The weeping pea tree (Caragana arborescens), also called the Siberian pea shrub or weeping pea shrub, is a deciduous shrub-like tree that has a fern-like, weeping form. This unique tree grows up to 8 feet tall and 6 feet wide, blooming with pea-shaped yellow flowers in late May. The weeping pea tree has satiny bark and delicate green leaves. Weeping pea trees are extremely hardy, tolerating winter temperatures down to -45 degrees Fahrenheit. The weeping pea tree can grow naturally into a full, wide shrub or be pruned into a small tree form.
Select a planting location for your weeping pea tree that's in full sunlight and has well-draining, lightweight soil. If you have heavier soil, mix into the soil some coarse sand.
Dig a planting hole for your weeping pea tree that's the same depth as the height of the root ball and twice the width. Mix into the displaced soil some organic compost or peat moss if your soil is nutrient-poor, so that you have no more than one part compost or peat to three parts native soil.
Remove the weeping pea tree's root ball carefully from the burlap sack or nursery container. Set the root ball into the planting hole with the weeping pea tree standing straight up.
Backfill the planting hole about halfway with the displaced soil, and then water the planting hole generously to help the soil to settle around the roots. Backfill the planting hole the rest of the way with the soil and water again deeply to soak the soil around the roots.
Press down the soil around the weeping pea tree's roots in the planting hole using your hands or feet. Spread a 2-inch-thick layer of bark mulch on the ground over the tree's root area, keeping the mulch about 1 inch away from the trunk.