Redroot Pigweed
Amaranthus retroflexus
An erect, annual herbaceous plant with a distinctive pinkish-red taproot. It features lance-shaped green leaves and dense, bristly terminal flower spikes consisting of numerous tiny green flowers.
- Light
- Full sun, requiring at least 6 to 8 hours of direct light per day for optimal growth.
- Water
- Moderate to low; once established, it is quite drought-tolerant. Water when the top few inches of soil are dry.
- Growth
- Summer annual; can grow between 1 to 6 feet tall with a stiff, pubescent (hairy) stem and a branched crown.
Care instructions
Provide full sun and well-drained soil. It is a highly adaptable, drought-tolerant plant that thrives in disturbed areas and gardens with minimal intervention.
Growing details
Sunlight
Full sun, requiring at least 6 to 8 hours of direct light per day for optimal growth.
Watering
Moderate to low; once established, it is quite drought-tolerant. Water when the top few inches of soil are dry.
Soil
Adaptable to various soil types, including loamy, sandy, or clay soils, preferably with a neutral to slightly acidic pH and good drainage.
Hardiness zone
Zones 3 to 11
Growth habit
Summer annual; can grow between 1 to 6 feet tall with a stiff, pubescent (hairy) stem and a branched crown.
Bloom season
Mid-summer to early autumn; produces small, green, wind-pollinated flowers arranged in thick, bristly panicles.
Propagation
Primarily via seeds, which are produced in large quantities and can remain viable in the soil for many years.
Common pests & issues
Commonly affected by aphids, flea beetles, and tarnished plant bugs; susceptible to damping-off in overly wet conditions.
Similar species
Amaranth albus (Tumble Pigweed), which has a more rounded, bushy growth habit, and Amaranthus hybridus (Smooth Pigweed), which has less bristly flower spikes.