A person may grow a plant because it has beautiful flowers, but other people may think that this plant is a weed for some reason. This may be for one of these reasons:
- It has pollen that makes them sneeze,
- It spreads seeds that will grow quickly,
- The roots go too far under the ground and can cause damage to houses or pipes,
- The roots spread quickly,
- The plant has poisonous berries,
- The plant has liquid (sap) in it that can hurt a person's skin,
If someone is farming a plant and it then moves outside the farm, the plant may then be called a weed.