Spiny Sida

Year-round

Spiny sida is a common, fast growing annual that shows up readily in sunny, disturbed Memphis garden soil, and it can be managed for pollinator value or kept in check depending on what you want from the bed.

• Grows best in full sun and average to poor, well drained soil, including disturbed or compacted spots.
• Small yellow flowers open in sunny conditions and provide some nectar for small pollinators.
• Stems carry small spines, so wear gloves when handling or pulling it.
• Self seeds readily, so decide early whether you want to let it spread or deadhead to control it.
• If you would rather not keep it, pull young plants before seed pods form to limit spread.

Because it self seeds freely in open soil, deadheading spent flowers keeps a bed looking tidy for an HOA-conscious front yard.

Fall

Flowering continues into early fall in Memphis, after which spiny sida sets its spiny seed pods.

• Blooming continues until the first fall frost slows growth.
• Seed pods that follow the flowers are bur like and can stick to clothing, shoes, and animal fur as they pass by, so mature plants near paths are worth pulling before the pods set.
• Pull plants before pods fully mature if you want to reduce next year's seedlings.
• Leave a few plants to seed if you are fine with it returning for pollinator value.

Winter

As an annual, spiny sida is killed by Memphis's first hard frost and will not return from the same roots next spring.

• Plants die back completely after the first fall frost, averaging around early November in Memphis.
• Remove dead stalks once they have browned, since the spines remain on dried stems.
• Seed that dropped over summer and fall stays in the soil and will germinate again next spring.
• No winter care is needed since it does not overwinter as a living plant.

Spring

Spiny sida germinates readily once Memphis soil warms after the last spring frost.

• Seed germinates in warm soil, typically after Memphis's average last frost in mid to late March.
• Pull unwanted seedlings early while the spines are still soft and easy to manage.
• If keeping some for pollinators, thin to a few well spaced plants rather than a dense patch.
• No fertilizer or soil amendment is needed to get it going.

Summer

Spiny sida thrives in Memphis's hot, humid summer, flowering steadily in full sun.

• Small yellow flowers open during the day in full sun through the summer.
• Tolerates heat, humidity, and dry spells without extra watering.
• Deadhead spent flowers regularly if you want to limit how much it reseeds.
• Watch for the small spines on stems when weeding nearby, especially with bare hands.