Planting Timeline
Showing dates for Painted Mountain in USDA Zone 7
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Painted Mountain · Zones 3–9
Growing Details
Zone-by-Zone Planting Calendar
| Zone | Indoor Start | Transplant | Direct Sow | Harvest |
|---|---|---|---|---|
| Zone 3 | April – May | May – June | May – June | August – September |
| Zone 4 | April – May | May – June | May – July | August – October |
| Zone 5 | April – May | April – June | April – July | July – October |
| Zone 6 | March – May | April – June | April – July | July – October |
| Zone 7 | March – May | March – June | April – July | June – October |
| Zone 8 | February – May | March – June | March – August | June – November |
| Zone 9 | January – May | February – June | February – August | May – November |
Complete Growing Guide
Start by choosing a sunny location with well-draining soil, as Painted Mountain corn thrives in full sun and tolerates poor soils better than sweet corn varieties. Work the soil to a depth of 6-8 inches and add a 2-inch layer of compost if available, though this hardy variety will perform well even in marginal conditions.
For direct sowing, wait until soil temperature reaches 50°F (most corn needs 60°F, but Painted Mountain is more cold-tolerant). Plant seeds 1-2 inches deep and 4-6 inches apart in rows spaced 30 inches apart. In zones 3-5, you can start seeds indoors 2-3 weeks before the last frost date to extend your growing season. Use biodegradable pots since corn roots don't like disturbance during transplanting.
When transplanting, handle seedlings gently and plant them at the same depth they were growing in their containers. Water thoroughly after transplanting and provide wind protection for the first week, as young corn plants are susceptible to wind damage.
Fertilize with a balanced 10-10-10 fertilizer at planting, then side-dress with nitrogen when plants reach knee-high (about 18 inches). Painted Mountain is less nitrogen-hungry than sweet corn, so don't over-fertilize or you'll get lush foliage with poor ear development.
Unlike sweet corn, Painted Mountain rarely requires staking due to its shorter stature and sturdy stalks. However, if you're in a windy location above 5,000 feet elevation, consider planting in blocks rather than single rows for mutual wind protection.
Avoid the common mistake of harvesting too early – unlike sweet corn, flour corn needs to dry on the stalk. Also, don't plant too close to sweet corn varieties if you want to save seeds, as cross-pollination will affect kernel quality. In northern climates, plant as early as soil conditions allow since this variety's cold tolerance is its greatest advantage.
Harvesting
Harvest Painted Mountain corn when the husks turn brown and papery, and kernels are hard and fully colored – typically 90-100 days from planting. Test kernel maturity by pressing your thumbnail into a kernel; it should dent slightly but feel firm and dry, not soft or milky like sweet corn.
The colorful kernels will display their full rainbow of reds, blues, yellows, and purples when ready. Ears should feel heavy and full, with kernels that don't easily dent when pressed. Harvest in late morning after dew has dried but before afternoon heat builds up.
Twist and pull ears downward with a sharp motion to remove them from the stalk. Each plant typically produces 2-3 ears. If frost threatens before ears are fully mature, harvest them anyway – Painted Mountain's cold tolerance means light frost actually helps the drying process. Leave husks on during initial drying to protect kernels from moisture and pests.
Storage & Preservation
After harvest, leave husks on and hang ears in a well-ventilated, dry location for 4-6 weeks until kernels are completely dry (15-20% moisture content). Test by removing a few kernels – they should be hard and difficult to dent with your fingernail.
Once fully dried, remove husks and store whole ears in breathable containers like mesh bags or cardboard boxes in a cool, dry place. Properly dried ears will keep for 2-3 years. For longer storage, remove kernels from cobs and freeze for 48 hours to kill any insect eggs, then store in airtight containers.
Grind kernels into flour using a grain mill or high-powered blender as needed – whole kernels store better than flour. For decorative use, spray dried ears with clear acrylic sealer to preserve colors and prevent insect damage.
History & Origin
Painted Mountain corn was developed by Dave Christensen in Montana during the 1980s and 1990s through careful selection and breeding of various Native American flour corn varieties. Christensen, working at elevations above 4,300 feet with short growing seasons, specifically bred this variety to mature quickly while tolerating cold temperatures that would kill other corn varieties.
The variety incorporates genetics from Mandan, Hidatsa, and other Plains Indian corns, as well as some South American high-altitude varieties. Christensen's goal was creating a flour corn that could reliably mature in areas with growing seasons as short as 90 days and survive light frosts.
Released commercially in the late 1990s, Painted Mountain quickly gained popularity among homesteaders, organic farmers, and gardeners in northern climates. Its development represents a modern approach to traditional plant breeding, combining indigenous genetics with systematic selection for extreme climate adaptation. Today, it's considered one of the most cold-tolerant flour corns available to home gardeners.
Advantages
- +Exceptional cold tolerance – survives light frosts that kill other corn varieties
- +Extremely short maturity period of just 90 days makes it viable in zone 3 climates
- +Thrives in poor soils where sweet corn would fail
- +Stunning ornamental value with rainbow-colored kernels perfect for fall decorations
- +Excellent disease resistance with minimal pest pressure compared to sweet corn
- +Produces nutritious flour with superior protein content compared to modern dent corn
- +Compact plants rarely require staking even in windy locations
Considerations
- -Not suitable for fresh eating like sweet corn – kernels are hard and starchy
- -Requires grain mill or high-powered blender to process into usable flour
- -Lower yields per plant compared to modern dent corn varieties
- -Seeds can be expensive and harder to find than common corn varieties
- -Cross-pollinates with other corn, affecting seed saving if multiple varieties are grown nearby
Companion Plants
Plant Together
Sunflowers
Attracts beneficial insects and pollinators, provides windbreak protection
Marigolds
Repels corn earworms, aphids, and other harmful insects
Nasturtiums
Acts as trap crop for aphids and cucumber beetles, deters corn borers
Dill
Attracts beneficial insects like parasitic wasps that control corn pests
Borage
Improves soil health, attracts pollinators, may deter hornworms
Radishes
Quick-growing ground cover, helps break up compacted soil
Black Beans
Fixes nitrogen in soil for corn, part of traditional Three Sisters planting
Winter Squash
Ground cover suppresses weeds, retains soil moisture, completes Three Sisters guild
Keep Apart
Black Walnut
Releases juglone toxin that severely stunts corn growth and development
Tomatoes
Both are heavy nitrogen feeders creating competition, attract similar pests like hornworms
Fennel
Releases allelopathic compounds that inhibit corn germination and growth
Pests & Disease Resistance
Resistance
Excellent cold tolerance and good disease resistance overall
Common Pests
Corn earworm, birds, raccoons, squirrels
Diseases
Generally disease resistant, occasional rust in humid conditions