The answer to 'why is my sod invasive plants' is that your sod may have become infested with weeds or other unwanted plants. This can happen for a few common reasons, such as poor soil preparation, improper installation, or lack of maintenance. Invasive plants can quickly take over your new sod, crowding out the desired grass and creating an unsightly lawn.
To address this issue, you'll need to first identify the specific invasive plants in your sod and then take steps to remove them. This may involve hand-pulling weeds, applying targeted herbicides, or even completely replacing the affected sod. If the problem is severe or you're unsure how to proceed, it's best to consult a professional landscaper who can assess the situation and recommend the best course of action.