Saw Palmetto (Serenoa repens)

Silver saw palmetto palms (Serenoa repens) are native to Florida and the southeastern U.S. These palms are unusually cold-hardy and can be grown in USDA regions 7 through 11. They are a common understory plant often found in sprawling clusters in south Florida’s pine flat woods and oak woodlands. Read on to learn more about growing these plants.

I. Appearance and Characteristics 

Serenoa repens, commonly known as saw palmetto, is a small palm, growing to a maximum height around 200–300 cm (6.6–9.8 ft).

It is the sole species in the genus Serenoa. The genus name honors American botanist Sereno Watson.

It is endemic to the subtropical and tropical Southeastern United States, most commonly along the south Atlantic and Gulf Coastal plains and sand hills. It grows in clumps or dense thickets in sandy coastal areas, and as undergrowth in pine woods or hardwood hammocks.

Erect stems or trunks are rarely produced, but are found in some populations. It is a hardy plant; extremely slow-growing, and long-lived, with some plants (especially in Florida) possibly being as old as 500–700 years.

Saw palmetto is a fan palm, with the leaves that have a bare petiole terminating in a rounded fan of about 20 leaflets. The petiole is armed with fine, sharp teeth or spines that give the species its common name. The teeth or spines are easily capable of breaking the skin, and protection should be worn when working around a saw palmetto. The leaves are light green inland, and silvery-white in coastal regions. The leaves are 1–2 m in length, the leaflets 50–100 cm long. They are similar to the leaves of the palmettos of genus Sabal. The flowers are yellowish-white, about 5 mm across, produced in dense compound panicles up to 60 cm long.

The fruit is a large reddish-black drupe and is an important food source for wildlife and historically for humans. The plant is used as a food plant by the larvae of some Lepidoptera species such as Batrachedra decoctor, which feeds exclusively on the plant.

II. How to Grow and Care

Sunlight

Saw palmetto thrives best in full sun conditions where it can receive direct sunlight for the majority of the day. This exposure is conducive to saw palmetto’s optimal growth and health, enhancing its ability to produce dense foliage and robust roots. In terms of light tolerance, saw palmetto is flexible enough to grow in partial sun, although this might result in slower growth and potentially less vigor compared to plants in full sun. The species is well-adapted to various light scenarios, often showing resilience by subtle adjustments in leaf orientation to maximize light absorption. Recommended outdoor planting positions include open areas or spots with minimal overhead obstruction to ensure ample sunlight access.

Watering

Adapted to the moist, well-drained soils of its native coastal habitats, saw palmetto thrives with moderate moisture levels. It exhibits a balance between drought resistance and a preference for consistent hydration. Watering should be done once every 1-2 weeks, ensuring soil moisture without over-saturation. Typically grown outdoors due to its resilience and size, saw palmetto benefits from natural rainfall patterns, aligning with its need for periodic watering in cultivation settings.

Soil

They are adapted to Florida’s sandy soils and don’t require any soil amendments unless grown out of their normal range in clay soils.

Fertilizing

Fertilize saw palmetto sparingly with a balanced or high nitrogen formula during the growing season for robust growth and fruiting. Apply 1-2 times per year, ensuring a light application each time. Overfertilization can harm saw palmetto, so avoid excess. Adjust feeding with seasonal growth; less in winter. Use granular, slow-release products for steady nutrient delivery. Wear gloves, and water saw palmetto post-application to aid absorption. This targeted approach ensures saw palmetto’s vitality and resilience.

Pruning

Remove old brown leaves and stems as needed. Cut the dead leaves off at their base.

Propagation

Saw palmetto’s propagation is primarily achieved through sowing, ideally in spring. This plant has moderate propagation difficulty, and successful signs include new leaf growth. Ensure proper seed stratification for optimal germination rates.

Transplanting

For saw palmetto, late winter to early spring (S3-S4) is an optimal time for transplanting. During this period, the plant sends out new roots, allowing for better establishment at the new location. It prefers sandy and well-drained areas, with full sun to partial shade. Carefully choose the transplant site for long-term success.

Repotting

Repot saw palmetto every 1-2 years to accommodate its slow growth and moderate-sized, shrubby form. Optimal timing is early spring, aligning with its active growth phase. Select a slightly larger pot with good drainage to encourage healthy root expansion. Post-repotting, place saw palmetto in bright, indirect light and water moderately, avoiding saturation to ensure robust recovery. Careful handling is vital due to its sharp leaf margins.

III. Uses and Benefits 

• Medicinal uses

Saw palmetto extract has been studied as a possible treatment for people with prostate cancer and for men with lower urinary tract symptoms associated with benign prostatic hyperplasia (BPH). As of 2023, there is insufficient scientific evidence that saw palmetto extract is effective for treating cancer or BPH and its symptoms.

One 2016 review of clinical studies with a standardized extract of saw palmetto (called Permixon) found that the extract was safe and may be effective for relieving BPH-induced urinary symptoms compared against a placebo.

• Other uses

Indigenous names are reported to include: tala or talimushi (“palmetto’s uncle”) in Choctaw; cani (Timucua); ta ́:la (Koasati); taalachoba (“big palm”, Alabama); ta:laɬ a ́ kko (“big palm”, Creek); talco ́:bˆı (“big palm”, Mikasuki); and guana (Taíno, possibly). Saw palmetto fibers have been found among materials from indigenous people as far north as Wisconsin and New York, strongly suggesting this material was widely traded prior to European contact. The leaves are used for thatching by several indigenous groups, so commonly that a location in Alachua County, Florida, is named Kanapaha (“palm house”). The fruit may have been used to treat an unclear form of fish poisoning by the Seminoles and Lucayans.