varieties of dahlias bloom in fewer numbers of weeks,
so this will help determine if bloom time can be optimized within
specific varieties or forms of dahlia (ie: border dahlia vs
dinner plate dahlia). I will record the success rate of
overwintering for each plot. I will also record the first
bloom date for each plot. I will then determine the
significance of any difference between the
plots.
High tunnel space is valuable,
and this data could help determine if it is worth using high
tunnel space for this crop, or conversely, if the difference is
not significant enough to devote this space to dahlias and would
be better spent on other crops.
If at least some varieties of
dahlias could bloom in early June, or better yet, May (peak
Spring wedding season in this region) this could make a high
value flower, even more valuable for local cut flower
farmers. This research will give growers more data to
consider if overwintering their dahlias is beneficial to their
operation.
Objectives:
-
Evaluate the effectiveness of 4
methods of overwintering dahlias -
Record first bloom dates for
dahlias among the 4 different methods as well as of the control
group of Spring-planted dahlia tubers. -
Share findings through
(minimum) 2 blog posts, 2 social media posts, a published
article in a cut flower specific publication, and 1 field
day.
Cooperators
- (Researcher)
Research
To implement my project, I laid out my 5 test plot areas. The 3 field grown ones were in an area that I have historically planted to dahlias. The 2 high tunnel plots were planted in an area where the high tunnel would be constructed. Note: due to grant timing and high tunnel wait times, dahlias were planted prior to high tunnel construction. As originally described, I planted 50 dahlia tubers in each of the 5 test plots. Plots 1, 4, and 5 (field grown) were planted April 22 (at or near the average last Spring frost date). Plots 2 and 3 (high tunnel) were planted May 12th. I used two varieties of dahlias, one called Arbtax and one called Caitlin’s Joy. Both varieties are ball form dahlias. Dahlias plants were grown and tended to in a traditional way including being supported with steel t-posts and baling twine arranged in the so-called Florida Weave pattern. Dahlias were fertilized, weeded, and harvested from as usual for cut flower production.
Plots 2 and 3 (high tunnel), unfortunately, were a total crop loss to excessive rainfall after planting. I replanted dahlia tubers (different variety) on June 17. However, additional rainfall following planting caused another crop failure. We continued the research as planned on Plots 1, 4, and 5 and will re-try the high tunnel plots in 2025.
After our first killing frost in October, we began the processes of digging tubers or overwintering. First, the dead dahlia plant material was cut about 1” above the soil surface. Then, for the traditional plot (1), we dug up the dahlia tubers, washed the soil off, and packed them in crates to store in the flower cooler until Spring. For the overwintering plots (4 and 5), we added 8-12” of straw mulch and weed barrier tarp (4) or just the weed barrier tarp (5) and secured with landscape staples.
In spring, we will determine the effectiveness of the various methods. If the overwintering is successful, we will compare bloom times between the overwintered dahlias and the traditionally planted dahlias which will be planted approximately April 22, 2025 (weather-dependent). A statistically significant earlier bloom period would, in my hypothesis, result in increased financial benefit due to low (or no) supply of dahlias in late Spring or very early summer in my market.
The effectiveness of different methods cannot be determined until Spring 2025. However, data has been collected on plant survival rates during growing season in order to determine how many subsequently survive the winter. I have also measured the time, per plant, to dig, wash, and pack dahlia tubers versus time per plant to cover or mulch and cover each plant. This information will be valuable in determining economic values of each method for consideration by dahlia growers.
Educational & Outreach Activities
Participation Summary:
I currently have one blog post drafted, but not published that outlines the goal of the research and the methods. I plan to have a field day in the Summer of 2025 once effectiveness of methods can be seen. If overwintering plots do not survive, there would not be anything to see, unfortunately. Either way, I will have additional blog posts which I can site in social media posts targeted to fellow dahlia growers, that will summarize the results of the study by comparing the various methods.
Learning Outcomes
The biggest lesson I have learned so far is the importance of site considerations. I knew, going in, that dahlia tubers were susceptible to rot due to excess moisture. However, I have never had such total and complete dahlia crop failures in my 5 years and thousands of tubers planted as I did this year. Though I was able to grow hundreds of tubers, in addition to my research plot, I also lost more than I ever have before. The difference between my field grown plots and my high tunnel plots is the field grown is on a 5% slope whereas the high tunnel area is flat (ideal for high tunnel construction.
Under normal circumstances, the high tunnel would have protected the tubers from excess rainfall, however, due to grant timing and high tunnel manufacturer waitlist, I was not able to have it constructed in time (though I would have built it prior to the overwintering period by constructing it around/over the previously planted dahlias - had they survived).
My concern is for the field grown plots for those who live in an area with wet winters. I am unsure if the tarp or mulched and tarped methods would be enough to prevent rot in field conditions where the plots may wick water from adjacent wet soil rather than it shedding away or infiltrating into deeper soil levels.
I expect more lessons to be learned as the study continues through the winter to understand the impacts to the overwintering plots.