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Rainbow Corn

Rainbow · Poaceae

Multicolored ornamental flint-style corn grown for dry decorative ears and meal or popcorn-like use rather than fresh sweet eating. Long-season plants need warmth, full sun, and block planting for complete pollination. Key facts: 105–115 days to maturity, 8+ hours of sun, 8–12 " spacing. Not recommended for containers.

Updated April 19, 2026 · Backed by 3 cited sources
Overview

At a Glance

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

Days to maturity
105–115 days
Sun
8+ hours
Full Sun
Spacing
8–12 "
between plants
Seed start
0 weeks
before transplant
Container
Not recommended
Needs 10+ gal if attempted
Height
6–10 ft
at maturity
Planting window

Zone Planting Guide

Switch zones to see whether this plant is a strong fit, what frost timing looks like, and any extra notes worth planning around.

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
Time5–10 days
Optimal temperature70°F
Seed depth1"
Moving outdoors
Transplanting
Minimum soil temp60°F
Harden off0 days
Moisture
Watering
Weekly1–1.5 "
NeedsConsistent
Drip, furrow, or deep sprinkler
Root zone
Soil
pH range5.8–7
PreferredWell Drained Fertile Soil With Organic Matter
Corn - Rainbow seeds

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When you shop through this link, SoilStack earns a small commission at no extra cost to you. It's how we keep the site free and the calendar ad-free. Every product on this page was hand-selected based on university extension research.

Corn - Rainbow seeds

Heirloom variety from Seeds Now.

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Resilience

Plant Health

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

Tolerance
Heat: Moderate Cold: Low Drought: Low

Common Issues

Poor Pollination

Cause: Single-row planting or drought at silking.

Prevention: Plant in blocks and irrigate consistently during tasseling and silking.

Corn Earworm

Cause: Moths lay eggs on fresh silks and larvae feed in ears.

Prevention: Harvest promptly and protect silks if pressure is high.

Lodging

Cause: Wind, shallow rooting, or excessive nitrogen can topple stalks.

Prevention: Hill lightly at the base and avoid overfeeding late.

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 intensityModerate feeder
RecipesRoot Drench, Worm Castings Topdress
Timing
Harvest

Harvest when husks are papery brown and ears are fully dry with hard glossy kernels.

Expected yield0.4–1.2 lbs/plant
Storage365 days — Dry thoroughly and store in a cool dry place.
Plant relationships

Companion Planting

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

What you'll need

Growing Supplies

Based on Rainbow Corn'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.

university University of Minnesota Extensionseed_catalog Park Seed rainbow corn listinginference GDD estimate from long-season ornamental/flint corn production
Internal links

Rainbow Corn Planting Dates by Zone

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