Raspberries grow on a hearty bush that is able to withstand many pests, diseases and other problems. Gardeners don't normally cultivate the bushes themselves for their beauty, but they can look rustic and well manicured if you care for them meticulously. This includes killing any grasses or other plants that begin to grow around your raspberry bushes. Use an herbicide to kill the weeds without damaging the raspberry bush or fruit.
Casoron 4G is effective in killing broadleaved weeds such as Canada thistle and quackgrass. Quackgrass is an especially common raspberry weed that can be tough to remove. Removal might require several applications of Casaron 4G. Avoid applying the herbicide when the plant is in production.
Poast is an herbicide that will kill weeds around your raspberry bush without harming it. It is effective in killing actively growing grass that is between 3 and 8 inches tall. Apply it several times to remove all weed grasses. Never apply Poast closer than 45 days before harvesting your raspberries.
Princep is effective in killing broadleaved weeds around and in your raspberry bush without affecting the plant. Apply the herbicide in the fall for long-lasting weed control. Don't apply the herbicide when the raspberries are actually developing.
You can use other herbicides, such as RoundUp, that are not raspberry-safe, but take care that it doesn't get onto the raspberry bush. This requires spot spraying weeds only as they pop up through the ground. Avoid applying herbicide when the berries are developing.
Manually picking the weeds around the raspberry bush is an organic weed removal method. This is also the only method possible when the raspberry is actually developing, as herbicides can damage the fruit and can be toxic. Pull weeds from the base to help ensure that you also pull out the weed roots.