Smilax aspera aka Rough Bindweed

Smilax aspera is a vigorous evergreen climber that typically reaches about 3 meters in cultivation, though stems can extend up to 15 meters in the wild when climbing through trees. The plant grows in a distinctive zigzag pattern, using hooked thorns and tendrils to anchor itself to surrounding vegetation. Growth is fast, and the plant can form dense, impenetrable thickets if left unchecked.

Smilax aspera tolerates temperatures down to approximately -10°C when fully dormant, making it hardy in USDA zones 8–11. It thrives in warm Mediterranean climates and performs best in temperate to subtropical conditions. Prolonged freezing temperatures or frost while actively growing can damage or kill the plant.

Smilax aspera produces small, fragrant flowers from late summer through autumn (August–October). The flowers are arranged in axillary umbels, measuring 3–5 mm across with six greenish-yellow to cream tepals. They emit a notably sweet, heavy perfume. The plant is dioecious, meaning male and female flowers appear on separate plants—both are needed for berry production.

Yes, Smilax aspera flowers have a distinctly heavy, sweet perfume. The fragrance is produced during the late summer to autumn bloom period and serves to attract pollinating insects such as bees and small flies. The scent is notable enough that multiple botanical references specifically mention it as a characteristic feature of the species.

Smilax aspera can be propagated by seed, division, or cuttings. Seeds require cold stratification and may take over two years to germinate—sow in March in a warm greenhouse. Division is done in early spring when new growth appears; pot smaller divisions and keep in shade until established. Half-ripe stem cuttings can be taken in July. The plant is dioecious, so both male and female plants are needed to produce viable seed.

Smilax aspera is primarily an outdoor plant, thriving in USDA zones 8–11. It succeeds in most soil types in sun or semi-shade and is well-suited to Mediterranean, subtropical, and warm temperate climates. It tolerates temperatures down to -10°C when dormant. The plant makes an excellent impenetrable hedge or screen, and can be trained on trellises, arbors, or allowed to scramble through existing vegetation.

Smilax aspera is native to a broad range spanning Macaronesia, the Mediterranean basin (southern Europe including Spain, France, Italy, Greece, Croatia, Albania, Montenegro, Malta, Cyprus, Portugal), through the Middle East (Turkey, Israel, Lebanon, Syria, Jordan), Central and East Africa (Ethiopia, Kenya, Democratic Republic of Congo), and into temperate and tropical Asia (India, Nepal, Bhutan, Sri Lanka, Myanmar, Pakistan). It inhabits Mediterranean scrubland, forest edges, riverbanks, and ravines, typically at elevations from sea level to 2,000 meters.

Smilax aspera benefits from regular pruning to control its vigorous, scrambling growth. Remove dead or damaged stems and cut back wayward growth to maintain shape and prevent the plant from becoming an impenetrable tangle. Pruning is best done in late winter or early spring before new growth begins. Wear thick gloves when handling, as the stems are armed with sharp, hooked thorns.

Smilax aspera is pollinated by insects, primarily small flies and bees attracted by the flowers' heavy sweet perfume. The plant is dioecious—male and female flowers are borne on separate plants—so cross-pollination between different individuals is required for fruit and seed production. After successful pollination, female plants produce clusters of globose berries (6–10 mm diameter) that ripen from red to glossy black, with seeds dispersed by birds.

Yes, several parts of Smilax aspera are edible. Young shoots can be eaten raw or cooked as an asparagus substitute, and the tendrils are also consumed. The root has historically been used to flavor beverages and is the basis for the traditional sarsaparilla soft drink. The rhizomes contain substantial carbohydrates and vitamin C. However, the berries should not be eaten—they contain approximately 2% saponins which can cause gastrointestinal irritation.

The root of Smilax aspera has been used medicinally since antiquity—Dioscorides documented it in the first century CE as an antidote for poisons. The root possesses alterative, demulcent, depurative, diaphoretic, diuretic, stimulant, and tonic properties. It is traditionally used as a springtime tonic and body cleanser, often combined with woody nightshade. Ripe fruits are applied topically for scabies treatment. The European Commission advises caution due to unproven efficacy claims, and the plant should be avoided during pregnancy.

Beyond food and medicine, Smilax aspera has several practical uses. A red dye can be extracted from its ripe tendrils. The plant's dense, thorny growth makes it an effective impenetrable hedge or barrier in warm climates. It also has parasiticide properties. The species is considered very ornamental and is grown for its glossy evergreen foliage, fragrant autumn flowers, and decorative red-to-black berries.

Smilax aspera is generally considered non-toxic. PFAF lists no known hazards, and the ASPCA classifies related Smilax species as non-toxic to dogs, cats, and horses. Young shoots and roots are edible. However, the berries contain approximately 2% saponins which can cause stomach pain, nausea, vomiting, and diarrhea if consumed, and may cause hemolysis (destruction of red blood cells) in larger quantities. The sharp thorns can also cause mechanical injury. Keep berries away from children and pets.

Smilax aspera is evergreen and does not have a pronounced dormancy, but growth slows in winter. Summer is the active growth period when regular watering is most important. Flowers appear in late summer through autumn, followed by berries that ripen through winter. In zones at the edge of its hardiness range (USDA 8), provide winter protection such as mulching the root zone against hard frosts.

Smilax aspera is notably resistant to pests and diseases. No significant pest or disease issues are documented in major botanical references, which is consistent with its vigorous, somewhat invasive nature. The tough, leathery leaves and thorny stems provide natural deterrence against herbivores. In cultivation, standard monitoring for common garden pests like aphids or scale insects is sufficient.

Rough Bindweed requires a bit more attention and knowledge to thrive, making it a suitable plant for those with some gardening experience.

Rough Bindweed should be watered regularly, allowing the soil to dry out between waterings.

When growing Rough Bindweed, it is important to pay attention to the soil type you are using. This plant is very sensitive to dry soil and needs a potting soil that retains moisture. A good soil should still be well-draining and contain lots of organic matter. Coco coir or sphagnum moss are great options to provide the Sarsaparille with the nutrients and moisture it needs. The added organic matter will also help the soil retain water and prevent the Rough Bindweed from drying out too quickly. Before planting, make sure to mix compost or manure into the soil for extra nutrients. Also, make sure to water the Sarsaparille regularly, making sure to keep the soil evenly moist but never soggy. With the correct soil and watering regimen, the Rough Bindweed will thrive and bring lots of beauty to your home.

To ensure optimal growth, the Rough Bindweed prefers bright diffused light for 6-8 hours each day. Insufficient light can result in slow growth and leaf drop, so it's important to find a well-lit location for this plant. Place it near a window, within a distance of 1 meter (3 feet), to enhance its potential for thriving.

The Rough Bindweed should be repotted either when it doubles in size or annually, whichever comes first. Providing new potting soil with all the vital nutrients annually is enough to support the growth of the plant, and thus, there is no need for fertilizer. Remember that plants derive their energy from the sun, not fertilizer.