nope, I don't have that much space. wish i had a few acres to grow on.
Thanks WTF, this is a plan for planting in a smaller space.
I'm going to try to talk my wife into trying this in one corner of our garden.
Note: A 10 x 10 foot square of space for your Three Sisters garden is the minimum area needed to ensure good corn pollination. If you have a small garden, you can plant fewer mounds, but be aware that you may not get good full corn ears as a result.
How to plant:
Please refer to the diagrams below and to individual seed packets for additional growing information.
1. Choose a site in full sun (minimum 6-8 hours/day of direct sunlight throughout the growing season). Amend the soil with plenty of compost or aged manure, since corn is a heavy feeder and the nitrogen from your beans will not be available to the corn during the first year. With string, mark off three ten-foot rows, five feet apart.
2. In each row, make your corn/bean mounds. The center of each mound should be 5 feet apart from the center of the next. Each mound should be 18 across with flattened tops. The mounds should be staggered in adjacent rows. See Diagram #1
Note: The Iroquois and others planted the three sisters in raised mounds about 4 inches high, in order to improve drainage and soil warmth; to help conserve water, you can make a small crater at the top of your mounds so the water doesn�t drain off the plants quickly. Raised mounds were not built in dry, sandy areas where soil moisture conservation was a priority, for example in parts of the southwest. There, the three sisters were planted in beds with soil raised around the edges, so that water would collect in the beds (See reference 2 below for more information). In other words, adjust the design of your bed according to your climate and soil type.
3. Plant 4 corn seeds in each mound in a 6 in square. See Diagram #2
4. When the corn is 4 inches tall, its time to plant the beans and squash. First, weed the entire patch. Then plant 4 bean seeds in each corn mound. They should be 3 in apart from the corn plants, completing the square as shown in Diagram #3.
5. Build your squash mounds in each row between each corn/bean mound. Make them the same size as the corn/bean mounds. Plant 3 squash seeds, 4 in. apart in a triangle in the middle of each mound as shown in Diagram #4.
6. When the squash seedlings emerge, thin them to 2 plants per mound. You may have to weed the area several times until the squash take over and shade new weeds.


Link:
http://www.reneesgarden.com/articles/3sisters.html