Illustration
Cosmic Red
Cosmos sulphureus 'Cosmic Red'
Cosmic Red blooms from June through October.
Months here are Northern Hemisphere months; in the Southern Hemisphere, shift them by six months.
Growing Cosmic Red
Plant it in full sun. It prefers low water. Expect it to reach about 16 in tall and 16 in wide at maturity, in roughly 1 year (a house reading).
Pets
- No toxic listing found for dogs and cats in the sources we check.
Lists differ and none is complete. If a pet eats a plant and seems unwell, call a veterinarian or a pet poison helpline.
No toxicity note is on file for Cosmic Red. That is not a clearance: check its safety for people and pets before planting.
What was checked
Nine facts were checked against named botanical sources, each recorded beside the sources that carried it: mature height and spread, hardiness zones, sun, water, bloom months and color, the trait tags, and years to mature size, which rests on a recorded house rule where no publisher states one and is marked so. Soil, diseases, pests, toxicity and the plant's own names have not yet been read for this plant, and its trait tags are the ones a feature uses rather than every word a page prints. Each fact above carries its own mark. The planting, spacing and size sections are derived from these checked facts by a fixed rule, not checked separately, and the plant type is the library's own classification.
When to plant Cosmic Red
Wait until all danger of frost has passed, then plant out Cosmic Red into warm soil; in most zones that means late spring. Planted then, it flowers from June to October.
Month-by-month timing for your zone is on the planting calendar. Derived from the plant's category, zones and bloom months plus typical zone frost dates, not checked separately.
How big does Cosmic Red get?
16 intall5 ft 7 inan adult16 inwideSee Cosmic Red in a garden plan: the planner shows it in 3D beside everything else you add, growing toward this size over the years.
How far apart to plant Cosmic Red
Derived from the mature spread above by a fixed rule, not checked separately: spacing is the spread, center to center.
Space Cosmic Red about 16 in apart, center to center, so each plant has room to reach its full width.
Add Cosmic Red to a garden plan and the planner draws it at its full width, so you see the spacing before you buy.
Where these facts come from
Cosmic Red's height, spread, hardiness zones, sun, water, bloom color and trait tags were checked against 7 published sources on October 25, 2026. Each one is linked below with every fact it carried, which can include a fact this page still marks as not yet checked, because a source carrying a value is not the same as the value being held to the standard. Facts not in that list, and the planting, spacing and size sections, are not covered by these sources.
- sedanfloral.comSedan Floralheight, spread, hardiness zones, sun, water, bloom months and color and trait tags
- specialplants.netSpecial Plantsheight, water, bloom months and color and trait tags
- Missouri Botanical Gardensun, water and trait tags
- navigate.botanicgardens.orgDenver Botanic Gardensbloom months and color and trait tags
- NC State Extensionsun, water and trait tags
- ag.ndsu.eduNorth Dakota State Universityheight and spread
- benary.comBenarysun
How the checking works, and what each standard covers, is on the verified plants page.
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Design a garden with this
Drop this plant onto a 3D plan, see how it fills in, and watch your whole garden bloom across the year.