Weeding a garden sounds like fools play. But the Devil is in the details:
A Hoe or Cultivator will lessen this hand task, but there will always be weeds growing too close to favored plant roots to risk hoeing. It is usually best to pull weeds while they are small, and their roots are too. There are bad weeds and Good Weeds.
Types of weeds:
Some weeds have shallow roots; others like Dandelion and alfalfa have deep tap roots. Some are thorny; some are poisonous; some bristle with toxic hairs. In addition, there may be various insects or bees among the weeds. It is wise to wear leather gloves, which will protect your hands and give a better grip on those stubborn weeds which seem to terminate in China.
When to weed:
The best time to weed is early morning when the soil is damp. A recent rain will make the job easier. A good sprinkling the previous day will also prove beneficial. A week of sunshine may turn the soil into concrete, where your best effort will only succeed in breaking the weed off at ground level giving the roots new determination and vigor.
How to weed:
Always pull straight up toward the sky. If you pull at an angle, you risk breaking the weed off and leaving its root in the soil. Later there will be a tiny sprout growing up from this relatively mature root system, allowing very little chance of extracting the root without using a garden tool.
Most weeds will respond to a firm grasp at ground level, but some may need to be grasped just below the soil line which may require minimal tillage. If the weed is long enough, use both hands to increase your grasp. Be sure you are pulling evenly on every stem that grows from the roots. This will give a more positive grasp on the roots
If the weed roots are so intertwined with plant roots that you fear damage to your plants, then it may be best to cut off the weed at or under ground level every day or two until there is no further evidence of growth.
How to dispose:
Weeds make satisfactory mulch, providing their roots are not allowed to touch the soil and if they contain no seeds which may germinate and make matters worse. Weeds laid between the rows with roots resting on top of previously pulled weeds, will expose them to the drying sunshine.
They can also be added to a compost pile assuming they contain no seeds, or you will be planting weeds wherever you use Compost. Any weeds with seeds attached are best destroyed in a burn barrel. If Poisonous plants are included, be aware that there have been reports of sensitive persons reacting to the smoke.
from the staff of Garden Grapevine.com