Skip to main content

Crop and Pest Management Guidelines

A Cornell Cooperative Extension Publication
Skip Navigation LinksHome > Cornell Guidelines > 2024 Trees and Shrubs Table of Contents > 4 Weed Management in Nursery Crops > 4.8 Description and Characteristics of Herbicides Registered for Nursery and Landscape Use > Surflan, Surflan Flex
Page Contents
44787

Surflan, Surflan Flex

Common Name: oryzalin

Formulations: 4AS, 3.2 AS

Uses: Selective preemergence, surface-applied herbicide for control of annual grasses and many broadleaf weeds in established and newly planted field grown trees and shrubs, ground covers, bulbs, landscape ornamentals, Christmas trees, and some container grown ornamentals.

Amount of active ingredient

Amount by formulation

AS

Per Acre

2 to 4 lb.

2 to 4 qt.

Per 1,000 sq. ft.

1.5 to 3 fl. oz.

Major Weeds Controlled: Annual grasses such as crabgrass, barnyardgrass, ryegrass, and johnsongrass (from seed). Broadleaf weeds controlled include pigweed, bittercress, common chickweed, spurge, and yellow woodsorrel. At the higher rate partial control of velvetleaf, horseweed, and smartweed is obtained.

Major Weeds Not Controlled: Established weeds. Poor or erratic control of ragweed, asters, groundsel, jimsonweed, galinsoga, nightshade, morningglory, mouseear chickweed, dodder, and Venice mallow has been reported.

For Best Results: Apply 0.5 in. of water to activate. May be shallowly cultivated (1 to 2 inches) to improve effectiveness. May be tank mixed for improved broadleaf control following label directions.

Cautions and Precautions: Do not use in conifer seedbeds or transplant beds. Rooted cuttings should be established two weeks or more before application. Overapplication may result in crop injury. Do not apply to pots smaller than four inches wide. Residues from spring applications may inhibit the establishment and growth of fall-seeded grasses (such as oats or rye) used as a winter cover crop. Injury has been observed on slender deutzia, Douglas fir, techny arborvitae, and eastern hemlock.

Residual Activity: Two to eight months of weed control depending on rate, irrigation practices, weed spectrum, and soil type.

Volatility and Leaching Potential: Little volatility or photodegradation. Stable on the soil surface for several weeks without incorporation. On coarse soils low in organic matter a limited amount of leaching can occur.

Symptoms and Mode of Action: Inhibits root development by affecting cell division. Typical injury symptoms include swollen, stubby roots. These symptoms are most commonly seen on affected grasses. No significant absorption or translocation. May cause girdling and stem swelling when used on young fir or spruce seedlings.

Manufacturer: UPL NA

EPA Reg. Nos.: Surflan AS: 70506-44

Surflan Flex: 70506-308