Customer Service Hours
Mon-Fri 8-4 MST
Features
Family
Poaceae
Native
Americas
Life Cycle
Annual
Plant Height
Tall (Greater than 24")
Further Information
Growing Conditions
Frost Sensitive
Plant Resistance
Goss's Wilt Resistant
About ["Flint Corn"]
Zea mays (hybrid)
7"–8" ears with yellow kernels that dry to a rich orange color. It has pearl shaped kernels and about 80% of them will have a round, mushroom shape when popped. Tolerant to Grass's wilt disease.
Planting ["Flint Corn"]
Plant Spacing
A group of 2 seeds every 12"
Light Required
Full sun
Plant Height
Tall (Greater than 24")
Planting Depth
1"–1 ½"
Coverage & Planting Details
| Coverage | This packet sows up to 18 feet. |
|---|---|
| Row Spacing | 24"–36" |
| Seed Depth | 1"–1 ½" |
| Seed Spacing | A group of 2 seeds every 12" |
| Thinning | When 4" tall, thin to 1 every 12" |
| Germination | 5–10 days |
| Start Indoors | Not recommended; roots sensitive to transplanting. Best results occur when seedlings are transplanted less than 2 weeks old. |
| Direct Sow | RECOMMENDED. 1 to 2 weeks after your average last frost date, and when soil temperature is at least 60°F, ideally 65°–90°F |
| Growing & Harvesting | Let the ears dry on the stalks. The kernels are ready for harvest when they are hard and you can no longer leave a mark on them with your fingernail. Before the first fall frost, give each ear a twist until it breaks off. Peel back the husks, then hang the ears in a cool, dark, dry place for 4 to 6 weeks to cure. This is important to prevent mold and to dry to the optimal moisture percentage for popping. (In a perfect popcorn world, that would be 13½–14%.) After that, the cobs are ready for popping or storing. To strip off cured kernels, twist the cobs back and forth to loosen them (gloves are recommended). |
Find Your Frost Date & Grow Zone
Average First Frost Date
October 19
Average Last Frost Date
May 19
Your Hardiness Zone is
5b
Send Your Recommendation
Total 5 star reviews: 7 Total 4 star reviews: 0 Total 3 star reviews: 0 Total 2 star reviews: 0 Total 1 star reviews: 0
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Rating
Which best describes you as a gardener?
7 reviews
- Lisa P.Verified BuyerRated 5 out of 5 stars11/15/25Big ears!
I love this variety of popcorn. It has become a yearly must in my garden! The ears are large and pollinate easily, producing full ears.
Which best describes you as a gardener? IntermediateBIBotanical Interests11/24/25Hey Lisa,
Thank you so much for sharing your photo of our Robust Pop R400MR Popcorn Corn Seeds! Amazing!!! We love hearing that this variety has earned a permanent spot in your yearly garden rotation! Love homegrown popcorn! Thanks for sharing your growing success with us. Keep on growing 🌻️
- AlexandraVerified BuyerRated 5 out of 5 stars9/28/25My first corn to reach maturity!
Never had luck growing any kind of corn, it’s always been infested with caterpillars/earwigs, but I decided to take one more stab at it this year. I hadn’t done a popping corn, so it seemed like a good experiment. The seeds germinated well, and thrived in my three sisters garden. I planted about 15 stalks and wound up with one good ear per stalk. Very excited to try popping it next!
Which best describes you as a gardener? IntermediateBIBotanical Interests9/29/25Hey Alexandra,
What a fantastic review! We're absolutely thrilled to hear that your Robust Pop R400MR Popcorn Corn Seeds finally gave you that corn growing breakthrough you've been hoping for - there's nothing quite like that feeling of success after previous struggles!
Your experience with pest issues in the past is so relatable! Caterpillars and earwigs can be such persistent problems with corn, and it's incredibly frustrating when you put in all that work only to have pests take over. The fact that your Robust Pop corn powered through and delivered such great results really shows what a resilient variety this is.
We love that you chose to experiment with popcorn corn for this attempt - what a perfect way to try something new while tackling that corn growing challenge! And your three sisters garden setup sounds absolutely perfect for corn. That traditional companion planting method creates such a supportive growing environment, and it's clear your Robust Pop corn thrived in that setup.
Getting one good ear per stalk from 15 plants is exactly the kind of solid, reliable production that makes Robust Pop R400MR such a winner! That's a fantastic harvest, especially for your first successful corn crop. There's something so satisfying about seeing those ears develop and knowing you're going to have homegrown popcorn to enjoy.
We're so excited for you to experience that first batch of homegrown popped corn - there's truly nothing like the flavor and satisfaction of popping corn you grew yourself! Your success story will be so encouraging for other gardeners who've struggled with corn in the past but want to give it another try.
Keep on growing 🌻️
- Karen S.Verified BuyerRated 5 out of 5 stars6/12/235 Stars
Planted the seeds a week ago and they are already several inches tall!!
- Edward M.Rated 5 out of 5 stars6/8/235 Stars
Germinates well. Bought it thinking that, hey, maybe I can grow some popcorn myself. And, I did, 3 years ago. Ever since then, I have been saving a little bit of the seed for the future year, and it germinates+grows well.
- AmberVerified BuyerRated 5 out of 5 stars5/9/225 Stars
We have grown this popcorn for three years using the three sisters method. We get one to two ears per stalk. We love the big golden stalks hanging to dry in the house during the gray, rainy days of late fall in Ohio. The kernels pop up big and round and taste so fantastic. I can't grow enough! It makes a lovely Christmas gift.