What actually is a weed?
The dictionary says that a weed is “a wild (not deliberately cultivated) plant growing where it is not wanted”. By this definition, virtually any plant that is growing where we do not want it to grow is a weed.
The plant you classify as a ‘weed’ will compete for air, light, plant food and space. They deprive cultivated plants of these requirements and reduce their vigour, yield or beauty. They also compete for your time!
Weeds not only affect the growth of nearby plants, but they are unsightly. Getting rid of weeds is essential to keep the garden looking tidy. In addition, some, like the dandelion, contain sap which can cause skin rashes on sensitive people.
On a cultural level, weeds can be a natural home for harmful insects and plant diseases. Very often these pests can over-winter on weeds ready to attack garden plants the next spring. They are also prolific seed producers – for example the poppy can produce 16,000 seeds per plant.
Unless you have a large garden where there is space to have a completely wild area, it is much better to get rid of weeds as soon as possible.