Two kinds of corn tasseling together spoil each other's kernels
Two kinds of corn tasseling together spoil each other's kernels. Sweet corn pollinated by popcorn, field or ornamental corn goes starchy, and supersweet pollinated by any other corn loses its sugar. Keep different corn types 250 feet apart or 14 days apart in tasseling.
Promising If you skip this, you lose real yield. The planner warns you.
How it works
Corn is wind-pollinated and the pollen parent sets the kernel's endosperm (xenia), so a sweet-corn ear fertilized by a starchy type stores starch, and a supersweet ear fertilized by any other type reverts to the toughness of field corn. Standard, sugary-enhanced and synergistic sweet corns need no isolation from each other.
What to do about it
Grow one kind of corn per garden, or separate kinds by at least 250 feet, or stagger sowings so their tasseling is at least 14 days apart; popcorn takes a month longer, so sow it first.
The evidence
Evidence: checked against 7 sources in the research-based literature.
The 7 sources
Sweet corn pollinated by popcorn will be tough and starchy
Isolate ornamental corn from sweet corn and field corn to prevent cross-pollination. Isolation can be achieved by planting the different types of corn at least 250 feet from one another
Supersweets (Sh2) should be isolated from any other type of corn tasseling at the same time to ensure sweetness and tenderness
All sweet corn varieties should be isolated from field corn by 250 feet or 14 days
Isolate from all other sweet corn types. Cross-pollination between Shrunken (sh) and any other types will result in starchy, tough kernels
Because popcorn takes a month or longer than sweet corn to mature, it is best to plant the popcorn first
If sweet corn is planted downwind of popcorn or field corn, kernels will be starchy instead of sweet.
Plants it applies to
How this rule has changed
Every change is dated, newest first. The full record, with each reason, is in the data download.
- Advice on what to do added
- Wording made clearer
- Added to the rules
Cite this page
Milpa Gardens. "Two kinds of corn tasseling together spoil each other's kernels. Sweet corn pollinated by popcorn, field or ornamental corn goes starchy, and supersweet pollinated by any other corn loses its sugar. Keep different corn types 250 feet apart or 14 days apart in tasseling." Evidence grade: Promising. https://milpa.garden/rules/two-kinds-corn-tasseling-together-spoil-each/
A garden planner built on graded evidence. Every claim states its evidence grade and links its sources on the page. Cite it with the grade, and add the date you read it.
How we grade evidence
- Well established
- The rule names its mechanism and is settled, by sources a person has read and checked or by plain arithmetic and geometry.
- Promising
- The mechanism is named and the literature backs it. A few questions are still open.
- A good hunch
- Plausible by its mechanism, but field studies are thin, so treat it as a lean.
- Contested
- The evidence points both ways, or no study has tested it, so the planner does not enforce it.
- Refuted
- The claim did not survive its sources. It is kept so the folklore can be answered.