Garlic (Allium sativum L.) is in the onion family. For thousands of years it has been grown for culinary and medicinal uses. Garlic grows in a wide range of conditions. While most production is in mild areas, such as California, some varieties grow well in cold climates, often with better flavor.
There are two types of garlic. Hardneck (or topset) garlic produces false flower stalks called scapes, which are also edible. It typically has about a half dozen cloves per bulb. Softneck garlic typically has more than twice as many cloves and generally has a longer storage life than hardneck varieties. Softneck garlic dominates commodity production, but many growers in New England prefer hardneck types for retail sales due to their flavor and appearance. Hardneck varieties often have a reddish-purple clove covering versus the white color common in softneck types.
After centuries of cultivation, garlic has lost the ability to produce seeds. Therefore, it is vegetatively propagated by saving bulbs and planting individual cloves from which new bulbs form. The small bulbils produced on hardneck scapes can be used for propagation, but it takes several years of planting and selection to achieve marketable size bulbs.
Although many different variety names are used in garlic commerce, recent genetic research suggests there are only about 10 major varieties of garlic. These express different characteristics from one location to another, complicating variety identification. Since there is no standardization of varieties, as with potatoes, one must take garlic variety names with a grain of salt. It's a good idea to start out with several different varieties produced in your area, selecting and saving those that perform best.
A well-drained soil with good tilth and plenty of organic matter is ideal for garlic. Garlic has a shallow root system; excess moisture, compaction, or droughty conditions will reduce yields. The optimum soil pH is between 6 and 7. Since garlic commences growth very early in the season, it is important to have soil nutrients available at that time. The table below gives timing guidelines for use of quick-release sources, particularly for nitrogen. Adjust timing if using a slower release material. Since garlic has such an early start, avoid fields that are slow to drain in the spring
| PLANT NUTRIENT RECOMMENDATION ACCORDING TO SOIL TEST RESULTS FOR GARLIC | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| GARLIC | NITROGEN (N) LBS PER ACRE | PHOSPHORUS (P) LBS P2O5 PER ACRE | POTASSIUM (K) LBS K2O PER ACRE | ||||||
| SOIL TEST RESULTS | VERY LOW | LOW | OPTIMUM | ABOVE OPTIMUM | VERY LOW | LOW | OPTIMUM | ABOVE OPTIMUM | |
| Broadcast and Incorporate in fall | 40 | 150 | 100 | 25-50 | 0 | 150 | 100 | 50 | 0 |
| Sidedress in spring when shoots are 6 inches high | 40 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
|
Sidedress 3-4 weeks later |
40 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
| TOTAL RECOMMENDED | 120 | 150 | 100 | 25-50 | 0 | 150 | 100 | 50 | 0 |
Garlic is planted in the fall since it requires a cold temperatures to induce bulb formation. Planting typically occurs from October in northern New England to early November in southern areas. The goal is to time planting for good development of roots, but not enough time for the shoots to emerge from soil before winter. Many different planting arrangements are used by growers depending on irrigation, mulching, and weed control systems. Planting cloves too densely can reduce bulb size, while spacing too far apart reduces yield per area of land. Common planting arrangements include 2-row beds 30" apart on center with 6" spacing in and between rows, 3- or 4-row beds with 6-8" in and between rows; single rows spaced 24-30" with 6" in-row spacing. Wide row spacing between rows allows for easy mechanical cultivation for weed control; multiple rows per bed allow for use of plastic mulch to control weeds.
Garlic varieties differ in size and weight of cloves; generally, there are about 50 cloves in a pound. Large cloves tend to produce the most vigorous plants and largest bulbs; therefore, small cloves are often not planted. Bulbs should be separated no more than a day or two before planting so they do not dry out. Cloves should always be planted with the root side down, so the top of the clove is 1" below the soil surface. Plant only healthy-looking cloves to avoid disease and nematode problems.
A layer of clean straw mulch is typically applied to garlic at planting to avoid drastic soil temperature fluctuations and heaving in the winter and early spring. The garlic will grow through the mulch in the spring. Alternatively, garlic can be planted into plastic mulch. Either will conserve soil moisture and suppress weeds. It may be advisable to remove straw mulches in very wet springs to allow soil to dry out and thus reduce the threat of soil borne diseases. In very cold growing areas, removing mulch can also speed soil warming and garlic growth in the spring. Because garlic is shallow-rooted, irrigation is very beneficial during dry periods.
Clipping scapes from hardneck garlic once fully curled, just below the curl, has been found to improve bulb size. Scapes are edible, and can be sold and used as a garlic-flavored vegetable similar to scallions.
Although variable depending on variety and growing conditions, 1 lb of garlic 'seed' bulbs will usually yield 4-8 lb at harvest. Garlic may be ready to harvest over several weeks during July. When the lower third of leaves turn brown, it is advisable to pull several bulbs to check for maturity. Cut the bulbs in half width-wise, and check whether cloves have fully filled out within the skins. If so, they are ready to harvest. Pull, dig, and/or undercut the bulbs to remove them. Unless a lot of soil is adhered to the bulbs, they do not need to be washed at harvest (although some markets may demand it). Place the harvested plants on wire racks or tie in bundles for hanging to cure for several weeks in a dry area with good ventilation. After curing, tops can be cut to leave about an inch remaining, and root should be trimmed closely. If necessary, bulbs may be brushed or the outer skin gently rubbed off to clean them.
Seed garlic should be stored at 50ºF with relative humidity of 65-70%. Cloves sprout most rapidly between 40-50ºF. Garlic for table stock should be stored at 32ºF and 65-70% relative humidity. Well-cured bulbs stored at proper conditions should keep for 6-7 months. Relative humidity in storage is lower than for most vegetables because high humidity causes root growth and mold.
NOTE: For the disease control products listed below, one product trade name and formulation is provided for each active ingredient (common name) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same active ingredient. Please see Table 25 and Fungicides and Bactericides Alphabetical Listing by Trade Name for more information on products with the same active ingredients.
The symbol OG indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more detail.
The most common controls for leek and garlic diseases include the use of disease-resistant cultivars and pathogen-free seed and bulbs, as well as cultural practices including crop rotation and crop residue management that restrict the pathogens.
Blue mold is typically most problematic as a storage disease, although it can infect seed cloves as well, and cause poor stands. Several Penicillium species cause blue mold, and these species are common in soil, on plant and animal debris, and in senescing plant tissues. Some species may be carried on infected cloves or seed. The mold presents as a mass of blue-gray fungal growth on the bulb, and in the field yellowed and stunted plants may be observed. These pathogens typically invade bulbs through wounds, mechanical bruises, or freezing injury. Control other diseases in the field to prevent avenues for infection. Harvest bulbs with a minimum of bruising and wounding, and dry promptly. Store bulbs at 40°F with low relative humidity. Some countries recommend treating with fungicides before storage.
thiophanate methyl (Topsin M 70WP): 1.0 lb/100 gal; REI 72h, Group 1. Pre-plant treatment by immersion of garlic cloves in suspension for at least 5 minutes.
Avoid excessive soil moisture by improving soil drainage or planting on raised beds. Seed and soil treatments with fungicides are a recommended practice.
mefenoxam (Apron XL): 0.085 to 0.64 fl oz/100 lbs seed; REI 48h, Group 4. Not effective for Rhizoctonia.
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.
During extended periods of cool, humid weather, this disease can be highly destructive, causing losses in both yield and bulb quality. Practice a 3- to 4-year rotation. Plant on well-drained soil and orient rows in the same direction as prevailing winds. Avoid overhead irrigation. A regular program of fungicide spraying based on climatic conditions and disease forecasts should be followed.
ametoctradin plus dimethomorph (Zampro): 14.0 fl oz/A; PHI 0d, REI 12h, Groups 45 and 40.
azoxystrobin (Quadris): 9.0 to 15.5 fl oz/A; PHI 0d, REI 4h, Group 11. Do not make more than 1 application of Quadris before alternating with fungicides that have a different mode of action.
azoxystrobin plus chlorothalonil (Quadris Opti): 2.4 to 3.6 pt/A; PHI 14d, REI 12h, Groups 11 & M5. See label for tank mix precautions.
azoxystrobin plus propiconazole (Quilt Xcel): 17.5 to 21 fl oz/A; PHI 14d, REI 12h, Group 11 & 3.
Bacillus amyloliquefaciens strain D747 (DoubleNickelOG): 0.25 to 3.0 lb/A; PHI 0d, REI 4 h, Group 44. Disease suppression only. For improved control; mix or rotate with a chemical fungicide.
copper hydroxide (Kocide 3000): 0.75 to 1.5 lb/A; PHI 0d, REI 48h, Group M1. Can cause phytotoxicity to leaves.
dimethomorph (Forum): 6.0 fl oz/A; PHI 0d, REI 12h, Group 40. Forum must be applied as a tank mix with another fungicide that has a different mode of action. Apply in adequate water.
famoxadone plus cymoxanil (Tanos): 8.0 oz/A; PHI 3d, REI 12h, Groups 11 & 27. Must be tank mixed with an appropriate contact fungicide with a different mode of action. Do not alternate or tank mix with other Group 11 fungicides.
fenamidone (Reason 500 SC): 5.5 fl oz/A; PHI 7d, REI 12h, Group 11. Do not make more than one application of Reason before alternating to a fungicide from a different resistance management group
fluazinam (Omega 500): 1.0 pt/A; PHI 7d, REI 12h, Group 29. Use sufficient water for thorough coverage, but not less than 5 gal./A.
mancozeb (Dithane F45): 2.4 qt/A; PHI 7d, REI 24h, Group M3.
mandipropamid (Revus): 8.0 fl oz/A; PHI 7d, REI 4h, Group 40.
mefenoxam plus chlorothalonil (Ridomil Gold Bravo SC): 2.5 pt/A; PHI 7d, REI 48h, Groups 4 & M5.
mefenoxam and mancozeb (Ridomil Gold MZ): 2.5 lbs/A; PHI 7d, REI 48h, Groups 4 & 18. Use sufficient water to obtain thorough coverage. Do not apply Ridomil Gold more than 4 times.
oxathiapiprolin & mandipropamid (Orondis Ultra): 5.5 to 8.0 fl oz/A; PHI 7d, REI 4h, Group 49 & 40.
phosphorous acid (Fosphite): 1.0 to 3.0 qt/in a minimum of 20 gal/A; PHI 0d, REI 4h, Group 33. Do not apply to plants that heat or moisture stressed. Do not apply directly to copper treated plants within 20-day interval to avoid plant injury.
pyraclostrobin (Cabrio EG): 12.0 oz/A; PHI 7d, REI 12h, Group 11. Do not rotate with other Group 11 fungicides.
Bulb and basal plate rot of garlic is caused by Fusarium culmorum and F. roseum. Symptoms include pre-emergence decay of cloves and seedlings, decay of the stem plate and storage leaves during the growing season, and postharvest decay of cloves in stored bulbs. Infected cloves will have sunken, circular brown lesions on their outer surface and/or basal plate. Foliar symptoms include curving, yellowing and necrosis of leaves beginning at tips, and wilt. Infection occurs mainly from the soil through the stem plate. Incidence of the disease increases with injury by onion maggot or other insects. Cloves may remain infected but non-symptomatic. The pathogen is disseminated in seed, soil, infected debris, and irrigation water. Hot water seed treatment has reduced garlic clove infection by 50%, but is not enough to provide commercially-acceptable control when clove infection is severe. Excess soil N favors Fusarium infection; take care to account for soil organic matter and cover crop N credits and not to over apply fertility. Long (4-year) rotations to non-susceptible crops may minimize losses. Storage at 40°F also helps. The most important control measure is the planting of resistant cultivars.
Alternaria porri is most likely to become problematic when temperatures are warm (77-85°F) with high humidity. Small lesions will form on stems or leaves, eventually enlarging and becoming tan or purple. Purple blotch is easily confused with Stemphylium leaf blight, which tends to produce darker lesions. While laboratory diagnoses are needed for proper identification, these two pathogens can be managed in the same way. Practice long rotations with unrelated crops, and use practices that reduce hours of leaf wetness, e.g. plant spacing and good air drainage. Plant resistant or tolerant varieties. Plow under crop residues promptly after harvest. Rotate fungicides throughout the growing season.
azoxystrobin (Quadris): 6.0 to 12.0 fl oz/A; PHI 7d, REI 4h, Group 11. Do not rotate with other Group 11 fungicides.
azoxystrobin plus chlorothalonil (Quadris Opti): 1.6 to 3.2 pt/A; PHI 14d, REI 12h, Groups 11 & M5. See label for tank mix precautions.
azoxystrobin plus difenoconazole (Quadris Top): 12.0 to 14.0 fl oz/A; PHI 1d, REI 12h, Groups 11 & 3.
azoxystrobin plus propiconazole (Quilt): 14.0 to 27.5 fl oz/A; PHI 14d, REI 12h, Group 11 & 3.
Bacillus amyloliquefaciens strain D747 (DoubleNickel LCOG): 0.25 to 3.0 lb/A; PHI 0d, REI 4 h, Group 44. Disease suppression only. For improved control; mix or rotate with a chemical fungicide.
boscalid (Endura): 6.8 oz/A; PHI 7d, REI 12h, Group 7. Do not make more than 2 consecutive applications before rotating to a fungicide with a different mode of action.
chlorothalonil (Bravo Weather Stik): 1.0 to 3.0 pt/A; PHI 7d, REI 12h, Group M5. When disease is present, use the higher rate.
copper hydroxide (Kocide 3000): 0.75 to 1.5 lb/A; PHI 0d, REI 48h, Group M1. Do not apply in a spray solution having a pH less than 6.5 or tank mix with Aliette.
cyprodinil plus fludioxonil (Switch 62.5 WG): 11.0 to 14.0 oz/A; PHI 7d, REI 12h, Groups 9 & 12. Do not make more than 2 consecutive applications before rotating to a fungicide with a different mode of action.
difenoconazole plus cyprodinil (Inspire Super): 16.0 to 20.0 fl oz/A; PHI 7d, REI 12h, Group 3 & 9. Apply in sufficient volume to achieve thorough coverage.
famoxadone plus cymoxanil (Tanos): 8.0 oz/A; PHI 3d, REI 12h, Groups 11 plus 27. Must be tank mixed with an appropriate contact fungicide with a different mode of action. Do not alternate or tank mix with other Group 11 fungicides.
fenamidone (Reason 500 SC): 5.5 fl oz/A; PHI 7d, REI 12h, Group 11. Do not rotate with other Group 11 fungicides.
mancozeb (Dithane F45): 2.4 qt/A; PHI 7d, REI 24h, Group M3.
polyoxin D (OSO 5%SC): 3.75 to13.0 fl oz/A; PHI 0d, REI 4h, Group 19.
propiconazole (Tilt): 4.0 to 8.0 fl oz/A; PHI 14d, REI 12h, Group 3.
pyraclostrobin (Cabrio EG): 8.0 to 12.0 oz/A; PHI 7d, REI 12h, Group 11. Do not rotate with other Group 11 fungicides (Quadris).
pyraclostrobin plus boscalid (Pristine): 10.5 to 18.5 oz/A; PHI 7d, REI 12h, Groups 11 & 7. Do not make more than 2 applications of Pristine before alternating with a fungicide with a different mode of action.
pyrimethanil (Scala SC Fungicide): 18.0 fl oz/A; PHI 7d, REI 12h, Group 9.
Ditylenchus dipsaci is a nematode species that infects germinating garlic seed and is primarily borne in seed cloves. The nematode itself has limited mobility, but can be easily spread in infested soil, on equipment, and in infected seed and plant material. D. dipsaci is common in all temperate regions. It is an obligate parasite of plants; populations of the nematode exhibit marked host preferences. The nematodes aggregate into a mass called nematode wool and with slow drying can persist in infested fields for long periods. Symptoms of garlic bloat include leaf yellowing, erratic stands, stunting, looping and bending of leaves, twisting, and growth deformities. Bulb damage can be mistaken for Fusarium basal plate rot with decay occurring both at the neck and the basal plate. Infected bulbs will lack roots. D. dipsaci can be controlled with long crop rotations including the elimination of volunteer onions, garlic, and host weeds. The primary method of controlling nematodes is hot water treatment of seed cloves. The standard regime is 30 to 45 minutes at 100ºF, 20 minutes at 120ºF, and then 10 to 20 minutes at 64-72ºF. Hot water treatment must be performed carefully to prevent damage to cloves. Chemical, physical, and cultural methods have been used to restrict damage, but most chemical treatments are no longer registered for use.
White rot is caused by Sclerotium cepivorum, which persists for a long time in soil. It is “activated” by root exudates produced by Allium crops. Affected plants will show yellowing older leaves and stunting, and small black sclerotia can be seen on the bulb. Disease development is favored by cool, moist soil conditions. There is little to be done once a field is infested with S. cepviorum, and crops should be rotated out of Alliums for as long as possible. Some fungicides (iprodione) provide protection for the establishment of garlic, but fungicide control is marginal for full-season crops. Soil fumigation may provide partial control. In general, neither fungicides nor fumigation have provided consistent, reliable, full-season control of white rot. Hot water treatment of garlic seed can reduce the potential to spread white rot sclerotia. Winter flooding and soil solarization can reduce the number of sclerotia. White rot symptoms are less severe on leeks.
azoxystrobin plus propiconazole (Quilt Xcel): 17.5 to 26 fl oz/A; PHI 14d, REI 12h, Group 11 & 3.
Bacillus amyloliquefaciens strain D747 (DoubleNickel 55OG): 0.12 to 1.0 lb/A as a soil drench; PHI 0d, REI 4 h, Group 44.
boscalid (Endura): 6.8 oz/A; PHI 7d, REI 12h, Group 7. Apply in-furrow at planting.
cyprodinil plus fludioxonil (Switch 62.5 WG): 11.0 to 14.0 oz/A; PHI 7d, REI 12h, Groups 9 & 12.
fludioxonil (Cannonball WP): 0.5 oz/1000 ft.; PHI 7d, REI 12h, Group 12. Apply in-furrow at planting.
iprodione (Rovral): 4.0 pt/A; REI 24h, Group 2. Apply in-furrow at planting. Do not make more than 1application per year.
tebuconazole (Orius 3.6F): 25.0 fl oz/A; PHI 7d, REI 12h, Group 3. Apply in-furrow at planting or over the top in a 4 to 6 inch band.
thiophanate methyl (Topsin M 70WP): 2.0 lb/A; REI 72h, Group 1. Apply in furrow.
NOTES: For the insecticides listed below, one product trade name and formulation is provided for each active ingredient (AI) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same AI. Please see Table 26 and Insecticides Alphabetical Listing by Trade Name for more information on these insecticides.
The designation (Bee: L, M, or H) indicates a bee toxicity rating of low, moderate, or high. See the Protecting Honeybees and Native Pollinators section for more details.
The symbol * indicates a product is a restricted use pesticide. See Pesticide Safety and Use for more details.
The symbol OG indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more details.
For more information on this pest and for cultural and chemical controls, see Allium Leafminer in the leek section.
abamectin (Agri-Mek* SC): 1.75 to 3.5 fl oz/A; PHI 30d, REI 12h, Bee: H, Group 6. Make 2 consecutive applications then rotate to a different mode of action. Make at least 2 consecutive applications of another mode of action before making additional Agri-Mek SC applications. Insect control can be reduced if used with a sticker or binder type product.
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, Group un. When using lower rates, combine with adjuvant for improved spray coverage and translaminar uptake.
cyantraniliprole (Exirel): 13.5 to 20.5 fl oz/A; PHI 1d, REI 12h, Bee:H, Group 28. Use with an adjuvant to maximize efficacy. Spreading and penetrating adjuvants can cause negative crop response.
cyromazine (Trigard): 2.66 oz/A; PHI 7d, REI 12h, Bee: H, Group 17. Apply when leafminers first appear. Do not apply more than 6 times or 1 lb/A per calendar year.
dinotefuran (Scorpion 35SL): 5.25 to 7 fl oz/A foliar, 8.75 to 10.5 fl oz/A soil; PHI 1d, REI 12h, Bee: H, Group 4A. Do not apply more than a total of 10.5 fl oz/A per season.
gamma-cyhalothrin (Declare*): 0.77 to 1.28 fl oz/A; PHI 14 days, REI 24h, Bee: H, Group 3A.
Isaria fumosorosea Apopka Strain 97 (PFR-97 20% WDGOG): 1 to 2 lbs/A; PHI 0d, REI 4h, Bee: M, Group M.
lambda-cyhalothrin (Warrior* II): 0.96 to 1.6 fl oz/A; PHI 14d, REI 24h, Bee: H, Group 3A.
permethrin (Pounce* 25WP): 6.4 to 12.8 fl oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.
pyrethrins (Pyganic EC5.0IIOG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.
spinetoram (Radiant SC): 6 to 10 oz/A; PHI 1d, REI 4h, Bee: M, Group 5. Efficacy improves with the addition of an adjuvant. Do not make more than 2 consecutive applications of Group 5 insecticides. Do not make more than 5 applications per year per crop.
Two genera of mites are known to infect species of Allium - a dry bulb mite, Aceria tulipae, and species in the genus Rhizoglyphus. Mites can survive in soil on decaying vegetation. Infected seed may fail to germinate. Plants grown from infected seed may lack vigor and produce stunted, deformed leaves. Plants may outgrow the damage if the infestation is not heavy, but mites may increase in number over the growing season and will remain in the harvested garlic. They are particularly troublesome in storage, causing desiccation and creating wounds that allow for entry of secondary pathogens.
Bulb mites are favored by mechanical injury, disease, cool soil temperatures, and soils with high organic matter content. Avoid adding manure and use fallow periods to eliminate crop residue. In smaller plantings, removing culls from the field immediately after harvest will reduce overwintering populations. Dark plastic mulch will increase soil temperatures and control mites. Plant clean seed and rotate out of Alliums for at least four years after an infestation. Avoid planting Allium crops directly after brassicas, corn, grain, or grass cover crops.
For more information on this pest and for cultural and biological controls, see onion maggot in the Onion section.
diazinon (Diazinon* AG500): 2 to 4 qt/A; REI 3d, Bee: H, Group 1B. Broadcast and incorporate just before planting. Will not control organophosphate-resistant onion maggots. DO NOT make more than one application per year.
Thrips are favored by hot, dry weather. Thrips typically feed under leaf folds and in protected inner leaves, although when populations are high they may feed on exposed leaf surfaces. This causes white scars on leaves that can reduce plant growth when severe, as well as provide entry points for foliar diseases. In severe infestations, the field may appear silvery in color. Both adults and nymphs cause damage.
Heavy rain or overhead irrigation can lower populations quickly. Lacewing larvae, pirate bugs, and predatory thrips are important natural enemies. Reduce populations by cleaning up crop residue after harvest to limit overwintering sites. Do not plant garlic near other Allium crops or alfalfa, clover, cucurbits, or brassicas, as these can harbor large populations of thrips that can migrate to garlic when these crops are cut or harvested. The most common controls for leek and garlic diseases include the use of disease-resistant cultivars and pathogen-free seed and bulbs, and cultural practices such as crop rotation and crop residue management that restrict the pathogens.
Begin applications when damage is first noticed. Repeat applications at 7- to 10-day intervals. Use a shorter interval in hot, dry weather. Use spreader-sticker for better coverage. Apply in early evening, using high pressure and 100 gal water/A for best results. See onion thrips in the Onion section for more information.
acetamiprid (Assail 30 SG): 5 to 8 oz/A; PHI 7d, REI 12h, Bee: M, Group 4A.
Beauveria bassiana (Mycotrol ESOOG): 0.25 qt to 1 qt/A; PHI 0d, REI 4h, Bee: L, Group UN. Treat when populations are low and thoroughly cover foliage. Takes 7 to 10 days after the first spray to see control. Repeat applications may be needed.
Burkholderia spp. strain A396 cells (Venerate XCOG): 1 to 8 qt/A; PHI 0d, REI 4h, Bee: M, Group UN. Suppression only.
Chenopodium extract (Requiem EC): 1.5 to 3 qts/A; PHI 0d, REI 4h, Bee: L, Group UN. Begin application as soon as thrips are seen. Thoroughly cover foliage.
Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 2 to 3 lb/A; PHI 0d, REI 4h, Bee: M, Group UN.
cyantraniliprole (Exirel): 13.5 to 20.5 oz/A; PHI 1d, REI 12h, Bee: H, Group 28. Suppression only.
deltamethrin (Delta Gold*): 1.5 to 2.4 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.
dinotefuran (Venom): 3 to 4 fl oz/A foliar, 5 to 6 fl oz/A soil; PHI 1d foliar, 21d soil, REI 4h, Bee: H, Group 4A.
gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 14d, REI 24h, Bee: H, Group 3A.
imidacloprid (Admire Pro): 14 oz/A; PHI 21d, REI 12h, Bee: H, Group 4A. Soil applications only.
kaolin (Surround WPOG): 25 to 50 lb/A or 0.25 to 0.5 lb/gal; PHI 0d, REI 4h, Bee: L. Suppression/repellence only. Good coverage into plant crown is essential. Generally compatible as a tank mix with other insecticides.
lambda-cyhalothrin (Warrior* II): 1.28 to 1.92 oz/A; PHI 14d, REI 24h, Bee: H, Group 3A.
malathion (Malathion 57 EC): 1.5 to 2 pt/A; PHI 3d, REI 24h, Bee: H, Group 1B.
permethrin (Pounce* 25WP): 9.6 to 12.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.
pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.
sodium tetraborohydrate decahydrate (Prev-AM): 100 oz/100 gal; REI 12h, Bee: L, Group 25. Do not apply in midday sun or mix with copper, sulfur or oils.
spinosad (Entrust SCOG): 4 to 8 oz/A; PHI 1d, REI 4h, Bee: M, Group 5. Suppression only. Use adjuvant for better control.
spinetoram (Radiant SC): 6 to 10 oz/A; PHI 1d, REI 4h, Bee: M, Group 5. Thorough coverage is essential. Efficacy improves with the addition of an adjuvant.
spirotetramat (Movento): 5 oz/A; PHI 3d, REI 24h, Bee: M, Group 23. Must be tank-mixed with a spray adjuvant with spreading and penetrating properties to maximize leaf uptake and sytemicity; don't use sticker adjuvants. Controls immature stages; may also reduce adult fertility.
zeta-cypermethrin (Mustang*): 3.2 to 4.3 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A.
NOTE: For the herbicides listed below, one product trade name and formulation is provided for each active ingredient along with preharvest interval (PHI), restricted entry interval (REI), resistance management group number, and example of rates and special instructions. In many cases, there are other products available with the same active ingredient. However, not all products with the same active ingredient are registered for use in a crop. Always check the product label to be sure that the crop is listed before using.
Garlic is not very competitive, so good weed control is critical. Mulch will control weeds and conserve moisture. If the mulch is removed, cultivation will likely be needed. It should be shallow so as not to damage roots.
See Stale Seedbed Technique in the Weed Management section.
glyphosate (Roundup Power Max): REI 12h, Group 9.
paraquat (Gramoxone SL 2.0*): restricted use. REI 12h, Group 22. Use 2 – 4 pts/A. May be fatal if swallowed or inhaled. Applicators must complete an EPA-approved paraquat training listed on the following website https://www.epa.gov/pesticide-worker-safety/paraquat-dichloride-training.... The training must be completed a minimum of every three years.
pelargonic acid (Scythe): PHI 1d, REI 12h, Group 17. Use a 3% -10% solution (3 to 10 gallons per 100 gallons).
Garlic is not very competitive, so good weed control is critical. Mulch will control weeds and conserve moisture. If the mulch is removed, cultivation will likely be needed. It should be shallow so as not to damage roots.
bensulide (Prefar 4E): REI 12h, Group 0. Apply 5 to 6 qt/A. Can be preplant incorporated by shallow cultivation (1"-2”) or applied preemergence and incorporated by irrigation within 36 hours of application. Grass control only; should be supplemented with cultivation or another registered herbicide for broadleaf control. See label for rotation restrictions.
dimethenamid (Outlook): PHI 30d, REI 12h, Group 15. This herbicide is a root and shoot growth inhibitor that controls susceptible germinating seedlings before or soon after they emerge from the soil. Do not apply until garlic has reached the 2 true-leaf stage or significant crop injury can occur. May be applied as a single application (up to 21 oz/A) or used in split applications. For split applications do not exceed a total of 21 oz/A per season. An initial application of 10 to 14 oz/A can be followed by another application of the remaining 7 to 11 oz/A. Applications must be a minimum of 14 days apart. Application rates are influenced by soil organic matter content. See label for info on application rates depending on soil type and organic matter content. See label for info on tank mixing with other herbicides.
flumioxazin (Chateau SW): REI 12h, Group 14. Apply up to 6 oz/A with 3 days of planting garlic and before garlic has emerged. Must be sprinkler or rainfall incorporated (0.5–0.75” of water) for preemergence weed control. Will control many broadleaf weeds and some grass species.
s-metolachlor (Dual Magnum): REI 12h, Group 15. MASSACHUSETTS AND NEW HAMPSHIRE ONLY. Make sure the label for your state is available for download before using this product. This is a restricted label available only 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.
pendimethalin (Prowl H2O): PHI 45d, 24 hr REI, Group 3. Apply 1.5 to 3.2 pt/A. Select rate based on soil texture. See label for detail. Can be used preemergence after planting but before crop emergence, after crop emergence when garlic is in the 1 to 5 true leaf stage, or at both timings. Emerged weeds will not be controlled.
carfentrazone (Aim EC): REI 12h, Group 14. Aim is a burndown herbicide and will injure any foliage it comes into contact with. Apply Aim to row middles of emerged crops with hooded sprayers to control emerged weeds, including crops grown on mulch or plastic. Prevent any spray from contacting the crop, or injury will occur. For best results, make application to actively growing weeds up to 4 inches tall and rosettes less than 3 inches across. Good coverage is essential for good control. Apply up to 2 oz/A per application, and do not exceed a total of 6.1 oz/ per season.
clethodim (Select Max): PHI 45d, 24hr REI, Group 1. Will control grass weeds only. Apply to actively growing grasses. See label for rate selection. Multiple applications permitted of 9 to 32 oz/A per application, minimum 14-days between applications, not to exceed 64 oz/A per year. Add 0.25% v:v nonionic surfactant (1 qt per 100 gal of spray). Can also be used as a spot-spray by mixing 1/3-2/3% (0.44 to 0.85 oz per gallon) Select Max and 0.25% v:v nonionic surfactant (0.33 oz per gallon). Spray to wet, but do not allow runoff of spray solution.
fluazifop (Fusilade DX): PHI 45d, REI 12h, Group 1. For grass weed control only. Apply up to 24 fl oz/A. See label to select rate based on grasses targeted for control. Can make up to 2 applications per year. Allow for minimum 14-days between applications, and not to exceed 48 oz/A per year. Apply to actively growing grasses (see product label for susceptible stage). Add either crop oil concentrate (0.5-1%, 0.5-1 gallon per 100 gallons of spray) or nonionic surfactant (0.25-0.5%, 1-2 qt per 100 gal of spray).
oxyfluorfen (Goal 2 XL): PHI 60d, REI 48h, Group 14. Provides early postemergence and residual control of many broadleaf weed species. For direct seeded garlic, apply 2 to 4 oz/A to garlic that has at least 3 fully developed true leaves. For transplanted garlic, apply 2 to 4 oz/A to garlic transplants as soon as possible after transplanting. Multiple treatments may be applied up to a maximum of 32 fl oz per acre preseason. For optimum postemergence control, apply when susceptible weeds are in the 2 to 4 leaf stage and actively growing. Application to weeds at later than 4 leaf growth stage may result in reduced weed control. Adjust nozzles for minimum spray contact with garlic plants, directing the spray to the soil at the base of garlic plants and adjacent bed top and furrow area. Do not tank mix or add adjuvants unless directed to do so on Dow supplemental labeling.
pelargonic acid (Scythe): PHI 1d, REI 12h, Group 17. Use a 3-10% solution (3 to 10 gallons per 100 gallons). Use a 3-5% solution for annual weeds, a 5-7% solution for biennial and perennial weeds, and 7-10% solution for maximum burndown. Delivery rate for boom applications should be 75-200 gals of spray solution per acre; 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. See label for complete details.
sethoxydim (Poast): PHI 30d, REI 12h, Group 1. Controls grass weeds only. Apply to actively growing grasses (see product label for susceptible stage). Maximum 1.5 pt/A per application, minimum 14-days between applications. Do not exceed 4.5 pt/A per year. Use with crop oil concentrate (2.0 pt/A) or methylated seed oil (1.5 pt/A). Note that crop oil can cause injury under hot and humid conditions. Can also be used as a spot-spray by mixing 1-1.5% (1.3 to 1.9 oz per gallon) Poast and 1% v:v crop oil concentrate (1.3 oz per gallon). Spray to wet, but do not allow runoff of spray solution.