Companion Planting

Companion Planting

Monty Don hit the headlines with his debut dog friendly Chelsea Flower Garden design with Jamie Butterworth. In a 20m by 10 m space it’s about twice the size of my garden area but set me thinking about who I share my garden with.

Can a garden be functional, ornamental and productive?

My current garden is very different from my previous (family) house. I enjoy being outdoors and want to continue working and accessing my garden as I advance into old age. Climate change is affecting weather patterns, can I also accommodate my declining agility, my family and pets, neighbours, casual visitors and wildlife in myriad forms, a pond, a greenhouse or summer house, woodstore, compost heap as well as growing my own vegetables and flowers in a constricted space? Perhaps I can’t please all but within the framework I can adopt various ideas.  

First and foremost mixed planting avoids any monoculture adding biodiversity. No serried ranks of vegetables, no bare ground. This applies to flower borders too. 

Possible Plant Pairings:

For a wildlife-friendly, colour-rich border:butterfly on lavender

·       Lavandula angustifolia (Lavender) + Echinacea purpurea (Coneflower). Attractive to bees and butterflies with similar water needs.

·       Salvia nemorosa + Achillea millefolium (Yarrow).  Long blooming season, great for hoverflies and lacewings.

·       Nepeta + Rosa ‘Gertrude Jekyll’.  Underplanting roses deters aphids with catmint scent.

 

 

tagetes gold gem

In an ornamental kitchen garden:

·       Allium cepa (onions) + Carrots.  Onions repel carrot root fly.

·       Brassicas + Tagetes (French Marigolds). Marigolds deter whitefly and their roots eelworm.

·       Tomatoes + Basil. In this classic pairing, basil repels pests and improves tomato flavour.

 

Traditional Cottage garden:

·       Delphinium + Alchemilla mollis. Gives height with airy froth below.

·       Foxgloves + Hosta. Shade lovers with structure and foliage contrast.

·       Campanula + Astrantia major .  Understory beauty with bee appeal.

 

digitalis lutea

Shade lovers:

·       Ferns + Brunnera macrophylla. Contrasting texture and blue-toned flowers.

·       Digitalis lutea + Pulmonaria. Pale foxglove with spotted lungwort attracts early pollinators.

·       Hellebores + Epimedium. Provides late winter interest and ground cover.

 

The Benefits of Compatible Planting

  1. Deterring garden pests. Certain plants naturally ward off pests through their scent or chemical compounds. 
  2. Attracting beneficial insects. Dill, fennel, and yarrow attract ladybugs, lacewings, and parasitic wasps, which eat harmful pests such as aphids and caterpillars. Lavender and borage attract bees and butterflies, boosting pollination and helping crops like tomatoes, cucumbers, and squash produce more fruit. 
  3. Supporting climbers. Tall or sturdy plants can act as natural trellises or supports for vines or climbing plants. This not only saves space but also reduces the need for artificial structures in the garden.
  4.  Suppressing weeds. Dense or low-growing companion plants can act as living mulch. By occupying available soil space, companion plants help minimize the areas where weeds can take root. 
  5. Maximising use of space. Carrots and onions can be interplanted since they utilise different soil depths and don't compete for the same nutrients. Fast-growing crops like radishes can be planted between slower-growing ones like broccoli, harvesting the former before the latter needs the space. This results in a more productive garden with a continuous harvest.
  6.   Improving flavour. Some companion plants are believed to enhance the taste of nearby vegetables: This could be due to subtle changes in soil chemistry or pest/pollination dynamics, leading to healthier and tastier produce.

 Deleterious Effects 

Rather than best buddies some combinations are better avoided. Allelopathic plants exhibit a natural phenomenon whereby allelochemicals released by these plants can inhibit growth of others. 

  • Particularly notorious is Fennel which can inhibit the growth of many other vegetables so is best grown separately.
  • Mint can be overbearing and smother adjacent plants.
  • Don’t plant your sunflowers amongst your potatoes, their roots may stunt potato growth.
  • Alliums (onions etc) should not be planted with legumes (peas and beans) 

 Other combinations are best avoided because they compete for the same nutrients or are susceptible to the same pests and diseases, such as tomatoes and brassicas or potatoes and tomatoes (solanum).

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