My vegetable garden is far from neat. I closely inter-plant different types of plants and steer clear of neat rows of single varieties. I’m a fan of companion planting and grow plants together that will assist each other in some way. My latest attempt at companion planting has been growing corn, beans and squash together – a trio known as the ‘Three Sisters’.
A Three Sisters garden thriving at Purple Pear Farm. Photo Mark Brown. (My Three Sisters are still only teeny seedlings)
The Three Sisters is a traditional Native American mixed-cropping method that has been practiced for centuries. The corn provides a structure for the beans to climb. The beans support the corn and increase the availability of nitrogen, and the squash shades the ground – deterring weeds and maintaining soil moisture.
Interestingly, the Three Sisters also complement each other nutritionally. Corn provides carbohydrates, the dried beans are rich in protein, and the squash provides vitamins.
Success with a Three Sisters garden requires careful attention to timing, varieties and spacing – otherwise you may end up with a snarl of vines overwhelming your corn that is impossible to harvest from.
Unfortunately, I learnt of the importance of timing only after I planted all three sisters at once. It’s wise to give the corn a little head start, planting it first. Add plenty of compost or aged manure, as corn is a heavy feeder and the nitrogen from the beans will not be available until the following crop. As corn is wind pollinated it needs to be planted in a block rather than narrow rows to ensure adequate pollination. Once the corn is around 15 cm tall, interplant with the beans and squash.
For the bean sister, select climbing or pole beans rather than bush or dwarf beans. Purple or yellow beans are easier to spot in among the corn. Another option is to use a shelling bean that can be left to dry on the plant. I planted borlotti beans, which I’ll be able to harvest fresh, and also leave to dry on the plant once I tire of trying to harvest from amongst the corn.
For the squash sister options include squash, pumpkin or zucchini. Apparently, a squash or pumpkin variety with trailing vines rather than a compact bush is best, but I went with zucchini – making sure to plant it on the edges so that I can reach it for easy harvesting.
I’m looking forward to seeing how my Three Sisters get along. I’m assuming my first attempt is going to be less than ideal, but I’m looking forward to learning from this first attempt and improving on it next year.
Originally published in my Newcastle Herald column 'Less is More' 5th October 2013.