White clover - also called Dutch clover - is found in lawns throughout the United States. It used to be considered an important part of lawn seed mixtures. Now, many consider it a weed because it is aggressive and has the ability to take over a lawn.
Oxalis is often wrongly identified as clover.
A very important pasture legume that is an appetizing and nutritious forage for livestock. Commonly planted in pastures with orchardgrass, ryegrass, or tall fescue.
Legumes are able to take nitrogen from the air and convert it into a form that plants can use. White clover used to be added to grass seed mixtures as a nurse plant with the idea that grass seedlings can benefit from the nitrogen it produces. However, the nitrogen fixed by legumes is not normally available to other plants -- the clover needs to be killed before the nitrogen is released into the soil for other plants to use.
Plant a clover food plot to keep deer out of flower beds:
Are deer eating your landscape plants? This works if you have enough land - plant a 5,000 square foot clover food plot on the outskirts of your property. The deer will feed there and leave your flower beds alone.
The ability to generate nitrogen allows it to thrive in infertile soils. Large patches in your lawn can be an indicator of low fertility.
In this case, fertilizing your lawn will not kill the clover, but it will help it become dense and vigorous, making it harder for the clover to spread.
Hand Weeding - Pulling or digging is effective if
you attack small patches before they spread. You must remove the entire
plant - stolons have the ability to regenerate if left behind. Once
they spread into large patches a chemical herbicide may be required.
Chemical Control - Herbicides are most effective when plants are
actively growing. If you choose to use a broadleaf herbicide, the fall
is the best time to start treatments. When clover is flowering in the
spring, herbicide effectiveness is reduced.
Often confused with yellow wood sorrel (Oxalis) and black medic.
Roots - Plants that grow from seed develop a deep strong tap root the first year. The taproot eventually dies as the creeping stems root at the nodes forming a fibrous root system.
Stems - Low-growing, prostrate stems that root at the nodes (joints) forming new roots and shoots.
Leaves - Compound leaves made up of three leaflets. Leaflets usually have a lighter green or white 'water mark' on the upper surface.
The flowers appear in early summer. They are white and sometimes have a
pinkish hue. Flowers occur on stalks that arise from the leaf axils.
Each flower head is round or globular in outline, approximately 1/2 to 1
1/4 inches long, and consists of 40 to 80 florets.
Clemson Cooperative Extension: http://www.clemson.edu/extension/hgic/pests/weeds/hgic2324.html
Virginia Tech Weed Identifiation Guide: http://www.ppws.vt.edu/scott/weed_id/trfre.htm
USDA Plants Database: http://plants.usda.gov