Squash guild
A Three Sisters variant centred on the squash: maize and climbing bean in the middle, an edging of nectar-rich flowers, nasturtiums and French marigolds.
The guild's plates
Introduction
The squash guild takes the logic of the Three Sisters and centres it on the plant that takes up the most room: the squash (or pumpkin). Around it, a block of maize stakes the climbing bean, which fixes nitrogen; along the edge, borage and phacelia call in bees and bumblebees, and nasturtium and French marigold are added. The whole thing fits in 6 to 10 m², a garden square or a mound.
Background
Each companion has a role. The squash covers the soil with its large leaves, keeps moisture in and smothers weeds: its historical role in the Three Sisters, analysed by the agronomist Jane Mt. Pleasant (Histories of Maize, 2006). The maize provides the vertical structure; the climbing bean fixes nitrogen from the air thanks to the Rhizobium bacteria in its roots (FAO), and part of that nitrogen returns to the soil with its residues. Borage and phacelia flower for a long time and are heavily visited by bees and bumblebees: squash flowers, male and female separate on the same plant, need insects to be fertilised (McGregor, Insect Pollination of Cultivated Crop Plants, USDA, 1976). Nasturtium attracts aphids (a trap plant to watch), French marigold only suppresses some nematodes as a dense planting before the crop: see the entries of these two plants for the limits of these effects.
Who this guide is for
Beginner gardeners who want to succeed with a first association, or gardeners who find the classic Three Sisters too crowded for their trailing squashes.
What to understand before starting
- A spot in full sun, a very rich, deep soil (mature compost or well-rotted manure added in autumn or spring) and water close at hand: squash drinks a lot.
- Seeds or plants: squash or pumpkin (2 to 3 plants), maize (a dozen seeds for a block), climbing bean, borage, phacelia, nasturtium, French marigold.
- A frost-free spring: squash, bean and maize are sown after the last frosts, once the soil has warmed (mid-May in most regions, later in the mountains).
Detailed steps
- Step 2
Sow the maize in a block
Sow the maize in a square (3 rows of 4, at 30-40 cm) rather than in a line: it is wind-pollinated, and a tight block guarantees well-filled cobs. Give it a two- to three-week head start.
- Step 6
Place nasturtium and French marigolds
A few nasturtiums along the edge (they attract aphids: watch them and cut them back if they get overloaded) and French marigolds in a group: take these companions as a helping hand, not a guarantee.
Concrete examples
- 3 × 3 m square: a block of 12 maize in the centre, climbing beans at their feet, 2 squashes on the south side, a border of borage and phacelia to the north, nasturtiums and French marigolds in the corners.
- Permaculture mound: maize and beans on the crest, squash on the sunny flank, nectar-rich flowers on the shaded flank.
- Small garden: a single pumpkin, 4 maize in a square, 4 beans, one borage and three nasturtiums, the rest of the square mulched.
Common mistakes to avoid
- Sowing bean and maize on the same day: the bean, faster, smothers the young maize.
- Planting the squash in the middle of the maize block: it lacks light and climbs over the cobs. Place it on the edge.
- Forgetting water: under the large leaves, the squash transpires a lot. A thick mulch and regular watering at the base are essential: bouts of drought favour powdery mildew.
- Letting the nasturtiums become an aphid hotbed: a trap plant has to be managed, cut back the overloaded stems.
Tips & best practices
- Choose a tall-stemmed maize (grain or popcorn varieties) rather than a dwarf sweetcorn, too short to stake.
- Hand-pollinate if insects are scarce: in the morning, rub a male flower (on a long stalk) against the pistil of a female flower (swelling at the base).
- Pick the beans regularly to prolong their production and let the squash ripen until the first cool spells.
- At the end of the season, cut the beans at the collar and leave the roots in the ground: the nitrogen of the nodules stays in the soil.
Frequently asked questions
- Why the squash rather than the classic Three Sisters?
- It is the same family of ideas: here the squash is given the room it demands and a border of flowers is added for its pollination, often the weak point of an isolated square.
- Can I replace the maize with a wooden stake?
- Yes. The bean will climb a tepee of poles, but you lose the cobs. Maize remains preferable if space allows.
- Do the companions really protect the squash from diseases?
- Not directly. Late-summer powdery mildew is driven mainly by humid air, cool nights and dry roots (it needs no water on the leaf to germinate): regular watering at the base, airing and removing badly affected leaves count for more than any companion.
Key takeaways
- Squash on the edge, maize in a block, bean at the foot of the maize, nectar-rich flowers, nasturtium and French marigold along the border.
- Timing makes the success: maize first, bean two to three weeks later, squash at the same time as the bean.
Sources
- Mt. Pleasant, J. (2006). The science behind the Three Sisters mound system: an agronomic assessment of an indigenous agricultural system in the northeast. In Staller, J.E., Tykot, R.H. & Benz, B.F. (dir.), Histories of Maize (p. 529-537). Academic Press.
- McGregor, S.E. (1976). Insect Pollination of Cultivated Crop Plants. Agriculture Handbook 496. Washington : USDA, Agricultural Research Service.
- Mollison, B. (1988). Permaculture: A Designers' Manual. Tyalgum : Tagari Publications.
- Hemenway, T. (2009). Gaia's Garden: A Guide to Home-Scale Permaculture (2e éd.). White River Junction : Chelsea Green.