With the drought forcing many people to import hay from out of state there is an increased possibility of importing weeds with that hay. Many of these weeds could cause problems, but here are three you may really want to keep an eye out for; diffuse and spotted knapweeds (Centaurea diffusa and Centaurea stoebe), and leafy spurge (Euphorbia esula). These weeds have not been found in Texas yet but are very invasive in several surrounding states. Knapweeds look similar to thistles. Spurge has a milky sap and showy yellow flower bracts. These plants, once established exude chemicals in the soil that inhibit the growth of favorable forage plants.They are intense competitors for water and can quickly crowd out native and desirable forage plants. Here are a few ideas on how to keep the risk of importing weeds at a relatively low level; check hay before you purchase or feed for weeds that you do not recognize, feed the hay in a confined area to control weed spread, and/or monitor your pastures for weeds that you do not recognize. Remember also that seeds from these weeds can lay dormant in the soil for several years, so continued monitoring is crucial. Control options for these weeds include most chemicals of the 2,4-D type, sheep or goats, prescribed burns, and bio-control with insects that are specific pests to these weeds. For more information you can visit the Samuel Roberts Noble Foundation. Continue to be on the lookout for these potentially noxious weeds and others as you purchase hay from surrounding states for your livestock.