How do weeds get into gardens?

weeds grow from the roots and nutrients left in the garden soil

There are many ways weeds can make it into gardens. Weed plants produce seeds that can be carried by the wind long distances and land anywhere - and a nicely taken care of garden can be heaven to a seed that otherwise might have had to try to grow in sidewalk crack. Seeds can also be carried on the fur of animals and passed through the digestive tract and excreted by birds and animals. If they land in a garden, they've found a home. Some weeds multiply through underground root systems. If one of these plants is in your neighbor's yard, an underground root extending into your yard can send up new shoots developing into a weed in your garden.