Annual
Nemesia
Nemesia strumosa · Scrophulariaceae
Also called: Cape Jewels, Pouch Nemesia
Nemesia (Nemesia strumosa) is a moderate-water annual well suited to Tucson and the low desert. It grows to 8-18 in tall by 6-12 in wide in full sun in winter, with a fast growth rate.
Nemesia at a glance
- Water use
- Moderate (established)
- Sun
- Full sun in winter; light afternoon shade as temperatures rise in spring helps extend the season.
- Mature size
- 8-18 in tall by 6-12 in wide
- Growth rate
- Fast
- Bloom
- Mixed and bicolor shades of blue, yellow, white, pink, red, orange, and purple, Late winter into spring (roughly Feb-May) in the low desert
- Cold hardiness
- Frost-sensitive; tolerates light frost but damaged by hard freezes, and quickly declines once daytime highs exceed ~80-85 F.
- Soil
- Fertile, moist, well-drained soil amended with compost; prefers slightly acidic to neutral but tolerates Tucson's alkaline soils with organic amendment.
- Native range
- South Africa (Cape region)
- Best used as
- Cool-season color beds, Containers and mixed pots, Borders and edging, Cottage-style winter/spring displays
- Wildlife
- Attracts bees and butterflies.
- Toxicity
- Not known to be significantly toxic; generally regarded as safe around pets and children, though it is not intended for consumption.
How to grow Nemesia in Tucson & the low desert
Watering
Keep soil consistently moist; nemesia dislikes both drought and waterlogging, so water every 2-4 days and never let it dry out completely. A cool-season annual in Tucson: plant transplants in fall (Oct-Dec).
Fertilizer & nutrients
Feed every 2-3 weeks with a balanced liquid fertilizer during active growth; a slow-release fertilizer at planting supports steady bloom, especially in containers.
Pruning & care
Pinch young plants to promote bushiness; shear back by about a third after the first flush to trigger rebloom. Deadheading tidies plants and prolongs flowering.
Notes
Most bedding nemesia sold are compact hybrids (often N. strumosa x N. versicolor) marketed under the N. strumosa name. A short-lived but showy cool-season annual for Tucson; plant in fall for late-winter to spring color and pull when summer heat sets in.
Sources: Missouri Botanical Garden / RHS nemesia taxonomy and culture; University of Arizona Cooperative Extension cool-season annual guidance; Tucson low-desert planting calendars (greenthingsaz.com)