Support Species
Learn how one plant can help another grow to its fullest potential with this primer on the art of strategic co-planting.
Support species are an integral part of our farm here at the Johnny Appleseed Organic Village. So much so, that our farm manager, Joshua Andersen, often refers to them as the most “crucial” aspect of our food growing systems.
While crunchy vegetables and succulent fruits are always the end goal, harvesting an abundant yield while naturally enriching the soil requires – well, some support!
In most natural ecosystems, you wouldn’t find any one plant without a consortium of at least two or more different species. This is because together, they work and function at a higher capacity than they ever could on their own.
Since we grow food in a way that mimics nature, incorporating specific support species provides “crucial” functions to support a healthy growing ecosystem for our crops. Some of these benefits include:
Biomass accumulation - Support species provide biomass for soil production when ‘chopped and dropped’ onto the ground surrounding a farm’s main productive crops. They are then allowed to decompose, enriching the soil.
Nitrogen fixation - We often use legumes as support species because their roots exude simple sugars and other compounds that attract rhizobium bacteria. These bacteria have a symbiotic relationship with the plant in which they harness atmospheric nitrogen (that otherwise wouldn’t be available to the plant) and make it accessible to the plant in exchange for carbohydrates.
Living nursery - Many support species act as a living nursery, providing shade for young seedlings when they are freshly transplanted in the field. At this delicate stage, direct sunlight could cause them to wither, but carefully-selected support species help protect them from the hot Georgia sun.
Hydration - Support species can help maintain soil and plant hydration by decreasing evapotranspiration — the movement of water from the surface of the earth into the atmosphere from the soil as well as from the surface of plants.
Cover cropping - Many small herbaceous species can be used for rotational cover cropping, as they reinvigorate soil that’s been diminished by the nutrient demands of the last crop.
By way of example, here are some of the support species we grow at the Johnny Appleseed Organic Village, as well as their associated benefits:
Sesbania herbacea (aka Coffeeweed)
• Biomass
• A short-term nitrogen-fixing legume
• Hydration
• Cover crop
Crotalaria juncea (aka Sunn hemp)
• Biomass
• A short-term nitrogen-fixing legume
• Hydration
• Cover crop
Vigna unguiculate (aka cowpea)
• Biomass
• A short-term nitrogen-fixing legume
• Hydration
• Cover crop
Cajanus cajun (aka pigeon pea)
• Biomass
• A short-term nitrogen-fixing legume
• Nursery tree
• Hydration
Sorghum x drummondii (aka Sudan grass)
• Excellent biomass accumulator
• Hydration
By incorporating support species into your farm’s regimen, you can be sure to reap many restorative benefits when it comes to the health of your soil and crops. Many support species can even be sourced on disturbed sites, such as near railroad tracks, roads and recently deforested areas near your farm.
The next time you’re out, observe what plant species you notice growing and take that as an indicator of what may perform well on your farm. What works for us here in south Georgia may not be what works for you — but the realm of support species is vast, and it is well worth the effort of exploring and implementing them into your growing operations.
Have you used support species to improve your growing operations? Have questions we didn’t address in this post? We’d love to continue the conversation.
