Slugs can cause significant damage to grass grown for seed, impacting stand and yield. The consistent mist and steady, high rainfall characteristic of the primary growing areas that are ideal for seed germination, are also ideal for slugs to feed, thrive and propagate. In no-till plantings, with more cover and harborage, the risk of slug pressure is further increased. Since they are hermaphrodites, a single pair of slugs or snails can breed and lay a clutch of 80-120 eggs. Breeding cycles can occur as often as every 4-8 weeks.

Many seed growers wait to treat until slug activity is apparent, performing only spot baiting, and miss the opportunity to favorably impact stand and yield by getting more timely control via an earlier preventative baiting program.

  • Slug


Juvenile slugs kill more emerging grass seedlings because they are often abundant in seedbeds. They also kill more seeds than larger adult slugs.

Slugs attack growing shoots and roots, killing the seedlings by destroying the growing points. If slugs are unable to reach the seeds, these shoots will be severely attacked but not necessarily killed. Seedlings are grazed by slugs feeding on the surface from the time they emerge, resulting in characteristic shredding of the blades.

Pocket Gopher Damage-Mounds
Pocket Gopher Damage Mounds
Pocket Gopher Damage Mounds

Controlling Slugs

For slug control in grass grown for seed, researchers and crop advisors agree that a three-pronged approach is the best preventative strategy:

  1. Surface applications: straight broadcast or blended with fertilizer
  2. In-furrow at planting
  3. Spot broadcast treatment

This approach need not increase input costs and may actually reduce them.

Surface Treatment

Innovative growers can apply preventative protection earlier by blending metaldehyde baits such as Metarex with fertilizer. Metarex’s weatherability and bulk density of 49 lbs. per cubic foot allows it to blend easily and uniformly with nitrogen fertilizers, broadcast consistently, and resist moisture in storage and when applied in the field. See our Recommended Spreader Settings table.

Pocket Gopher Damage-Mounds
Pocket Gopher Damage Mounds
Pocket Gopher Damage Mounds

In-Furrow at Planting

Applying Metarex in-furrow at planting is effective, since Metarex pellets are rain- and irrigation-resistant. Metarex granules resist heavy watering, holding their shape longer than other pellets. If pellets crumble or solidify the resulting pellet flow could be interrupted, reducing the consistency of the discharge. This would lead to reduced slug control as well as require frequent cleaning of gate openings and seed drill nozzles. Using Metarex enables growers to protect seedlings when they are most vulnerable: at pre-emergence.

Pocket Gopher Damage Mounds
Pocket Gopher Damage Mounds


Why Metarex?

The weatherability, pellet uniformity, mold resistance, palatability, and efficacy of Metarex all contribute to its performance in “at-planting” and “blended-with-fertilizer” applications. Integrated Pest Management (IPM) practices incorporating Metarex at reduced rates (per label directions) have been shown to achieve effective control and reduce crop damage.

Metarex 4% Metaldehyde Bait offers smaller, consistently-sized pellets produced using an exclusive manufacturing process that blends the active ingredient homogeneously throughout the pellet, while drying and hardening the pellet. This process is similar to that used for pasta. Pellets can become wet and will re-harden, offering irrigation and mold resistance, and yielding long field life. Metarex’s all-weather formula is rainfast up to 45 days under normal rainfall.

Metarex’s no dust formula reduces bait waste, and your applicator rig and clothing do not turn blue, saving you valuable clean-up time.

Metarex provides more baiting points (pellets) at approximately 35,400 per pound. Plentiful baiting points are critical for controlling slugs since slugs often do not venture far to feed, especially less-mobile juveniles.


Metarex’s all-weather formula is resistant to rain and watering. Pellets retain their shape longer, remaining effective and providing protection for up to four weeks.

Metarex pellets after 24 hours in an open Petri dish, 20mL water, 85% relative humidity. Photo credit: Dr. Hipólito O’Farrill, Entomologist, University of Puerto Rico – Mayagüez, 11/07.



Metarex’s pellet size uniformity helps it achieve more consistent dispersion and broadcast (often uniform up to 40-60 feet) when applied using electric spreaders. Highly-visible pellets help assure proper coverage and prevent over-application.

Metarex wet process results in 92% of pellets exactly the same 2.5 mm size <8% variance: 2.4 mm or 2.6 mm.


Metarex offers high palatability, with the bait carrier favored three-to-one versus fresh lettuce and carrots in slug trials. This high palatability equals quick attraction. After feeding, slugs dehydrate and die within 2-6 days.

Superior Palatability


Metarex provides more baiting points (pellets), at approximately 35,400 per pound. Plentiful baiting points are critical for controlling slugs since slugs often do not venture far to feed, especially less-mobile juveniles.

Metarex delivers efficacy for up to four weeks after application according to label directions at rates as low as 5 pounds per acre.

Respected researchers, pest control advisors and Certified Crop Advisors, including Dr. Glenn C. Fisher (OSU) Emeritus, Joe Cacka (Nutrien) Emeritus, and advisors with Western Ag Improvement, Simplot, and SureCrop have tested Metarex extensively under challenging field conditions. Contact your Distributor for more information.

Grass Graph
Gopher Chart

Top Graph: Tall fescue, Berger Farm, Willamette Valley (4 replications). Credit: Dr. Glenn C. Fisher, PhD., Oregon State University.

Bottom Graph: Grass seed trials, Tangent, OR 2/05-3/05. Credit: Joe Cacka, Certified Crop Advisor, Nutrien.

Application Directions

Apply at a rate of 5–20 pounds of product per acre (A). The maximum application rate is 20 pounds of product per acre (0.8 lb. ai/A) per application. A maximum of four applications are permitted at a minimum retreatment interval of 14 days. Applications to turfgrass (other than grass grown for seed or in State and/or Federal invasive mollusk eradication operations) are prohibited. Apply bait by broadcast alone or by broadcasting blended with fertilizer. Application may also be made at planting using in-furrow (seed drill) application equipment. See full label.  See information sheet

Clover Grown
Clover grown for seed
Vetch Grown
Vetch grown for seed
Brassica Grown
Brassica grown for seed

Additional Seed Crops

Metarex is labeled for additional seed crops in the State of Oregon (Special Local Needs (SLN) label OR-140005) including clover grown for seed, vetch grown for seed, and the following crops grown for seed: Alliums spp. (leek, bunching and dry bulb onions), arugula, beet (garden and/or sugar), crucifers (Brassica and Raphanus spp. including broccoli, Brussels sprouts, cabbage, cauliflower, Chinese cabbage, Chinese mustard, collards, kale, kohlrabi, rutabaga, turnip, mustard, radish, mustard spinach), dill, endive, lettuce, parsley, parsnip, spinach and Swiss chard.

Photo Credits

Clover: Oregon State University Extension
Vetch: Danielle Treadwell, Univeristy of Florida
Brassica: DeNoble Farm Fresh, Tillamook, OR