Water coleus plants liberally before trimming them. Pour water slowly into the soil until it feels moist at a depth of two inches.
Trim coleus plants in spring to encourage a bushy appearance. Snip off the top two inches from each stem using pruning shears. Make the cut just above a pair of leaves to promote branching.
Trim coleus plants in summer to encourage a blush of fresh, new growth. Cut back each stem by half using pruning shears. Make the cuts straight across one-quarter inch above a pair of mature leaves.
Trim coleus plants periodically during the summer months to remove their blossoms, which will encourage the plant to put on new foliage. Snip off the flower stalks near their point of origin using pruning shears. Make the cut flush with the stem from which they emerge.
Trim back coleus plants in late summer or autumn to correct a leggy appearance. Cut back the plant by approximately two-thirds. Cut each stem individually since cutting straight across will ruin the natural shape of the plant.