Ornamental flowers are tralanted in the parks and house spaces. These flowers are annual and seasonal and their planting is time consuming and their stablishment is low. Thus they may be replaced in place of the previous flower after grown in the nursery. The weeds in these fields could be controlled by avoiding seed germination and growth. In this experiment, the effect of some herbicides on weed control of warm season flowers including Marigold, Petunia, Ageratum was evaluated. In this study, five treatment of control, hand control, and herbicides, Treflan, Dacthal, and Gallant were in the first experiment, three times sampling and in the second experiment two times sampling were performed for measuring the presence of weeds, weed dry matter per each square meter, height, cover and persistence of the flower. The results of the first flower, showed that weed control was differed among different treatment. Hand control significantly had the highest weed control and treflan was the most effective herbicide. Weed eradication significantly increased flower height and hand control and treflan were the effective treatment. The interaction between herbicide treatment and time was highly significant. Also the highest cover was observed in hand control and terflan. The highest level of cover was achieved in the last time. Among flowers, only Petunia had significant difference for flower persistence and terflan was the most effective treatment in this regard. It seems that overall on weed eradicated, treflan treatment may be suggested for weed control. But regarding flower, treflan for Marigold, dacthal for Petunia and dacthal and gallant for Ageratum could be suggested. The results showed that weed eradication may not show the better flower cover. In the second experiment, hand control and treflan were also the most effective for two plants. Mean comparison of flower with length and flower height in Mathiola showed that hand control and treflan had not significant difference. Mean comparisons of cover diameter and plant height in viola showed that hand control and treflan were the better treatment. Also these treatments were the most effective regarding flower persistence in Mathiola. But in Viola there was not significant difference between these two treatments. Overal on weed eradicated, treflan could be suggested for weed control of both two flowers.
