Spinach

Spinach
Spinach Disease Control Spinach Insect Control Spinach Weed Control

Introduction

Spinach (Spinacia oleracea) is a hardy cool-weather crop, grown for use as a cooked green vegetable or for salad greens. Temperature for optimum production and high quality is 55-60°F with day length of approximately 12 hours. Winter spinach production in unheated high tunnels has expanded in New England to supply greens year-round. Under certain conditions, spinach will bolt (develop a seed stalk and flower), reducing quality. Bolting can occur during summer months, high temperatures and long days. For spinach plants overwintered in high tunnels, bolting may occur in early spring as days lengthen. The tendency to bolt varies with the cultivar, some being more resistant than others. Growers who want greens in summer should consider beet greens and/or Swiss chard as substitutes, since they produce better under high temperature and long day conditions. Malabar spinach (Basella alba) is not related to true spinach; it is a vining spinach-like crop native to tropical Asia and is well-adapted to growing in summer New England conditions.

Types and Varieties

There are 2 main types of spinach: smooth leaf and savoy (crinkled leaf). Both grow equally well and are marketed similarly, but the savoy type, because of its crinkled leaf, is more difficult to clean. Asian leaf types are relatively smooth with pointed leaves. Varieties best suited for winter production are often the fastest-growing varieties.

VarietyTypeSeasonDisease Resistance
Acadiasemi-savoySFDM 1-13,15,16
Carmelsemi-savoySFDM 1-11,13
Flamingo ImprovedAsianSFWDM 1-14,16
GerenuksavoySFWDM 1-7,9-20
Giant Winter OPsemi-savoyFWDM 1-11
Kolibrisemi-savoySFWDM 1-9,12-15,17
RangitotosmoothWDM 1-16,19
Red TabbysmoothSFWDM 1-9,11-13,20
SeasidesmoothSDM 1-11,15,16,19,20
SpacesmoothFWSDM 1-3,5,6,8,11,12,14,16,19
Sunangelsemi-savoySFWDM 1-9,11-20
Winter Bloomsdale OPsavoyWCMV

OP = open-pollinated, Seasons: S = spring, F = fall, W = winter. 

Resistant or tolerant to: DM: downy mildew (races indicated), CMV: cucumber mosaic virus

Soil Fertility

Apply lime according to soil test results to maintain soil pH at 6.5-6.8. Soils with low pH will result in slow growth and chlorotic leaves.

Because of sensitivity to magnesium (Mg) deficiency, older spinach leaves may tend to show yellow color similar to that caused by nitrogen (N) deficiency or downy mildew. Low levels of Mg in the soil can be corrected by using high-Mg lime (dolomitic) or by adding Mg to the fertilizer. Do not automatically apply more N to try to develop the desired deep green color. Rather, fertilize with Mg according to pre-plant soil tests and, if needed, test again mid-season and make a topical application of 10-15 lb magnesium sulfate (Epsom salts) in 100 gal water to correct any Mg deficiency. Spray to wet the foliage. If Mg was deficient, you will see a color change to dark green overnight. Spinach will accumulate excess nitrates if N is used in an attempt to induce green color. Thus, it is always best to check for Mg problems before applying extra N if plants have chlorotic pale green color or yellow lower leaves.

In winter high tunnel production, a single crop may be harvested for 6 months and therefore sidedressing may be necessary. Nitrogen use efficiency of crops is lower in cold temperatures, so more frequent sidedressing of small amounts of N will achieve better results than fewer applications of larger amounts of N. Avoid putting fertilizer directly onto crop foliage. The need for sidedressing will be influenced by pre-plant levels of N in the soil, which can vary widely between farms and high tunnels based on the soil nutrients remaining after the summer crop. Available N levels can be monitored mid-season using pre-sidedress nitrate tests. Sidedress with N if nitrate levels drop below 30 ppm.

Less nitrogen fertilizer will be needed if manure or legume sod was plowed down (see Table 1 and Table 2).

Plant Nutrient Recommendations According to Soil Test Results for Spinach

SOIL TEST RESULTSNITROGEN (N) - LBS PER ACREPHOSPHORUS (P) -
LBS P2O5 PER ACRE		POTASSIUM (K) -
LBS K2O PER ACRE
VERY LOWLOWOPTIMUMABOVE OPTIMUMVERY LOWLOWOPTIMUMABOVE OPTIMUM
Broadcast and incorporate60-8018012030-600-3018012030-600
Sidedress 3-4 weeks after planting3000000000
TOTAL RECOMMENDED90-11018012030-600-3018012030-600

Planting

Seed will germinate at soil temperatures of 32-60°F. Soil temperatures above 70°F will result in poor germination. Another cause for poor germination, more commonly seen in high tunnels is salt accumulation in the top 2" of high tunnel soil. Priming the seed (i.e. soaking the seed in water or another solution to kickstart the germination process prior to seeding) may improve germination, though there is no research-based seed priming protocol specifically designed for spinach. Spinach seed is short-lived and susceptible to damping-off. For good stands, start with new seed each year. Taking measures to prepare uniform, well-drained beds and to provide even irrigation can reduce variations in soil moisture that can lead to damping-off as well.

Spinach can be direct-seeded quite densely, at up to 3,000,000 seeds per acre (70 seeds per sq. ft.). Target harvest size may affect seeding density, with “teenage” or larger-sized spinach seeded less densely and baby-leaf spinach seeded at the higher density. Harvest method may also affect preferred seeding density. Growers harvesting by clear-cutting, either by hand or mechanically, may prefer denser seeding rates, whereas those harvesting lower leaves only may prefer wider spacing. After preparing a stale seedbed, denser seeding may help to control weeds. During dry conditions, irrigation may be necessary to germinate seeds. Seed 0.25-0.5" deep depending on soil moisture and temperature. Deeper planting is suggested in a warm, dry soil. Growers should attempt to seed to a stand as thinning is generally not recommended. 

Spinach can also be germinated in seed trays and transplanted at the desired site. This method is particularly useful  to get a head-start in production early in the season or for quickly establishing spinach after a summer crop in high tunnels. Seedlings are typically ready for transplant approximately 3 weeks after initial seeding. Again, plant spacing can vary based on target harvest size and method.
 

Field Culture

Main Season (Spring and Fall). Spinach can be seeded in the spring as soon as the soil can be worked. Sandy soils are generally preferred because they warm earlier in the spring. Two main crops are generally grown, one in the spring, another in late summer, seeded about 6 weeks before the average first frost.

Winter Season. Winter production of spinach by New England growers is now quite common. Stand-alone low tunnels equipped with heavyweight row cover (1.25 oz/yd2) and plastic (6 mil) result in good winter survival of spinach and allow for separate fall and spring harvests. However, accessing plants during winter months when the ground is frozen is challenging, and leaves may not be saleable during this this period. High tunnel production permits winter access and provides additional insulation, and can result in winter-long harvests if plants are established by late fall. If direct-seeding, a September seeding date is suggested. Higher total yields (fall through spring) will be obtained by the earliest fall planting dates, primarily due to higher fall production. Spring-only yields are less affected by fall planting date.

Plant growth slows with less than 10 hours of light per day, starting around November 10 in southern RI and October 30 in northern ME. Aim to have 4-5 true leaves on plants before you reach this point.

It is important to ensure adequate moisture is available for spinach during the fall, winter, and spring months, either by using drip or overhead irrigation. The majority of irrigation is needed in fall and spring. Little irrigation is needed in winter months when crop growth is slow. 

There are three common physiological disorders that may occur on winter-grown spinach. Spinach can withstand frost well, as long as leaves are not handled when frozen. Freezing damage can kill and brown leaf tissue. This can be minimized by using row cover. Row cover is not necessary for winter high tunnel spinach production in most of New England but can speed up growth even if not needed to keep plants alive. Oedema results when water pressure causes cells to burst, resulting in scab-like calluses on the leaves. This can be minimized by limiting irrigation and maintaining low relative humidity as temperatures drop and growth slows. Lastly, under winter and spring conditions, spinach leaves often develop glandular trichomes on upper and lower leaf surfaces, which resemble tiny water droplets or insect eggs. They are more common on young leaves. These trichomes are naturally occurring structures produced by the spinach leaves and are harmless.

Harvest

Spinach is usually harvested 37-45 days after seeding, but can take much longer to mature during late fall and winter. Harvesting can be done by hand, either by clipping mature leaves and leaving young leaves uncut, or by clear-cutting just above the growing point. Walk-behind and tractor-mounted mechanical harvesters can be used. Regrowth quality varies by harvest method and the growth habit of the cultivar. 

In summer and fall, harvest early in the day and cool immediately to 32°F to maximize shelf life (10-14 days). In the winter, wait until leaves have thawed before harvesting, as handling frosted leaves will cause damage. 

Good yields will range from 5-7 tons/A for fresh market and 10-12 tons/A for processing. In winter high tunnel production, growers report producing 0.4–0.6 lbs/sq ft. Spinach is sometimes field packed loose into crates or cartons. Whole plants are sometimes bunched with roots trimmed off for retail sales. Package as bushel baskets or crates containing 20-25 lb, cartons or wire-bound crates with 2 dozen bunches each, or loose leaf 12 film bags (10 oz per bag) in a master carton. Winter spinach is often sold bagged in smaller quantities.

Spinach Disease Control

Spinach Disease Control
Spinach - General Spinach Insect Control Spinach Weed Control

See also: Table 20: Fungicides and Bactericides Labeled for Vegetable Transplants.

Cladosporium Leaf Spot (Cladosporium variabile)

Cladosporium leaf spot, caused by Cladosporium variabile, was previously considered to be of minor importance in spinach crops but can be severe in spinach seed production and has become a widespread problem in winter high tunnel production. Symptoms begin on the foliage as pale/tan lesions that develop olive-green spores. The most conducive environment for disease development is cool and moist with temperatures between 59-68ºF and relative humidity above 80%; however, the fungus can grow under a wide range of temperatures, ranging from 41-86ºF. Spinach seeds carry the fungus, but it has not been determined whether the disease is transmitted via contaminated seed to soil or seedlings. It is not known how long the fungus can survive on spinach residues in soil or in weed hosts. C. variabile has been recovered from dried leaves and seed stocks up to 8 years old. Cultural controls rely mainly on sanitation, the removal of infected plants, spinach debris, spinach volunteers, and unused seed. Start with certified, disease-free seed or treat seed with hot water or bleach to reduce seedborne inoculum. Avoid covering wet plants with row covers. Cultivar susceptibility varies but is rarely reported by seed producers or distributors.

FRAC Group P06:

  • Bacillus mycoides isolate J (LifeGard WGOG): 1.0 to 4.5 oz/A; PHI 0d, REI 4h. Apply at first true leaf stage or after thinning. Refer to label for other appropriate rates and application volumes.

Downy Mildew (Peronospora effusa formerly, P. farinosa f. sp. spinacea)

Spinach downy mildew (SDM) is considered the most important disease of spinach and is favored by cool, moist conditions. The pathogen is host-specific to spinach and will not survive without a living host. Incidence of the disease appears to be increasing due to the increased use of high tunnels for winter spinach production. The potential overlap of field spinach and high tunnel spinach can create a “green bridge” for the disease, allowing the pathogen to transfer between fields and high tunnels. SDM begins as irregular yellow patches on upper leaf surfaces with purplish-gray sporulation on the undersides of leaves. Lesions may eventually dry out and turn brown. There are currently 19 numbered races of SDM, along with numerous "novel" races, and new races can emerge every year. SDM management relies on resistant cultivars, as well as managing relative humidity and leaf wetness. Select cultivars with resistance to races 1-19, if possible, and grow multiple cultivars that do not share the same gaps in resistance. Once infected, there is little that can be done to manage SDM. The pathogen can produce long-lived resting spores, called oospores, which can potentially survive in the soil without a living host; however, the role of oospores in season-to-season survival in New England is currently unknown. Rotate out of spinach for at least 2 years. Manage weeds.

FRAC Group 4:

  • mefenoxam (Ridomil Gold SL): 0.25 pt/A; PHI 21d, REI 48h. Do not apply to greenhouse or high tunnel crops. 

FRAC Group 7:

  • fluxapyroxad + pyraclostrobin (Merivon Xemium): 6.0 to 11.0 fl oz/A; PHI 1d, REI 12h, Groups 7 & 11. Suppression only. Do not apply as tank mix with other pesticides or anything other than water. Do not apply to greenhouse or high tunnel crops.

FRAC Group 11:

  • azoxystrobin (Quadris F): 12.0 to 15.5 fl oz/A; PHI 0d, REI 4h. Rotate with a non-Group 11 fungicide. Phytotoxicity may occur. Proceed with caution when using tank mixes. Do not apply to greenhouse or high tunnel crops.
  • famoxadone + cymoxanil (Tanos): 8.0 to 10.0 oz/A; PHI 1d, REI 12h, Groups 11 & 27. Must be tank mixed with an appropriate contact fungicide from a different FRAC Group. Do not alternate or tank mix with other Group 11 fungicides.
  • fenamidone (Reason 500SC): 5.5 to 8.2 fl oz/A; PHI 2d, REI 12h. Do not apply to greenhouse or high tunnel crops. Do not make more than one application before alternating with a fungicide from a different resistance management group.
  • fluxapyroxad + pyraclostrobin (Merivon Xemium): 6.0 to 11.0 fl oz/A; PHI 1d, REI 12h, Groups 7 & 11. Suppression only. Do not apply as tank mix with other pesticides or anything other than water. Do not apply to greenhouse or high tunnel crops.
  • pyraclostrobin (Cabrio EG): 12.0 to 16.0 oz/A; PHI 0d, REI 12h. May cause leaf injury. Do not apply with anything other than water. Do not apply to greenhouse or high tunnel crops. 

FRAC Group 21:

  • cyazofamid (Ranman 400SC): 2.75 fl oz/A; PHI 0d, REI 12h. Do not plant other crops not registered for this product within 30 days of the last application. 

FRAC Group 27:

  • cymoxanil (Curzate 60DF): 5.0 oz/A; PHI 1d, REI 12h. Use only in combination with a protectant fungicide. See label for crop rotation restrictions.
  • famoxadone + cymoxanil (Tanos): 8.0 to 10.0 oz/A; PHI 1d, REI 12h, Groups 11 & 27. Must be tank mixed with an appropriate contact fungicide from a different FRAC Group. Do not alternate or tank mix with other Group 11 fungicides.

FRAC Group 40:

  • ametoctradin + dimethomorph (Zampro): 14.0 fl oz/A; PHI 0d, REI 12h, Groups 45 & 40. Do not apply to greenhouse or high tunnel crops.
  • mandipropamid (Revus): 5.5 to 8.0 fl oz/A; PHI 1d, REI 4h. Addition of adjuvant is recommended. 

FRAC Group 43:

  • fluopicolide (Presidio 4SC): 3.0 to 4.0 fl oz/A; PHI 2d, REI 12h. Must be used in a tank mix with a fungicide with a different mode of action. Do not apply to greenhouse or high tunnel crops.

FRAC Group 45:

  • ametoctradin + dimethomorph (Zampro): 14.0 fl oz/A; PHI 0d, REI 12h, Groups 45 & 40. Do not apply to greenhouse or high tunnel crops.

FRAC Group 49:

  • oxathiapiprolin (Orondis Gold 200): 1.2 to 2.4 fl oz/A (foliar), 4.8 to 9.6 fl oz/A (soil application); PHI 0d, REI 4h. Apply at planting. Do not apply to greenhouse or high tunnel crops. 
  • oxathiapiprolin + mandipropamid (Orondis Ultra): 5.5 to 8.0 fl oz/A (foliar); PHI 1d, REI 4h, Groups 49 & 40. Apply with an adjuvant. Do not apply to greenhouse or high tunnel crops. 

FRAC Group BM02:

  • Bacillus amyloliquefaciens strain D747 (Double Nickel LCOG): 0.25 to 3 lb/A (foliar); PHI 0d, REI 4h.

FRAC Group M01:

  • copper hydroxide (Kocide 3000): 0.75 to 1.25 lb/A; PHI 0d, REI 48h. Do not apply in a spray solution having a pH less than 6.5 or tank mix with Aliette. An OMRI-listed formulation is available (Kocide 3000-OOG). Flecking may occur on spinach leaves.
  • copper oxychloride + copper hydroxide (Badge X2OG): 0.75 to 1.25 lb/A; PHI 0d, REI 24h (greenhouse), 48h (field). Flecking may occur. 

FRAC Group P01:

  • acibenzolar-S-methyl (Actigard 50WG): 0.5 to 0.75 oz/A; PHI 7d, REI 12h. Do not apply to plants that are stressed or when extended cold or/and cloudy conditions are expected. May cause crop injury to young seedlings.

FRAC Group P07:

  • fosetyl aluminum (Aliette WDG): 2.0 to 5.0 lb/A; PHI 3d, REI 24h. Lower rate of 2-3lb/A may be used when tank mixed with another fungicide labeled for downy mildew (do not mix with copper). 
  • phosphorous acid (Fosphite): 1.0 to 3.0 qt/20 gal foliar; PHI 0d, REI 4h. Do not apply to plants that are heat- or moisture-stressed or recently treated with copper products.

Seed Decay

Buy treated seed. Do not use treated seed for food, feed, or oil purposes.

  • azoxystrobin(Dynasty): 0.10 to 3.75 fl oz/100 lb seed; REI 14h, Group 11. 
  • fludioxonil (Maxim 4FS): 0.08 to 0.16 oz/100 lb seed; REI 12h, Group 12. For protection against seedborne and soilborne fungi. Does not control Pythium or Phytophthora.
  • mefenoxam (Apron XL): 0.085 to 0.64 fl oz/100 lb seed; REI 48h, Group 4. For Pythium damping-off protection. Do not use in greenhouse or enclosed environments. See label for restrictions.
  • thiram (Thiram 42-S): 8.0 fl oz/100 lb seed; REI 24h, Group M03.
  • Streptomyces sp. strain K61 (MycoStopOG): 0.04 to 4.0 oz/lb seed; REI 4h, Group BM02. 

Stemphylium Leaf Spot (Stemphylium botryosum)

This relatively new disease of spinach was first detected in California in 2001 and has since become a problem in high tunnel production. In the field, the disease spreads slowly and damage is limited. Symptoms include light gray/tan leaf spots 1/16-1/2" in diameter, with larger spots being more irregular. As spots age, they dry up and become papery in texture. The pathogen is known to be seedborne. Cultural controls rely mainly on sanitation, the removal of infected plants, spinach debris, spinach volunteers, and unused seed. Do not cover wet plants with row covers. Start with certified, disease-free seed or treat seed with hot water or bleach to reduce seedborne inoculum.

FRAC Group 7:

  • fludioxonil + pydiflumetofen (Miravis Prime): 9.2 to 13.4 fl oz/A; PHI 0d, REI 12h, Groups 12 & 7.

FRAC Group 12:

  • fludioxonil + pydiflumetofen (Miravis Prime): 9.2 to 13.4 fl oz/A; PHI 0d, REI 12h, Groups 12 & 7.

FRAC Group P06:

  • Bacillus mycoides isolate J (LifeGard WGOG): 1.0 to 4.5 oz/100 gal water/A; PHI 0d, REI 4h.

White Rust (Albugo occidentalis)

White rust is a very damaging disease of spinach that is found only east of the Rocky Mountains in the U.S. Symptoms begin as yellow spots on the upper leaf surface, while small, white pustules form on the undersides of leaves. The pathogen is not a true fungus but rather an Oomycete like the downy mildews. It produces oospores which can persist in soil and on contaminated seed for several years. Plant resistant cultivars and practice a 3-year crop rotation. Manage weeds. Apply preplant and foliar fungicides.

FRAC Group 4:

  • mefenoxam (Ridomil Gold SL): 0.25 pt/A; PHI 21d, REI 48h.  Do not apply to greenhouse or high tunnel crops. Shank application 21 days after planting or after the first cutting for control of white rust. 

FRAC Group 11:

  • azoxystrobin (Quadris F): 6.0 to 15.5 fl oz/A; PHI 0d, REI 4h. Quadris may be phytotoxic to spinach. Not for greenhouse or high tunnel use.
  • amoxadone + cymoxanil (Tanos): 8.0 to 10.0 oz/A; PHI 1d, REI 12h, Groups 11 & 27. Must be tank mixed with an appropriate contact fungicide from a different FRAC Group. Do not alternate or tank mix with other Group 11 fungicides.
  • fenamidone (Reason 500SC): 5.5 to 8.2 fl oz/A; PHI 2d, REI 12h. Do not apply to greenhouse or high tunnel crops.
  • pyraclostrobin (Cabrio EG): 8.0 to 12.0 oz/A. PHI 0d, REI 12h. Do not apply to greenhouse or high tunnel crops. May cause crop injury under certain conditions. Do not apply as tank mix with anything other than water. 

FRAC Group 21:

  • cyazofamid (Ranman 400SC): 2.75 fl oz/A; PHI 0d, REI 12h.

FRAC Group 27:

  • famoxadone + cymoxanil (Tanos): 8.0 to 10.0 oz/A; PHI 1d, REI 12h, Groups 11 & 27. Must be tank mixed with an appropriate contact fungicide from a different FRAC Group. Do not alternate or tank mix with other Group 11 fungicides.

FRAC Group 43:

  • fluopicolide (Presidio 4SC): 3.0 to 4.0 fl oz/A; PHI 2d, REI 12h. Must be used in a tank mix with a fungicide from a different FRAC Group. Do not apply to greenhouse or high tunnel crops.

FRAC Group M01:

  • copper hydroxide (Kocide 3000): 0.75 to 1.25 lb/A; PHI 0d, REI 48h. Do not apply in a spray solution having a pH less than 6.5 or tank mix with Aliette. An OMRI-listed formulation is available (Kocide 3000-OOG). Flecking may occur on spinach leaves.
  • copper oxychloride + copper hydroxide (Badge X2OG): 0.75 to 1.25 lb/A; PHI 0d, REI 48h. Flecking may occur.

FRAC Group P01:

  • acibenzolar-S-methyl (Actigard 50WG): 0.5 to 0.75 oz/A; PHI 7d, REI 12. Do not apply to plants that are stressed or when extended cold or/and cloudy conditions are expected. May cause crop injury to young seedlings. 

FRAC Group P04:

  • laminarin (Vacciplant): 14.0 to 22.0 fl oz/A; PHI 0d, REI 4h.

Cucumber Mosaic Virus (CMV)

CMV is found worldwide and infects over eight hundred crops and weed hosts. Symptoms include mosaic, mottling, stunting, and leaf distortion. This disease is transmitted by aphids in a nonpersistent manner; insecticides are of no value in controlling this disease. Start with virus-free seed. Eliminate weeds. Grow resistant varieties such as Winter Bloomsdale and Renegade.

Disease Control

Spinach Insect Control

Spinach Insect Control
Spinach - General Spinach Disease Control Spinach Weed Control

Aphids, primarily Green Peach Aphid (Myzus persicae)

Aphids in spinach are primarily green peach aphids. See the Pepper insect control section for more information on green peach aphid. Thresholds used in other regions may apply, including 1 aphid/plant on seedlings and 4-10 aphids per plant on older plants. Natural enemies often provide control. Aphid outbreaks can occur after using broad-spectrum insecticides due to the loss of natural enemies, so aphid-selective products should be used whenever possible. Take measures to cover the undersides of leaves if using materials that do not have translaminar or systemic movement.

IRAC Group 1:

  • malathion (Malathion 57EC): 1.6 pt/A; PHI 7d, REI 12h, Bee: H, Group 1B.

IRAC Group 3:

  • permethrin (Pounce* 25WP): 6.4 to 12.8 oz/A; PHI 1d, REI 12h, Bee: H.
  • pyrethrin (PyGanic EC5.0OG): 4.5 to 15.61 oz/A, or 0.25 to 0.50 oz/gal and 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M.
  • zeta-cypermethrin (Mustang* Maxx): 2.24 to 4 oz/A; PHI 1d, REI 12h, Bee: H. See resistance statement on label. Aphid control may be variable depending on species present and host-plant relationships.

IRAC Group 4:

  • acetamiprid (Assail 30SG): 2 to 4 oz/A; PHI 7d, REI 12h, Bee: M, Group 4A.
  • dinotefuran (Venom): 1 to 3 oz/A foliar, 5 to 7.5 oz/A soil; PHI 7d foliar, PHI 21d soil, REI 12h, Bee: H, Group 4A. Do not apply to vegetables grown for seed. For suppression of green peach and potato aphid only. 
  • flupyradifurone (Sivanto): 10.5 to 14 oz/A foliar for green peach aphids, 7 to 14 oz/A foliar for other aphids, 21 to 28 oz/A for soil; PHI 1d foliar, 21d soil, REI 4h, Bee: L, Group 4D.
  • imidacloprid (Admire Pro): 1.3 oz/A foliar, 4.4 to 10.5 oz/A soil; PHI 7d foliar, 21d soil, REI 12h, Bee: H, Group 4A. 
  • sulfoxaflor (Closer SC): 1.5 to 2 oz/A; PHI 3d, REI 12h, Bee: H, Group 4C. Do not apply to greenhouse or high tunnel crops.

IRAC Group 8:

  • sodium tetraborohydrate decahydrate (Prev-AM): 100 oz/100 gal; REI 24h, Bee: L, Group 8D. Do not apply in midday sun or mix with copper.

IRAC Group 9:

  • afidopyropen (Versys): 1.5 oz/A; PHI 0d, REI 12h, Bee: L, Group 9D. Do not apply to greenhouse or high tunnel crops.
  • pymetrozine (Fulfill): 2.75 oz/A; PHI 7d, REI 12h, Bee: L, Group 9B. Translaminar.

IRAC Group 21:

  • tolfenpyrad (Torac): 17 to 21 oz/A; PHI 1d, REI 12h, Bee: H. Not for lettuce aphid.

IRAC Group 23:

  • spirotetramat (Movento): 4 to 5 oz/A; PHI 3d, REI 24h, Bee: M. Must be tank-mixed with a spray adjuvant with spreading and penetrating properties to maximize leaf uptake and systemicity; don't use sticker adjuvants. Controls immature stages, may also reduce adult fertility. Do not apply to greenhouse or high tunnel crops.

IRAC Group 28:

  • cyantraniliprole (Exirel): 13.5 to 20.5 oz/A; PHI 1d, REI 12h, Bee: H. Do not use adjuvants in tank mix with Exirel in spinach. 
  • cyantraniliprole (Verimark): 6.75 to 13.5 oz/A soil at planting, 6.75 to 10 oz/A chemigation; PHI 1d chemigation, REI 4h, Bee: H. For control of green peach and suppression of potato aphid only. 
  • cyclaniliprole (Harvanta 50SL): 10.9 to 16.4 oz/A; PHI 1d, REI 4h, Bee: H. For best results, use with an effective adjuvant. Use high labeled rate for best performance. Melon aphid only. 

IRAC Group 29:

  • flonicamid (Beleaf 50SG): 2 to 2.8 oz/A; PHI 0d, REI 12h, Bee: L.

IRAC Group UN:

  • azadirachtin (Azatin OOG): 4 to 16 oz/A foliar or drench, 4 to 16 oz/100 gal in greenhouses; PHI 0d, REI 4h, Bee: L. When using lower rates, combine with adjuvant for improved spray coverage and translaminar uptake.
  • Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 2 to 3 lb/A; PHI 0d, REI 4h, Bee: M.
  • insecticidal soap (M-PedeOG): 1.25 to 2.5 oz/gal water; PHI 0d, REI 12h, Bee: L. Apply this product only on tank mix combination with labeled companion insecticide for green peach aphid. Do not mix with sulfur. 

Blister Beetles

See the Beets and Swiss Chard insect control section for information on blister beetles. A single spot spray with a broad-spectrum insecticide registered for caterpillars on spinach will control the beetles.

IRAC Group 3:

  • pyrethrin (PyGanic EC5.0OG): 4.5 to 15.61 oz/A, or 0.25 to 0.50 oz/gal and 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M..

Cabbage Looper (Trichoplusia ni) and Fall Armyworm (Spodoptera frugiperda)

See the Cabbage, Broccoli, Cauliflower, and Other Brassica Crops insect control section for information on cabbage looper (CL) and the Sweet Corn insect control section for information on fall armyworm (FAW).

IRAC Group 1:

  • carbaryl (Sevin XLR Plus): 1 to 2 qt/A; PHI 14d, REI 12h, Bee: H, Group 1A. Do not apply to crops or weeds in bloom. FAW only.
  • methomyl (Lannate* LV): 1.5 to 3 pt/A; PHI 7d, REI 48h, Bee: H, Group 1A. Do not apply if minimum daily temperature is less than 32°F. Do not apply to seedlings less than 3" in canopy diameter. CL may be resistant.

IRAC Group 3:

  • beta-cyfluthrin (Baythroid* XL): 1.6 to 2.4 oz/A CL, 2.4 to 3.2 oz/A FAW; PHI 0d, REI 12h, Bee: H. For FAW, controls 1st and 2nd instar larvae only.
  • bifenthrin (Brigade* 2EC): 2.1 to 6.4 oz/A; PHI 40d, REI 12h, Bee: H.
  • permethrin (Pounce* 25WP): 3.2 to 12.8 oz/A CL, 6.4 to 12.8 oz/A FAW; PHI 1d, REI 12h, Bee: H.
  • pyrethrin (PyGanic EC5.0OG): 4.5 to 15.61 oz/A, or 0.25 to 0.50 oz/gal and 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M.
  • zeta-cypermethrin (Mustang* Maxx): 3.2 to 4 oz/A; PHI 1d, REI 12h, Bee: H.

IRAC Group 5:

  • spinetoram (Radiant SC): 5 to 10 oz/A; PHI 1d, REI 4h, Bee: M. Do not apply to greenhouse or high tunnel spinach.
  • spinosad (Entrust SCOG): 3 to 6 oz/A looper, 4 to 8 oz/A armyworm; PHI 1d, REI 4h, Bee: M. Do not apply to seedlings for transplant.

IRAC Group 6:

  • emamectin benzoate (Proclaim*): 2.4 to 4.8 oz/A armyworm, 3.2 to 4.8 oz/A looper; PHI 7d, REI 12h, Bee: H. Do not apply to greenhouse or high tunnel crops.

IRAC Group 8:

  • sodium tetraborohydrate decahydrate (Prev-AM): 50 oz/100 gal; REI 24h, Bee: L, Group 8D. Do not apply in midday sun or mix with copper. CL only. 

IRAC Group 11:

  • Bacillus thuringiensis aizawai (XenTariOG): 0.5 to 1.5 lb/A looper, 0.5 to 2.0 lb/A armyworm; PHI 0d, REI 4h, Bee: L. For armyworm, use alone to control light populations or first and second instar larvae. Add a contact insecticide to control more mature larvae and higher populations. Must be ingested. For resistance management, may be rotated with Bt kurstaki products (Dipel).
  • Bacillus thuringiensis kurstaki (Dipel DFOG): 0.5 to 2 lb/A; PHI 0d, REI 4h, Bee: L. Must be ingested. For resistance management, may be rotated with Bt aizawai products (XenTari).

IRAC Group 18:

  • methoxyfenozide (Intrepid 2F): 4 to 8 oz/A early season on young plants, 8 to 10 oz/A mid- to late-season; PHI 1d, REI 4h, Bee: L. 
  • tebufenozide (Confirm 2F): 6 to 8 oz/A early season on young plants, 8 oz/A mid- to late-season; PHI 7d, REI 4h, Bee: L. 

IRAC Group 21:

  • tolfenpyrad (Torac): 21 oz/A; PHI 1d, REI 12h, Bee: H. Suppression of armyworms only. Not for CL.

IRAC Group 22:

  • indoxacarb (Avaunt): 3.5 oz/A; PHI 3d, REI 12h, Bee: H. CL only.

IRAC Group 28:

  • chlorantraniliprole (Coragen): 3.5 to 7.5 oz/A; PHI 3d, REI 4h, Bee: L. May be applied to soil at planting, through drip chemigation, or as a foliar spray. For CL only. Do not apply to greenhouse or high tunnel crops.
  • cyantraniliprole (Exirel): 10 to 17 oz/A CL, 7 to 13.5 oz/A FAW; PHI 1d, REI 12h, Bee: H. Do not use adjuvants in tank mix with Exirel in spinach. 
  • cyantraniliprole (Verimark): 6.75 to 13.5 oz/A soil at planting, 6.75 to 10 oz/A chemigation; PHI 1d chemigation, REI 4h, Bee: H. CL only.

IRAC Group UN:

  • Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 1 to 3 lb/A; PHI 0d, REI 4h, Bee: M.

Leafminer, Beet and Spinach

See the Beet and Swiss Chard insect control section for information on beet and spinach leafminers.

IRAC Group 3:

  • bifenthrin (Brigade* 2EC): 2.1 to 6.4 oz/A; PHI 40d, REI 12h, Bee: H.
  • permethrin (Pounce* 25WP): 6.4 to 12.8 oz/A; PHI 1d, REI 12h, Bee: H.

IRAC Group 4:

  •  dinotefuran (Venom): 1 to 3 oz/A foliar, 5 to 7.5 oz/A soil; PHI 7d foliar, PHI 21d soil, REI 12h, Bee: H, Group 4A. Do not apply to vegetables grown for seed.

IRAC Group 5:

  • spinetoram (Radiant SC): 6 to 10 oz/A; PHI 1d, REI 4h, Bee: M. Control may be improved with addition of an adjuvant. Do not apply to greenhouse or high tunnel spinach.
  • spinosad (Entrust SCOG): 6 to 10 oz/A; PHI 1d, REI 4h, Bee: M. Do not apply to seedlings for transplant. Control may be improved with addition of an adjuvant.

IRAC Group 6:

  • abamectin (Agri-Mek* SC): 1.75 to 3.5 oz/A; PHI 7d, REI 12h, Bee: H. Do not apply to greenhouse or high tunnel crops.
  • emamectin benzoate (Proclaim*): 3.2 to 4.8 oz/A; PHI 7d, REI 12h, Bee: H. Suppression only. Do not apply to greenhouse or high tunnel crops.

IRAC Group 17:

  • cyromazine (Trigard): 2.66 oz/A; PHI 7d, REI 12h, Bee: M. Do not apply to greenhouse or high tunnel crops.

IRAC Group 28:

  • chlorantraniliprole (Coragen): 5 to 7.5 oz/A; PHI 1d, REI 4h, Bee: L. May be applied to soil at planting, through drip chemigation, or as a foliar spray. Do not apply to greenhouse or high tunnel crops. For leafminer larvae only.
  • cyantraniliprole (Exirel): 13.5 to 20.5 oz/A; PHI 1d, REI 12h, Bee: H. Do not use adjuvants in tank mix with Exirel in spinach. 
  • cyantraniliprole (Verimark): 6.75 to 13.5 oz/A soil at planting, 6.75 to 10 oz/A chemigation; PHI 1d chemigation, REI 4h, Bee: H. 
  • cyclaniliprole (Harvanta 50SL): 10.9 to 16.4 oz/A; PHI 1d, REI 4h, Bee: H.

IRAC Group 30:

  • isocycloseram (Incipio): 2.1 to 4.1 oz/A; PHI 1d, REI 12h, Bee: H. Do not treat plants grown for transplanting. Not for use in greenhouses.

IRAC Group UN:

  • azadirachtin (Azatin OOG): 4 to 16 oz/A foliar or drench, 4 to 16 oz/100 gal in greenhouses; PHI 0d, REI 4h, Bee: L. When using lower rates, combine with adjuvant for improved spray coverage and translaminar uptake. 
  • insecticidal soap (M-PedeOG): 1.25 to 2.5 oz/gal water; PHI 0d, REI 12h, Bee: L. Apply this product only in a tank mix combination with a labeled companion insecticide. Do not mix with sulfur. 

Slugs

Damage appears as shredded foliage. Look for silvery slime trails on leaves or turn over soil clods or debris to find slugs during daylight hours. Grow plants away from moist, shaded habitats, use clean cultivation, control weeds, hand-pick/crush slugs, or scatter baits on the ground near infested plants. See the Cabbage, Broccoli, Cauliflower, and Other Brassica Crops insect control section for more information on slugs.

IRAC Group UN:

  • metaldehyde (Deadline Bullets): 25 lb/A maximum in single application, up to 3x/season; REI 12h, Bee: L. Apply to moist soil in the evening. Do not apply directly to or contaminate edible portions of plants.

Winter Cutworms (Noctua pronuba)

Winter cutworm is a newer, emerging pest in winter high tunnels. They are climbing, foliar-feeding cutworms that are particularly cold-hardy. The adults are large yellow underwing moths and are about 1" long and are active in the summer and fall. They lay eggs in masses on leaves. Winter cutworms vary in color with a dotted line along their backs and have a brown head capsule with black markings. Larvae are usually observed starting in August and feed in high tunnels throughout the fall and winter. Pupation occurs in the spring. They are active during our coldest months, with the worst damage occurring in November and December.

Damage includes large feeding holes and feeding on leaf margins in spinach, Swiss chard, lettuce, and carrots. These cutworms are nocturnal feeders and hide in the soil during the day. They are also highly mobile caterpillars.

Row covers or exclusion netting may work in some situations but needs to be timed with moth flights to prevent egg laying. Products used to target caterpillars may work for insecticides, but they need to be registered for use in high tunnels. Some efficacy has been seen with Bt products and spinosyns, but research is ongoing.

IRAC Group 5:

  • spinosad (Seduce): 20 to 44 lbs/acre, 0.5 to 1 lb/1000 sq ft.; PHI 1d; REI 4h; Bee: M. Spread bait on soil around plants. Do not apply to seedling leafy crops grown for transplant within a greenhouse or shade house.

IRAC Group 11:

  • Bacillus thuringiensis aizawai (XenTariOG): 0.5 to 1.5 lb/A; PHI 0d, REI 4h, Bee: L. Must be ingested. For resistance management, may be rotated with Bt kurstaki products (Dipel).
  • Bacillus thuringiensis kurstaki (Dipel DFOG): 0.5 to 2 lb/A; PHI 0d, REI 4h, Bee: L. Must be ingested. For resistance management, may be rotated with Bt aizawai products (XenTari).
Insect Control

Spinach Weed Control

Spinach Weed Control
Spinach - General Spinach Disease Control Spinach Insect Control

Stale Seedbed

 The following herbicides are nonselective and are used to control weeds which are present in a field prior to planting or before the crop emerges, which is especially useful for the Stale Seedbed Technique (see the Weed Management section for more information).

  • glyphosate (Roundup Power Max): PHI 14d, REI 4h, Group 9.
  • pelargonic acid (Scythe): PHI 1d, REI 12h, Group 0.

Preemergent Herbicides (before weeds germinate)

HRAC Group 15:

  • cycloate (Ro-Neet): 0.33 to 0.67 gal/A. PHI 21d, REI 48h. 1 application per year. Apply before, during, or immediately after planting.

  • s-metolachlor (Dual Magnum): PHI 50d, REI 24h. MA, ME, and NH only. Restricted label: Make sure the label for your state is available for download before using this product. Full label instructions are supplied to growers who apply through the website www.syngenta-us.com/labels/indemnified-label-login and agree to a waiver of liability. Main target weeds for this registration are galinsoga and yellow nutsedge.

Postemergent Herbicides (after weeds germinate)

HRAC Group 0:

  • pelargonic acid (Scythe): 3 to 10% solution. PHI 1d, REI 12h. Apply as vegetative burndown prior to planting, or as a directed and shielded spray during crop growth. Contact with crop will cause damage.

HRAC Group 1:

  • clethodim (Select Max): 9 to 16 fl oz/A. PHI 14d, REI 24h. Do not exceed 64 fl oz/A per year. Apply to actively growing grasses.

  • sethoxydim (Poast): 0.5 to 1.5 pt/A. PHI 15d, REI 12h. Do not exceed 3 pt/A per year. Apply to actively growing grasses. BASF has stopped production and will discontinue the registration at the end of 2027.

HRAC Group 4:

  • clopyralid (Stinger): 0.25 to 0.5 pt/A. PHI 21d, REI 12h. Do not exceed 0.5 pt/A per year. Apply when spinach is in the 2- to 5-leaf stage. Some leaf curling may appear, especially at high application rates. Spray additives are not recommended.

HRAC Group 9:

  • glyphosate (Roundup Power Max): 10 fl oz to 3.1 qt/A. PHI 14d, REI 4h. Do not exceed 5 qt/A per year.  Apply during fallow intervals, prior to planting, at planting, before crop has emerged, or to row middles with a hooded or shielded sprayer or wiper applicator. Spray contact will cause crop death.

HRAC Group 14:

  • carfentrazone (Aim EC): 0.5 to 2 fl oz/A. PHI 0d, REI 12h. Do not exceed 6.1 fl oz/A per season. Apply as a preplant burndown no later than 7 days before seeding or 1 day before transplanting crops, or apply with a hooded sprayer to row middles of emerged crops. Contact with crop will cause damage.
Weed Control