Cilantro (Coriandrum sativum), also known as coriander or Mexican parsley, is a popular culinary herb that is easy to grow in containers or herb gardens. Like other plants in our vegetable and herb gardens, there are companion plants that seem to help cilantro to flourish, and some plants that may hinder its growth somewhat. The concept of companion planting is based on anecdotal success (i.e., years of gardeners' experiences) rather than scientific research. Many of us may remember our parents or grandparents planting certain plants alongside others (like marigolds planted near tomatoes to help repel pests) and some gardeners continue these practices. There's a bit of folklore associated with this garden practice, as well as a fair amount of garden wisdom from experience, and it's interesting to try these methods out to see if they work.
Good Cilantro Companion Plants
Companion plantings often are recommended for the way that certain plants keep away pests or predators that might do harm. Aphids are a common garden pest and they love to eat cilantro, especially green peach and coriander aphids.
- Chervil is an aromatic culinary herb that helps keep pests away.
- Sweet alyssum in particular attracts lady beetles and green lacewing larvae, both of which will gobble up aphids.
- Coreopsis is also effective for attracting these useful insects.
Cilantro does well near plants that add nitrogen to the soil. Nitrogen converts to nitrates which add nutrients to your cilantro. Nitrogen producing plants include beans, peas, alfalfa, clover, and lupines:
- Beans such as string beans, pole beans, runner beans and wax beans can all be planted in early spring
- Peas are also an early garden crop that can help prepare the soil for herb planting as the soil warms
- Lupines produce nitrogen and are a beautiful perennial with colorful flowers loved by butterflies
Another thing to consider in choosing companion plants for cilantro is plants that may provide a bit of cooling shade. Avoid fruit-bearing plants like tomatoes and peppers, as these don't do well alongside the nitrogen-bearing plants you may be planting by your cilantro. One good bet is to plant some tall annual flowers.
- Cosmos are easy to direct sow after danger of frost has passed. They're butterfly magnets, too!
- Zinnias attract many pollinators and the large leaves and flowers provide good shade for late season herbs..
- Sunflowers can work too, but try smaller varieties (like Red Velvet or Lemon Queen or Italian White) so you don't get too much shade preventing ripening of fruits.
Bad Cilantro Companion Plants
There are some plants that should not be planted near cilantro. The rules for this aspect of companion planting have to do partly with different plants' needs: some herbs like more water than others. Cilantro does well with plenty of water, due to its shallow roots, so it should not be planted near herbs that like a well-drained, drier soil culture. This includes herbs from sunny Mediterranean regions such as:
- Lavender, which thrives in a sandy soil with intermittent watering
- Thyme, including the creeping varieties
- Rosemary, which likes a sunny bed with sandy soil
- Fennel tends to not be a good companion plant for most herbs, unfortunately, so keep it far from your cilantro, too. It secretes a substance that can inhibit growth.
Cilantro as a Companion Plant
Because it is what's known as a "cool season" herb, cilantro forms flowers fairly quickly in its growth cycle. This is known as "bolting" and it's good to let plants do this because the flowers formed (on your lettuces for example) make great pollinator food, and attract other beneficial insects. This makes cilantro a great companion to other plants in your herb or vegetable garden.
- Cilantro discourages potato beetles
- Planting cilantro, or making a tea from cilantro and spraying it onto plants, helps get rid of spider mites
- Cilantro attracts hoverflies, the larvae of which devour aphids
To ensure a constant supply of cilantro, sow some seeds every couple of weeks, so that once it flowers or "bolts" a fresh crop won't be far behind. Cilantro also attracts beneficial insects with its unique and pungent fragrance.
Resources for Companion Planting
There are plenty of books on companion planting. One good comprehensive one is The Complete Guide to Companion Planting by Dale Mayer. This book explains the basics of crop rotation to make the most of your garden soil,in addition to providing detailed guidelines for companion planting. If you're an avid flower gardener, or someone who wants to learn more about it, try Vegetables Love Flowers: Companion Planting for Beauty and Bounty by Lisa Mason Ziegler. The author is an organic gardener who has sold both vegetables and cut flowers at farmers' markets, and her book details the ins and outs of growing vegetables and flowers side by side.