Productive gardening isn’t all about cramming in as many vegetables as you can. If you haven’t got plenty of insect-attracting flowers mixed in too, you’re missing out on one of the most important elements of any garden: nature’s army of pollinators and beneficial insects.
Growing flowers among your crops turns what might otherwise be a purely utilitarian space into a place of intense beauty. It’s remarkable what a splash of colour can do to spruce things up and lift the whole feel of a place. But it’s more than that. You’ve heard of flower power, right? Well, it’s true: flowers actually boost crop growth by fuelling the bug life that help plants grow to their full potential!
Start with tough, resilient flowers that, with any luck, will pop up time and again. The flowers below are all self-seeders, which means the seeds they drop will survive to come up next spring. Sow once, enjoy for many years to come! The best flowers for this purpose are frost-hardy annuals – that’s plants that grow, flower, and set seed within a single season, and don’t mind a little cool weather.
The three flowers below are each perfect for growing in the vegetable garden because they not only attract pollinating insects like bees, but also pest predators such as hoverflies, lacewings and ladybirds.
Number one is calendula, with its warm, sunny flowers. Also known as pot marigold, calendula thrives in pretty much any garden soil, including poorer soils. It loves the sunshine but does okay in light shade too. What an accommodating flower! You can eat the petals – they look fab in salads and soups – and it’s a great companion plant because studies have shown it helps to repel pests like aphids, brassica-eating caterpillars, and armyworms.
Calendula is best sown direct where it is to grow. Prepare your soil in advance by raking it to create a fluffy texture that’s good for sowing into. Just to be sure, and to give an extra helping hand, it’s also worth forking in a little garden compost.
Set the seeds about a half inch (1cm) deep. You can sow them quite closely, and then thin them once they’ve germinated. If you’re impatient, or just want to cover all bases, it’s worth also sowing some seeds into plug trays at the same depth. Once the roots have filled their plugs, later in spring, you can plant them where you want them to grow.
I’m a big fan of calendula. In fact, when I worked at a plant nursery as a teenager I once potted up a calendula growing in my front garden that ended up – honestly! – in one of the show gardens at the Chelsea Flower Show. The garden won a gold, so I like to think I played my part!
Nasturtiums are a real boon for the bees, and it makes a really great companion plant too, luring the butterflies that lay brassica-eating caterpillars away from your vulnerable crops like kale and broccoli. Nasturtiums are also edible, from the leaves to the flowers to the super-spicy seedpods.
Sow into plug trays under cover, or wait until closer to your last frost date to sow direct. Although they are frost hardy, nasturtiums are a touch on the delicate side to start with, so patience is a virtue when it comes to sowing times for this plant.
Poached Egg Plant
My third hardy annual is poached egg plant (Limnanthes). It’s not hard to see how it gets its name – what a stunner! Poached egg plant is loved by pollinators, plus it attracts the pest predators like aphid-hungry hoverflies. It grows in sun or partial shade, and prefers a free-draining soil.
Sow poached egg plant seeds fairly thickly directly outdoors, then thin the seedlings to about 4in (10cm) apart once they’re up. Like calendula and nasturtium, hardy poached egg plant will readily self-seed, so I’m hoping their sunshine cheer will be with me for many summers to come.
A little-known benefit of poached egg plant is that it can be dug into the ground before it sets seed to serve as a cover crop or green manure, so it’s also good for sowing in spaces that will be planted later on with autumn crops.
Of course, it’s worth sowing half-hardy, or frost-tender annuals (which won't survive cooler weather) too. Here’s my top three.
Alyssum is another flower that’s great at attracting hoverflies. It’s a small, almost ground-hugging annual, which makes it a super choice for slotting in here and there among aphid-vulnerable crops such as lettuce, as well as for edging to beds.
Marigolds are a great companion flower to tomatoes, especially greenhouse-grown tomatoes, as their scent helps to deter whitefly.
Then finally there’s zinnia. It’s a bit taller at around 2ft (60cm) or more, so should offer a bit of height as well as cheer. Zinnias are great for butterflies, particularly monarch butterflies and painted ladies. Give zinnia a sunny spot – it’s good for both the plants and the nectar-sipping butterflies that come to visit. Taller varieties may need to be staked to prevent the plants from flopping over.
For best germination, sow each of these tender annuals very thinly into seed flats or pots of lightly-firmed, moist seed-starting mix. Cover with a very fine sprinkling of vermiculite or a little more of the seed-starting mix. Thoroughly mist spray to moisten the sown seeds.
They will need a little warmth to get them going, so cover the trays with polythene, secured in place by a rubber band, then pop them into a tray covered with a humidity dome for extra snugness. Place them indoors on a warm windowsill, just above a gentle heat source to speed germination if possible. Ideally, they’d be at around 75ºF (23ºC). Use a heated propagator if possible, as it will be more consistent and faster.
Once the seedlings are large enough to handle, transplant them into their own large plug trays to grow on. Once your last expected frost date has passed, acclimatise them to outdoor conditions over the course of a week or so (a process known as ‘hardening off’).
Many common herbs are fantastic sources of nectar and pollen for all sorts of beneficial bugs. High up on my list are basil and parsley, which last year I had bobbing about at ground level beneath my climbing beans. They looked great, and my beans were trouble-free all season long. Coincidence? Maybe, but I’m going to do this again this year.
Many herbs can be bought as living herbs from the grocery store very cheaply indeed. These can then be split up and re-potted, to grow on a bit before planting out into their final positions a few weeks later.
There’s one herb you don’t often see for sale in the grocery store though, and that’s dill. Simply scatter the seeds where they are to grow once the weather has warmed up a little. Rake the seeds in to ensure good contact with the soil, then give them a thorough watering to set them on their way.
Dill flowers are almost identical to beautiful fennel, which is a taller perennial herb. Consider planting it for many years of insect-attracting blooms. There are lots of other insect-friendly flowering perennial herbs you can include, such as chives, rosemary and sage.
What a beautiful way to boost crop growth! What vegetable garden-friendly flowers are you planting this season? Tell me in the comments below.