Companion Planting and Other Natural Pest Controls

Memorial Day weekend signaled the start to full-blown gardening season in my region.  The tiny seeds I started in cups 8 weeks prior were now hearty seedlings ready to be transplanted, the cold-hardy seeds I started in the garden around the same time are coming up, and the stack of seed packets I set aside for planting once the danger of frost had past were now ready to meet the soil. The next step was to figure out where each one should go. To make those decisions, there are a few things I like to keep in mind. First, I look at the sketches I made in my garden journal indicating where things were planted over the last few seasons. This way, I can be sure that I'm rotating crops and not planting the same crops in the same beds for at least 2 or 3 seasons. Crop rotation results in better harvests by breaking disease cycles and helping the soil maintain a healthy balance of nutrients, organic matter, and microorganisms. Field trials demonstrate that crops planted in the same plot season after season experience a sharp decline in yields and a sharp increase in disease and pest infestation, when compared to crops that are rotated.

seedlings started 8 weeks ago, now ready for transplanting

The second important consideration when deciding where to plant my seeds and seedlings is the practice of companion planting. Certain plants benefit from sharing garden space with other plants either because they attract beneficial insects or repel the not-so-beneficial ones. There are lots of resources online about companion planting, but my favorite source of info on the subject comes from a book called Carrots Love Tomatoes:  Secrets of Companion Planting for Successful Gardening by Louise Riotte. I found this gem of a book in a box of freebies at the end of someone's driveway while out for a run one drizzly morning and it insisted on coming home with me. I dried it out and dove in. 

Here are a few things I learned and applied to this year's garden: The Brassica family of vegetables including broccoli, Brussels sprouts, cabbage, and cauliflower is aided by the Allium family which includes onions, garlic, leeks, and shallots when it comes to keeping away wireworms. Beans and corn are happy together and help prevent beetle infestations. Native Americans knew a lot about companion planting and coined the term "three sisters" referring to corn, beans, and squash and the symbiosis that occurs when they are grown together. Lettuce and spinach enjoy sharing space with radishes, since the radishes keep the leaf miners off the other two. Cucumbers benefit from the company of radishes to deter ground beetles. There are also two flowering plants that I love to add to my garden as a method of companion planting:  marigolds and sweet alyssum. The marigolds help keep hornworms off of the tomatoes and sweet alyssum attracts numerous predatory wasps and other beneficial insects that feed on the insects that would otherwise feed on your plants. Plus, they add a fun pop of color to the garden landscape and the alyssum has a sweet honey aroma that I can't get enough of.

Sweet Alyssum

Marigold

Glass Gem Corn

With crop rotation and companion planting in mind, I made a mental map of where I wanted everything planted, set some speakers up on the porch, cranked up the tunes, and got to work. I prepped most of the beds by adding a few heaping shovels of our compost, churning the soil, and dropping in rows of seeds or seedlings. Some plants, like those in the Brassica family, prefer more alkaline soil, so I skipped the compost on those beds. I direct-seeded rows of Georgia collards and Laxton's Progress #9 shelling peas from High Mowing Organic Seed Company.  I also seeded rows of Rattlesnake pole beans, Sacaton Brown Tepary beans, Glass Gem corn, and Cochiti corn all of which are seeds saved from extinction by a nonprofit organization that works to collect and preserve endangered traditional seeds called Native Seeds Search.  I then transplanted all of my seedlings into beds and finished by mulching around them with straw to serve as both a blanket and weed deterrent.

Sweet Alyssum planted with my Brassicas

tomatoes planted with marigolds

Two final projects in the arena of natural pest control involved making beer traps for slugs and neem oil spray. Slugs are a common pest in my garden, so I made traps by filling a wide-mouth can or dish with beer and burying it at ground level in several of the beds. Slugs love beer, and when they come to drink it, they fall in and drown. The traps have to be refreshed after rain and it's good to periodically dump out the drowned slugs so they don't get smelly. Neem oil spray is a chemical-free way to deter pests and can be made by combining 1 liter of water and 1/2 teaspoon of unscented dish soap, shaking it, then adding a teaspoon of neem oil. Neem oil can be purchased where organic garden supplies are sold or online through Organix South. Only make as much as you will use in one application, as the neem oil breaks down and loses its effectiveness once it is mixed with the other ingredients. Use the spray as a preventative, spraying leaves and soil about once a week. In instances of infestation, make a more concentrated solution and spray it more frequently.

It is important to keep in mind that with crop rotation, companion planting, and other natural pest controls, the goal is not total annihilation, but rather to keep the garden insect population in a healthy balance. Many garden insects are beneficial and using harsh chemicals for pest control kills insects and other organisms regardless of their role in the garden. This adversely affects the balance of the garden

love your pollinators

ecosystem, the health of the garden soil, the health of the pollinators, and health of the environment as a whole. According to a national water quality inventory conducted in 2000, agricultural pollution is the number one source of water quality impairment to rivers and lakes and is the second largest source of impairment to wetlands.  Additionally, it is a major contributor to the contamination of our groundwater. If that doesn't get your attention, then consider the pollinators who especially

need our help now, as their numbers are decreasing dramatically. Without them we lose the ability to grow fruits and vegetables without the tedious and impractical process of hand-pollination. When I consider these issues, it seems worthwhile to use a gentler, more natural approach to dealing with garden pests.

With a sore body and the satisfaction that comes with a hard day of physical work, I sat on the porch swing marveling over the garden with all of its new life and daydreaming about the fruits of my labor.

Garden from the porch