All together now
Here’s a good idea somebody had thousands of years ago – arrange plants that benefit each other close together. Certain plants benefit nearby plants by being aromatic and stinky, by exchanging underground chemicals and nutrients, or by spreading out big floppy leaves to discourage unwanted invasives.
Plant symbiosis is a name for the ability of plants to benefit each other in one way or another. Sometimes certain juxtapositions are deleterious, and it is important to know the difference. Much of the companion planting data is anecdotal, and only recently have there been scientific studies. Nevertheless, we shall proceed undeterred in passing along advice of all kinds.
Asparagus seems to like having a few parsley plants mixed in; however, parsley is a biennial and develops in its second year into a tall, bushy specimen with a long taproot which would interfere with nearby asparagus crowns. Maybe harvest parsley at the end of the first season.
Parsley also is a happy companion for tomato plants because it attracts hoverflies which eat roving gangs of aphids and feed on hornworm eggs which is a good thing.
Tomato plants also benefit from the presence of marigolds and basil which repel whiteflies. Marigolds roots exude an underground chemical which hinders the growth of certain nematodes. According to folks who spend lots of time looking through microscopes at soil, some nematodes prey on tiny garden pests and that’s a good thing, but some are pests which attack your favorite garden plants such as tomatoes. Marigolds (to the rescue) deter the gangster nematodes.
Basil pairs well with tomatoes in recipes and in gardens. Gardeners throughout history claim the aroma of basil repels white flies and hornworms but its nearby presence seems to boost tomato production. Won’t hurt to try. Interplant basil among tomatoes and see if the proximity makes a difference and add an assortment of marigolds for color and magical protection.
Also, regarding tomatoes, and this is important, a European observer claimed tomatoes protected gooseberries from insect pests. Maybe you already knew that. I had no idea.
Radishes are a good companion for peas, and beside cucumber plants they keep cucumber beetles away. Supposedly lettuce nearby makes radishes tender, but chervil makes radishes hotter. Have you ever grown chervil? Do you ever wonder who noticed these things in the first place, and was a years’-long study done by graduate students to analyze the effect of chervil on radishes? Just like speed limits, these are suggestions.
Lettuce and beets get along. They play cards with snow peas on Tuesday nights. In fact, behind snow peas on a trellis there’s a shady area for one more lettuce crop late spring before the weather gets too warm and peas fade. Plant beets and radishes on the front side, and everything will be finished just in time to plant your second cucumber crop on the trellis.
Experiments in mid-20th century demonstrated that bush beans produced better when planted in strawberry beds compared to bush beans left by themselves with no one to talk to. Strawberries also experienced a boost, so there is something else to try. Strawberries also like borage, and so do I. As a side note, pine straw is the recommended mulch for strawberries.
Allelopathy is the name for plant companionships, just so you know, and an example is while a carrot is shooting downward, it exudes a chemical which has a positive effect on nearby peas. It’s like when you smile, I feel better or something similar but more chemical. Carrots take most of a month to germinate, so plant radishes between the carrots rows to mark the spot, and radishes will be mature and be gone by the time carrots sprout, plus radishes will have loosened the soil for your prize-winning carrots.
And if carrot flies are your nightmare, plant salsify and it will scare them away. Now you know where to plant your salsify.
To put this in perspective, one renowned source claimed, “When charlock seeds are present in the soil, they are awakened by the presence of oat seed.” Not only that, beets are harmed by charlock! You have been warned.