Water use in floriculture varies sharply by production setting, irrigation control, and whether the crop is grown under protection or in the open. In 2023, U.S. horticultural operations irrigated 1.7 billion square feet under protection, while floriculture and bedding represented 891.9 million of those square feet. National figures show the scale of the sector; historical greenhouse guidance and a 1994–1995 rose trial provide more specific planning benchmarks.
Table of contents
- U.S. floriculture irrigation footprint
- Protected horticulture: 2018 and 2023
- Where irrigation water comes from
- Irrigation systems, wells, and hydroponics
- Greenhouse irrigation and cooling demand
- Planning rates for greenhouse and nursery water
- Cut-flower rose water use by irrigation control
U.S. floriculture irrigation footprint
The USDA’s Irrigation and Water Management: Highlights Results from the 2023 Irrigation and Water Management Survey reported 1.7 billion square feet of protected horticultural area irrigated in 2023. The protected area increased by 197 million square feet between 2018 and 2023. These figures describe irrigated area, not a single crop-specific water total.
Floriculture and bedding accounted for 891.9 million irrigated square feet under protection in 2023. Nursery crops accounted for 478.7 million square feet, food crops under protection for 209.8 million square feet, and propagative materials for 157.7 million square feet. Together, these categories show that floriculture and bedding were the largest named protected-horticulture category in the USDA highlight.
Horticultural operations also irrigated 598,980 acres in the open in 2023. Floriculture and bedding represented 33,884 of those irrigated open acres. The protected and open-area measures use different units because the USDA reports protected production in square feet and open production in acres.
Source: USDA, Irrigation and Water Management: Highlights Results from the 2023 Irrigation and Water Management Survey, 2023.
Protected horticulture: 2018 and 2023
USDA Table 46 provides a broader protected-horticulture view. It includes nursery, greenhouse, floriculture, and other horticultural crops, so its totals should not be read as floriculture-only measurements.
| Measure | 2018 | 2023 |
|---|---|---|
| Operations irrigating protected horticultural crops | 24,876 | 26,716 |
| Irrigated protected area | 1,525,130,873 sq. ft. | 1,721,886,383 sq. ft. |
| Irrigation water received | 9,912,941,000 gal. | 14,994,073,000 gal. |
In 2023, 26,716 operations irrigated protected horticultural crops by all methods, compared with 24,876 operations in 2018. Irrigated protected area was 1,721,886,383 square feet in 2023 and 1,525,130,873 square feet in 2018. The corresponding irrigation-water totals were 14,994,073,000 gallons in 2023 and 9,912,941,000 gallons in 2018.
The table therefore documents both a larger irrigated protected area and a higher reported irrigation-water total in 2023. It does not identify how much of the total was used by floriculture alone, nor does it establish a universal water requirement per square foot for every flower crop.
Where irrigation water comes from
Across U.S. farms, 53.1 million acres were irrigated with 81.0 million acre-feet of water in 2023, according to the USDA irrigation survey highlight. Groundwater from wells supplied 43.9 million acre-feet. On-farm surface water supplied 8.6 million acre-feet, while off-farm water supplied 28.5 million acre-feet.
The same source reports the source mix as 54% groundwater from wells, 11% on-farm surface water, and 35% off-farm water. Those percentages describe U.S. irrigation water applied in 2023, rather than a floriculture-only source mix.
For protected areas specifically, irrigation wells provided 67% of water in 2023. This protected-area figure is useful context for greenhouse and other covered production, but it does not specify the share used by flowers, bedding plants, nursery crops, or other protected horticultural categories.
Source: USDA, Irrigation and Water Management: Highlights Results from the 2023 Irrigation and Water Management Survey, 2023.
Irrigation systems, wells, and hydroponics
Sprinkler systems were used by 106,253 U.S. farms in 2023 and covered 30.8 million irrigated open acres. Gravity systems were used by 67,994 farms and covered 18.3 million irrigated open acres. Drip, trickle, and low-flow micro systems were used by 60,160 farms and covered 6.4 million irrigated open acres.
| Open-area irrigation method | Farms | Irrigated open area |
|---|---|---|
| Sprinkler | 106,253 | 30.8 million acres |
| Gravity | 67,994 | 18.3 million acres |
| Drip, trickle, and low-flow micro | 60,160 | 6.4 million acres |
| Hydroponic distribution | 139 | Less than 0.1 million acres |
Hydroponic distribution was reported by 139 farms in the USDA open-area irrigation table for 2023, covering less than 0.1 million irrigated open acres. That placement in the open-area table is a reporting detail; it should not be treated as a complete measure of every hydroponic or greenhouse system in the country.
The national well count was 456,058 irrigation wells used by 114,889 farms in 2023. Farms using groundwater for irrigation averaged 4.0 wells per farm. These well statistics describe irrigation infrastructure nationally, while the 67% protected-area figure describes the source of water for protected production.
Source: USDA, Irrigation and Water Management: Highlights Results from the 2023 Irrigation and Water Management Survey, 2023.
Greenhouse irrigation and cooling demand
North Carolina State guidance estimates greenhouse irrigation at 2 quarts per square foot of covered area per day, also stated as 20 liters per square meter per day. The source presents these as a 1996 guidance estimate, not as a 2026 national measurement.
For a one-acre greenhouse, the same guidance estimates approximately 22,000 gallons of irrigation water per day, or approximately 83 kiloliters per day. These figures are planning estimates: actual use depends on the crop, covered area, weather, irrigation controls, and operating schedule.
Cooling can add a separate demand. North Carolina State guidance gives peak pad-and-fan cooling demand as approximately 19 gallons per minute for one acre of greenhouse and average demand as approximately 11 gallons per minute. Using pad-and-fan cooling for 12 hours per day is estimated at about 8,000 gallons per acre per day.
The cooling guidance also reports peak evaporative cooling use of 0.045 gallons per 1,000 cubic feet per minute of fan capacity, or 0.17 liters per 1,000 cubic feet per minute of fan capacity. It states a cited peak cooling-capacity conversion of 472 liters per second of fan capacity and peak cooling demand of 180 liters per hectare per minute for an acre-scale greenhouse. Twelve hours of pad-and-fan cooling is estimated at about 75 kiloliters per hectare per day.
Source: North Carolina State University, Water Supply and Water Quality for Nursery and Greenhouse Crops, 1996 and 1999 guidance estimates.
Planning rates for greenhouse and nursery water
For container crops, the North Carolina State guidance recommends planning for a single overhead sprinkler nozzle requiring 4–7 gallons per minute, also stated as 15–26 liters per minute. This is a nozzle requirement, not a complete greenhouse water-use total.
The same source advises container nurseries to plan a minimum 30-day supply of one acre-inch of water. One acre-inch of planned nursery irrigation equals 27,154 gallons per acre, or 102.8 cubic meters per hectare. The recommendation is labeled 2002 guidance and should be used as a planning benchmark rather than a current national consumption statistic.
These benchmarks separate three different questions: daily irrigation demand for covered area, short-term peak flow for cooling, and stored supply for nursery resilience. A greenhouse can therefore have a daily irrigation estimate, a larger instantaneous cooling-flow requirement, and a separate reserve target. Keeping those units and time periods distinct prevents a flow rate from being mistaken for a daily volume.
Source: North Carolina State University, Water Supply and Water Quality for Nursery and Greenhouse Crops, 2002 guidance recommendation.
Cut-flower rose water use by irrigation control
A UC Davis commercial cut-flower rose trial measured two irrigation approaches during 1994–1995. The grower-controlled beds received 17,302 gallons during the test period, while the soil-moisture-tension beds received 10,928 gallons. The trial concerns specific rose beds and should not be generalized to all floriculture operations.
The grower-controlled beds averaged 24.4 irrigations during the test period, compared with 17.9 irrigations for the soil-moisture-tension beds. Average water applied per irrigation was 0.76 gallons per square foot for the grower-controlled beds and 0.42 gallons per square foot for the soil-moisture-tension beds.
Daily rates in the trial were 0.092 gallons per square foot per day for grower-controlled beds and 0.067 gallons per square foot per day for soil-moisture-tension beds. The figures provide a historical example of how irrigation control can change applied water in a cut-flower setting, but they are not a current national rose benchmark.
| UC Davis rose-trial measure | Grower-controlled beds | Soil-moisture-tension beds |
|---|---|---|
| Water during test period | 17,302 gal. | 10,928 gal. |
| Average irrigations | 24.4 | 17.9 |
| Water per irrigation | 0.76 gal./sq. ft. | 0.42 gal./sq. ft. |
| Daily water use | 0.092 gal./sq. ft./day | 0.067 gal./sq. ft./day |
Source: UC Davis, Tensiometer-based irrigation of cut-flower roses, 1994–1995 test.