Three Sisters: Corn, Beans & Squash

The traditional trio: corn carries the beans, beans feed the soil, squash shades out weeds.

Bed 200 × 200 cmMedium

Season timeline

Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
  • Sow the corn
  • Sow beans and squash
  • Harvest the corn
  • Pick the beans
  • Harvest the squash
  • Clear the bed

Bed layout

Maize30 cmMaize30 cmMaize30 cmMaize30 cmBean10 cmBean10 cmBitter bottle gourd90 cmBitter bottle gourd90 cm

Crops in this bed

Step by step

  1. Sow the cornMay

    In mid-May, after the last frost, sow corn in blocks rather than single rows so it pollinates well.

  2. Sow beans and squashJun

    When the corn stands about 20 cm tall, sow beans at each stalk and squash between the mounds.

  3. Harvest the cornAug–Sep

    Pick the cobs when the silks turn brown and the kernels squirt milky juice.

  4. Pick the beansAug–Oct

    Pick pods every few days to keep the plants producing right up to the frosts.

  5. Harvest the squashSep–Oct

    Cut the fruits with a piece of stem once the rind hardens, and before the first frost.

  6. Clear the bedOct–Nov

    Chop the spent stalks and vines for compost; leave the bean roots in the soil, they hold the nitrogen.

Harvest calendar

CropJanFebMarAprMayJunJulAugSepOctNovDec
Maize
Maize: Aug
Maize: Sep
Bean
Bean: Aug
Bean: Sep
Bean: Oct
Bitter bottle gourd
Bitter bottle gourd: Sep
Bitter bottle gourd: Oct

The bed over the season

Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
  • Maize · Sowing
  • Maize · Growing
  • Maize · Harvest
  • Bean · Sowing
  • Bean · Growing
  • Bean · Harvest
  • Bitter bottle gourd · Sowing
  • Bitter bottle gourd · Growing
  • Bitter bottle gourd · Harvest

Why this combination works

The Three Sisters is a centuries-old Native American planting method. Corn grows first and becomes a living trellis for the climbing beans, which in turn fix nitrogen from the air and feed all three crops. Squash sprawls between the stalks, and its broad leaves work as a living mulch that shades out weeds and keeps the soil moist. Together the trio uses light, soil and space more completely than any of them alone.

Tips

Wait until the soil is properly warm; corn sown into cold ground sulks and beans rot. Sow the beans only once the corn stands about 20 cm tall, or they overwhelm the young stalks. Choose a pole bean, not a bush type. Water at the base of the mounds; the squash canopy hides dry soil.