The answer to 'aeration has weeds' is that aeration can sometimes lead to an increase in weeds in your lawn. This is because aeration creates small holes in the soil, which can allow weed seeds to germinate more easily. Additionally, aeration can disturb the soil and bring weed seeds closer to the surface where they can sprout.
Some common causes of weeds after aeration include inadequate soil preparation, poor lawn maintenance, or the presence of existing weed seeds in the soil. Symptoms may include an increase in broadleaf weeds, grassy weeds, or a general decline in the health and appearance of your lawn.