Perennial Ragweed, Western Ragweed, Cuman Ragweed

Ambrosiapsilostachya

Family
Asteraceae (ass-ter-AY-see-ee)
Genus
Ambrosia (am-BRO-zhuh)
Species
psilostachya (sil-oh-STAK-yuh)
Synonym
Ambrosia californica
Ambrosia coronopifolia
Ambrosia cumanensis
Ambrosia rugelii
Sun Exposure
Full Sun
Foliage
Herbaceous
Height
12-18 in. (30-45 cm)
18-24 in. (45-60 cm)
24-36 in. (60-90 cm)
36-48 in. (90-120 cm)
Spacing
12-15 in. (30-38 cm)
15-18 in. (38-45 cm)
18-24 in. (45-60 cm)
24-36 in. (60-90 cm)
Hardiness
USDA Zone 6a: to -23.3 °C (-10 °F)
USDA Zone 6b: to -20.5 °C (-5 °F)
USDA Zone 7a: to -17.7 °C (0 °F)
USDA Zone 7b: to -14.9 °C (5 °F)
USDA Zone 8a: to -12.2 °C (10 °F)
USDA Zone 8b: to -9.4 °C (15 °F)
USDA Zone 9a: to -6.6 °C (20 °F)
USDA Zone 9b: to -3.8 °C (25 °F)
USDA Zone 10a: to -1.1 °C (30 °F)
USDA Zone 10b: to 1.7 °C (35 °F)
Danger
Pollen may cause allergic reaction
Bloom Color
Bright Yellow
Inconspicuous/none
Bloom Time
Mid Summer
Late Summer/Early Fall
Mid Fall
Other Details
Category
Perennials
Water Requirements
Drought-tolerant; suitable for xeriscaping
Foliage Color
Where to Grow
Bloom Characteristics
Bloom Size
Other details
May be a noxious weed or invasive
Soil pH requirements
Patent Information
Propagation Methods
Self-sows freely; deadhead if you do not want volunteer seedlings next season
Seed Collecting
Regional

This plant is said to grow outdoors in the following regions:

Calabasas, California

Arlington, Texas

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Gardener's Notes:

0
positive
1
neutral
0
negative
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Oklahoma City, OK (Zone 7a) | November 2004 | neutral

This plant spreads from rhizomes and is a perennial. It produces a fruit, called a bur, that is greenish-brown and has spines. It can b...Read More

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