Ipomoea cholulensis: The Vibrant Orange Morning Glory

Ipomoea cholulensis, also known as the Orange Morning Glory, a member of the Tropaeolaceae family, is an annual twining herbaceous plant. It originates from South America and features heart-shaped leaves.

Umbel-like inflorescences arise from the axils, showcasing vibrant orange-red flowers with a yellow throat. The plant produces an ovate fruit. Though native to South America, it’s widely cultivated in various parts of China, such as Shaanxi, Hebei, Jiangsu, Fujian, Hubei, and Yunnan.

The Nasturtium prefers sunny environments but isn’t stringent about the number of sunlight hours it receives. The plant doesn’t handle cold well and thrives in well-lit areas.

Typically, it’s planted in gardens across China, where its vining nature allows it to ascend trellises, fences, and trees. It’s also suitable for pot cultivation on balconies where it can be trained to climb, forming a floral display.

Additionally, it can be used as a ground cover, covering the ground to obscure unsightly objects.

Morphological Features:

This annual herb has twining, smooth, and hairless stems. Its heart-shaped leaves measure 3-5 cm in length and 2.5-4 cm in width, ending in a sharp tip.

The leaves have entire margins, which might sometimes appear polygonal or occasionally deeply lobed, resembling a palmate structure. The petioles are delicate and almost as long as the leaf blades.

The axillary umbel-like inflorescences bear 3-6 flowers, supported by slender peduncles longer than the petioles. Each flower stalk, roughly 1 cm long, holds two small bracts. The calyx consists of 5 unequal segments, which are ovate-lanceolate in shape.

The corolla, shaped like a tall saucer, displays an orange-red hue with a yellowish throat. Its slender tube suddenly expands at the throat, resulting in five deep lobes. Five stamens, slightly unequal in length, protrude from the corolla.

The ovary is quadrilocular, with each locule bearing a single ovule. The fruit is small, spherical, and about 5 mm in length, enclosing 1-4 ovate or spherical seeds.

Growth Environment:

The Orange Nasturtium thrives in warmth and is frost-sensitive. Its growth significantly slows in colder temperatures.

Optimal germination occurs at temperatures ranging between 20-25°C. It’s best suited for sunny environments, without strict requirements for the duration of sunlight.

Distribution Range:

Originally from South America, the Orange Nasturtium is frequently cultivated in Chinese gardens across provinces like Shaanxi, Hebei, Jiangsu, Fujian, Hubei, and Yunnan.

Primary Value:

1. Ornamental Value:

Nasturtiums are climbers, making them ideal for greening environments with a backdrop, such as pergolas, fences, and adjacent to trees. They’re also apt for pots on balconies where they can be trained to ascend, forming a floral trellis.

Furthermore, they serve as ground-cover plants, sprawling across the ground to mask unsightly areas.

2. Medicinal Value:

Nasturtiums are recognized for their cooling and detoxifying properties. The entire plant or just its root can be used for medicinal purposes.

Known as “Jin Feng Mao” in traditional medicine, it’s effective against ailments like dysentery, bloody stools due to intestinal wind, metrorrhagia, hemorrhoids, and bloody stools.

Growth and Propagation

Seed Sowing

Generally, direct sowing in open ground is done in early spring, around April. When seedlings reach a height of 10 cm, they are transplanted. They are often sown under garden fences or on either side of a pergola, with thin ropes dropped for the plant to twine around. For those living in apartments, shallow pots can be used for sowing.

Cutting Method

Tender branch cuttings are often taken from this year’s growth in late spring to early autumn, while hardwood cuttings are made from the previous year’s growth in early spring.

When taking tender branch cuttings, during the period from late spring to early autumn when the plant is vigorously growing, choose this year’s robust branches. After cutting the branch, select the sturdy part and cut it into sections of 5-15 cm in length, each containing more than three leaf nodes.

When cutting, it’s crucial to ensure that the upper cut is about 1 cm away from the top leaf node and is made horizontally, while the lower cut is about 0.5 cm from the bottom leaf node and is slanted.

Both cuts should be clean, using a sharp knife. The method for hardwood cuttings is the same as for tender branch cuttings. After cutting, cover with a 50%-80% shade cloth.

Once roots appear, remove the shade cloth at 4:00 pm on sunny days and replace it before 9:00 am the next day. The optimal temperature for root formation is 20-30°C, with a relative humidity of 75%-85%.

Layering Method

Choose a healthy branch, and about 15-30 cm below the tip, remove a ring of bark approximately 1 cm wide, just deep enough to remove the epidermis.

Use a thin film of about 10-20 cm in length and 5-8 cm in width, place some damp garden soil on it, and wrap it around the girdled section, tying the film’s ends tightly and ensuring it bulges in the middle. After about 4-6 weeks, roots will form.

After rooting, cut off the branch along with the roots to establish a new plant.

Pest and Disease Control

When aphids appear sporadically, they can be gently brushed off with a water-dipped brush and killed. If there’s a larger aphid infestation, it’s advisable to use a pesticide spray.

Suitable formulations include 40% Imidacloprid or 80% Dimethoate emulsion diluted 1000-1500 times, 2.5% Rotenone at 1000 times dilution, or a mixture of tobacco lime water at 60 times dilution (with an added 0.1% detergent) among others.

It’s also crucial to protect and utilize natural predators of aphids. Major predators of aphids include the ladybugs like Harmonia axyridis, Coccinella septempunctata, and Propylea quatuordecimpunctata, as well as aphid midges and lacewings. These predators play a vital role in controlling aphid populations.