Caragana rosea: Nature’s Beauty in Yellow and Light Pink

The Caragana rosea, or Red Pea Shrub, is an upright shrub. Its bark is gray-brown or gray-yellow. The slender twigs are angular, gray-brown, and hairless.

The pinnate compound leaves are alternate, with the stipules on the long branches persisting and hardening into spines.

The flowers are yellow or light pink, blooming from April to May. It grows on hillsides, along ditches, or within shrublands. The plant’s height ranges from 60 to 100 cm.

The flowering period is from April to June, and the fruiting period is from June to July. It is found in Northeast, North, and East China, as well as in the southern parts of Henan and Gansu. It grows on hillsides and in valleys. The type specimens are collected from China.

Physical Features

The shrub is 0.4 to 1 meter tall. The bark is green-brown or gray-brown. The twigs are slender with pronounced ridges. The stipules on the long branches form thin spines, measuring 3-4 mm, while those on the short branches fall off.

Leaf stalks are 5-10 mm long, falling off or persisting as spines. Leaves are in a pseudo-palmette arrangement, with 4 tiny leaves in a cuneate obovate shape, 1-2.5 cm long, 4-12 mm wide. The apex is round or slightly concave, with a thorny tip and wedge-shaped base.

The leaves are nearly leathery, dark green on top, and light green underneath, hairless, with occasional sparse soft hairs along the veins on the edges and undersides of the leaves. The flower stalk is single, 8-18 mm long, with a joint above the middle and hairless.

The flower calyx is tubular, not expanding or only slightly expanding at the bottom, 7-9 mm long, about 4 mm wide, often purple-red, with the calyx teeth triangular, tapering, and densely covered with short soft hairs on the inside. The corolla is yellow, often purple-red or entirely light red, turning red when fading, 20-22 mm long.

The banner petal is long ovate or obovate, with a concave apex and tapering to a wide petal stalk at the base. The wing petals are long ovate and linear, with the petal stalk slightly shorter than the petal blade.

The keel petals have petal stalks and blades of almost equal length, with inconspicuous ears. The ovary is hairless. The pod is cylindrical, 3-6 cm long, with a tapering tip. The flowering period is from April to June, and the fruiting period is from June to July.

Distribution Range

The Red Pea Shrub is found in Northeast, North, and East China, as well as in the southern parts of Henan and Gansu. It grows on hillsides and in valleys. The type specimens are collected from China.

Propagation Methods

The Red Pea Shrub can be propagated through seed sowing, cutting, and division.

Seed Sowing

After the fruits ripen in autumn, they should be collected promptly and exposed to the sun for a few days. After the seed shells crack, the seeds can be retrieved.

The seeds can be sown in autumn or stored for sowing in the following spring. Before sowing, the seeds can be soaked in warm water around 30°C for 2-3 days. Once the seeds have absorbed enough water, they can be placed in a container and covered with a damp towel for germination.

When the umbilicus of the seed cracks, the seeds can be sown. Row sowing is recommended, with 4-5 grams of seeds per square meter and a row spacing of 15 cm. After sowing, cover the seeds with soil, press down, and water thoroughly.

Cuttings

Cuttings can be taken from April to May. Choose robust, pest-free branches from plants that flower abundantly. The branches should be one or two years old and should be cut into 10-15 cm pieces, each with 3-5 buds.

Remove the lower branch spines but keep the leaves at the upper end of the cutting. The bottom end should be cut diagonally about 0.5 cm below the node. Insert about 1/3 to 1/2 of the cutting into sandy soil, leaving 1-2 buds above ground, then water thoroughly.

To increase the survival rate of the cuttings, use indolebutyric acid rooting powder by dipping the cuttings in a solution with a concentration of 500 mg/kg for 5-10 seconds before planting.

Division

The Red Pea Shrub can be divided in early spring before the sap starts flowing. When dividing, the whole plant can be dug up and cut into several clumps with a sharp knife.

Generally, a clump consists of 3-5 plants. The bark at the cut should not be broken. The cuts should be treated with sulfur powder or quicklime, and the lateral roots and root hairs should be protected.

Cultivation Techniques

Timing:

The Red Pea Shrub can be planted in the spring and autumn seasons.

Planting

Both spring and autumn are suitable for planting, but late autumn or early winter is better for the North China region. After the leaves fall in autumn, the Red Pea Shrub enters its dormant period when nutritional growth essentially stops.

At this time, the buds are fully differentiated, making this the optimal period for transplanting. For autumn-planted Red Pea Shrub, when the soil temperature rises in spring, it starts to sprout fibrous roots and lateral roots.

As the temperature rises, the buds start to sprout, and the plant can absorb water and nutrients through the new roots to meet the needs of its growth, greatly improving the survival rate of the seedlings.

Method: The diameter of the planting hole for the Red Pea Shrub should be 60-80 cm, and the depth should be 45-50 cm. The bottom of the hole should be filled with compound fertilizer containing nitrogen, phosphorus, and potassium. Then, fill the hole with planting soil, cover it with soil, and press down, watering thoroughly afterwards.

Water and Fertilizer: In spring, the Red Pea Shrub can be top-dressed with compound fertilizer when watering the green shoots, using about 100 grams per plant. In winter, apply 3-5 kg of organic fertilizer. The Red Pea Shrub can fix nitrogen, so less nitrogen fertilizer should be applied.

Instead, apply more phosphorus and potassium fertilizer to promote the formation of flower buds. After transplanting, manage the seedlings by keeping the soil dry and moist.

During the appropriate period, bake the seedlings to inhibit excessive growth, moderate the tree vigor, promote stout stems, dense internodes, dwarf plant shape, and abundant flowers.

During the flowering period, if there is drought or excessive rain, there will be phenomena such as flower drop, rotten flowers, and flower damage. Timely irrigation and drainage work should be done.

Pruning: During the growth period, young plants should be pinched to promote branching and increase the number of flowers.

In winter and early spring, diseased branches, dead branches, inner cavity branches, weak branches, and excessively long branches should be removed to reduce the consumption of nutrients and water and to maintain a reasonable amount of branches and leaves.

Prune dense branches and shorten flower branches after flowering. Preserve some spring shoots and autumn shoots to keep the branches loose, increase the light-receiving surface of the crown, promote ventilation and light transmission, and improve the light utilization rate of the plant group.

Primary Value

The Red Pea Shrub is dense with branches and leaves. Its corolla is butterfly-shaped and yellow with a hint of red, resembling a golden bird.

The flowers, leaves, and branches can be used for ornamental purposes. In gardens, it can be planted in clusters on lawns or combined with slope plants, beside rocks, or as ground-cover plants.