Spinach is a hardy cool weather crop, ideal for an early New England market. Temperature for optimum production and high quality is 55°F to 60°F with day length of approximately 12 hours. Seed will germinate at soil temperatures of 32°F to 60°F and the young plants can withstand temperatures as low as 15°F to 20°F. Under the hot temperatures and long days of summer, spinach will bolt (develop a seed stalk and go to seed), which makes it unmarketable. The tendency to bolt varies with the cultivar, some being more resistant than others.

Spinach is grown for use as a cooked green vegetable or for greens in a salad. Growers who want greens for the market in the summer should consider beet greens and/or Swiss chard as substitutes. They produce well under high temperature and long day conditions.

There are two main types of spinach: smooth leaf and savoy (crinkled leaf). Both grow equally well and are marketed the same, but the savoy type, because of its crinkled leaf, is more difficult to clean.

Spinach can be seeded in the spring as soon as the soil can be worked. Sandy soils are generally preferred because they drain early and warm a little quicker. Two main crops are generally grown, one in the spring, another in late summer, seeded about six weeks before the average first frost. Growers in New England are having some success with overwintering spinach. A floating row cover can be used for protection. For overwintering spinach, particularly in northern areas, an early September seeding date is suggested. Survival of the early crop has been satisfactory following a mild winter with good snow cover.

Normally, plan on 40 to 50 days to harvest under good growing conditions, with 60 to 70 days for very early plantings. Good yields for fresh market will range from 5 to 7 tons/A and 10 to 12 tons/A for processing. Market spinach is usually washed before marketing, and if cut early in the day and iced, can have a storage life of 10 to 14 days. The most common containers are bushel baskets, tubs or crates, each holding 18 to 25 lb.

Varieties

Fall

• Melody (DM1-3,CMV)
• Whale (DM 1-7)
• Samish (DM 1-4)
• Tyee (DM 1-30)
• Space (DM 1-3)
  

Spring

• Tyee (DM 1-30)
• Unipak (CMV, DM)
• Spinner (DM 1-4)
• Melody (DM 1-2, CMV)

CMV: Cucumber Mosaic Virus resistant
DM: Downy Mildew resistant

Spacing and Seeding

Desired plant stand is 6 to 8 plants per foot of row and 12” between rows. This requires 8 to 10 lbs of seed per acre (1/2 to 1 oz per 100 feet of row). Seed 1/4” to 1/2” 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.

Lime

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

Fertilizer

Because of sensitivity to magnesium deficiency, older spinach leaves may tend to show yellow color similar to a nitrogen deficiency. Low levels of magnesium in the soil can be corrected by using high magnesium lime (dolomitic) or by adding magnesium to the fertilizer. Do not automatically apply more nitrogen to try to develop the desired deep green color. Rather make a topical application of 10 to 15 lb magnesium sulfate (Epsom salts) in 100 gal water. Spray to wet the foliage.

If magnesium was deficient, you will see a color change to dark green overnight. Spinach will accumulate excess nitrates if nitrogen is used in an attempt to induce green color. It is always best to check for magnesium problems before applying extra nitrogen if plants have chlorotic pale green color or yellow lower leaves.

Promote efficient nitrogen use by sidedressing nitrogen when crop need is apparent. Avoid putting fertilizer directly onto crop foliage.

Less nitrogen fertilizer will be needed if manure or legume sod was plowed down (see nitrogen credits).

Harvest

Spinach can be harvested from 37 to 45 days after seeding. The entire plant can be cut off just above ground level when there are five to six leaves. Higher yields result when plants have 10 to 12 leaves.

Spinach is sometimes field packed loose into crates or cartons averaging 18 lb net. Whole plants are sometimes bunched, like carrots, when going directly to retail markets. Spinach is usually washed before being marketed. Spinach should be kept cool and shaded after harvest. Spinach harvested early in the day, then iced will have a much better shelf life. Storage life is 10 to 14 days. Package as bushel baskets or crates containing 20 to 25 lb, cartons or wire-bound crates with 2 dozen bunches each, or 12 film bags (10 oz per bag) in a master carton. 

Weed Control

NOTE:  For the herbicides listed below, one product trade name and formulation is provided for each active ingredient (common name) as an example of rates, days to harvest (dh), REI, and special instructions. In many cases there are other products available with the same active ingredient. Please see Table 17 and Alphabetical Listing by Trade Name for more information on products with the same active ingredients. 

Stale Seedbed

glyphosate (Roundup 4S): 1 to 5 qt/A (REI 12h, Group 9). See Stale Seedbed Technique.

Preplant Incorporated

cycloate (Ro-Neet 6E): 3 to 4 pt/A (REI 12h, Group 8). Preplant incorporated. Use lower rate during hot weather and/or dry soil conditions. To reduce the risk of crop injury, apply and incorporate 7 to 10 days before planting, then rework soil at planting. Use on sandy mineral soils only.

Postemergence

pelargonic acid (Scythe 4.2): 3% to 10% (REI 24h, Group 27). Use a 3-5% solution for annual weeds (4-6 oz/gal water), a 5-7% solution for biennial and perennial weeds (6-9 oz/gal water), and 7-10% solution for maximum burndown (9-13 oz/gal water). Delivery rate for boom applications should be 75 to 200 gal spray solution/A; complete coverage of weed foliage is essential. Use a DIRECTED/SHIELDED SPRAY; contact with crop will cause injury. For hand-held equipment, spray to completely wet all weed foliage but not to the point of runoff. Repeat applications as necessary. Tank mixes are allowed with this product. These include tank mixes with glyphosate (Roundup), sulfosate (Touchdown), and residual herbicides. See label for complete details.

phenmedipham (Spin-aid 1.3 EC): 3 to 6 pt/A (40 dh, REI 24h, Group 5). Do not use when expected high temperatures will be above 75°F. For best results, spray when weeds are in the 2-leaf stage. Use the 6-pint rate only on well-established crops that are not under stress. Spinach plants must have at least six true leaves. For processing spinach only.

clopyralid (Stinger 3S): 2.5 to 5 oz/A (21 dh, REI 12h, Group 4). Apply once or twice to control certain perennial and annual broadleaf weeds when the crop has between 2 and 5 leaves. Do not exceed 8 oz/acre/crop. Stinger controls weeds in the composite and legume families. Common annuals include galinsoga, ragweed, pineappleweed, clover, and vetch. Perennial weeds controlled include Canada thistle, goldenrod species, aster species, and mugwort (wild chrysanthemum). Stinger is very effective on small seedling annual and emerging perennial weeds less than 2” to 4” tall, but is less effective and takes longer to work when weeds are larger. Use 2 to 4 ounces/A to control annual weeds less than 2” tall. Use 4 to 8 ounces/A to control larger annual weeds. Apply 8 ounces/A to suppress or control perennial weeds. Spray additives are not needed or required by the label and are not recommended. Stinger is a postemergence herbicide with some soil residual activity. Observe replant restrictions on the label or injury may occur from herbicide carryover.

sethoxydim (Poast 1.5L): 1 to 2 pt/A (15 dh, REI 12h, Group 1) postemergence. Apply with crop oil concentrate at 2 pt/A. Apply to actively growing weed grasses (see product label for susceptible stage of growth). Do not cultivate for five days prior or seven days after Poast application. Do not apply Poast when air temperature exceeds 90°F and when the relative humidity exceeds 60%.

Insect Control

NOTE:  For the insecticides listed below, one product trade name and formulation is provided for each active ingredient (common name) as an example of rates, days to harvest (dh), REI, and special instructions. In many cases there are other products available with the same active ingredient. Please see Table 20 and Alphabetical Listing by Trade Name for more information on products with the same active ingredients.

Aphids, Leafminers

Aphids found in spinach are primarily green peach aphid (see Pepper Section for more information). Thresholds used in other regions may apply and include one aphid/plant on seedlings and 4 to 10 aphids per plant on older plants. Natural enemies often provide control. Use selective products to conserve natural enemies.

For leafminers, treat when eggs or first tiny mines are noticed. Repeat in 7 to 10 days. Timing and coverage are very important; mid-May, late June and mid-August are critical periods. Remove weed hosts including lambsquarter, nightshade, chickweed and plantain. Use deep plowing in spring to reduce population.

abamectin (Agri-Mek* 0.15 EC): 8 to 16 oz/A (7 dh, REI 12h, Group 6). Leafminers only.

acetamiprid (Assail 30SG): 2 to 4 dry oz/A (7 dh, REI 12h, Group 4). Aphids only.

azadirachtin (Neemix 4.5): 4 to 7 oz/A (0 dh, REI 12h, Group 18). For aphids, suppression and adult feeding deterrent; for leafminer, larvae only. OMRI listed.

bifenthrin (Capture* 2EC): 2.1 to 6.4 oz/A (40 dh, REI 12h, Group 3A). Leafminers only.

chlorantraniliprole (Coragen): 5.0 to 7.5 oz/A (1 dh, REI 4h, Group 28). Leafminers only. For drip application, must be applied uniformly in the root zone and do not apply more than twice per season. For foliar application an adjuvant MAY NOT be used.

cyromazine (Trigard): 2.66 dry oz/A (7 dh, REI 12h, Group 17). For leafminers only.

dinotefuran (Venom 20SG): 7 to 11 dry oz/A foliar or 18 to 21 dry oz/A soil (7 dh foliar, 21 dh soil, REI 12h, Group 4A). For resistance management purposes, do not use foliar spray after soil application or following another nicotinoid (Group 4A) insecticide application on the same crop.

emamectin benzoate (Proclaim*): 3.2 to 4.8 oz/A (7 dh, REI 12h, Group 6). Leafminers only. Suppression only.

endosulfan (Thionex* 50W): 1.5 to 2 lb/A (21 dh, REI 24h, Group 2A). For Green Peach aphid only.

flonicamid (Beleaf 50SG): 2 to 2.8 dry oz/A (0 dh, REI 12, Group 9C). For aphids only.

imidacloprid (Admire Pro): 4.4 to 10.5 oz/A (21 dh, REI 12h, Group 4A). For aphids only. See plant-back restrictions. To avoid resistance, do not use another nicotinoid (Group 4A) insecticide if Admire Pro was used at planting.

imidacloprid (Provado 1.6F): 3.8 oz/A (7 dh, REI 12h, Group 4A). For aphids only. See plant-back restrictions. To avoid resistance, do not use a Provado foliar application following another nicotinoid (Group 4) insecticide application on the same crop.

insecticidal soap (M-Pede): 2.5 oz/gal water (0 dh, REI 12h). Spray to wet all infested plant surfaces. Apply with companion aphicide. OMRI listed.

malathion (Malathion 57EC): 2 pt/A (7 dh, REI 12h, Group 1B).

permethrin (Pounce* 25WP): 6.4 to 12.8 oz/A (1 dh, REI 12h, Group 3A).

pymetrozine (Fulfill): 2.75 oz/A (7 dh, REI 12h, Group 9A). Selective control of aphids including green peach aphid. Translaminar. Apply before populations build up.  Not for leafminer.

pyrethrin (PyGanic EC5.0): 4.5 to 18 oz/A (0 dh, REI 12h, Group 3A). OMRI listed. For aphids only.

pyrethrins + piperonyl butoxide (Pyrenone): 1 tsp/gal, or 1 to 12 oz/A (0 dh, REI 12h, Group 3A).

sodium tetraborohydrate decahydrate (Prev-AM): 100 oz/100 gal (0.5 dh, REI 12h, Group 25). Do not apply in midday sun or mix with copper, sulfur or oils. Aphids only. CT only.

spinosad (Entrust): 2 to 3 dry oz/A (1 dh, REI 4h, Group 5). For leafminers only. Efficacy improves with the addition of an adjuvant. OMRI listed.

spinosad (SpinTor 2SC): 6 to 10 oz/A (1 dh, REI 4h, Group 5). For leafminers only. Use with a silicone adjuvant.

spirotetramat (Movento): 4-5 oz/A (3 dh, REI 24 h, Group 23). Immature stages; may also reduce adult fertility. Aphids only.

zeta-cypermethrin (Mustang*): 2.4 to 4.3 oz/A (1 dh, REI 12h, Group 3A). Aids in control.

Blister Beetles

The margined blister beetle, sometimes called the “old fashioned potato beetle” is the most common blister beetle attacking unsprayed vegetables in New England. See Blister Beetles in the Eggplant section for more information on this pest. A single spot spray with a broad-spectrum insecticide registered for caterpillars on spinach will control the beetles.

pyrethrin (PyGanic EC5.0): 4.5 to 18 oz/A (0 dh, REI 12h, Group 3A). OMRI listed.

pyrethrins + piperonyl butoxide (Pyrenone): 1 tsp/gal, or 1 to 12 oz/A (0 dh, REI 12h, Group 3A).

Cabbage Looper and Fall Armyworm

See Cabbage Section for more information on cabbage looper and Sweet Corn Section for more information on fall armyworm.

Bacillus thuringiensis aizawai (XenTari): 0.5 to 1.5 lb/A (0 dh, REI 4h, Group 11). Must be ingested; apply when larvae are actively feeding. High rate for armyworms.Treat small 1st and 2nd instar FAW larvae. OMRI listed.

Bacillus thuringiensis kurstaki (Dipel DF): 0.5 to 1 lb/A (0 dh, REI 4h, Group 11). Must be ingested; apply when larvae are actively feeding. Use high rate at cool temperatures. Use a spreader-sticker. OMRI listed.

beta-cyfluthrin (Baythroid* XL): 1.6 to 3.2 oz/A (0 dh, REI 12h, Group 3A). Use higher rate for first and second instar larvae FAW.

bifenthrin (Capture* 2EC): 2.1 to 6.4 oz/A (40 dh, REI 12h, Group 3A).

carbaryl (Sevin XLR Plus): 1 to 2 qt/A (14 dh, REI 12h, Group 1A). For FAW only.

chlorantraniliprole (Coragen): 3.5 to 5 oz/A (1 dh, REI 4h, Group 28). For CL only. For drip application, must be applied uniformly in the root zone and do not apply more than twice per season. For foliar application an adjuvant MAY NOT be used.

emamectin benzoate (Proclaim*): 2.4 to 4.8 oz/A for Armyworm, 3.2 to 4.8 oz/A for looper (7 dh, REI 12h, Group 6).

indoxacarb (Avaunt): 3.5 oz/A (3 dh, REI 12h, Group 22). For CL only.

methomyl (Lannate* LV): 1 1/2 to 3 pt/A (7 dh, REI 48h, 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. Cabbage loopers may be resistant.

methoxyfenozide (Intrepid 2F): 4 to 10 oz/A (1 dh, REI 4h, Group 18). Use lower rates when plants are small or infestations are light. Insect growth regulator. Works on all instars. Feeding stops within hours but death takes several days.

permethrin (Pounce* 25WP): 3.2 to 12.8 oz/A (1 dh, REI 12h, Group 3A).

pyrethrin (PyGanic EC5.0): 4.5 to 18 oz/A (0 dh, REI 12h, Group 3A). For cabbage loopers only. OMRI listed.

pyrethrins + piperonyl butoxide (Pyrenone): 1 tsp/gal, or 1 to 12 oz/A (0 dh, REI 12h, Group 3A).

sodium tetraborohydrate decahydrate (Prev-AM): 50 oz/100 gal (0.5 dh, REI 12h, Group 25). Do not apply in midday sun or mix with copper, sulfur or oils. Cabbage looper only. CT only.

spinosad (Entrust): 1 to 2 dry oz/A for CL; 1.25 to 2.5 dry oz/A for FAW (1 dh, REI 4h, Group 5). OMRI listed.

spinosad (SpinTor 2SC): 3 to 6 oz/A for cabbage looper, 4 to 8 oz/A for fall armyworm (1 dh, REI 4h, Group 5).

tebufenozide (Confirm 2F): 6 to 8 oz/A (7 dh, REI 4h, Group 18). Insect growth regulator which causes early, lethal molt in caterpillars. Must be ingested. Feeding stops within hours.

thiodicarb (Larvin* 3.2EC): 16 to 30 oz/A for FAW, 24 to 30 for CL (14 dh, REI 48h, Group 1A).

zeta-cypermethrin (Mustang*): 3.4 to 4.3 oz/A (1 dh, REI 12h, Group 3A).

Disease Control

NOTE:  For the products for disease control listed below, one product trade name and formulation is provided for each active ingredient (common name) as an example of rates, days to harvest (dh), REI, and special instructions. In many cases there are other products available with the same active ingredient. Please see Table 22 and Alphabetical Listing by Trade Name for more information on products with the same active ingredients.

Cucumber Mosaic Virus (CMV)

CMV is found worldwide and infects over 800 crop and weed hosts.This disease is transmitted by aphids in a nonpersistent manner; insecticides are in no value in controlling this disease. Start with virus-free seed. Eliminate weeds such as chickweed, pokeweed, and milkweed. Grow resistant varieties such as Blight Resistant Savoy, Savoy Hybrid 612 and Melody.

Downy Mildew (Peronospora farinosa)

Considered the most important disease of spinach, this disease like other downy mildews, is favored by cool, moist conditions. The varieties Savoy Hybrid 612 and Melody are resistant to downy mildew (Blue Mold).

azoxystrobin (Quadris): 12.0 to 15.5 fl oz/A (0 dh, REI 4h, Group 11). Apply at the first sign of disease and rotate with a fungicide other than a strobilurin in 7 to 14 days if necessary. Do not apply more than 2.88 qt/A. Quadris can by phytotoxic to spinach. See label for precautions.

cupric hydroxide (Kocide 3000): 0.75-1.25 lb/A. (0 dh, REI 24h, Group M1). Apply on a 7-10 day interval as soon as disease appears. This product may cause flecking.

fluopicolide (Presidio): 3.0-4.0 fl oz/A. (2 dh, REI 12h, Group 43). Must be used in a tank mix with a fungicide with a different mode of action.

fosetyl aluminum (Aliette WDG): 2 to 5 lb/A (3 dh, REI 12h, Group 33). Apply when disease is first evident.

mefenoxam (Ridomil Gold EC): 1.0-2.0 pt/A (21 dh, REI 48h, Group 4). Must be applied pre- and post-plant for effective control of Downy Mildew. Incorporate into soil mechanically or with irrigation. See label for instructions and precautions.

potassium salts of phosphorous acid (ProPhyt, Fosphite, Phostrol): Rates vary according to formulation. See labels. 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.

Streptomyces grieoviridis strain K61 (MycoStop):  0.08 oz/lb seed.

White Rust (Albugo occidentalis)

A very damaging disease of spinach that is found only east of the Rocky Mountains in the USA. Plant resistant cultivars and practice crop rotation. Apply preplant and foliar fungicides.

azoxystrobin (Quadris): 12.3 to 15.4 fl oz/A (0 dh, REI 4h, Group 11). Apply at the first sign of disease and rotate with a fungicide other than a strobilurin in 7 to 14 days if necessary. Do not apply more than 2.88 qt/A. Quadris can by phytotoxic to spinach. See label for precautions.

cupric hydroxide (Kocide 3000):  0.75-1.25 lb/A. (0 dh, REI 24h, Group M1). Apply on a 5- to 7-day interval as soon as disease appears. This product may cause flecking.

fosetyl aluminum (Aliette WDG): 2 to 5 lb/A (3 dh, REI 12h, Group 33). Apply when disease is first evident.

fluopicolide (Presidio): 3.0-4.0 fl oz/A. (2 dh, REI 12h, Group 43). Must be used in a tank mix with a fungicide with a different mode of action.

mefenoxam (Ridomil Gold EC): 1.0-2.0 pt/A (21 dh, REI 48h, Group 4). Must be applied pre- and post-plant for effective control of white rust.  Incorporate into soil mechanically or with irrigation. See label for instructions and precautions.

potassium salts of phosphorous acid (ProPhyt, Fosphite, Phostrol): Rates vary according to formulation. See labels. Do not apply to plants that are heat or moisture stressed or recently treated with copper products.