In a recent survey users of our Garden Planner told us the feature they’d most like to see was one to help them with companion planting. So we’ve spent many months diligently researching exactly that, so you can spend mere seconds selecting the best companion planting combinations for your garden. Here are the results...
Planning Your Companion Planting
The new companion planting feature in our Garden Planner makes it easier than ever for you to find perfect matches for your plants. Simply select a crop, then click on the heart-shaped Companion Planting button. The selection bar will then show only those plants that your chosen crop will love. Select one and drop it into place.
If you’re looking for a companion plant to fit between two crops, hold down the Shift key on your keyboard and click on each crop. Click the Companion Plants button and the plants in the selection bar are filtered to show companions suitable for either of the selected crops. To remove the filter, just click on the heart again. When you select companions for more than one plant, the selection bar will show all the possible companion plants for each of the individual crops selected. Using an ‘add-on’ approach like this keeps the selection process simple, while giving you a wider range of companions to choose from.
Choosing Companion Plants
With many thousands of possible companion planting combinations we decided, right from the start, to include only those backed up by scientific evidence. Research must have proved why they’re good companion plants – we wanted proven associations, not just hearsay! So let’s look at a few examples of companion plant pairings that made the grade.
Many flowering plants attract pest-eating insects. Poached egg plants draw in hoverflies which control aphids on nearby lettuce. Borage attracts bees and tiny pest-eating wasps, making it a great companion for tomatoes. Another scientific study found that crimson clover grown with broccoli expanded the local spider population, which in turn controlled pests.
Some companion plants, such as nasturtium, lure insect pests away from crops. Nasturtiums can be planted close to broad beans so that blackfly will gorge themselves on the nasturtiums while ignoring the beans. The same companion also attracts hungry caterpillars away from brassicas like cabbage.
Some plants have a very strong smell, confusing pests by masking the scent of its host plant. Garlic, for example, has been found to deter the green peach aphid, so we’ve included it as a perfect companion to vulnerable fruits such as peaches and nectarines.
Other Benefits of Companion Planting
In many instances plants make suitable companions because they offer some sort of physical advantage. Tall-growing sunflowers offer shade and support for scrambling cucumbers and climbing beans, which in hotter climates can become sun-stressed.
The Three Sisters method of growing beans, corn and squash together works because the large leaves of sprawling squash help to smother weeds, and the beans use the corn as a support to scramble up while fixing nitrogen at their roots to the benefit of the other sisters.
Legumes such as beans and peas are also used to aid other crops with their nitrogen-fixing abilities. One experiment saw the size of potato tubers increase when potatoes were planted with beans.
Similarly, borage has been shown to add trace minerals to the soil, which in turn improves the flavour and growth of strawberries.
Companion planting can help improve your growing, but it’s important not to get too fixated by it. Crop rotation, correct spacing and good soil management are the most important influences on your growing – think of companion planting as a bonus! If you have any tried-and-tested companion planting combinations you know and trust, tell us what they are by dropping a comment below.