Broccoli

Brassica oleracea (italica variety) (Brassicaceae or cabbage family)

Production, Main Crop

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Soil preparation and rotation

• Broccoli should not follow other members of the Brassica family for 3 years.
• Total nutrient uptake is 165 lbs. of N, 10 lbs. of P and 210 lbs. of K.
• Apply compost and other amendments based on the results of a soil test.
• Spread lime as needed to increase both the pH and Ca levels. Dolomite lime will also increase Mg levels. Spread gypsym when calcium levels are low but pH is correct.
• A fertilizer company can add OMRI-listed potassium sulfate to compost if it doesn’t have enough K to meet the crop’s needs. If this isn’t possible, spread the correct amount of fertilizer and incorporate it before planting. Alternatively, you can side-dress it during cultivation. Divide the recommended rate of the soil test in half if side-dressing. 
• Test for boron and apply only as recommended by the soil test. A fertilizer company can add boron to compost to optimize boron distribution. If this isn’t an option, distribute soluble boron through a water solution with a sprayer directly on the soil. If applied directly on the crop, don’t exceed more than 1 lb. of boron per acre to avoid leaf burn. Incorporate compost and plant broccoli in raised beds or on flat ground.
• Fall broccoli does well when planted after a spring seeding of oats, forage peas and bell beans at a rate of 45 lbs. of oats, 100 lbs. of peas and 100 lbs. of bell beans per acre. This cover crop can supply all of broccoli’s N needs. Mow before the oats start flowering to avoid oats reseeding. Alternatively, remove oats from the seeding mix for easier incorporation.
• You can also plant fall broccoli through a rolled and crimped cover crop of Austrian winter peas. Plant this cover crop in early September at a rate of 200 lbs. to ensure good weed control. In this case, take a soil test in the preceding year and fertilize as needed to provide enough nutrients for both the Austrian winter peas and the vegetable crop. Inoculate seed and reduce N application to enhance N uptake by N-fixing bacteria. To properly kill peas, use a no-till planter (without seed in the box) and slice the cover crop with the coulters of the drill. 
• Broccoli does best in cooler climates or during spring and fall in warmer climates. Cooler nighttime temperatures are crucial during head formation and to a much lesser degree in its vegetative stage. Warm nights cause inflorescence (uneven sized flower buds), making it unmarketable.

Common recommended fertilizer rates¹

Nitrogen	Phosphorus	Potassium	pH
120	0-160	0-200	6.2-6.5
1Rates are for New York and are from Cornell University’s Nutrient Guidelines for Commercial Vegetable Production (2019). Check the Cornell website for updated guidelines, or consult with local experts for recommended rates outside New York.

Varieties

• New York variety trial
• Washington State, Oregon, Wisconsin and Minnesota variety trial

Greenhouse guidelines

• EZ Seeder seeder plate #16

Cell pack tray	Germination temp	Growth temp	Hardening off	Notes
72, 98 or 128	75°–85°	60°	Less water	Take plants outside 1 week before planting in the field. Put plug trays on a wire mesh bench to encourage air pruning.

Seeding time and number of successions

• In spring, plant broccoli in a greenhouse 5 weeks before you expect to transplant in the field.
• Plant successions at intervals of 10–14 days starting 4–5 weeks before you have prepared the ground for planting.
• In the northern United States, start planting fall successions at the end of May and go through June. In more southern regions, start later and end later for a harvest that goes into late fall and winter.
• Broccoli needs cool nights during maturation, so succession planting during summer is greatly dependent on location.

Signs to watch for and what to do

• Purpling leaves indicate a phosphorus deficiency in the potting soil; purpling in the field or greenhouse often indicates cold soil. Early use of a greenhouse with heated air can still leave the soil of the cell pack cold due to the cold floor. Address this issue of cold soil possibly causing a P deficiency before you start feeding the plants with a liquid P solution.

Transplanting tips

• Watch transplants during late spring for signs of getting leggy from too much warmth. If this happens, put them outside to harden.
• Transplants should have 4 true leaves and pull easily from their tray. Plants should generally not be older than 4–5 weeks.
• Stocky plants have a higher survival rate in the field. When transplants are lush, remove some leaves to reduce transplant shock.

Transplanting in 5- or 6-foot raised beds

Rows	In-row spacing	Planting depth (inches)	Notes
2-3	8 inches for bunching; 12 inches	Bury long plants as deep as possible without covering true leaves.	Even when plants slightly wilt, they always come back. Adjust mechanical transplanters so there is good contact between the plug or root ball and the soil.

Cultivation procedures

• Ensure plants are properly rooted before cultivation. Use sweeps (with torsions if possible) in combination with a finger weeder, usually 7–10 days after transplanting or as soon as possible without damaging the plants. Alternatively, use a tine weeder; this works better when you use bare root transplants because tine weeders tend to uproot plugs.
• Hand hoe in between plants as necessary.
• Use a finger weeder in combination with side knives for a second pass when new weeds emerge. Alternatively, if you want very slight hilling, use spring hoes in combination with side knives.
• If you need a third cultivation, use Lilliston rolling cultivators and hill aggressively without burying the plants.

Insect and disease protection

• Control black rot (Xanthomonas) by purchasing clean seeds, keeping the greenhouse clean and exposing seeds to hot water treatment. Some organic seed suppliers hot treat their seeds, so check with them before applying your own treatment, as double treatment can affect germination.
• Flea beetles
  • Cover the crop with floating row covers or insect netting after transplanting to avoid flea beetle damage. Keep covered until harvest. Alternatively, use a spinosyn-based product like Entrust. 
  • If possible, follow Extension bulletins that publish the timing of each generation of flea beetles, or place yellow sticky cards at plant height to monitor their presence. Check the cards at least twice a week.
  • Spray beneficial nematodes on heavily infected land to control flea beetle grubs and avoid future generations. Flea beetles tend to overwinter in nearby hedgerows and grass strips.
• You can prevent cutworms by spraying the soil with the beneficial nematode Steinernema carpocapsae. Once the pest is in the crop, control the population by spraying the crop with Bacillus thuringiensis kurstaki, or spread a baited product containing spinosyn, like Seduce, around the plants.
• Scout for the eggs of imported cabbage worms or diamondback moths on the underside of leaves. When the small worm population is more than 2 per plant, spray a Bacillus thuringiensis (Bt aizawai or Bt kurstaki) product, such as XenTari, or a spinosyn-based product, such as Entrust, every week until the population is under control. Alternate your spraying schedule by using Bt products along with a spinosyn-based product to avoid resistance buildup.
• Selecting resistant varieties is the best way to control bacterial soft rot.
• Choose tolerant and well-domed varieties to avoid brown bead (a physiological disorder). 
• Buttoning up—when a small-framed plant forms a premature small head—usually occurs in the earliest plantings. Some varieties are more tolerant than others.
• To avoid hollow stem, plant closer in the row and choose less susceptible varieties. Hollow stem is another physiological defect caused by high N and K levels in soil.
• To avoid Alternaria leaf spot, plant far away or upwind from earlier-planted cole crops and avoid overhead irrigation. Regular applications of Bacillus amyloliquefaciens, available as Double Nickel, have shown the best controls in research. Bacillus subtilis, available as Serenade, and mineral oil like JMS Stylet-Oil has shown some control for a few growers. Don’t mix any mineral oil with adjuvants, as this will cause leaf burn. Regular sprays with giant knotweed extract, such as Regalia, appear to reduce Alternaria as well.
• Cabbage maggots: To reduce infestation of cabbage maggots on young seedlings, cover seedlings with floating row covers or insect netting as you would for flea beetles. Maggots appear in 3–4 generations in the Northeast, starting in early spring. 
• Swede midge has become a problem for many growers in the northern United States in recent years. As it is an invasive species, it has no native enemies. Exclusion through row covers or insect netting in combination with rotating more than ½ mile away from last year’s crop may provide effective protection.

Other cultural practices

• Irrigate frequently for optimum yield and plant health. Frequency depends on soil type, evaporation, precipitation and the particular needs of the crop. 

Double cropping and/or cover cropping

• You can plant a cover crop after earlier-planted broccoli. Before planting it, mow the broccoli plants as low as possible with a flail mower. Also, incorporate the residue with a disc to avoid overwintering of insects and diseases.
• Later plantings can be overseeded with a mixture of crimson and red clover, or sweet clover by itself, at a rate of 20 lbs. per acre. This is done right before the last cultivation. Alternatively, plant cereal rye up until a few weeks before harvesting and before the end of October. Take great care to avoid having seeds get caught in the plants.

Additional resources

• Organic Production and IPM Guide for Cole Crops

Production, Early Crop

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Soil preparation

• Cultural practices are similar to Broccoli, Main Crop except that early broccoli is planted on plastic mulch. For super-early broccoli, use infrared transmitting mulch to increase soil temperature. 
• Avoid too much plant debris from a previous cash crop or cover crop, as you’ll want to lay plastic as early as possible in the growing season.

Transplanting in 5- or 6-foot raised beds

Rows	In-row spacing	Planting depth (inches)	Notes
2	12 inches	As deep as possible	Use a 12-inch wheel and add kelp or fish fertilizer to the water as directed by the product label.

Cultivation procedures 

• Cover plants with floating row covers.
• Cultivate with a rolling cultivator or spyder between plastic to control weeds. 
• If desired, plant a cover crop like oats and peas between plastic, or use weed fabric.
• After harvest, incorporate the cover crop and plant debris to allow for bare fallow.
• Follow with cover crops like rye and vetch.

Harvest

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Ready-to-harvest and quality indicators

• For a full head: Florets are dark green and still tightly bunched, each about 0.1-inch in size. Heads are usually domed. Once the florets are loose, they don’t store very long and may flower in a cooler.
• Hot weather (86° in the day and over 77° at night) can cause broccoli to grow a sterile or deformed crown, resulting in an unmarketable product.

Harvest procedures

• Wash hands and sanitize knives before harvesting.
• Harvest in the morning hours to avoid field heat accumulation.
• Harvest twice a week and with great care for optimum product.
• Don't harvest heads with traces of head rot or brown bead.
• Separate and discard any broccoli that might have been contaminated with bird feces.
• Don't expose broccoli to warm temperatures and make regular trips to the wash and pack shed during harvest.

Washing and sorting procedures

• Wash hands and rinse boots before entering the wash-and-pack shed, and cover up field clothes with a bib. If a long-sleeve shirt contains soil, remove this as well.
• Place broccoli in room temperature water with an appropriate sanitizer to wash. Use the guide How to Wash Produce Using a Peracetic Acid Solution to establish how much hydrogen peroxide and peracetic acid solution to add to water. 
• Hydrocool broccoli in a washing tub filled with iced water to remove field heat. It is advisable to slowly cool down warm broccoli before exposing it to ice water, as the florets will absorb the water. Any contaminant in the water will then enter the broccoli.
• Smaller heads are bunched together with a strong rubber band, or they can be sorted out and counted at a higher rate per box if each head in the box is about the same size and weight.

Additional resources

• Wholesale Broccoli Packing
• Post Harvest Factsheet
• Production Guide for Storage of Organic Fruits and Vegetables

Packing and storage summary for broccoli

Cleaning in the field	Remove leaves from stems
Packing in the field	Prevent any damage by handling broccoli very carefully in picking crates.
Packing for delivery	The standard is 14-count and 18-count bunches per 1 ⅑-bushel box, weighing 21 lbs. Customers accept 10-, 12- and 16-count as well. For loose crown cut, pack 10 or 20 lbs. in waxed ½- or 1 ⅑-bushel boxes. See the International Federation for Produce Standards for the correct PLU code. Add the prefix 9 for organic crops. Use clean boxes of choice for a CSA and farmers market.
Storage	In a cooler at 32°, packed with ice when available. Broccoli is sensitive to ethylene exposure. Allow for good air exchange and don’t store with crops that release ethylene.

This material is based upon work that is supported by the National Institute of Food and Agriculture, U.S. Department of Agriculture through the Sustainable Agriculture Research and Education (SARE) program. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and should not be construed to represent any official USDA or U.S. Government determination or policy.