Segment Title: Tennessee Cut Flower Trials and Market Research
Segment: 03 of 08
Webinar Date: July 23, 2026
Speakers: Natalie Bumgarner, Associate Professor and Extension Specialist in Residential and Consumer Horticulture, University of Tennessee; Celeste Scott, Commercial Horticulture Specialist for West Tennessee, UT Extension
Recorded introduction: Narrated by Bethany Harris, then Whitney Ottinger
Moderator: Gabrielle LaTora, Agriculture and Natural Resources Agent, Fulton County, Georgia
Duration: 30:30.7 (1830.719 s, measured)
Series: Cut Flower Symposium
CEU Categories: [PENDING]
NARRATIVE SUMMARY
Natalie Bumgarner and Celeste Scott report three years of warm season cut flower work at the University of Tennessee, funded by a specialty crop block grant. Scott opens with how the program started. Interest in cut flower production picked up during the COVID era, a Center for Profitable Agriculture grant paid for travel that included a visit to Utah, and the meet and greets that followed packed the house and turned people away. The state contact list has passed 300 growers and a state association is forming.
The trials run in two places, Knoxville and Jackson, six hours apart with different soils and climates. Scott grew on fabric, Bumgarner on plastic, to cut down on time. Fertility was the first variable: one pound of nitrogen per thousand square feet for low, then two pounds for medium and three for high, delivered as a 20-10-20 soluble fertilizer through a Dosatron. The University of Maryland’s numbers were the only guidance they had for the region. Year one compared low against medium, year two low against high, and this year adds a no-fertility control alongside all three.
Zinnias responded. Bumgarner shows Knoxville trends toward more stems per square foot as nitrogen rose, with Benary’s Giants producing fewer, larger, high quality stems. Scott’s Jackson counts ran lower because she cut oversized stems early on and because her plot was newly prepared ground rather than the established organic farm soil at Knoxville. Zinderellas produced the highest cull percentage. Queeny Limes have to be cut at peak color or they look dingy in midsummer heat.
Celosia gave Bumgarner her clearest fertility response in the plume types. Scott lost two years of Jackson celosia data to early planting, root bound transplants, and off-target herbicide from a neighboring row crop plot. Sunday Green delivered long thin stems, Flamingo Feather re-bloomed several weeks after a hard cut, and Kurume brought a smaller coxcomb form.
Sunflowers moved from fertility to spacing, since every cut was a single stem. Two plants on nine-inch centers gave the highest share of heads under four inches and the lowest share above six. Bumgarner closes on grower and consumer surveys, willingness to pay, and five enterprise budgets built for a quarter acre.
CHAPTER TIMESTAMPS
0:00 Recorded Introduction: Bumgarner and Scott
0:56 A Multi-State Program, and How Tennessee Got Here
3:13 The Specialty Crop Block Grant and What It Funded
4:11 Building the Trials Around What Growers Grow
5:15 First-Year Scope and the Data That Overwhelmed Us
6:13 Fertility Treatments and the Maryland Baseline
7:19 Zinnias: Zinderellas, Benary’s Giants, Agaves, Queenys
8:59 Jackson Zinnia Results and Why They Read Lower
10:14 Zinnia Takeaways: Nitrogen, Culls, Harvest Timing
10:56 Celosia Types and the Knoxville Fertility Data
12:34 Why the Jackson Celosia Data Was Thrown Out
13:28 Celosia Cultivars: Sunday Green to Kurume
14:37 Sunflowers: From Fertility to Spacing
15:29 Three Spacing Treatments, Six-Inch to Nine-Inch
16:39 How Spacing Changed Flower Head Diameter
18:34 Sunflower Takeaways and the And More
19:40 Trialing Summary and Production Guides
20:01 Marketing: The Grower and Consumer Surveys
22:05 When and Where Consumers Buy
24:04 Barriers, Willingness to Pay, and the Budgets
26:03 Closing and Handoff to the Moderator
26:38 Q&A: Leaf-Footed Bugs on Sunflowers
28:04 Q&A: Where to Start, and What to Plant
QUESTIONS & ANSWERS
Q: Why run the same trials in two locations instead of one?
A: Scott says Knoxville and Jackson sit about six hours apart, with different growing conditions, different soil types, and different temperature climates. Running replications in both was how they meant to support growers across the whole state rather than one corner of it. The two sites also grew under different mulch: Scott used fabric and Bumgarner used plastic, a choice they made to cut down on time.
Q: What fertility rates did they compare, and how were they delivered?
A: Scott says the only guidance they had for the area came from the University of Maryland, which breaks fertility into three categories. They set low at one pound of nitrogen per thousand square feet, medium at two pounds, and high at three. The nitrogen went out as a 20-10-20 soluble fertilizer through a Dosatron injector. Year one compared low against medium, year two compared low against high, and the current year adds a no-fertility control so all four levels run side by side.
Q: Did zinnias respond to added nitrogen, and what did the two sites show?
A: Bumgarner reports Knoxville trends toward more stems per square foot as they moved up the fertility scale, with those trends holding when they went to the high rate in year two. Benary’s Giants carry larger flowers and produce fewer stems per square foot, but the quality is high. Scott’s Jackson counts came in lower for two reasons she names: she was cutting much larger stems at the start of the trial before her harvest practice settled, and her plot was a brand new prepared site while Bumgarner was planting into organic farm ground that had been in production for years and carried existing nutrients and loosened soil. The trend was the same at both sites.
Q: Which zinnias gave them trouble, and why?
A: Scott says Zinderellas were their highest cull percentage. Queeny Limes are good flowers but have to be harvested at peak for best color, or they look dirty and dingy, which can turn a grower off, especially in the middle of the warmest part of the season. She also notes late season disease and insect pests as a recurring problem on zinnias generally.
Q: What happened to the Jackson celosia data?
A: Scott calls herself a poor celosia grower for those two years and gives the reasons. In 2024 she planted too early because the transplants were getting root bound, and both constricted root growth and cool night temperatures can induce early flowering, so the numbers were not reliable. In 2025 her plot, which sits at a production row crop research facility, took off-target herbicide damage from a neighboring plot, since rectified. Both years of Jackson celosia data were discarded. The celosia fertility numbers in the talk are Bumgarner’s Knoxville data.
Q: Which celosia cultivars performed, and what were they good for?
A: Scott says Sunday Green gave reliably long, thin stems, which matters with celosia because fasciation can produce a beautiful bloom on a stem too thick to fit what you need. Sunday Orange, added the following year, bloomed well but the stem standards were not as comparable. Flamingo Feather was a favorite filler with very long stems and re-bloomed several weeks after a hard cut. Pampas Plume was good for quality and versatility. Kurume, an older cultivar they added last year, gave a smaller coxcomb form with variability in shape. Bumgarner adds that the largest fertility response across the celosia types showed up in the plume types, and that the more vigorous celosia showed more variability than zinnia did.
Q: Why did they stop testing fertility on sunflowers?
A: Scott says they ran sunflowers on fertility in year one and then realized every cut was a single stem sunflower, so fertility was unlikely to change the number of stems they got per plant. What they did see was a lot of variability in flower head size. From there they switched to spacing treatments, aiming to push head size in a predictable direction while using plant spacing templates growers already have for other crops.
Q: Which sunflower spacing produced the most usable flower heads?
A: Scott compared one plant on six-inch spacing, two plants per hole on six-inch centers, and two plants per hole on nine-inch centers. The single plant on six inches gave a fairly even distribution of heads below four inches and above four inches, plus a high percentage above six inches in diameter, which are less versatile for mixed bouquets. Two plants on six-inch centers, which brings the effective population down to a three-inch pattern, gave the highest percentage of heads under four inches measured petal to petal. Two plants on nine-inch centers gave the highest percentage under four inches and the lowest percentage at six inches and above. She wants to replicate that result this year.
Q: Where do Tennessee growers sell, and where are consumers actually buying?
A: Bumgarner puts the two survey sides next to each other. From the grower survey, farmers markets and direct to consumer are the highest outlets, with pick your own and some CSAs behind them, and respondents could select more than one option. From the consumer survey, asked about cut flowers generally, the grocery store number is very high, while far fewer growers reported selling at grocery stores. When the word local is added to the question the grocery store share drops and mass merchandisers, wholesale clubs, local florists, and farmers markets pick up, but a large share of local cut flower customers are still buying from grocery stores, which she reads as a point about highly accessible locations.
Q: What did the consumer survey say about how the purchase decision gets made?
A: About 62 percent were buying for gifts. Bumgarner puts a little less than 40 percent in the growing-for-themselves category, and 40 percent or higher reported the purchase as an impulse. Asked at what point they decided to buy, a third knew what they wanted before entering the shopping area, 50 percent knew they wanted it when they saw it, and 16 percent do not recall deciding at all. She treats the middle and last groups as the audience a grower can capture on accessibility. Willingness-to-pay surveys separately show that as the share of local flowers in a bouquet rises, consumers are willing to pay an increasingly large amount for it.
Q: My sunflowers are getting hit by leaf-footed bugs. Any organic options?
A: Scott answers this one from the chat. Most of the insect feeding damage she saw on sunflowers was on foliage, and flower head or petal damage showed up mainly on the lighter colored flowers. If blooms are harvested at the right time the petals should not be fully expanded yet, so a grower may be able to forgo treatment even with pest insects in the field. If pressure warrants control, she points to horticultural oils and insecticidal soaps, with three conditions: coverage has to be excellent for those products to work, they leave little to no residual so they need reapplying regularly following label directions, and they can cause phytotoxic issues in warm season temperatures.
Q: I’m starting cut flowers in middle Georgia. What size garden should I start with, and what should I plant?
A: Scott repeats that warm season cut flowers are the gateway for new growers, mostly easy from seed, and that they fit different setups. Her team started transplants indoors because the trials needed certain plant population counts, but many Tennessee growers direct seed warm season annuals. She recommends a combination of filler, foliage, and focal: zinnias as a start, celosia as either focal or filler depending on cultivar, gomphrena as a light filler with the caution that it takes time to harvest, Frosted Explosion as an annual panicum grass for foliage and filler, ornamental millets that come into their own later in autumn, and basil, which has to be cut after the stems begin to feel woody or it wilts past reviving. Bumgarner adds that the UT enterprise budgets are set up to grow about a quarter acre across five different cultivars, on the principle that nobody starting out needs an acre of zinnias.
ADDITIONAL RESOURCES
Named on camera by the speakers:
- UT enterprise budgets for five warm season annuals, available on their website. Bumgarner shows a QR code on the slide at 25:36 and asks for grower feedback and additions. No web address is spoken on the recording, so the link has to be supplied by the speakers or the symposium organizers before publication.
- Production guides from the trialing work, described at 19:48 as being assembled and headed for publication. Not yet available at the time of the talk.
- University of Maryland cut flower fertility guidance, which Scott names at 6:16 as the only guidance available for the region and the basis for their three-category low, medium, and high structure.
- UT Center for Profitable Agriculture, the source of the first grant, which funded the specialty crop scouting and the travel that included the visit to Utah.
- Pick Tennessee Conference, the statewide conference where the cut flower interest from the local meet and greets carried over.
- A Tennessee state association for cut flower growers, described at 2:59 as under development, to support growers with marketing, budgeting, and education.
SOURCE NOTES
This is a full-track segment at 30:30.7 and the standard Stage 2 targets applied without light-track scaling. Four things about the source shaped the file.
Two presenters, and attribution was the defect to guard against. The corrected transcript carries 127 Bumgarner blocks and 250 Scott blocks, with two turn boundaries moved at Stage 1 after being read on both sides. The split holds through this file: Scott ran the Jackson plots, the trial design, the cultivar takeaways, and the sunflower spacing work; Bumgarner ran the Knoxville data, the grower and consumer surveys, and the enterprise budgets. Every claim above is attributed to the speaker who made it, and the celosia section says outright which site each number came from, because the Jackson celosia data was discarded and the fertility figures are Knoxville’s alone.
Chapter density is about one marker every 80 seconds, 23 across 30:30. That is denser than one every 3 to 5 minutes. The talk moves crop by crop and then question by question through a survey deck, so markers were placed at genuine transitions and every one was checked against a block start time in the corrected transcript. The closest pair, 26:03 to 26:38, is 35 seconds apart and clear of YouTube’s 10 second minimum. The last marker is 2:26 before the end.
One rate was left as spoken at Stage 1 and is worth knowing about. At 6:29, block 86, Scott sets low fertility at one pound of nitrogen per thousand square feet. At 6:34, block 87, she gives medium as two pounds and high as three pounds “per square foot.” Stage 1 left that as spoken rather than normalizing it. The Q&A above states all three rates on the per-thousand-square-feet basis she establishes in the preceding block, which is the reading the sentence supports. If the recording is ever revisited for another purpose, this is the line to listen to.
One phrase in the spacing section remains a hub watch item. At 15:18, block 196, Scott refers to spacing templates people may already be using in “burnt fabrics,” left as spoken at Stage 1 as probable trade usage for pre-burned landscape fabric and still pending audio confirmation. Nothing in this file rests on it. The spacing answers use her clean phrasing at 15:55, block 204, “fabric templates that they already have.”
Zero open flags. All seven [VERIFY] markers raised at merge were closed against the recording in sweep 2 on 2026-08-09, before any derived file existed. Two of those resolutions are load bearing here: the cull percentage at 10:36 is a trial result about Zinderellas, and Kurume is the celosia cultivar named at 12:03 by Bumgarner and at 14:19 by Scott. Both appear in the Q&A above.
Verification, run from _Verify/ on the corrected SRT before writing:
COVERAGE CHECK GTBOP_Transcript_2026-07-23_BumgarnerScottUTResearch.srt
media duration 1830.719 s (30:30.719)
blocks 402
covered 1799.235 s
coverage 98.28 %
gaps >= 3.0 s 0
blocks starting past media end 0
blocks ending past media end 0
verdict PASS
SRT HYGIENE GTBOP_Transcript_2026-07-23_BumgarnerScottUTResearch.srt
blocks 402
time range 0:00.001 to 30:30.220
baseline Natalie and Celeste_parakeet.srt (402 blocks)
block count 402 = 402 MATCH
skeleton 804/804 lines byte-identical PASS
sequence numbers 1..402 contiguous PASS
lines over 42 chars 0 of 1081 (0.0 %)
blocks over 2 lines 197 of 402 (49.0 %) caption-editor pass, not a defect
open markers 0
verdict PASS
Processed for UGA Center for Urban Agriculture / Cut Flower Symposium Archives
Source: Corrected SRT (Stage 1), GTBOP_Transcript_2026-07-23_BumgarnerScottUTResearch.srt (402 blocks, 6,226 words)