3 Magic Flowers to Repel Pests and Feed Your Soil

24 June 2023, written by Benedict Vanheems

There are three flowers that I reckon are essential for any veggie garden. Keep reading or watch our video to find out what they are!

Comfrey

Comfrey has got it going on! Its gorgeous, drooping clusters of almost bell-shaped blooms are a big favorite of bees, particularly bumblebees. Comfrey also attracts plenty of hungry pest-munchers such as tiny parasitoid wasps, lacewings and spiders.

This is a fast-growing and reliable flower. Mine were planted last spring. They’re already starting to bulk out nicely, and eventually they’ll form a really satisfying clump. Comfrey’s a really super plant because it’s easy to grow, is rarely bothered by slugs, and will even put up with a little shade. The wild variety of comfrey can spread – a lot! – so instead opt for the variety ‘Bocking 14’, which is a sterile, garden-friendly variety that’s far-better behaved!

The real joy of comfrey, however, isn’t in the flowers – fab as they are – it’s in their leaves. Wear gloves when cutting comfrey as the little prickles on the stems and leaves can irritate delicate hands, causing a rash.

Comfrey leaves are powerful stuff. They contain lots of nitrogen, loads of potassium and a host of trace elements too, which makes them an excellent natural slow-release fertiliser. There are lots of ways to use them:

1. Cut and drop the leaves around plants that will appreciate an extra boost – fruit trees and bushes for example, as well as fruiting vegetables like tomatoes and squash. You could even combine comfrey leaves with a topping of grass clippings to give your hungry plants even more nutrients to guzzle!

2. Add comfrey leaves to the bottom of planting holes. This works well for fruiting vegetables, or use it to line the bottom of potato trenches. Their searching roots will stumble upon the comfrey leaves just as they’re beginning to break down and release their nutrients back into the soil.

3. Add comfrey leaves to your compost heap.

4. Dig them into the soil early in the season like a cover crop or green manure to enrich the soil for a future crop.

5. Dry the leaves then crumble them into homemade potting mixes for a little extra nutrition.

“comfrey-feed” — Comfrey can be used to make free plant food by steeping it in water

6. Make a quick-acting liquid fertiliser (my absolute favourite way to unlock the power of comfrey!). Stuff comfrey leaves into a large bucket until it’s about three-quarters full. You can speed the process along by chopping the leaves up a bit first if you want. Push the leaves down to pack them in, then cover them with water, ideally rainwater. Cover the bucket with a lid or towel because comfrey can pong as it breaks down. Leave it for about a month, and then it’s good to use.

Dilute your liquid fertiliser with water – at least one third to two-thirds water – and water it on around your fruiting plants like tomatoes. And the sludge? Just dump it onto the compost heap or back around your comfrey clump.

7. For something even stronger, try a comfrey concentrate. It’s made in a similar way to the liquid fertiliser, only this time no water goes in. Just pack your container with the leaves, then weigh them down with a few bricks. This method gives a really thick, black, almost treacle-like liquid after a few weeks. Collect it up in a labelled bottle then dilute one part of the comfrey concentrate with 15 parts water when needed.

Comfrey is a member of the borage family, Boraginaceae. And so is my second must-grow flower: borage itself!

Borage

Beautiful, blue-bloomed borage is arguably even more stunning than comfrey. And it pulls in even more bees – if that’s possible! Like comfrey, borage attracts all sorts of bees, especially bumblebees, earning borage alternative names such as ‘bee’s friend’ and ‘bee flower’.

Now imagine you’ve got borage dotted about at the ends of your productive vegetable beds. It’s going to create plenty of air traffic, as bulky bumblebees move between the flowers. All this very noisy, sometimes chaotic movement can put off a lot of smaller bugs, including many pests! Borage has been found to dissuade insects such as tomato hornworm and cabbage white butterflies, probably because of all the frenetic bee activity around them. So by simply growing more borage in the veggie garden, you’re creating a decidedly more intimidating environment for these common pests.

Borage is an annual flower that dies at the end of the season, but it readily self-seeds, so once you’ve got it up and running you should have a steady succession of borage plants, for years to come. If you find you have too many, either remove any seedlings you don’t want, or transplant them somewhere else. Like comfrey, the leaves also make excellent fodder for the compost bin – a welcome addition of greens to balance out any browns like prunings.

“borage-ice-cubes” — As an added bonus, beautiful borage flowers are edible!

A Mediterranean native, borage grows best in full sunshine. It’s a good companion to tomatoes and cabbages, and is also said to improve the flavor of strawberries. The chunky seeds can be sown anytime from late spring to early summer into prepared soil.

You can harvest the leaves and use them in much the same way as comfrey, but I reckon that in this instance it’s the flowers that bring home the bacon. They’re pretty – and edible. Drop them into drinks as a star-gazey garnish, as the crowning glory to a cake, or perhaps into salads along with other edible blooms like nasturtiums. Borage flowers have a crisp, refreshing cucumber flavor – just the job for a quenching tumbler of fruit punch!

Once borage starts flowering it should go on and on for several weeks, but you can encourage plants to produce more flowers by deadheading, or removing, the old ones. You can also rejuvenate plants midseason by pruning them back about halfway.

“Marigolds” — French marigolds are well-behaved plants that can help draw in pest predators

French Marigold

The third member of my tempting trio is French marigold, a well-behaved frost-tender annual that needs little introduction. What I love about French marigold is its compact shape, which means it sits quite happily – neatly and undemandingly – beneath taller plants like tomatoes.

It adds a splash of color to the productive garden but, more usefully for us veggie growers, it attracts a slew of pest predators: lacewings, hoverflies, tiny wasps, ladybirds – you name it!

Marigolds have deep cultural significance in so many places across the world – this is a special plant! In India they take centre stage in many religious ceremonies, and in Mexico they’re used to decorate graves. What a lovely idea!

If you’ve had problems with nematodes in past years, consider growing marigolds and then, towards the end of the season, chop up the plants and dig them into the soil where they’ll release natural chemicals that will interfere with those nuisance nematodes.

Don’t forget to deadhead marigolds regularly to keep the flowers coming, and give them a sunny spot to help them bloom to their full potential. The flowers can also be eaten in moderation. They have a citrusy tang that’s ideal in salads or as a garnish to desserts. Lovely stuff!

Marigolds, comfrey and borage are my must-grow vegetable garden flowers, but I would love to know what yours are! Let me know in the comments below.