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Cosmos Sensations Mix Flowers

Mix · Asteraceae

Cosmos Sensations Mix is a tall heirloom garden cosmos blend best matched to Cosmos bipinnatus, with large single flowers in pink, rose, magenta, and white shades on airy 4-5 foot stems. It is an All-America Selections winner valued for easy direct sowing, long summer bloom, and strong pollinator appeal. The Seeds Now page text appears to describe sulphur cosmos generically, but the Sensation Mix cultivar name aligns with the classic tall bipinnatus mixture grown for borders and cut flowers. Key facts: 70–75 days to maturity, 8+ hours of sun, 12–24 " spacing. Can be grown in containers with care (5+ gallon minimum).

Updated April 19, 2026 · Backed by 5 cited sources
Overview

At a Glance

The essentials first: timing, light, spacing, seed-starting, container fit, and overall size.

Days to maturity
70–75 days
Sun
8+ hours
Full Sun, 8 10 Hours
Spacing
12–24 "
between plants
Seed start
4 weeks
before transplant
Container
Possible
Needs 5+ gal minimum
Height
4–5 ft
at maturity
Planting window

Zone Planting Guide

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This card updates instantly with viability, frost timing, and any planting notes for your selected zone.

Care

Growing Guide

Everything in one place: seed starting, transplant timing, watering, soil, and structural support.

Seed starting
Germination
Time7–14 days
Optimal temperature72°F
Seed depth0.125"
Moving outdoors
Transplanting
Minimum soil temp65°F
Harden off5 days
Moisture
Watering
Weekly0.5–1 "
NeedsLow
Drip or base watering
Root zone
Soil
pH range6–7.5
PreferredWell Drained Soil With Average To Poor Fertility
Resilience

Plant Health

Stress tolerance, resistance notes, and the most common problems to watch for as plants mature.

Tolerance
Heat: High Cold: Low Drought: High

Common Issues

Flopping

Cause: Rich soil, too much water, or shade

Prevention: Grow in leaner soil and stake only if needed

Self Seeding

Cause: Plants make abundant seed heads

Prevention: Deadhead regularly if volunteers are not wanted

Late Bloom

Cause: Overfertilization produces foliage instead of flowers

Prevention: Do not fertilize cosmos

Feeding & picking

Nutrition & Harvest

How hungry the plant is, what ripe harvest looks like, and how long the crop keeps after picking.

Feeding
Nutrition
Feeding intensityLow feeder
RecipesWorm Castings Topdress
Timing
Harvest

Cut stems when flowers are newly open and petals are fresh, or collect dry seed heads for saving.

Expected yield0.15–0.3 lbs/plant
Storage5 days — Fresh stems hold several days in water; dry mature heads well before saving seed.
Plant relationships

Companion Planting

Helpful neighbors can support growth or deter pests. Keep antagonistic plants separated to reduce stress and competition.

Avoid planting near
Herb Fennel
What you'll need

Growing Supplies

Based on Cosmos Sensations Mix's growth profile -- recommendations matched to this variety's specific requirements.

Drip irrigation / soaker hose kit

Every gardener benefits from putting water at the root zone instead of on the leaves, because drip and soaker systems reduce foliar disease pressure by limiting leaf wetness and soil splash. A quality kit should include a backflow preventer, filter, pressure reducer, and UV-resistant tubing.

Source: Iowa State University Extension; Colorado State University Extension; UMass Extension

Soil test kit

A soil test gives a baseline for pH and nutrient status so gardeners can add only what the soil actually needs. Prioritize a mail-in or lab-affiliated kit whenever possible because extension guidance notes that laboratory testing is more accurate than instant readers.

Source: University of Maryland Extension; Purdue Extension; Montana State University Extension

Quality bypass pruners

Extension guidance favors bypass designs because they make cleaner, closer cuts on living tissue than anvil types. Look for hardened steel blades that can be sharpened, a comfortable grip, and a cutting capacity matched to real home-garden stems.

Source: University of New Hampshire Extension; Iowa State University Extension; Purdue University Extension

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Research

Sources

Reference material and extension guidance used to build this growing guide.

seed_catalog Seeds Nowuniversity Utah State University Extensionreference Park Seedreference Johnny's Selected Seedsreference Seed Savers Exchange
Internal links

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