With their clean growth habit and evergreen foliage, barberry shrubs (Berberis thunbergii) include year-round appeal to landscaping within U.S. Department of Agriculture plant hardiness zones 5 to 8. Many barberries comprise wine-red or gold leaf, though cultivars such as Kobold (B. thunbergii “Kobold”) and Sparkle (B. thunbergii “Sparkle”) are valuable because of their green leaves. Green-leaved barberry cultivars have to be propagated vegetatively to faithfully reproduce their foliage color since the shrubs seldom grow true from seed. It is a simple procedure, though green barberries spread most reliably if the cuttings are treated with hormone and kept very warm.
Propagate green barberries in spring after new growth has emerged on the ends of the unwanted branches and all of the blooms have faded. Prepare a rooting pot before collecting the cuttings since softwood stems dry out fast once severed.
Fill a 4-inch square grass with completely rinsed coarse sand. Pour water on the sand until it feels quite moist and the water starts to trickle from the drainage holes in the base of the pot. Allow it to drain for about 15 minutes before potting the cutting edge.
Collect a 4- to 6-inch-long cutting from the tip of a healthy, vigorous side branch — one with a leafy tip and a green, pliant stem. Sever the cutting 1/16-inch under a group of leaves using sharp bare shears.
Pull off each of the leaves along the bottom half of their green barberry cutting to expose the growth nodes. Coat the exposed development nodes and the severed end of this cutting edge with 0.5-percent IBA rooting hormone. Gently tap the stem to knock loose the excess hormone.
Poke a planting hole at the middle of this moistened sand. Be sure the hole just deep enough to hold the defoliated part of this green barberry cutting. Insert the cutting into the planting hole and then firmly press the sand from your stem to eliminate any air pockets.
Cover the pot with a 2-gallon clear plastic bag to hold heat and humidity across the green barberry cuttingdown. Establish the covered pot in a sheltered spot with incredibly bright but indirect light. Warm the grass with a propagation mat set into 70 F in case daytime temperatures are below 65 F.
Mist the green barberry cutting with a spray bottle every other day to maintain the leaf plump and hydrated. Check the moisture level at the sand every time you mist and then add water if it feels dry at the upper inch. Avoid letting the sand or the cutting dry out.
Evaluation for roots in about three weeks by gently pulling on the base of the stem. Feel for a lack of motion, meaning that it has set down roots. Transplant the green barberry to a 4-inch container filled with potting soil two weeks after rooting.
Grow the green barberry under light colour because of its first summer. Provide water when the soil feels dry at the upper inch. Acclimate it to guide sun over the course of one week to prepare it for planting.
Transplant the green barberry to your sunny bed with fast-draining dirt in autumn. Space shrubs 3 to 6 feet apart. Spread a 3-inch-thick layer of mulch around the shrubs to protect the roots.