The best time to remove weeds is before their flowering and fructification, otherwise controlling them can be very difficult. After they have flowered and fructified, their seeds can spread very fast, and hence, the weeds should be removed more often and precautions should be taken in advance in the following year. Mulching: During the seed stage, covering the soil with sawdust, straw or black mulches can effectively inhibit seed germination and the growth of seedlings. In the winter or spring, this method is often used to inhibit the seeds in the soil from germinating. If the weeds have already flowered and fructified, then the method can also be used to prevent more seeds from falling into the soil. Pulling out: Wear gloves or use tools to remove weeds before their fructification. If the soil is too dry, then water the soil thoroughly to make it softer, which can help to remove the root systems of the weeds. After that, deep tillage can be adopted to remove bits of weed roots left in the ground. This method works particularly well for weeds that are low-growing or in their seedling stages. Mowing: Mowing weeds before their fructification can effectively control their spread. Especially for annual weeds, frequent mowing can inhibit their growth and fructification, and thus can remove them effectively within the year. Ploughing: Be sure to plough and pull out all roots of perennial weeds before planting. The roots should be discarded, exposed to the sun for a long time, or buried deep. You can also use the roots to make organic fertilizer and compost the weeds. During the seedling stage, it can be removed effectively with herbicide. When you plant it in a flowerpot: When seeds are mature, move the flowerpot away from other plants, and dispose of its scattered seeds timely to prevent it from spreading. The soil where it has grown cannot be discarded directly. Instead, the soil needs to be buried 0. 5-1 feet deep. Clean the flowerpot thoroughly before it is used for other plants so as to prevent the remaining seeds from re-germinating. Note: When removing weeds, especially those which are toxic, thorny and have allergenic sap, be sure to wear gloves and avoid direct contact with them. When removing weeds during their bloom time, be sure to wear special masks to prevent pollen allergy.