Lactuca

Several species of wild lettuce (Lactuca spp., Asteraceae family) are common in nurseries and landscapes and are very similar to sowthistle (Sonchus spp.). These species are winter annuals but may also germinate in the spring or summer in irrigated nursery crops or landscapes. Seedlings form a rosette of waxy leaves with variable, lobed leaf margins. Wild lettuce leaves are similar to sowthistle leaves but lack prickles on leaf margins. In warm weather, plants bolt to about 3 to 4 feet tall, but some species may reach 8 feet in height. Flowers are pale yellow and form on branched heads. Seedhead is similar to a dandelion but smaller. Seeds have a pappus that aids wind and water dispersal. Avoid letting plants go to seed. Consider a preemergence broadleaf herbicide labeled for use.