It is often a challenge to keep weeds under control around fruit trees. You don't want to run the rick of damaging the surface roots by tilling the soil, nor do you want to spray poisons around the tree that might ruin the soil. Clover weed is especially aggressive and hard to weed out by hand as any runners left behind will quickly sprout into new plants. There is a solution.
Manually remove as much of the weeds as possible, including the clover, by hand. You will not be able to work the soil with a tool because you run the chance of hurting the citrus tree roots sitting just below the soil. If you have just a few trees, the top of the soil can be lightly scraped with a hoe to remove the clover and weeds.
Spray on a herbicide that is listed as pre-emergent. This kills weeds before they actually appear. The ideal application is on bare soil, but mostly bare will work, too.
Mulch around the base of the tree with several inches of straw or compost to reduce the chance of the clover coming back. The mulch will suffocate the weeds as well as conserve moisture for the tree and keep the soil temperature down during hot spells.
Spread weed matting if the infestation is very strong. It is a weed barrier that will allow the rain to penetrate. This, applied with the mulch, is a very effective control used by many gardeners to keep weeding to a minimum.
Apply a nonsystemic weed killer to catch any weeds that have made it through your mulch and/or weed matting. You should not have much of a problem with clover around citrus trees after following these recommendations.