Growing Flowers as Companions
June 18, 2013 at 10:40 AM
Space is at a premium in most raised bed gardens. When we do planting plans for clients, sometimes we’re asked why we include flowers in vegetable gardens that are already tight on space. We do it because flowers add to the garden’s beauty as well as its overall health. The right flowers will help your garden by attracting pollinating insects, repelling destructive insects, providing a source of food and healing plants, and of course adding beauty and increasing your enjoyment of the garden.
Even though most of our gardens are relatively small and decidedly urban, at Verdura Culinary Gardens we have the same focus most organic farmers do: creating a thriving mini-ecosystem with beneficial interrelationships in each garden. Companion planting is an inexact and not always easy-to-define science that essentially involves making constructive use of plant relationships to encourage life and growth. Flowers play an important role in this system.
Here are some examples of our favorite flowering companion plants and why we value them.
Many heirloom vegetables – non-hybrid squash, for example – rely on pollinators like bees. Without them, the young squash start to form but never reach maturity, withering soon after their blossoms die back. Growing flowers that attract pollinators helps ensure a harvest, even during the cooler-than-usual summers we sometimes have here in the Pacific Northwest.
Borage is one of our favorite companion flowers. We plant it near squash as a pollinator, and tomatoes and strawberries because it enhances flavor and yield. Both flowers and leaves are edible; the periwinkle blue flowers make a gorgeous garnish to a salad (try topping a salad with both nasturtium and borage blossoms). Tea made from borage leaves is known to be helpful for everything from recovery from surgery to soothing insect bites and remedying digestive disturbances. Its leaves are rich in vitamin C, calcium, potassium and mineral salts. Oh, and apparently it will also cure a hangover!
Borage can grow vigorously, and not everyone is fond of its rather prickly leaves and habit of self-sowing. We joke that we’ve never had to buy borage seeds after our first year; we just harvest volunteers each spring from various gardens and then transplant them! We usually give the plant a couple of square feet of space in a raised bed and then prune it regularly for shape.
Both summer and winter squash, including pumpkins, have an important role in the garden as nutritious vegetables, of course. But their colorful yellow blossoms are an additional bonus, providing an edible delicacy that at a farmers market or store is quite expensive, if available at all.
Squash plants have both male and female flowers. Male blossoms have long, slender stems while the females are attached to the end of the immature squash. Both can be harvested, but keep in mind that both are necessary for the pollination, so it’s important not to harvest too aggressively. Cutting the occasional blossom or two is just fine, particularly if you have several plants or a particularly robust one.
Dipping the just-harvested blossoms in a batter and deep frying them is a common treatment. For a less messy but delicious option, try slicing the blossoms and adding them to scrambled eggs. Their delicate, peppery flavor harmonizes very well with eggs.
Almost everyone knows that these cheerful annuals are good for a garden. But why? Turns out they’re very hardworking pest deterrents. They help control aphids, nematodes, cabbage loopers, Mexican bean beetles and cabbage worms. Inexpensive, colorful and easy to grow, marigolds have a tidy growth habit and are easily incorporated into a square foot garden. They are particularly good companions for tomatoes. Beans and plants in the cabbage family (cabbage, collards, cauliflower, kale, kohlrabi, broccoli and mustards) are less friendly with marigolds, so to the extent that we can, we plant them in other areas of the garden. Obviously, with small gardens this is not always possible.
If you grow marigolds, be sure to choose the scented French or Mexican varieties. Unscented marigolds won’t help you - the scent is what repels pests like whiteflies. The roots also exude a substance that kills destructive nematodes, with protection often lasting two or three years beyond the annual planting. Sadly, the traditional scented varieties seem to be more and more scarce in garden centers these days.
Our experience with marigolds is somewhat mixed because they attract slugs, which are always an issue around here. As with any plant in the garden, we try them out and use them where they seem to be a success, turning to other remedies when they’re not. In recent years we have been turning more and more to calendula instead.
A member of the same family as marigolds, calendula or pot marigold does not attract slugs and, in my view, is more attractive. Plus, it’s edible - its pretty orange petals are often added to salads for a kick of color. It can be made into a soothing tea. And it’s anti-inflammatory and antiseptic. It soothes, heals and helps regenerate skin, and is often added to lip balms, salves and lotions. Health claims for calendula range from menstrual disorders to cancer. We can’t speak to that, but we do love it in the garden, where it is easy to grow, makes great cut flowers, and has similar benefits to marigolds.
Nasturtiums are excellent companions to radishes and cabbage family plants, deterring whiteflies, cucumber beetles, squash bugs, and striped pumpkin beetles, and improving growth and flavor of these plants. Nasturtium is a great “trap” crop for aphids, which it attracts away from other garden plants. We inspect it regularly for tiny black aphids and if our nasturtium does get infested, we just tear out the plant mid-season, taking an entire colony of aphids out of the garden and away from our vegetables.
Nasturtiums are also lovely in raised bed frames, spilling over the sides and visually softening the hard edges. The flowers are vibrant and add great visual appeal to a vegetable garden. The leaves, flowers and seeds of nasturtiums are all edible. The flowers are a great addition to salads, although we do recommend you dress the salad first, then sprinkle the flowers on top. As with many flowers, they are delicate and wilt easily if in contact with acidic dressing.
Some flowers are worth growing just as window dressing, and sweet alyssum certainly qualifies. It does attract bees, but we love it mainly for its delicious scent and low-growing habit. An easy to grow annual, alyssum comes in white as well as various shades of purple and rose. Like borage, it self-sows rather freely, so we sometimes manage to grow new plants from last year’s seeds that have sprouted.
We include sunflowers in many of our gardens, usually opting for the dwarf varieties because their smaller stature (2 1/2 to 3 feet tall) is better suited to urban gardens. Even non-seeding sunflowers provide an ongoing supply of cut flowers and help attract desirable insects to the garden.
Many insects are attracted to the tall, bright flowers, including bees and other pollinators. The real reason we grow them, though, is simply that they have such great visual appeal: they make us smile.
Sunflowers are good companion plants for cucumbers, improving their growth and productivity. We grow cucumbers on trellises or other vertical supports, so planting three foot tall sunflowers in front of or in between cucumbers is an easy way to populate the north edge of the garden with a visually appealing backdrop.
There are countless other flowers worth growing in an urban vegetable garden – dwarf varieties of lavender or echinacea, for example, or cosmos in a border. Whether grown for color, nutrition or pest deterrence, flowers deserve some space in any healthy organic garden.