Annual Flower · 28 varieties

Cosmos

Name: Cosmos growing data
Creator: GardenTrack

Cosmos bipinnatus

Asteraceae — the same plant family as head lettuce, leaf lettuce, common sunflower, purple coneflower and 12 more here. Relatives share pests and diseases, which is why rotation plans group by family.

Cosmos (Cosmos bipinnatus) is an annual flower. It wants full sun and pH 6–8 soil, with about 0.5–1 in of water weekly. It matures in about 50–85 days from sowing, or 42–70 days from setting out a transplant. Watch for aphids and powdery mildew. Below: its full sourced profile from 5 extension sources, plus a planting calendar timed to your frost dates.

Sun Full sun

Water Low

Matures 42–70 days — from transplantest from transplant

Mature size 1–6 ft

Spacing 12–36 in

Soil pH 6–8

Frost Tender

When to plant cosmostypical · zone 6b

Your zone

…or your ZIP, for your real frost dates

Germinating

Seedlings

Growing

Flowering

Typical dates for zone 6b — set your zone or ZIP for yours. This calendar assumes the crop is started indoors. Timing is a guide from the crop's sourced growth stages; confirm with your local frost dates and extension before you sow.

Growing cosmosevery fact says where it came from

What we will not put a number on

We do not give a feeding rate for this crop, and that is deliberate rather than a gap. The figures published by extension services are pounds of nitrogen per acre for a production field — they do not convert safely to a raised bed or a pot without knowing your soil test and your fertilizer's analysis, and guessing errs toward burning roots. It is also why every chart you find online disagrees with the next one.

We give watering as a depth per week rather than gallons per plant, because that is how it is actually measured and how the published figures are written. A gallons-per-plant number depends on your spacing, your soil and whether the plant is in a pot — so it would look more precise than it is.

Site & soil

Sun: Full sun
Soil pH: 6–8
Soil texture: Clay, Loam, Sandy, Well drained
Frost tolerance: Tender

No published figure for the temperature frost starts to hurt it and the temperature that would kill it. We looked — where a number is missing here it is missing from the research, not skipped. The crop’s frost and heat tolerance above still applies.

The plant

Mature height: 1–6 ft
Mature spread: 2–3 ft
Growth rate: Fastest
Spacing in row: 12–36 in
Between rows: 18–36 inest
Planting depth: 0.125 in
Container size: 2–5 gal — low end is the minimum, high end is betterest
Support: Self-supporting
Grown from: Direct sow, Transplant

There is no line here for which parts are eaten, because we have no figure to put there. We went looking and wrote down what we read — it is missing on purpose, not because nobody checked.

Water & feeding

Water needs: Low
Water per week: 0.5–1 in/wkest
Critical water: Germinationest
Feeding: Low

Timing & fruiting

Days to maturity: 50–85 days from seed · 42–70 days from transplantest
Harvest cues: First flowers

Planted again for autumn

Set plants out by: early Sep typical · zone 6b

42 days to maturity from setting a plant out — that is what our sources measure for this crop, so this is a date for planting out and not a sowing date, counted back from the first frost above. Not published for anywhere in particular: it is your own frost date and this crop's own figure, which is why it works wherever you are. A days-to-maturity figure is a catalog number for a good season rather than a promise, and a cold month moves it.

What tends to go wrongmost-cited first

PestsAphidsLeafhoppersLoopers

DiseasesPowdery mildewStem cankerGray moldSouthern blight

Compiled from the extensions cited below. Which ones actually show up depends on your region — your extension's local list is the last word.

All 28 varietiesthe ones with their own page are linked

Variety	Type	Habit	Days	Color	What it is known for
Afternoon White		Upright	42–70	White	Johnny's Selected Seeds describes this asgood for cutting and putting in a vase
Apricotta		Upright	42–70	Pink	Swallowtail Garden Seeds describes this asgood for cutting and putting in a vase
Bright Lights Mix	Bright Lights	Upright	42–70	Yellow, Orange	Botanical Interests describes this asgood for cutting and putting in a vase · draws bees and butterflies
Cosmic Orange	Cosmic	Upright	42–70	Orange
Cosmic Yellow	Cosmic	Mounding	42–70	Yellow	Benary describes this asextra rows of petals
Cupcakes Blush	Cupcakes	Upright	42–70	Pink	Johnny's Selected Seeds describes this asgood for cutting and putting in a vase
Cupcakes Mix	Cupcakes	Upright	42–70	White, Red, Purple	Select Seeds describes this asgood for cutting and putting in a vase
Daydream		Upright	42–70	Bicolor	Swallowtail Garden Seeds describes this asgood for cutting and putting in a vase · draws bees and butterflies
Double Click Cranberries	Double Click	Upright	42–70	Red	Johnny's Selected Seeds describes this asextra rows of petals · good for cutting and putting in a vase
Double Click Mix	Double Click	Upright	42–70	Bicolor	Johnny's Selected Seeds describes this asextra rows of petals · good for cutting and putting in a vase
Double Click Rose Bonbon	Double Click	Upright	42–70	Pink	Johnny's Selected Seeds describes this asextra rows of petals · good for cutting and putting in a vase
Double Click Snow Puff	Double Click	Upright	42–70	White	Johnny's Selected Seeds describes this asextra rows of petals · good for cutting and putting in a vase
Fizzy Series	Fizzy	Upright	42–70	White	Johnny's Selected Seeds describes this asextra rows of petals · good for cutting and putting in a vase
Ladybird Lemon	Ladybird	Dwarf	42–70	Yellow	University of Illinois Extension records this asdeer usually leave it alone · gets by on less water · takes the heat · draws bees and butterflies · drops seed and comes back on its own · good for cutting and putting in a vase
Ladybird Scarlet	Ladybird	Dwarf	42–70	Red, Orange	University of Illinois Extension records this asdeer usually leave it alone · gets by on less water · takes the heat · draws bees and butterflies · drops seed and comes back on its own · good for cutting and putting in a vase
Picotee		Upright	42–70	Bicolor
Psyche Mix	Psyche	Upright	42–70	Bicolor
Psyche White	Psyche	Upright	42–70	White
Purity		Upright	42–70	White	Applewood Seed Company describes this asgood for cutting and putting in a vase · draws bees and butterflies
Rubenza		Upright	42–70	Red, Orange	Johnny's Selected Seeds describes this asgood for cutting and putting in a vase
Seashells Mix		Upright	42–70	Bicolor	Floret Flower Farm describes this asgood for cutting and putting in a vase
Sensation Mix Heirloom	Sensation	Upright	42–70	White, Red, Purple	Johnny's Selected Seeds describes this asgood for cutting and putting in a vase
Sonata Carmine	Sonata	Upright	42–70	Red	University of Illinois Extension records this asdeer usually leave it alone · gets by on less water · takes the heat · draws bees and butterflies · drops seed and comes back on its own · good for cutting and putting in a vase
Sonata Mix	Sonata	Upright	42–70	Bicolor	University of Illinois Extension records this asdeer usually leave it alone · gets by on less water · takes the heat · draws bees and butterflies · drops seed and comes back on its own · good for cutting and putting in a vase
Sonata Pink	Sonata	Upright	42–70	Pink	University of Illinois Extension records this asdeer usually leave it alone · gets by on less water · takes the heat · draws bees and butterflies · drops seed and comes back on its own · good for cutting and putting in a vase
Sonata White	Sonata	Upright	42–70	White	PanAmerican Seed describes this assmall enough for a pot
Xanthos		Upright	42–70	Yellow
Xsenia		Upright	42–70	Bicolor	Swallowtail Garden Seeds describes this asgood for cutting and putting in a vase

Sources5 cited · 5 organizations

Johnny's Selected Seeds
Missouri Botanical Garden
NC State Extension
University of Illinois Extension
Utah State University Extension

We compile bare facts from these university-extension and horticultural sources, never copied prose. 13 of the 19 values on this page carry a citation. The rest are marked est; hover one and it says why — either nobody publishes a figure we could point at, or a person set it and attached no source. Figures vary with climate and seed source; confirm with your local extension before you buy.

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