Star Jasmine (Trachelospermum jasminoides)

Star jasmine is a popular flowering vine in California and the southern United States, where it’s grown both vertically (like up a trellis) and as a spreading ground cover. It’s very fragrant and is known to attract bees—the fragrance is similar to that of a jasmine shrub, though this is a different group of plants. 

I. Appearance and Characteristics 

Trachelospermum jasminoides is a species of flowering plant in the family Apocynaceae, native to eastern and southeastern Asia (Japan, Korea, southern China and Vietnam). Common names include Confederate jasmine, star jasmine, Confederate jessamine, and Chinese star jessamine.

This plant, and the variegated cultivar ‘Variegatum’, have gained the Royal Horticultural Society’s Award of Garden Merit.

Trachelospermum jasminoides is an evergreen woody liana growing to 3 m (10 ft) high. When they meet a wet surface, they emit aerial weed roots, otherwise they surround the support (they are twining). If cut, like most Apocynaceae, they exude a white latex, resembling sticky milk. Young twigs, initially pubescent, become glabrous with age. The leaves are opposite, oval to lanceolate, 2–10 cm (3⁄4–3+7⁄8 in) long and 1–4.5 cm (3⁄8–1+3⁄4 in) broad, with an entire margin and an acuminate apex. Dark green in summer, the leaves turn bronze in winter.

The fragrant flowers, which are borne in spring to early summer, are white, 1–2 cm (3⁄8–3⁄4 in) diameter, with a tube-like corolla opening out into five petal-like lobes. The white, rotated actinomorphic flowers have a calyx formed by five narrow, smooth, reflexed sepals 2−5 mm , much shorter than the corolla tube. The latter has a dilated tube in the middle, 5−10 mm long, terminating in 5 obliquely bypassed lobes, all curved, resembling a helix turning counterclockwise. The five stamens are inserted in the middle of the corolla tube.

It will flower in full sun, partial shade, or total shade, and requires well-drained soil (if constantly kept damp it may succumb to fungal infection), moderate water, moderate fertilizer, and a climbing structure (whether a trellis or another plant is secondary). Propagation is most commonly done with cuttings/clones.

It is widely planted in California and also particularly in the Southeastern United States, where its hardiness is confined to USDA Zones 8–10.

II. How to Grow and Care

Sunlight

Star jasmine will thrive in full sun or part shade, but for maximum flowering potential, choose a spot that gets lots of light. The vine will produce the most blooms if it gets at least eight hours of sunlight per day. If you choose to grow your star jasmine as a ground covering and it spends a lot of time shaded by larger plants or trees, you may see a reduction in the number of blooms the plant produces.

Temperature and Humidity

Star jasmine is a fairly cold-hardy plant and can tolerate temperatures as low as 10 degrees Fahrenheit (though generally, not for a prolonged period of time). On average your jasmine will grow and bloom best in temperatures ranging from 60 to 75 degrees Fahrenheit. Additionally, star jasmine loves humid conditions and will thrive best in a moderately moist environment.

Watering

In order for your star jasmine to grow successfully, it should be watered regularly. For most plants and locations this means once a week, but you may need to increase your cadence if your environment is especially hot or dry, or if you’ve planted your jasmine in a container. A good rule of thumb is to water your star jasmine when the top inch of soil is dry and allow the soil to dry out in between waterings.

Soil

Fortunately, Star Jasmine does not need deep soil to grow well, so it can be grown successfully in containers – but the soil or growing medium in which it is planted must be free-draining, as this is a plant that does not like to have wet feet. 

Ideally, the soil or growing medium should be moderate to high in fertility, and have a neutral to alkaline pH, but Star Jasmine will also grow in slightly acidic soils.

Fertilizing

Caring for Star Jasmine also involves paying attention to their fertilizer needs. These plants are not overly demanding regarding nutrients, but providing them with the right fertilizer can significantly enhance their growth and overall health. A balanced, slow-release fertilizer with an N-P-K ratio of 10-10-10 or similar is a good choice.

It’s best to apply this fertilizer in the early spring, just before the growing season begins. This will give your Star Jasmine the necessary nutrients to produce lush foliage and exquisite star-shaped flowers. Be mindful not to over-fertilize, as too much of a good thing can harm the plant. Follow the recommended dosage on the fertilizer packaging, and you’ll be on your way to enjoying a thriving Star Jasmine in your garden.

Planting Instructions

Pruning

Pruning Star Jasmine is essential to maintain its healthy shape and control its growth. Those twining stems like to wander! It’s best pruned right after the big seasonal flowering. This evergreen climber can become quite vigorous, so regular pruning helps keep it in check and encourages better flowering. The best time to prune is early summer after the main bloom period. Start by removing any dead or diseased branches, as well as those that are growing in unwanted directions. Trim the vine to shape it and to manage its size.

Remember that Star Jasmine flowers on the previous year’s growth, so avoid heavy pruning during late summer and fall to ensure a bountiful display of fragrant blooms in the following spring. Additionally, pruning can help rejuvenate an older, overgrown plant and encourage new, healthy growth. Always use sharp and clean pruning tools to prevent damage to the plant.

Propagation

Propagating Star Jasmine is a fantastic way to multiply these fragrant vines and enhance your garden’s beauty. With a few straightforward steps, you can propagate your Star Jasmine and enjoy its enchanting presence in multiple areas of your outdoor space.

• Selecting a Proper Specimen

When propagating Star Jasmine, choosing a healthy and mature specimen for your cuttings is crucial. Look for a vigorous vine with strong growth and vibrant leaves. Healthy plants are more likely to produce successful cuttings.

• Cutting Preparation

To propagate Star Jasmine, you’ll need to take softwood or hardwood cuttings. Softwood cuttings are best taken in late spring or early summer, while hardwood cuttings are typically collected in late winter. Softwood cuttings should be around 6 inches long, while hardwood cuttings can be a bit longer, about 8-10 inches. Be sure to cut just below a leaf node, where the roots will form.

• Rooting

Prepare your cuttings by removing the lower leaves, leaving only a few at the tip. Dip the cut end of the cutting in the rooting hormone, which will encourage the development of roots. Plant the cutting in a well-draining potting mix, burying it about an inch deep. Water the cutting thoroughly, and place it in a sheltered spot with indirect sunlight. Keep the soil consistently moist but not waterlogged. It may take several weeks for the cutting to develop roots. You can test for root development by gently tugging on the cutting – if there’s resistance, roots are forming.

Overwintering

In regions with milder winters, this evergreen vine will continue to flourish. However, it may need a little extra attention in colder climates to survive the winter months.

Before winter sets in, it’s advisable to trim your Star Jasmine slightly to remove any dead or damaged growth. This improves its overall appearance and prevents diseases from taking hold. During winter, it’s vital to protect your Star Jasmine from harsh cold, frost, and strong winds, which can damage the tender leaves. You can use mulch or frost cloth to insulate the roots and branches.

If you’re growing Star Jasmine in a pot, consider moving it to a more sheltered location, like a garage or greenhouse, during the coldest periods. While they can handle a light frost, extended exposure to freezing temperatures can be detrimental. Keep the soil moderately moist during winter, as overly dry or waterlogged soil can be harmful.

Pests and Diseases

Common Pests and Plant Diseases

Star Jasmine is an incredibly resilient plant with its lush green leaves and fragrant white blossoms. However, it’s not immune to a few common pests and plant diseases. Here, we’ll explore potential adversaries and how to address them effectively.

Aphids

Aphids are among the most common pests that can afflict your Star Jasmine. These tiny, soft-bodied insects are usually green or yellow and can congregate on the undersides of leaves. They feed by piercing the plant and sucking its sap, leading to stunted growth and distorted foliage.

To combat aphids, use a strong water jet to wash them off the leaves. In severe cases, insecticidal soap or neem oil can be used more aggressively. Regularly inspect your Star Jasmine for aphids and take prompt action to prevent infestations.

Mealybugs

Mealybugs are another common pest that can trouble your Star Jasmine. They are small, soft-bodied insects covered in a white, waxy substance. Mealybugs, like aphids, feed on plant sap and can lead to yellowed, stunted growth.

To deal with mealybugs, you can use a cotton swab soaked in rubbing alcohol to dab them off the plant. Alternatively, insecticidal soap or neem oil can be effective. Frequent inspections of your Star Jasmine will help you catch and address mealybug infestations before they become too problematic.

Japanese Beetles

Japanese beetles are voracious leaf-eating insects that can cause severe damage to various plants, including Star Jasmine. They have a distinct metallic green body with copper wings. These beetles skeletonize leaves by eating the tissue between veins, resulting in a lace-like appearance.

To control Japanese beetles, you can physically remove them from your Star Jasmine by gently shaking the plant to dislodge them into a container of soapy water. Applying insecticidal soap or neem oil can also help. Additionally, using traps can reduce the beetle population in your garden. Regular monitoring is crucial during their active season, typically from June to August.

Powdery Mildew

Powdery mildew is a fungal disease that can affect Star Jasmine, especially in humid conditions. It appears as a white, powdery substance on the leaves and can lead to reduced photosynthesis and growth.

Preventing powdery mildew is crucial. Ensure your Star Jasmine has good airflow around its foliage, and avoid overhead watering, as wet leaves provide an ideal environment for the fungus. If powdery mildew does appear, treat it with a fungicidal spray specifically designed for this purpose.

Common Problems

Star Jasmine, a captivating and fragrant vine, may face several common plant problems. However, you can keep your Star Jasmine flourishing and looking its best with the right solutions. Let’s explore these issues and how to address them:

Yellowing Leaves

One common problem with Star Jasmine is the yellowing of leaves. Various factors, including overwatering, nutrient deficiencies, or inadequate sunlight can cause this. To address this issue, first, assess your plant’s water needs. Ensure you’re not keeping the soil too wet, as well-draining soil is vital. Check your plant’s exposure to sunlight; Star Jasmine typically thrives in partial to full sun. If you suspect a nutrient deficiency, consider feeding your plant a balanced, slow-release fertilizer during the growing season. Prune any yellowed leaves to encourage new, healthy growth.

Leggy Growth

Star Jasmine is known for its lush, dense foliage, but sometimes it may become leggy with sparse growth. This can happen when the plant isn’t getting enough light and stretching to reach for more. To combat this problem, provide your Star Jasmine with sufficient sunlight, ideally 4-6 hours of indirect sunlight daily. Pruning can also help to encourage bushier growth. Trim the longer, leggy branches, stimulating lateral growth, resulting in a fuller, more compact appearance.

Fading Fragrance

If you notice your Star Jasmine isn’t as fragrant as it used to be, it might be due to environmental factors or improper care. A decline in fragrance can result from insufficient sunlight, which affects the plant’s ability to produce essential oils responsible for the scent. Ensure your Star Jasmine receives adequate sunlight for optimal fragrance. Additionally, avoid overfeeding with high-nitrogen fertilizers, as this can lead to vigorous vegetative growth at the expense of flowering. Prune your plant to encourage better air circulation, enhancing the fragrance.

III. Uses and Benefits 

• Ornamental uses

Trachelospermum jasminoides is commonly grown as an ornamental plant and houseplant. In gardens, public landscapes, and parks it is used as a climbing vine, a groundcover, and a fragrant potted plant on terraces and patios.

• Other uses

A valuable perfume oil is extracted from the steam distilled or tinctured flowers and used in high end perfumery. In a dilute form, tinctured flowers are much used in Chinese, Vietnamese and Thai incense. A bast fiber is produced from the stems.