Asparagus

Asparagus
Asparagus Disease Control Asparagus Insect Control Asparagus Weed Control

Introduction

Asparagus (Asparagus officinalis) is a perennial crop that usually produces well for 10-15 years, so choose a site with that in mind. Avoid areas where this tall crop could shade other crops. Select soils that are deep and well-drained, such as sandy loams or well-drained loams. However, the water table should not be more than four feet below the surface. The site should not have been planted with asparagus for a long period, preferably never. This is to minimize asparagus crown rot (Fusarium moniliforme) which can survive for a long time in the soil even without a host. Land cropped to corn within three years should also be avoided since some strains of F. moniliforme can also infect corn. Avoid areas subject to late spring frosts as emerging spears are easily injured. Site preparation should begin at least one year prior to planting in order to properly adjust soil pH, fertility, and eliminate serious perennial weed problems.

Types and Varieties

All-male hybrids that are tolerant to crown or root rot caused by Fusarium species should be grown. The varieties listed here are also tolerant to rust. 'Mary Washington' and some other old varieties are still available, but are half male and half female plants, making them highly susceptible to crown rot, and are less productive than all-male hybrids. Male plants do not expend energy producing seed and are thus more vigorous than female plants. Also, the lack of seed precludes the growth of nuisance seedlings which are not productive and act as weeds. 

Asparagus Varieties:

  • Millennium
  • Purple Passion (purple)

Soil Fertility

The year before planting, adjust the pH and build fertility in the soil based on soil testing results (see Table below). Asparagus does not tolerate acid soils. Apply lime to maintain soil pH at 6.8-7.0. This may require yearly applications of lime. For new beds, deeply incorporate lime to ensure proper pH at crown depth.

Asparagus is planted fairly deeply and the roots are known to penetrate deeper than six feet. Since there is little downward movement of phosphorus in the soil, it is important to get phosphorus into the root zone before planting. Till deeply and mix fertilizer material well into the deep root zone.

Less nitrogen fertilizer will be needed if legume sod was plowed down or if manure was applied (see Table 1 and Table 7). The second year after planting, the asparagus should receive fertilizer in the early spring and late summer. In subsequent years the bed should be fertilized after each harvest season. Base fertilizer rates on soil test results. 

Asparagus has moderate requirements for boron. For soils low in boron, apply 1-2 lbs per acre of actual boron every three years to asparagus plantings.

Plant nutrition recommendation according to soil test results for asparagus

SOIL TEST RESULTSNITROGEN (N) - LBS PER ACREPHOSPHORUS (P) -
LBS P2O5 PER ACRE		POTASSIUM (K) -
LBS K2O PER ACRE
VERY LOWLOWOPTIMUMABOVE OPTIMUMVERY LOWLOWOPTIMUMABOVE OPTIMUM
NEW ASPARAGUS BEDS
Broadcast and incorporate5015090300200150750
In bottom of furrow at planting0303030300000
TOTAL RECOMMENDED501801206030200150750
ESTABLISHED HYBRID ASPARAGUS BEDS
Broadcast after cutting season751509030-600300150750
TOTAL RECOMMENDED751509030-600300150750
ESTABLISHED NON-HYBRID ASPARABUS BEDS
Broadcast after cutting season501509030-600200100500
TOTAL RECOMMENDED501509030-600200100500

Planting

Crowns. Plant healthy one-year-old crowns in raised beds at the bottom of 8-in. deep furrows. Be sure the bud is facing up and roots are spread out. Space crowns 12" apart in rows 54-60" apart. Closer spacing produces higher yields in early years, but thinner spears in older beds. This will require 8,712-9,680 crowns per acre or 100 crowns per 100 row-feet. This spacing is for hybrids and is somewhat greater than was recommended for less vigorous non-hybrids. Cover with 2" of soil. During the rest of the season the furrow should be filled in bit by bit, without covering the asparagus foliage.

Transplants. Fields can also be planted with 8- to 12-week-old asparagus seedlings after the danger of frost has passed. Plant spacing is the same as for crowns. Care must be taken in order to prevent the small young ferns from being smothered by soil, especially after heavy spring showers. To accommodate the growth pattern of asparagus roots, use trays with straight, non-foam, non-tapering cells measuring 2"x2"x3". Use a sterilized medium consisting of half sand and half peat or use a commercial seed starting mix. Seed germination will take at least three weeks and the soil must be kept uniformly moist during this time. Young seedlings should be fed with quarter- or half-strength soluble fertilizer solution once each week or as needed. The nitrogen in this fertilizer should be in the nitrate form because young seedlings are sensitive to ammonium sources of nitrogen. The seedlings should be grown in the greenhouse for 6-8 weeks followed by two weeks of hardening off, prior to planting after the danger of frost has passed.

Field Culture

It is essential to maintain healthy fern growth during the first two growing seasons. Weed control is easily accomplished by slowly filling in the trenches over the course of the first season. These cultivations can be timed with flushes of weeds. Be sure ferns are not covered. During the second year the beds must be kept weed-free, especially during late summer and fall. Weed competition late in the season will restrict crown growth. Close attention must be given to insects and diseases that attack young ferns. As ferns become vigorous and full, diseases can cause the ferns to die prematurely, especially in late summer and early fall during periods of humid weather. Fungicides should be applied to control this foliage decline.

Mow brush in early spring before spear emergence followed by shallow discing, no deeper than 2-3 in. in order to prevent crown injury. Some growers remove ferns in the late fall or burn the ferns during the winter. This can destroy rust and purple spot inoculum and reduce harboring sites for insects such as asparagus beetles. Beds can also be disced immediately after harvest to control weeds prior to herbicide application.

Harvest and Storage

Spears may be harvested two times at the beginning of the second season. The harvest season is increased one to two weeks in subsequent years and should be six to eight weeks in mature beds, depending on plant health during the previous summer and fall. If spears are predominantly small in diameter, harvest should be stopped. Overcutting causes rapid decline in bed vigor. Spears can be snapped or cut at or below the soil surface. Avoid injury to newly emerging spears.

Once spears have been bunched and trimmed, they should be placed upright in shallow trays of water and kept cool. Ideally, they should be refrigerated at 32-36ºF and 95-99% relative humidity in order to maintain sugar content and tenderness. Storage life under ideal conditions is 14-21 days. Asparagus has a very high respiration rate and benefits from misting when on display.

Mother Stalk Harvest Method (trial only). In Japan and China, harvest throughout the summer is common. In this method, spring harvest is carried out for two weeks, after which three or four strong spears are left to grow into full ferns. From this point, newly emerging spears can be harvested throughout the season into early fall. Spear production is influenced by soil temperature and nutrient availability. Fertigation is usually practiced with this method. Plants have been shown to have similar longevity as those harvested in the spring only.

Asparagus Disease Control

Asparagus Disease Control
Asparagus - General Asparagus Insect Control Asparagus Weed Control

Crown Rot (Fusarium species)

Vigorously growing plants are less susceptible to crown rot. Buy top quality crowns. Use new land or land where asparagus has not been grown for 10 years. Use tolerant varieties.

Rust (Puccinia asparagi)

Rust disease attacks fern foliage and can spread rapidly, affecting production in subsequent years. Fern residues should be removed and destroyed prior to spear emergence in the spring. Control volunteer asparagus plants that might be infected. Resistant cultivars are not available. Apply fungicides after spear harvest is complete.

FRAC Group 3:

  • myclobutanil (Rally 40 WSP): 5.0 oz/A; PHI 180d, REI 24h. Begin applications after spears have been harvested. Observe a 30-day plant-back interval between the last application and planting new crops at the treatment site.

  • tebuconazole (Monsoon): 4.0 to 6.0 fl oz/A; PHI 180d, REI 12h. Begin applications after spears have been harvested. Do not make more than 3 foliar applications per year.

FRAC Group 11:

  • mancozeb plus azoxystrobin (Dexter Max): 2.0 to 2.2 lb./A; PHI 180d, REI 24h, Groups M03 &11. Begin applications after spears have been harvested. Alternate with fungicides outside of Group 11.

FRAC Group BM01:

  • thyme oil (Guarda): See label for rate; PHI 0h, REI 0h. See label for application methods and rates. Ensure thorough coverage to the point of runoff (15-25 gallons per acre).

FRAC Group BM02:

  • Bacillus amyloliquefaciens strain D747 (DoubleNickel 55OG): 0.25 to 3.0 lb/A; PHI 0d, REI 4h. Disease suppression only. For improved control, mix or rotate with a chemical fungicide.

FRAC Group M01:

  • copper (Badge SC): 1.0 to 2.5 pt./A; PHI 0d, REI 48h. For suppression. Tank mix with other products registered for rust control. Addition of sticker/spreader recommended.

FRAC Group M02:

  • sulfur (Microthiol DisperssOG): 10.0 to 30.0 lb/A; PHI 0d, REI 24h. Apply to ferns after cutting.

FRAC Group M03:

  • mancozeb (Dithane Rainshield F45): 1.6 qt/A; PHI 180d, REI 24h. Begin applications after spears have been harvested.

  • mancozeb plus azoxystrobin (Dexter Max): 2.0 to 2.2 lb./A; PHI 180d, REI 24h, Group M03 &11. Begin applications after spears have been harvested. Alternate with fungicides outside of Group 11.

FRAC Group M05:

  • chlorothalonil (Bravo Weather Stik): 2.0 to 4.0 pt/A; PHI 190d, REI 12h. Do not apply within 190 days of the harvest of spears in the following season.

FRAC Group P04:

  • laminarin (Vacciplant): 14.0 to 22.0 fl oz/A; PHI 0d, REI 4h. See label for application methods and restrictions.

Disease Control

Asparagus Insect Control

Asparagus Insect Control
Asparagus - General Asparagus Disease Control Asparagus Weed Control

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 27 and Insecticides Alphabetically Listed by Trade Name for more information on these insecticides.

The symbol * indicates a product is a restricted use pesticide. See Pesticide Safety 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.

Asparagus Aphids (Brachycorynella asparagi)

Asparagus aphids are small (1.6-2 mm), oval, green to gray aphids that may be covered in a waxy secretion. They overwinter as eggs on asparagus residue in the field. Eggs hatch in spring and nymphs and adults feed on spears, then on ferns. During the summer, wingless females produce live young (nymphs) which develop into reproductive females in 8-10 days. Populations can build up rapidly, especially in hot, dry weather. Aphids feed on new growth and cause shortening of internodes, rosetting, or ‘witch's broom’ appearance of the foliage. High aphid populations reduce root growth and plant vigor and may kill seedlings. Younger plantings are most vulnerable, especially 2- or 3-year-old plantings that are not being harvested. Cold winters and aphid infestation have a synergistic effect on plant health, greater than either factor alone. Asparagus aphids can also vector viruses, including asparagus virus I and II (AV-I and AV-II) and tobacco streak virus (TSV). During harvest, monitor any plantings that are not being harvested. After harvest, scout ferns for signs of feeding injury and aphid colonies, especially in the basal regions of the plant. Cultural controls include harvesting spears in spring, because only volunteer plants and young plantings that are not harvested will allow aphids to survive and multiply. Remove dead ferns during the fall or winter and control between-row volunteers through spring tillage or herbicides. Natural biocontrol is provided by insect predators such as lady beetles, lacewings, predatory midges, and syrphid fly larvae, by the parasitic braconid wasp, Diaeretiella rapae, and by a fungal pathogen that is more active in humid climates. Treat ferns when populations are low, if 5% of ferns show injury. Conserve beneficials by using a selective product. Scout again in 5-7 days to determine if further treatment is needed.

IRAC Group 1:

  • dimethoate (Dimethoate 4EC): 1 pt/A; PHI 180d, REI 48h, Bee: H, Group 1B. Systemic. Apply after last harvest. 
  • malathion (Malathion 57EC): 1.5 to 2 pt/A; PHI 6d, REI 12h, Bee: H, Group 1B.

IRAC Group 3:

  • pyrethrin (PyGanic EC5.0OG): 4.5 to 15.61 oz/A, 0.25 to 0.50 oz/gal; PHI 0d, REI 12h, Bee: M.

IRAC Group 4:

  • acetamiprid (Assail 30SG): 2.5 to 5.3 oz/A; PHI 1d, REI 12h, Bee: M, Group 4A.

IRAC Group 9:

  • pymetrozine (Fulfill): 2.75 oz/A; PHI 170d, REI 12h, Bee: L, Group 9B. Apply to ferns after harvest and before populations build to damaging levels. Allow a minimum of 30 days between applications.

IRAC Group UN:

  • insecticidal soap (M-PedeOG): 1.25 to 2.5 oz/gal water; PHI 0d, REI 12h, Bee: L. Apply with companion insecticide. Do not mix with sulfur. 
  • mineral oil (SuffOil-XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L. Apply as needed.

Asparagus Miner (Opbiomyia simplex)

This fly was introduced to North America from Europe and is present wherever asparagus is grown. It feeds only on asparagus and is found primarily on older stalks bearing ferns. The adult fly is shiny black, 3-4 mm long, with clear wings. Larvae are whitish, legless, tapered at both ends, with black mouth hooks at one end. Pupation takes place in the larval mine on the stalk. Overwintering puparia are usually in mines near or below ground level. There are 2 generations per year. Adults emerge in May and lay eggs underneath the epidermis of stems, usually near the base of the plant. Larvae feed in June, pupate inside their larval mines, and a second generation of adults emerges and lays eggs in late July or early August. Second generation larvae feed through August and pupate in the fall, overwintering until the following spring. Larvae feed just beneath the surface of the stem, burrowing upwards or downwards and forming mines. While direct feeding damage can girdle stems if there are several mines per stalk, the effect of miners on yield is usually minimal and the injury is largely cosmetic. The most important injury from asparagus miner is due to its association with Fusarium spp. and its ability to vector this pathogen into the plant through feeding wounds. Cultural practices to reduce damage from asparagus miner include removing overwintering stalks and destroying wild asparagus in the vicinity of commercial plantings. Select varieties that are resistant to Fusarium to reduce disease.

IRAC Group 4:

  • acetamiprid (Assail 30SG): 5.3 oz/A; PHI 1d, REI 12h, Bee: M, Group 4A. Suppression only.

Cutworms

Caterpillars hide under the soil surface adjacent to the plant stem during the day and feed after dark. Crooks (misshaped spears) are often caused by cutworms injuring tips at or just below the soil surface or feeding on the sides of young spears. For best results, make pesticide applications between midnight and dawn while cutworms are feeding above ground. Synthetic pyrethroids (group 3A) may work best during cool weather in May. See cutworms in the Pepper and Tomato (Outdoor) sections for more information on black and variegated cutworms.

IRAC Group 1:

  • carbaryl (Sevin XLR PLUS): 1 qt/A prior to fern growth, 2 qt/A on ferns; PHI 1d, REI 12h, Bee: H, Group 1A. Do not apply to crops or weeds in bloom.
  • methomyl (Lannate* LV): 1.5 to 3 pt/A, 1.5 pt/A variegated cutworm; PHI 1d, REI 48h, Bee: H, Group 1A.

IRAC Group 3:

  • permethrin (Pounce* 25WP): 3.2 to 6.4 oz/A; PHI 1d, REI 12h, Bee: H.

IRAC Group 5:

  • spinosad (SeduceOG): 20 to 44 lb/A, 0.5 to 1 lb/1000 sq ft.; PHI 60d, REI 4h, Bee: M. Scatter bait on soil around plants. For postharvest protection of ferns only.

IRAC Group UN:

  • Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 2 to 3 lb/A; PHI 0d, REI 4h, Bee: M.

Asparagus Beetles and Japanese Beetle

The common asparagus beetle (Crioceris duodecimpunctata) and spotted asparagus beetle (Crioceris asparagi) overwinter as adults in protected areas along fields. They feed and lay eggs in the crop, pupate in the soil, and have 2 or sometimes 3 generations per year. Both species are less than 3/8" long. The common asparagus beetle (CAB) has a bluish-black body with cream-colored square or rectangular spots, while the spotted asparagus beetle (SAB) is tan to orange with 12 round, black spots. Eggs of CAB are dark brown, laid standing on end in rows along the spears, with 3-10 in each cluster. During harvest, adult feeding by CAB on spears or the presence of CAB eggs can render the crop unmarketable. CAB larvae have 4 instars and are wrinkled, plump, hump-backed, and dull gray or brown with black head and legs. CAB larvae may cause severe defoliation of ferns and decline of the planting. SAB larvae are yellow or orange and feed only on berries. During harvest, scout for adults and eggs on sunny afternoons. Treat spears if >10% of the plants are infested with beetles or 1-2% have eggs or damage. Scout ferns for all life stages of both pests and treat if 50-75% are infested. If possible, spot spray along edges of planting where overwintering adults colonize the field and/or band insecticide over the row to help conserve natural enemies. Use selective insecticides on ferns. During harvest, snap or cut spears close to the soil surface daily and eliminate volunteer plants or treat them with an insecticide to use them as a trap crop. Disk old ferns lightly in the fall and clean areas around planting of debris to reduce overwintering populations. Eliminating female plants, and thus berries, can reduce or eliminate SAB populations. Japanese beetles may feed on ferns in mid-summer.

IRAC Group 1:

  • carbaryl (Sevin XLR PLUS): 1 qt/A prior to fern growth, 2 qt/A on ferns; PHI 1d, REI 12h, Bee: H, Group 1A. Do not apply to crops or weeds in bloom.
  • dimethoate (Dimethoate 4EC): 1 pt/A; PHI 180d, REI 48h, Bee: H, Group 1B. Apply after last harvest. Asparagus beetle only.
  • malathion (Malathion 57EC): 1.5 to 2 pt/A; PHI 6d, REI 12h, Bee: H, Group 1B. Asparagus beetle only.
  • methomyl (Lannate* LV): 1.5 to 3 pt/A; PHI 1d, REI 48h, Bee: H, Group 1A. Asparagus beetle only.

IRAC Group 3:

  • permethrin (Pounce* 25WP): 3.2 to 6.4 oz/A; PHI 1d, REI 12h, Bee: H. For Japanese beetle control, use high rate.
  • pyrethrin (PyGanic EC5.0OG): 4.5 to 15.61 oz/A, 0.25 to 0.50 oz/gal; PHI 0d, REI 12h, Bee: M.

IRAC Group 4:

  • acetamiprid (Assail 30SG): 2.5 to 5.3 oz/A asparagus beetle, 5.3 oz/A Japanese beetle; PHI 1d, REI 12h, Bee: M, Group 4A.

IRAC Group 5:

  • spinetoram (Radiant SC): 4 to 8 oz/A; PHI 60d, REI 4h, Bee: M. Postharvest protection of ferns from asparagus beetles only.
  • spinosad (Entrust SCOG): 2-4 oz/A; PHI 1d spears, REI 4h, Bee: M. For asparagus beetles only. May also be applied to ferns for postharvest protection. 

IRAC Group UN:

  • Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 2 to 3 lb/A; PHI 0d, REI 4h, Bee: M. Asparagus beetle only. 
  • kaolin (Surround WPOG): 12.5 to 25 lb/A, 0.25 to 0.5 lb/gal; PHI 0d, REI 4h, Bee: L. Suppression of asparagus beetles only. If complete control is needed, consider using supplemental controls.
  • mineral oil (SuffOil-XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L. Apply as needed. For beetle larvae only.
Insect Control

Asparagus Weed Control

Asparagus Weed Control
Asparagus - General Asparagus Disease Control Asparagus Insect Control

New Plantings

HRAC Group 0:

pelargonic acid (Scythe): 3 to 10% solution. PHI 1d, REI 12h. Apply for vegetative burndown during site preparation, prior to crop emergence from soil, as a directed and shielded spray, or as a harvest aid. Contact with crop will cause damage. 

HRAC Group 1:

clethodim (Select Max): 9 to 16 fl oz/A. PHI 1d, REI 24h. Do not exceed 64 fl oz/A per year. Apply to actively growing grasses. 

fluazifop (Fusilade DX): 16-24 fl oz/A. PHI 1d, REI 12h. Do not exceed 26 fl oz/A. Apply to actively growing grasses.

sethoxydim (Poast): 2.5 pt/A. PHI 1d, REI 12h. Do not exceed 5 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 3:

pendimethalin (Prowl H2O): Up to 8.2 pt/A. PHI 14d, REI 24h. 1 application per year. Can be applied to newly planted crowns but NOT to a newly seeded crop. When applying to newly planted crown asparagus, ensure crowns are fully covered with 2-4” of soil. Contact with crop will cause damage. On sandy soils do not use more than 2.4 pt/A.

trifluralin (Treflan HFP): 1 to 4 pt/A. REI 12h. Do not exceed 4 pt/A per year. Apply prior to planting new crowns or immediately after planting seed but prior to crop germination. Can apply to dormant asparagus after removing mature ferns, or immediately after the last harvest. Incorporate with two passes in opposite directions within 24 hours of application.

HRAC Group 5:

  • linuron (Lorox DF): 1 to 4 lb/A. PHI 1d, REI 24h. For pre- and postemergence control of many annual broadleaf weeds. For newly planted seeds or crowns, first apply activated charcoal in a 1” wide band above seeds or crowns. Application rates are dependent on asparagus establishment and application timing.
  • terbacil (Sinbar WDG): 1 to 2 lb/A. PHI 5d, REI 12h. Do not exceed 2.5 lb/A per year. For newly planted seeds or crows, first apply activated charcoal in a 1” wide band above seeds or crowns. In established asparagus, apply prior to spear emergence or immediately after clean cutting.

HRAC Group 9:

  • glyphosate (Roundup Power Max): 10 fl oz to 3.1 qt/A. PHI 5d (spot treatment) or 14d (all other uses), 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, or as a spot treatment to no more than 10% of the field area to be harvested. Spray contact can cause plant death. Spray additive recommendation varies with formulation–see label.

HRAC Group 22:

  • paraquat (Gramoxone SL 2.0*): 1.7 to 2.7 pt/A. PHI 6d, REI 48h. 1 application per year. Apply before planting, before spear emergence, or immediately after a clean cut. Spray contact can cause crop death. May be fatal if swallowed or inhaled. Restricted use: Applicators must complete an EPA-approved paraquat training every 3 years: https://www.epa.gov/pesticide-worker-safety/paraquat-dichloride-training-certified-applicators.
  • diquat (Reglone): 1.5 to 2 pt/A. PHI 1yr, REI 24h. Only use during site preparation prior to planting. 

Preemergent Herbicides for Established Beds Only

Once asparagus is established, more herbicides can be used safely, which are listed below. Products listed above can continue to be used except for diquat, which is only for use prior to planting.

HRAC Group 0:

  • napropamide (Devrinol 2-XT): Up to 2 gal/A. REI 24h. 1 application per year. Apply to a weed-free soil surface.

HRAC Group 4:

  • quinclorac (Quinstar 4L): Up to 12.6 fl oz/A. REI 12h. 1 application per year. Apply to the soil after the last harvest, before the first frost. Do not apply when crops are stressed.

HRAC Group 5:

  • diuron (Diuron 4L): 0.8 to 3.2 qt/A. REI 12h. Do not exceed 4.8 qt/A per year. Apply no earlier than 4 weeks before spear emergence and no later than the early cutting period. A second application can be applied immediately following the final harvest if rainfall is expected.
  • metribuzin (Metribuzin 75): 1.3 to 2.6 lb/A. PHI 14d, REI 12h. Do not exceed 2.6 lb/A per year. Apply as a single application in the spring before spears emerge or as a split application (once in spring and once after harvest but before fern emergence). 

HRAC Group 12:

  • norflurazon (Solicam DF): 2.5 to 5 lb/A. PHI 14d, REI 12h. Apply to weed-free soil. Incorporate and activate with water through irrigation or rainfall within 4 weeks of application.

HRAC Group 13:

  • clomazone (Command 3ME): 42.7 fl oz/A. PHI 14d, REI 12h. 1 application per year. Apply prior to spear and weed emergence or after a clean cut. Temporary partial whitening of leaf or stem tissue may occur but should not affect yield. Contact with crop will cause damage.

HRAC Group 14:

  • flumioxazin (Chateau SW): 6 fl oz/A. PHI 14d, REI 12h. 1 application per year. Must be applied to dormant asparagus, at least 2 weeks before spear emergence, or after the final harvest. Crop injury may occur if soil has been disturbed within 60 days prior to application or if asparagus is not dormant.
  • sulfentrazone (Aquesta 4F): 4.5 to 12 fl oz/A. PHI 14d, REI 12h. 1 application per year. Apply in the spring prior to spear emergence. Do not use on soils that have less than 1% organic matter.

HRAC Group 15:

  • s-metolachlor (Dual Magnum): PHI 16d,REI 24h. Group 15. 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.

HRAC Group 27:

  • mesotrione (Callisto): 3 to 7.7 fl oz/A. REI 12h. Do not exceed 7.7 fl oz/A per year. Apply in the spring prior to spear emergence, or after harvest, or both. When using after harvest, eliminate emerged spears or crop injury may occur.

Postemergent Herbicides for Established Beds 

HRAC Group 2:

  • halosulfuron (Sandea): 0.5 to 1.5 oz/A. PHI 1d, REI 12h. Do not exceed 2 oz/A per year. For use in transplanted crowns and established beds only. For transplanted crowns, apply no sooner than 6 weeks after fern emergence. For established beds, apply before, during, or at the end of harvesting season. May cause temporary stunting or twisting of ferns on certain varieties. If targeting nutsedge, split applications during and after harvest are recommended.

HRAC Group 4:

  • 2,4-D sodium salt (Amine 4): 3 to 4 pt/A. PHI 3d, REI 48h. Do not exceed 4.2 pt/A per year. If spears are present, apply immediately after a clean cut. Cut and discard any malformed spears immediately. 2,4-D is hazardous to most horticultural crops—contact with spray or spray drift can cause serious crop damage.
  • clopyralid (Spur): 0.5 to 0.67 pt/A. PHI 2d, REI 12h. Do not exceed 0.67 pt/A per year. Apply to actively growing weeds. If spears are present, apply immediately after a clean cut; contact with emerged spears may cause twisting.
  • dicamba (Clarity): 8 to 16 fl oz/A. PHI 1d, REI 24h. Do not exceed 16 fl oz/A per year. If spears are present, apply immediately after a clean cut. Contact with emerged spears may cause twisting; cut and discard any malformed spears immediately.

HRAC Group 14:

  • carfentrazone-ethyl (Aim EC): 0.5 to 2 fl oz/A. PHI 5d, REI 12h. Do not exceed 3.8 fl oz/A per year. Apply as a broadcast application after harvest to control broadleaf weeds and existing asparagus tissue.

There is limited local data available for quinclorac (Quinstar), carfentrazone (Aim), sulfentrazone (Aquesta), and diquat (Reglone). There may be potential crop injury concerns with use of these products in our region.

Weed Control