Frequently Asked Questions
Everything you need to know about companion planting
Getting Started with Companion Planting
What is companion planting and how do I get started with it as a beginner?
Companion planting is the practice of growing specific plants together to improve each other's growth, health, and productivity. Beginner gardeners can start by using our pre-designed companion plots like the Salad Garden or Herb Corner, which group proven plant companions together. Simply follow the spacing recommendations and plant the suggested plants in the same bed or container.
How do I use the Rootmates garden planner to design my own companion planting layout?
The garden planner tool lets you interactively design a 5×5 grid garden. Select plants from our database, place them on the grid, and the tool shows you which companions work well together. You can save your design by printing it or taking a screenshot. The planner also highlights compatible and incompatible plant combinations in real-time.
What are the main benefits of companion planting in home gardens?
Companion planting offers multiple benefits: natural pest control (some plants repel harmful insects), improved soil nutrition (nitrogen-fixing plants enrich soil for heavy feeders), better pollination (flowering plants attract bees), reduced competition for water and nutrients (plants with different root depths), and enhanced flavor and growth (certain combinations improve taste and vigor). These benefits reduce the need for synthetic pesticides and fertilizers.
How many plants should I include in a companion planting group or guild?
Most effective companion planting combinations include 3-5 plants. Our curated plots follow this principle. Small groups allow you to manage spacing easily and ensure each plant gets adequate light, water, and soil nutrients. Larger gardens can use multiple companion groups with 3-4 feet of space between each group.
Specific Plant Combinations
What are the best companion plants to grow with tomatoes?
The best companions for tomatoes are basil (repels hornworms and improves flavor), marigolds (deter nematodes and soil pests), and carrots (different root depths prevent competition). Our Tomato Guild plot combines these plants in an optimized layout. Avoid planting fennel, leeks, or brassicas near tomatoes.
Which herbs grow well together in a Mediterranean herb garden?
Mediterranean herbs like basil, oregano, thyme, rosemary, and sage thrive when planted together. They prefer similar conditions: full sun, well-draining soil, and moderate water. Our Mediterranean Kitchen plot shows the ideal spacing and arrangement for these culinary herbs that work perfectly together in cooking.
Can I plant lettuce and carrots together in a small garden space?
Yes! Lettuce and carrots are excellent companions that pair well in small spaces. Lettuce grows quickly and shallowly while carrots develop deep roots, so they don't compete. Our Salad Garden combines these with radishes and spinach—all cool-season crops that mature at different times, maximizing your harvest from limited space.
What plants naturally repel pests without chemicals or pesticides?
Many plants act as natural pest deterrents: marigolds repel nematodes and mosquitoes, basil deters hornworms and flies, thyme wards off cabbage moths, nasturtiums trap aphids, and garlic repels many insects. Our Pest Defense Patrol plot combines these plants to create a chemical-free pest management system for your garden.
What can I plant with beans to improve nitrogen in my garden soil?
Beans themselves are nitrogen-fixers—they naturally enrich soil. Pair them with nitrogen-hungry plants like corn, squash (the classic Three Sisters combination), cucumbers, or tomatoes. You can also interplant with comfrey or clover for additional nitrogen accumulation, making beans an excellent choice for sustainable gardening.
Gardening Challenges & Solutions
How do I prevent pests from damaging my vegetable garden using companion planting?
Strategic companion planting creates natural pest barriers. Plant basil near tomatoes to repel hornworms, marigolds near vegetables to deter nematodes, and nasturtiums as "trap crops" that attract aphids away from other plants. The combination of aromatic plants and beneficial insects attracted by flowering companions creates an ecosystem where pests have difficulty establishing.
Why are some plants not growing well together, and how do I fix spacing issues?
Poor growth often results from inadequate spacing (competition for light, water, nutrients) or incompatible root depths. Review our plots for proper spacing guidelines. Rule of thumb: shallow-rooted plants (lettuce, basil) can grow close together; deep-rooted plants (tomatoes, carrots) need 2-3 feet spacing; tall plants (sunflowers, corn) shouldn't shade shorter companions. Our garden planner shows compatible spacing visually.
Which plants should I avoid planting near each other?
Some plant combinations reduce growth and productivity: avoid fennel with most vegetables (allelopathic properties), sunflowers near hazelnuts (nutrient competition), brassicas near tomatoes (different pest pressures), and leeks near beans (competition). Generally, observe nature's spacing—don't crowd plants, match root depths, and ensure adequate sunlight for shade-sensitive species.
How do I grow a productive shade garden with companion plants?
Shade gardens require shade-tolerant plants like ferns, hostas, hellebores, lemon balm, and peonies. Our Shade Sanctuary plot demonstrates how to create a lush, productive shade garden. These plants actually prefer dappled shade, suffer in full sun, and create beautiful woodland aesthetics while minimizing pest and disease pressure common in sun-exposed gardens.
Planning & Timing
When should I plant companion planting gardens—spring, summer, or fall?
Timing depends on your plants' seasons. Spring gardens work best for warm-season crops (tomatoes, peppers, squash). Fall gardens suit cool-season crops (lettuce, kale, root vegetables). Our plots indicate seasonal timing: Three Sisters is summer, Salad Garden is spring/fall, and Herb Corner works year-round. Check your USDA hardiness zone for specific dates.
How do I plan a companion planting layout for my specific garden size and climate?
Start by identifying your zone, sunlight (6+ hours for most vegetables), and space. Use our curated plots as templates, adjusting spacing for your garden size. The garden planner lets you experiment with layouts at any scale. Consider succession planting—replacing early-harvest crops with others throughout the season—to maximize productivity from limited space year-round.
What's the best way to rotate crops in a companion planting system?
Crop rotation prevents soil depletion and pest buildup. Follow this simple pattern: Year 1 - heavy feeders (tomatoes, corn, squash), Year 2 - nitrogen fixers (beans, peas), Year 3 - root vegetables (carrots, beets). Companion groupings help rotation—plant your Tomato Guild where beans grew last year. This cycle maintains soil health naturally without synthetic fertilizers.
Using Rootmates
How do I find companion plants for a specific vegetable on Rootmates?
Use the search bar to find any plant, then view its detail page showing ideal companions. You can also browse our companion plots to see curated combinations featuring that plant. The garden planner provides real-time feedback—if you select a plant, it highlights compatible and incompatible neighbors.
Can I print or export my garden plan from the Rootmates planner?
Yes! The garden planner has a print button that formats your design perfectly for printing. Print to PDF, take screenshots, or simply print directly from your browser. The printout shows the 5×5 grid with plant emojis, names, companion hints, and planning tips—everything you need to reference while planting in your garden.
Where can I buy seeds for the plants Rootmates recommends?
Each plant page includes "Find Seeds" links to Amazon. All our plots also feature "Get All Seeds" buttons that generate curated searches for complete plant sets. We're Amazon Associates, so your purchases support Rootmates while you shop—no extra cost to you.
Does Rootmates work on mobile phones and tablets?
Absolutely! Rootmates is fully optimized for mobile devices. The garden planner, plant search, and companion plots all work smoothly on smartphones and tablets. You can research plants, design gardens, and check companion compatibility while shopping at the nursery or working in your garden.
Data & Research
How does Rootmates compile its companion planting data and research?
Our data comes from public domain sources including USDA publications, university extension offices, and established horticultural research institutions. We prioritize peer-reviewed scientific evidence over garden folklore. Learn more on our About page.
Is companion planting scientifically proven to work?
Yes! Companion planting has extensive scientific support. USDA studies confirm pest-repelling properties of plants like marigolds. University research documents nitrogen fixation in legumes. Multiple studies validate the Three Sisters (corn, beans, squash) synergy. While some folklore lacks evidence, our curated combinations are based on peer-reviewed research and practical gardening success.
Can I suggest new plant combinations or companion relationships to Rootmates?
We're always interested in documented companion planting combinations backed by research or extensive gardening experience. Please share through our contact page with scientific citations or university extension references.
Ready to start your companion planting journey? Browse our curated garden plots, use the interactive garden planner, or search for specific plants to discover the perfect companions for your garden!