I grew my '3 sisters' bed as per carol klein. this was sweetcorn, climbing beans, and butternut squashes underneath. My whole plot was a write-off this year (after 15 years, my first truly disastrous one), with the exception of this bed. It was well-mulched with rotted horse manure, water-retaining gel (ho ho - i must have mixed this in on the one day we didn't have rain) and thoroughly weeded. At the end of the bed were sweet peas and sunflowers, to attract good germinating buggie beasties. the sweetcorn was fantastic; big cobs, well-pollinated, delicious. The beans were a bit rampant, and needed extra canes (they were purple climbing beans- very pretty, and easier to find when picking!). The squashes did very well, too - much more so than in previous years, and they were HUGE and delicious. Good job they keep well! Also they did a fantastic job of smothering any weeds that tried to come up. I will definitely do this planting scheme again, and recommend it!