Trachycarpus fortunei, the windmill palm, is dioecious, meaning individual plants are either male or female. Telling them apart can be tricky before they reach maturity, because they look identical as juveniles. Here’s how you can distinguish them:
1. Flower Appearance
- Male flowers:
- Grow in branched clusters (inflorescences) that hang down.
- Small, yellowish-green, and produce pollen.
- More numerous than female flowers.
- Female flowers:
- Also in clusters, but less dense and slightly larger.
- Typically whitish or pale green.
- Will develop into fruit after pollination.
2. Fruit Production
- Female palms produce small, round, blue-black fruits (drupes) about 1–1.5 cm in diameter, usually after successful pollination.
- Male palms never produce fruit.
Note: Fruit only appears after the tree reaches maturity, which can take 5–10 years.
3. Inflorescence Structure
- Male inflorescences are longer, more branched, and hang lower, often giving a “weeping” effect.
- Female inflorescences are shorter and more upright, and the flowers are more robust to support fruit development.
4. Practical Tips
- If you want a fruiting female palm, you’ll need at least one male nearby for pollination.
- For ornamental use, both sexes are visually similar, so gender is usually irrelevant unless fruiting is desired.