What Hedges Are Resistant to Agricultural Chemicals?

Types of Hedge Plantings

• Organic farm hedgerows are often created with native plant materials such as Ceanothus (California), native azaleas (eastern United States) or Brazilian bluewood (Southwest). Hedges of sumac, wax myrtle and mountain laurel are also native to the Southwest. The Lady Bird Johnson Wildflower Center has a national database for local native plants (see Resources). Native hedges are adapted to local rainfall, soil nutrient content and weather patterns, and do not need the upkeep of non-native varieties. Native hedge species are more likely to resist the damaging effects of exposure to agricultural chemicals than non-native varieties.

Types of Chemicals

• Hedges in home landscaping such as privet, laurel, holly, juniper, wild roses or lilacs are sometimes exposed to synthetic fertilizers, weed killers and pesticides. Agricultural chemicals such as these work on contact or as systemic poisons. Contact chemical herbicides such as Reward are effective against annual weeds, killing only the part of the plant that is exposed to the chemical. Systemic herbicides such as Roundup are absorbed by plants through their leaves and roots and may affect surrounding vegetation. Manufacturer's label warnings and safety data sheets warn users to spray only targeted areas to avoid damage to other plants.

Hedges on the Farm

• Plants such as elderberry, coffeeberry, coyote brush and yarrow provide flowering hedgerows that also feed birds with their berries, nectar and pollen. Some hedge plants such as bay laurel, flannel bush and manzanita are hardy resisters to chemical damage and also enhance the surrounding soil biology. Evergreen hedge rows such as juniper and yew provide valuable wind control for tender plants .Hedgerows also provide erosion control with their extensive root systems.

Chemical Injury Symptoms

• Hedges are exposed to agricultural chemicals indirectly through wind drift or contaminated water supplies. Organic and sustainable farming practices do not include the use of toxic chemicals, but hedgerows may be affected by neighboring farming practices. Signs of chemical injury include reduced plant vigor, stunted growth, cupped leaves, crinkled or feathered leaves, yellowing or mottled color and death of leaf edges. Hedges such as lilac and roses are more susceptible to chemical damage than hardier evergreen hedges such as juniper or privet.