 Fortunately, it has a weak root system. Unfortunately, each plant can produce up to about 1200 seeds per year, which remain viable in the soil for up to five years. Henbit is a small annual that has pretty red purple flowers and interesting foliage. But after a few years, it can form a mass of foliage and plants that can easily smother young vegetable and flower seedlings. If you don't get it in time and it's left to flower,