Companion Planting 101: How to Harmonize Plants in Your Greenhouse

Companion Planting 101: How to Harmonize Plants in Your Greenhouse

Looking for new ways to help your greenhouse garden truly flourish?

Welcome to the world of companion planting, an ingenious approach to gardening that brings plants together for mutual support.

This age-old technique boosts your garden's health, optimizes your gardening space, and elevates crop yield—all while keeping chemical use to a minimum.

In this guide, we'll explore the benefits of companion planting, highlight perfect plant pairings, and share essential tips for seamlessly integrating this practice into your greenhouse garden.

Ready to give it a try? Let's dive in.

What is Companion Planting?

Companion planting is the smart gardener’s strategy of placing different plants together to tap into their natural synergies. It's like creating a supportive neighborhood for your plants, where some members keep pests at bay, others invite beneficial insects for pollination, and a few even boost their garden companions' overall growth and flavor. This method not only enriches your garden's ecosystem but also enhances the health and yield of your plants in a natural, sustainable way.

Images from Planta Greenhouses’ customers.

What Are The Benefits of Companion Planting?

Discover just some of the ways companion planting can benefit your garden:

  • Pest Management: Certain plants can be used as natural repellents, reducing the need for pesticides and keeping your garden eco-friendly.
  • Improved Pollination: Flowering companions draw in more pollinators, boosting your garden's fruit and vegetable production.
  • Enhanced Soil Health: Some plants can naturally pump essential nutrients back into the soil, ensuring your garden thrives.
  • Natural Support: Taller plants can shield more delicate ones from harsh sun and offer a climbing frame for beans and peas.
  • Disease Prevention: Spacing out plants susceptible to the same diseases can prevent them from spreading, making your garden a healthier place.
Images from Planta Greenhouses’ customers.

What Plants Like and Dislike Growing Together?

Learn which plants thrive together and which should stay apart.


Good Companions

Bad Companions


  • Basil enhances flavor and repels flies and mosquitoes.
  • Marigolds deter hornworms and attract beneficial pollinators.
  • Garlic acts as a natural pest repellent.
  • Potatoes can share blight (a disease) with tomatoes.
  • Cabbage and broccoli inhibit growth due to nutrient competition.
  • Rosemary depletes essential soil nutrients.


  • Basil repels aphids, spider mites, and flies.
  • Onions deter pests that affect peppers.
  • Spinach benefits from the shade peppers provide.
  • Beans can inhibit pepper growth.
  • Brassicas compete for nutrients.
  • Strawberries attract pests like slugs that are harmful to peppers.


  • Radishes help break up compacted soil.
  • Beets don’t compete for nutrients due to different root depths.
  • Chives and garlic deter aphids.
  • Fennel inhibits the growth of nearby plants.
  • Celery can attract pests common to lettuce.
  • Parsley causes lettuce to bolt prematurely.


  • Chamomile can help reduce fungal diseases.
  • Carrots benefit from how onions help repel carrot flies.
  • Onions deter aphids, helping strawberries grow successfully.
  • Asparagus competes for nutrients with onions.
  • Sage’s differing conditions can be problematic.
  • Legumes can have stunted growth due to onions disrupting beneficial bacteria.


  • Chives repel pests like carrot flies and aphids.
  • Beans and peas improve soil fertility, benefiting carrots.
  • Rosemary and sage deter carrot flies.
  • Dill attracts pests harmful to carrots.
  • Potatoes compete for soil resources.
  • Celery increases the risk of shared pest infestations.


Images from Planta Greenhouses’ customers.

Tips for Companion Planting in a Greenhouse

Maximizing the benefits of companion planting in a greenhouse involves careful planning and consideration of each plant's needs:

  • Space Management: Understand each plant's growth habits and space requirements to maximize greenhouse space.
  • Microclimate Management: Create microclimates to accommodate the diverse needs of different plants, considering factors like shade and humidity.
  • Soil Health: Rotate crops to prevent soil depletion, manage soil-borne diseases, and incorporate plants that enrich the soil.
  • Pest and Disease Monitoring: Regular inspection can catch issues early, even with companion planting's natural pest management.
  • Watering Needs: Group plants with similar needs to ensure each plant receives the right amount of water.
Images from Planta Greenhouses’ customers.

Unleash the Power of Your Garden

Companion planting transforms your greenhouse into a vibrant ecosystem where plants support each other for a lush, productive garden. It's an innovative, natural approach to gardening that yields incredible rewards. 

Whether you're just starting or a seasoned green thumb, incorporating companion planting principles can bring harmony and abundance to your garden.

So, get to know your plants, experiment with different combinations, and watch as your garden thrives in ways you never imagined.

Ready to dive into the world of greenhouse gardening? Check out our resource library for comprehensive articles and guides, or explore our DIY Greenhouse Kits to begin building your very own garden oasis.

Why Nova Greenhouses?

Back to blog