Larimer County Vegetable Trials

Tomato Trials

Members of the Colorado State University Extension Master Gardener program in Larimer County completed two tomato trials.

One trial consisted of 12 early-maturing, in-ground varieties that was conducted in 2019 & 2021. The second trial conducted in 2020 & 2021 featured 3 small-fruited varieties for containers.

You can see the results of those trials below. 

Sweet Pepper Trial

In 2022 & 2023, Larimer County Master Gardeners completed a trial of 15 sweet pepper varieties. The trial included 3 varieties of lunchbox peppers. 

The results are available below. 

A crate of tomatoes
Seed starting planters, filled with soil and labeled.

Where Can I Find These Varieties?

We do not endorse any specific company or variety.  All varieties are "commercially available," meaning they can be purchased by the general public. If you want to grow one of the varieties mentioned in a trial, we recommend you check with local nurseries or online garden supply retailers. 

No endorsement of products mentioned is intended, nor is criticism implied of products not mentioned.

View a printable PDF of the tomato trial results here

Top-performing Varieties:

After evaluating two years of data, Hybrid New Girl was the earliest maturing and had the highest fruit yield in the field trials.  Blind taste tests were utilized to determine what varieties had the best flavor. Hybrid New Girl was rated as having the best flavor for 2019 and 2021.  

Sample cups of various tomatoes along with a score sheet and a pen

In-Ground Varieties Trial Details

Jon Weiss, CSU Extension Master Gardener in Larimer County
Alison O’Connor, PhD, Horticulture Agent, CSU Extension

Cut tomatoes sit on plates with small cups.

Materials & Methods:

Hybrid and open-pollinated tomato varieties were included, along with determinate (bush) and indeterminate growth habits. The trial design for both years were replicated and randomized. Tomatoes were grown in the greenhouse and transplanted on June 5, 2019, and June 10, 2021 at the CSU ARDEC-South research farm. Tomatoes in 2019 were planted into ground beds covered with black plastic and irrigated with drip irrigation. Tomatoes in 2021 were planted into ground beds without black plastic and irrigated via furrow irrigation. Harvesting was done as needed as individual varieties ripened.

Results:

By comparing the tables, some varieties were consistent year to year, despite differing temperatures, growing season length, and weather events (hail). Overall, the trial results offer the home gardener valuable information to help determine what varieties to grow in northern Colorado.

Table 1. Maturity, Yield, and Fruit Size

Table 1. Maturity, Yield, and Fruit Size
Variety    Maturity*
2019		Maturity*
2021		Yield – lbs.
2019		Yield – lbs.
2021		Average Fruit
Size – oz.
2019		Average Fruit
Size – oz.
2021
Polbig 245.152.23.73.1
Valley Girl 240.8967.12.52.9
Celebrity 35369.14.64
Early Girl 252.864.92.32.9
New Girl1182.992.82.32.3
Moskvich 317.355.31.62.6
Carbon 361.471.3**5.95.9
Chef's Choice Black 342914.45.2
Big Beef 276.884.44.63.9
Mtn. Fresh Plus  37.204.90
Mtn. Merrit  22.704.70
Mtn. Rogue  18.703.40
Galahad 204902.7
Defiant 2068.602.4
Damsel 3054.903.4

 *Maturity for 2019: 1 = first variety harvested
*Maturity for 2021: 1 = first variety harvested while 3 = later maturing varieties

Table 2. Flavor

Flavor
VarietyTexture
2019		Texture
2021		Sweetness
2019		Sweetness
2021		Overall Flavor
2019		Overall Flavor
2021
Polbig3.52.92.61.62.92.3
Valley Girl22.52.11.722.4
Celebrity3.42.62.31.83.12.6
Early Girl32.92.232.53.2
New Girl3.63.12.83.13.23.4
Moskvich2.82.42.72.72.83.1
Carbon2.62.72.922.72.7
Chef's Choice Black2.72.53.22.43.22.8
Big Beef2.82.82.222.72.9
Mtn. Fresh Plus0 0 0 
Mtn. Merrit2.9 2.2 2.2 
Mtn. Rogue3.2 2.8 2.7 
Galahad 3 2.4 2.8
Defiant 2.2 1.5 2.3
Damsel 2.8 3 3.2

View a printable PDF of the container tomato trial results here

Top-performing Varieties:

Hybrid Patio Choice Yellow stood out as an early, high-yielding, large cherry size variety whose compact plant habit cascaded over the container.  

Tomatoes growing on a vine.

Container Varieties Trial Details

Jon Weiss, CSU Extension Master Gardener in Larimer County
Alison O’Connor, PhD, Horticulture Agent, CSU Extension

Purpose

There has been an explosion of interest in the growing of fresh vegetables by homeowners around the country. Many of these homeowners have extremely limited space and are looking for varieties to fill that confined space.

Small-fruited tomato (i.e., cherry, pear, grape) varieties are popular, but the vast majority have a larger, sprawling plant habit that may not work for small spaces. To address this issue, the Larimer County Master Gardeners conducted a three-variety evaluation trial. The varieties in the trial have a more compact habit and are commercially available.

Small yellow tomatoes grow on the vine

Varieties

  • Patio Choice Yellow (round yellow fruit)
  • Cherry Falls (round cherry fruit)
  • Totem (round cherry fruit)

Methodology

Tomatoes were seeded and grown in the greenhouse, until transplanting on June 6, 2021 into large containers as part of the CSU Annual Flower Trials. Each container had a single plant and were irrigated and fertilized via drip irrigation. Five containers per variety were utilized (with the exception of Totem that only had four replications). The plants were randomized within the allotted area and grown by trial staff.
Maturity, yield, and average fruit size were collected for each variety.

Results

Cherry Falls was an early maturing variety with a compact, somewhat open growth habit. Totem had a dense growth habit and was the latest maturing of the three. Patio Choice Yellow was as early as Cherry Falls, with larger fruit, and higher yield. Overall, the results offer the home gardener valuable information to help determine what varieties to grow in northern Colorado.

Variety Yield Results (ounces)

Variety Yield Results (ounces)
Harvest DateCherry FallsPatio Choice YellowTotem*
8/1016.925.62.2
8/1790.095.218.8
8/2449.0175.162.6
8/3149.0195.060.0
9/715.0108.488.4
9/1411.039.360.4
9/212.411.939.4
Average Fruit Size (ounces)0.30.60.2
*Yield based on four plants

Variety Harvest Totals (pounds)

Variety Harvest Totals (pounds)
 Cherry FallsPatio Choice YellowTotem*
Total harvested
fruit (pounds)		15.740.720.7
Average harvest per
plant (pounds)		3.18.15.1

*Yield based on four plants

View a printable PDF of the 2022-2023 trial results here

2022 - 2023 Pepper Trials Results

Purpose of the study

There has been an explosion of interest in backyard production of fresh vegetables around the country. Sweet peppers are a favorite to grow on the Colorado Front Range, though selection of varieties is challenged by the relatively short growing and harvest season. Members of the Colorado State University Extension Master Gardener program in Larimer County, in cooperation with the CSU Specialty Crops program, conducted a trial with 15 sweet pepper varieties in 2022 and 2023.

A seed tray of sweet pepper starts

Materials and Methods

Hybrid and open-pollinated pepper varieties known to be early to early mid-season in maturity were selected. Twelve varieties were sweet bell peppers and three were “lunchbox” type. Peppers were grown in the greenhouse and transplanted in early June in 2022 and 2023 at the CSU ARDEC-South (Fort Collins, Colo.) research farm. The plants were planted into ground beds covered with black plastic and irrigated with drip irrigation. It was a replicated and randomized trial.


Three plants from each replication were harvested. There were three harvests during 2022 and two in 2023 – the final harvest removed all fruit from plants. Heat and rabbit damage affected the pepper plants in 2022, so theoretical yields were used for each variety. During 2023, the cool, wet spring and temperature variations throughout the growing season slowed plant development. In 2022, 16 participants provided feedback on pepper taste and overall flavor.

A group of Master Gardeners harvest sweet peppers and gather data.

Fast Facts

  • Sweet peppers are a favorite of backyard gardeners, but the Colorado Front Range short growing season limits varieties that can be grown successfully.
  • There were 15 pepper varieties in the research trial.
  • Peppers were evaluated for flavor and yield.
Multiple small yellow sweet peppers sit on a scale to find the weight of the group.

Results & Comments

All varieties averaged less than 24" in plant height. The variety 'Ace’ was the earliest maturing variety in both years. 'Olympus' was the highest yielding variety for both years. For those wanting to grow a stuffing pepper, both ‘Olympus’ and ‘King Arthur’ are good choices. The varieties with largest fruit size in 2022 and 2023 were ‘Olympus’ and 'King Arthur' respectively. ‘Purple Beauty’ scored the lowest in taste from participants.


Of the “lunchbox” varieties, 'Just Sweet' stood out by its high yield, flavor, and larger fruit size. Though 'Cajun Belle' is sold as a sweet pepper, it does have a spicy heat. Overall, these trial results offer the home gardener valuable information to help determine what varieties to grow in northern Colorado.

A sweet pepper sits on the ground next to a label stating it's variety (
Variety2022
Average fruit yield per plant (lb)		2023
Average fruit yield per plant (lb)		2022
Average Fruit Size (oz)		2023
Average Fruit Size (oz)		Overall
Flavor
Ace6.14.03.73.23.1
Flavorburst5.23.95.94.33.2
Goldenstar4.54.16.14.43.2
Gourmet3.93.64.33.7N/A
King Arthur4.74.48.65.03.5
Milena4.53.55.44.5N/A
Ninja3.54.45.44.33.2
Olympus6.14.56.25.43.3
Purple Beauty4.23.43.33.02.4
Sprinter5.54.34.93.93.4
Staddon's Select5.74.13.63.1N/A
Sweet Sunrise4.33.14.42.93.2
Cajun Belle*2.82.30.60.7N/A
Eros*3.13.40.80.72.8
Just Sweet*5.03.41.21.04.3

 

Table details:

  • Flavor scale: 1 = lacking flavor; 5 = great flavor (n = 16 participants)
  • *Lunchbox variety
Thanks to the following:

Dr. Mark Uchanski and Jane Davey, CSUSpecialty Crops Program; the CSU Department of Horticulture and Landscape Architecture; ARDEC-South faculty and staff; and the many Larimer County Master Gardeners who supported this research project.

 


Larimer County Colorado State University Extension

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Fort Collins, CO 80524-2004

Phone: (970) 498-6000

 

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