If there was a search for plants that bring real risk into a gardener’s life—say, the way helmet-to-helmet tackles bring risk into a football game—the porcupine tomato (Solanum pyracanthum) would be on the list of contenders. Large orange thorns are its most noticeable trait: They cover the plant, sticking straight out of the stems and blue-green leaves, and even surrounding the small greenish fruits. It’s clearly no teddy bear—and its hidden weapon is even more dangerous. This tropical perennial is a relative of the tomato and of deadly nightshade, and like some other members of Solanaceae, it contains toxins that are poisonous to humans. Its tissue-paper purple flowers might look delicate, but this native of Madagascar is playing for keeps. Plants may regrow after foliage is frozen, and they can recover from extended drought; they also produce many seeds, and each tiny seedling that sprouts rapidly starts producing the characteristic thorns. Forget football—this is more like Stephen King.
Common name: Porcupine tomato, firethorn nightshade
Botanical name: Solanum pyracanthum
Plant type: Tropical perennial
Zones: 9 to 11 (annual in lower zones)
Height: 3 to 5 feet
- Sun: Full sun to part shade
- Soil: Well-drained, rich
- Moisture: Average to dry
- Mulch: To keep roots moist
- Pruning: None needed
- Fertilizer: None needed
Pests and diseases
- Generally free of pests and diseases
- To state the obvious: Don’t plant porcupine tomato in a high-traffic area, or a place that’s accessible to children or pets.
- This plant is best kept in a container to eliminate any possibility of it naturalizing. In Zones 9 and higher (perhaps even Zone 8 to be sure), be sure to deadhead before the plant sets seeds, or within a generation you could find yourself battling a prickly, poisonous forest.
All in the family
- Porcupine tomato is a member of Solanaceae, a large family containing close to nearly 3,000 species. It’s a family full of contradiction: Some members are important agricultural crops and others are among the deadliest of plants.
- Familiar edibles in the genus Solanum (which contains nearly half of Solanaceae’s species) are potatoes (S. tuberosum), tomatoes (S. lycopersicum) and eggplants (S. melongena).
- Poisonous members of the family include mandrake (Mandragora officinarum), jimsonweed (Datura stramonium) and deadly nightshade (Atropa belladonna).
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