BattenBlooms
PL. —Helianthus annuusBotanical illustration — drop image
Helianthus annuus

Sunflower

Summer
2a–11bHardiness zone
Peak bloom windowZone 6b · frost-offset weeks
Winter
Not in bloom
Spring
Peak bloom
Summer
Peak bloom
Fall
Not in bloom
Peak bloom
In bloom
Background

Sunflowers are the most openly joyful plant in the cutting garden — tall, generous, and impossible to misread. Direct sow after last frost into warm soil and they'll be blooming in 70–80 days. For cutting, branching varieties give far more stems per plant than single-stem types; look for 'Lemon Queen', multi-stem ProCut varieties, or any branching type that produces multiple flowers per plant.

Harvest timing matters: cut when the petals are just lifting away from the face and the centre disc is still tight and green. Left too long, they drop pollen everywhere and vase life collapses. Succession-sow every two weeks from last frost through midsummer for continuous harvest into autumn.

Good companions
Zinnia elegansCosmos bipinnatusCucumis sativus 'Silver Slicer'Cucurbita pepoZea mays
Keep apart
Phaseolus vulgaris 'Black Turtle'Solanum tuberosum
Care guide
SunFull sun — 6–8 hours minimum
WaterModerate; deep watering once established
SoilWell-draining, average fertility; tolerates poor soils
Spacing12–24 inches depending on variety
Height2–12 feet
Zone2a – 11b
WinterAnnual — compost spent plants after first frost.
Native RegionAZ, CA, CO, IA, ID, IL, IN, KS, MN, MO, MT, ND, NE, NM, NV, OK, OR, SD, TX, UT, WA, WY
Direct sow
Seasonal tasks
spring
sowDirect sow after last frost into warm soil
summer
sowSuccession-sow every 2 weeks through midsummer
cutHarvest when petals lift and the disc centre is still tight
watchWatch for powdery mildew on lower leaves in humid spells
fall
watchLeave a few heads standing for birds after the season ends
Common problems

Powdery mildew

Symptoms

White or grey powdery coating on leaves — usually starting on older growth in humid conditions or when nights cool.

Treatment

Improve air circulation by thinning plants. Apply neem oil or potassium bicarbonate spray at first sign. Avoid overhead watering.

Aphids

Symptoms

Clusters of small soft insects on new growth and flower buds.

Treatment

Knock off with a strong jet of water. Ladybirds and lacewings are natural predators. Insecticidal soap as last resort.