Farming Guide: Florida Brussels Sprouts

Introduction:

Although not commonly produced in Florida, Brussels sprouts (Brassica Oleracea L) are increasingly grown commercially in Columbia County, FL. In the USA, Brussels sprout production occurs primarily in California and New York but can be grown over the winter months in Florida. Optimal temperature range for Brussels sprouts is about 58 – 60°F. Planting date in Florida, generally occurs between October and December which provides a cooler climate. Harvest usually occurs March – April. While Brussels sprouts can withstand frost and freezing conditions, temperatures significantly below freezing (32°F) can damage Brussels sprouts.

Planting and soil conditions:

The distance between plants is generally 15-24 inches and distance between rows is 24-40 inches. Brussels sprouts should be grown in well-drained soil conditions with target pH of 6.5. UF/IFAS fertilizer recommendations are the same for Brussels sprouts, broccoli, and cauliflower. The recommended nitrogen fertilizer rate is 175 lbs. per acre. UF/IFAS guidelines for petiole sap testing in Brussels sprouts do not exist and based on limited testing during the 2022 season do not reliably compare to other similar crops like broccoli. UF/IFAS petiole sap testing guidelines do exist for broccoli but only for nitrate-nitrogen levels, which I am noting because some growers plan on planting broccoli in the same field as Brussels sprouts. Otherwise, plant tissue sampling is the most reliable method to determine Brussels sprouts nutrient concentrations during the growing season. Boron is an important micro-nutrient for Brussels sprouts and broccoli especially in sandy North Florida soils where it is often deficient due to the mobility of boron in the soil. In situations where boron is deficient, an application of 1.5 lbs. of boron per acre is recommended.

Pre- and post-emergent herbicide options:

Preemergent or pretransplant herbicide options include glyphosate for pre-transplant burndown and S-metolachlor (Dual Magnum, may require an indemnification agreement). Postemergence or posttransplant options include pendimethalin (Prowl, applied at the base of the crop within three days of transplanting) and glyphosate (applied only to row middles) (Wells et al. 2023).

Varieties and pest management:

Brussels sprouts varieties include ‘Jade Cross’ or ‘Royal Marvel’ which have an 85-day maturity. While, ‘Long Island Improved’ (an open pollinated variety), ‘Prince Marvel’, and ‘Valiant’ have a 90-day maturity (Westerfield 2022). Brussels sprouts can be planted from seed or by transplant. Common insect pests include loopers, imported cabbage worms, and aphids (Stephens 2018). Nematodes can also be a significant problem in Florida sandy soils. The most problematic plant parasitic nematodes in Florida for cole crops such as Brussels sprouts include root-knot nematodes (Meloidogyne spp.), sting nematode (Belonolaimus longicaudatus), stubby-root nematodes (Nanidorus minor), and awl nematodes (Dolichorus spp.) (Grabau & Noling 2021). Crop rotation and use of nematicides should be considered for nematode management. Nematicides options for Brussels sprouts include gaseous soil fumigants utilized prior to planting or liquid products such as Velum (fluopyram) applied at planting. The UF/IFAS nematode assay lab can be used to assess nematode populations in fields prior to planting. Plant diseases such as downy mildew, Fusarium wilt, blackleg, and black rot can be problematic in Brussels sprouts production (Westerfield 2022; Stephens 2018). Brussels sprouts should be harvested when they are full sized and firm prior to turning tough or yellow. Harvest of the earliest Brussels sprouts located at the lower section of the plant occurs first about three months after planting (Stephens 2018).

Storage

The ideal storage conditions of Brussel Sprouts post-harvest are under refrigerated conditions maintaining a temperature of 32 – 34°F and relative humidity of 90 – 95% (Stephens 2018).

References:

Grabau, Z. J., & Noling, J. W. (2021). Nematode Management in Cole Crops: NG024/ENY024, rev. 11/2020. University of Florida Cooperative Extension Service, Institute of Food and Agriculture Sciences, EDIS, 13-13. Retrieved from https://edis.ifas.ufl.edu/publication/NG024

Stephens, J. M. (2018). Brussels Sprouts—Brassica Oleracea L. (Gemmifera Group): HS567. University of Florida Cooperative Extension Service, Institute of Food and Agriculture Sciences, EDIS. Retrieved from https://edis.ifas.ufl.edu/publication/MV034

Wells, B., Smith, H. A., Zotarelli, L., Dittmar, P. J., Dufault, N. S., Desaeger, J., & Wang, Q. (2023). Cole Crop Production: Vegetable Production Handbook Chapter. 6, CV122/HS724, University of Florida Cooperative Extension Service, Institute of Food and Agriculture Sciences, EDIS. Retrieved from https://edis.ifas.ufl.edu/publication/CV122

Westerfield, B. (2022). Home Garden Brussels Sprouts. Circular 1069. University of Georgia Extension. Retrieved from https://extension.uga.edu/publications/detail.html?number=C1069&title=home-garden-brussels-sprouts