COMPANION PLANTING: "Alas dear Rue, I love thee not!" declares Basil.

• Rue, planted near roses & raspberries is beneficial.  It also deters Japanese beetles.  But you will rue the day you plant it near Basil!
• Tomatoes and Basil are said to enhance each other's flavor when planted together.  And, we are assured by ATTRA that tomatoes like the Onion Family, Nasturtium, Marigold, Asparagus, Carrot, Parsley and Cucumber.  However, they find the Irish potato, fennel and the Cabbage Family not to their liking!  Potatoes and Tomatoes share the same blights and growing close to each other can help spread it.
• Dill and Carrots are traditionally cast as enemies though no scientific research yet supports this observation by gardeners.
• Beans and Peas do not like to be near onions and garlic.  Ever.  Bush Beans do like cucumbers, strawberries, celery and summer savory. 
• Peppers and Beans are both susceptible to anthracnose. When planted side-by-side, if one gets it the other will easily follow.  This disease ruins fruits by causing dark, soft spots to appear.
• Beets and the Cabbage family (kale, Brussels sprouts, cabbage, collards, etc) like each other and they both like members of the onion family.  They are in agreement that they don't like pole beans!  The cabbage family is even more fussy.  Dill, Strawberries and Tomatoes are on their "Do Not Plant Near Me" list.
• Squash, including Pumpkins, like nasturtiums, corn and marigold.  But they plead with you not to plant them near potatoes!
• Kale is buddy-buddy with beets, celery, beans, strawberries, or tomatoes.
• Lettuce planted near or where Broccoli was planted may be doomed to thrive or even grow.  Research shows it is sensitive to the chemicals in residues left by broccoli which can hinder seed germination and growth.

For more about Companion Planting and who in the plant world helps or hinders who, do a  search for your vegetable or plant + Companion Planting.  We searched asparagus this year and onions and garlic are the last things asparagus wants to see growing next to it!  Of the 9 asparagus roots Rob planted 2 years ago, only 3 spindly plants survived.  Both years had members of the onion family planted alongside these long-lived spring vegetables. May 2022

For more references & info:

• Mother Earth's In-depth Companion Planting Guide 
• a free printable Companion Planting Guide for the Garden
• ATTRA's free download on Companion Planting & Botanical Pesticides: Concepts & Resources 
• Companion Planting Charts on Herbs, Fruit and Vegetables

Rodale's Organic Gardening publication on the subject in the

Do your own experiments and observations.  Last year Joan planted 2 beds of tomatoes.  You would expect the sunny bed to do better than the shadier one, but the opposite was true.  So, what was the difference?  The shadier bed had grown Brussels sprouts previously and although many Companion Guides assert that tomatoes don't like brassicas (especially cauliflower and cabbage) Brussels sprouts appear to be one brassica that has a beneficial effect on tomatoes.  Joan's shadier patch bore more tomatoes than her sunny one and the plants were healthier than those in the other patch. July 19, 2016