Sunflower
Sources last read 13 September 2026.
Forgiving Among the more tolerant plants here.
Also called comb flower, Common Sunflower, golden, golden flower of Peru, Kansas Sunflower, St Bartholomew's star and Wild Sunflower.
Toxicity is partly unassessed
- Not assessed for cats. This plant is not on the ASPCA list. That is not a finding of safety: none of the sources read for this site gives an answer either way. Treat it as unknown.
- Not assessed for dogs. This plant is not on the ASPCA list. That is not a finding of safety: none of the sources read for this site gives an answer either way. Treat it as unknown.
- Not assessed for people. RHS publishes no harm statement for this plant. That is not a finding of safety: none of the sources read for this site gives an answer either way. Treat it as unknown.
What the sources say about its care
- Light
- Full sunRHS · read 13 September 2026
- Water
- Moist but well-drainedRHS · read 13 September 2026
- Humidity
No source read publishes a humidity figure for any plant on this site. What follows is general guidance for foliage plants.
ASHRAE recommends indoor relative humidity between 30% and 60% 30–60%Penn State Extension · read 13 September 2026- Temperature
How cold this tolerates, not what it prefers. No source read for this site publishes a preferred range for a plant indoors.
H4 — -10 to -5°C -10 to -5 °CRHS · read 13 September 2026- Soil
- Chalk, Clay, Loam, Sand; pH Alkaline or NeutralRHS · read 13 September 2026
- Toxic to cats
- Not on the ASPCA list. That is not a finding of safety.ASPCA · read 13 September 2026
- Toxic to dogs
- Not on the ASPCA list. That is not a finding of safety.ASPCA · read 13 September 2026
- Harmful to people
- No statement of harm to people is published for this plant; that absence is not evidence it is safe.RHS · read 13 September 2026
How it usually goes wrong
- Brown, papery patches on the leaves nearest the glass
The damage on the sunflower faces one way. Turn the pot round and the other side is clean.
Even a plant described as full sun can take more through glass than it would outdoors, because glass removes the breeze that carried the heat away.
Telling it apart: The edge of the damage. Scorch has a sharp boundary; rot and infection have a soft, spreading one.
RHSSunflower brown leaf tips and edges: causes- Buds that yellow and drop on a leafy plant
Buds appear on the sunflower and then fall while still closed, often within days of the plant being moved, turned or left to dry out.
Its source places it in full sun. A bud formed in that light and then turned away from it, or left in drying compost, is the first thing the plant gives up.
Telling it apart: A fallen bud under a magnifying glass. Insects or scarring point at pests; a clean bud points at a change or at water.
RHSSunflower leaves turning yellow: causes- Leaf tips go crisp and brown
On a sunflower the browning starts furthest from the midrib and works inward, and it crumbles rather than smears. The centre of each leaf is untouched.
Transpiration rises as the air dries, and the tissue furthest from a vein loses first. Penn State Extension notes there is no single humidity figure that suits every indoor plant, which is why this site publishes a range rather than a number. That applies while it is grown indoors; its RHS rating of H4 describes a plant that also grows outside, where the air is seldom that dry.
Telling it apart: Whether the damage advances. Dry air marks a leaf and stops; rot keeps going.
Penn State ExtensionSunflower brown leaf tips and edges: causes- Torn or browned leaves on one side after windy weather
The sunflower looks battered rather than sick. Leaves are nicked and browned at the edges, and the damage is heaviest on the most exposed side.
Its source describes a sheltered spot. In an exposed one, wind both dries the leaves and damages them physically, which is why the marks follow the direction of the weather.
Telling it apart: Timing. Damage that appeared after one windy day is weather; damage that builds slowly is water or roots.
RHSSunflower brown leaf tips and edges: causes- Yellow, limp leaves at the base
The lowest leaves of the sunflower go yellow and translucent at the stalk and drop with a light pull, while the compost stays wet.
Soil described as moist but well-drained is a drainage instruction as much as a watering one. Compost that stays saturated suffocates the fine roots that do the drinking.
Telling it apart: The soil, not the leaf. Wet compost under yellowing leaves points one way and dry compost the other, and the leaves alone will not tell you which.
RHSSunflower leaves turning yellow: causes
Not sure which it is? Ask the diagnosis questions for Sunflower.
Routine care
- Propagation
- SeedNC State Extension · read 13 September 2026Sow seed or divide. Every 2-4 years, split established clumps to gain plants and keep them vigorous. Sowing seeds indoors has more guidance.RHS · read 13 September 2026
- Pruning
- Pruning is not needed.RHS · read 13 September 2026
- Pests and diseases
- Snails and slugs can attack it. Disease risks: sclerotinia diseases and powdery mildews.RHS · read 13 September 2026
Move something and watch
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About the plant
The common sunflower is a large annual forb in the daisy family Asteraceae. The domesticated form of common sunflower is harvested for its edible seeds, which come in two types: oil and confectionary seeds. Oilseed sunflowers are widely grown globally and represent the fourth most used vegetable oil in the world. They also are used widely as bird food or as food for livestock. In contrast, confectionary sunflower seeds are often eaten as a snack food or in baking. There also are horticultural sunflower varieties that are used as plantings in domestic gardens for aesthetics. Wild plants are known for their multiple flower heads, whereas the domestic sunflower often possesses a single large flower head atop an unbranched stem.
From Wikipedia, CC BY-SA 4.0 · read 13 September 2026
- Native range
- SW. U.S.A. to MexicoWorld Checklist of Vascular Plants, June 2026 release, CC BY.Kew WCVP · read 13 September 2026Southwestern United States to MexicoNC State Extension · read 13 September 2026
- Climate
- temperateWorld Checklist of Vascular Plants, June 2026 release, CC BY.Kew WCVP · read 13 September 2026
- Growth form
- annualWorld Checklist of Vascular Plants, June 2026 release, CC BY.Kew WCVP · read 13 September 2026Annual; habit erectNC State Extension · read 13 September 2026Columnar upright (deciduous)RHS · read 13 September 2026
- Size
- Height 18–120 in; width 18–36 inNC State Extension · read 13 September 2026Height 2.5-4 metres; spread 0.5-1 metres after 1 yearRHS · read 13 September 2026
- Flowering
- Flowers black, brown/copper, gold/yellow, orange, purple/lavender; blooms in fall, summerNC State Extension · read 13 September 2026Flowers brown in summer; yellow in summerRHS · read 13 September 2026
- Uses
What sources record people using this plant for. A traditional or medicinal use listed here is a record of use, not advice to eat it or treat anything with it.
Indians made flour from ground seeds and baked it into cakes. They put a poultice of crushed plants on snakebites and took a flower infusion for chest pain or lung problems. A purple-gray dye comes from the seeds. Seeds also provide cooking oil and livestock feed, and serve as a snack or garnish. The petals can be eaten too; young flower buds may be steamed like artichokes.NC State Extension · read 13 September 2026
Common problems with Sunflower
More of the Asteraceae family
Barberton daisyEdges of the leaves brown while the middle stays sound
Purple passionLeaf blade tips go crisp and brown
String of pearlsDry scorched spots after a move into a sunnier spot
Banana VineSourced care, difficulty not yet judged
Blue ChalksticksSourced care, difficulty not yet judged
Candle PlantSourced care, difficulty not yet judged
Plants with similar care
Blue passion flowerA thin dry rim that crumbles between the fingers
Bush lilyDry, curled edges on leaves near a heater
Dog roseEdges of the leaves brown while the middle stays sound
English lavenderBuds form and fall before they open
Flaming KatyA thin dry rim that crumbles between the fingers
Hardy fuchsiaBrown, papery patches on the leaves nearest the glass
Sources
- ASPCA · read 13 September 2026
- Kew WCVP · read 13 September 2026
- NC State Extension · read 13 September 2026
- Penn State Extension · read 13 September 2026
- RHS · read 13 September 2026
- Wikipedia · read 13 September 2026
What this does not cover
The figures above are what published sources say, not measurements of the plant in your room. They say nothing about your pot size, your water, the season, or how far from the glass the plant stands, and those decide more than any figure here does.
Humidity has no species figure because no source read for this site publishes one, and the only temperature published for this plant is a cold floor. The simulator fills those gaps with general figures for its kind of plant, marked as general and listed on how we read sources. Where a toxicity row says the plant was not assessed, that is the absence of a finding and not a finding of safety.
If something is already wrong, the diagnosis tool asks about the soil, the window and the watering, which is where the answer usually is.