Just as we structure our lives by our associations with friends, family, and business colleagues; so plants also form useful relationships with other plants.
Our human associations are based on things we have in common with others. We may form friendships based on shared interests, or spend time with members of our biological family.
We may enjoy the company of others in our profession, or with those who share our passion for music, for tennis, or for gardening.
When planning pots, beds, borders, and landscapes, we generally plan in terms of groups, or associations, of plants.
Something like Lego blocks, or notes in a chord; certain plants go well together.
These associations must first take into account shared needs for a certain amount of light and moisture.
It is wise to also consider what sort of soil is best for a grouping of plants, and what temperatures they need for best growth.
Beyond these basic considerations for what plants have in common, we look towards how their differences may compliment one another.
Vining plants, like Clematis, which will grow up a trellis, may share a pot with a bushy or trailing plant to shade their roots.
An indeterminate tomato plant filling a tomato cage benefits from shorter basil and marigold plants at its base which shade the soil and repel certain insects and predators.
Just as a composer relies on certain chords and phrases to compose a melody, so a gardener benefits from a repertoire of plant associations to construct a garden.
And these associations are peculiar to the gardener and the environment of a particular garden.
The associations depend on which plants a gardener enjoys, the style and mood of the garden, and the growing conditions with which a gardener must work.
Most of us gardeners are drawn to particular plants. I visited with a woman a few weeks ago who loves boxwood shrubs. A fellow blogger has a garden full of day lilies, which he hybridizes.
Some gardeners go to great lengths to grow tomatoes or squash each year, and others want a shady garden full of Hostas and ferns.
Personally, I love every species and color of Iris.
And I collect English roses, and always want a summer garden full of delicious herbs. And I absolutely want something in bloom in the garden each and every day of the year.
Living in a forest, these obsessions are not always compatible with reality.As I plan what will grow in borders, beds, and pots throughout the gardening year, I have learned to rely on certain plants, and combinations of plants, which I know from experience will grow together successfully.
Relying on perennials as much as possible, and on plants I can keep through the winter; simplifies the process of moving from one season into the next.
But there is still shopping to be done in spring and fall. Knowing which associations of plants one wishes to recreate each year helps organize the process.
For example, German re-blooming Iris, Iris germanica, thrive in the sunny areas of this garden. They are drought tolerant, don’t mind our Virginia summers, and are not bothered by deer.
They are absolutely lovely for the few weeks each year of bloom. Whether in bloom or not, German Iris are always a presence in the garden since their signature sword like leaves persist through most of the year.
I like growing Iris near roses. They have similiar needs for light and feeding, and they look good together.
Wandering through a garden in Warm Springs, Virginia, I found a brilliant combination of Iris,day lily, and daffodils planted together.
The growing day lily and Iris foliage hid the daffodil’s leaves when the flowers were finished. Iris bloom soon after the daffodils, and then day lily carries the planting on into the heat of summer.
I now grow Iris and daffodils together in some sunny areas of the garden. And I add Columbine to the mix, along with sun tolerant ferns.
By early summer, the canopy of shrubs and trees has grown in enough to shade the ferns, and the daffodils and Iris have already enjoyed many weeks of strong sun when they most needed it.
Many country gardeners, especially in the Piedmont of Virginia, grow perennial low growing Phlox around their Iris bed.
In springtime, you’ll see wide expanses of pink, white, and lavender Phlox blooming around island beds of Iris. These plants thrive in full sun, and take very little care.
I also plant Lavandula stoechas “Otto Quast” at the base of both roses and Iris. This Spanish Lavender, with finely cut foliage, sports abundant large blooms at the same time the Iris bloom in late April to early May. L. “Otto Quast” has a long season of bloom, over many weeks in late spring and early summer.
It isn’t destroyed by rain and humidity as some other Lavenders are in our Virginia summers. The brilliant purple blooms work well with the colors of the Iris blossoms and English roses. This evergreen Lavender looks good at the front of a bed whether in bloom or not.
Another hardy association is Lamb’s Ears, Stachys byzantina, with roses, Dianthus, and Echinacea. A drought tolerant full sun perennial, Lamb’s Ears are disliked by deer.
They divide easily in spring and display stunning silvery foliage through most of the year. Their purple blooms in early summer are quite beautiful and attract many nectar loving insects. I’ve spread these throughout sunny areas of the garden.
One way to bring unity to a garden is to repeat plants and associations of plants from one area to the next.
Even with a tremendous variety of genus, species, and cultivars of plants throughout the garden, narrowing the selections to repeat colors and forms again and again weaves the many individuals into a patterned tapestry which feels harmonious.
I have incorporated Iris into at least six different planting areas. In all of those areas, they are paired with a silver foliage plant such as Lamb’s Ears, Lavender, Dusty Miller, or Artemesia.
In most of those areas, they are growing near an English rose shrub. Silver foliage, with white or purple blooms nearby, also weave throughout the summer beds.
White Dianthus often grows with Dusty Miller, purple or tricolor sage, and grey Winter Thyme. These reliable plants look beautiful together, and help extend the season over many months.
Shade associations are built around various species of ferns, Hellebores, Heuchera, Begonias, Coleus, Caladiums, and Fuchsias.
The Fuchsias and Begonias must be grown in pots out of reach of the deer, or in hanging baskets.
After discovering that Impatiens, which I’ve always grown in abundance in shady areas, are simply deer candy; they are reserved for hanging baskets well away from where deer can reach.
They always complement ferns, and grow well at the base of cane Begonias.
I also like to plant cane Begonias with Caladiums to hide their leggy stalks.
This season I’ve added garlic cloves, chives, and onion starts to many associations in the garden because their aroma repels deer. There are green garlic plants growing out of potted arrangements on the front patio.
There are also a large number of scented geraniums in flowerbeds and pots for the same reason.
I’m experimenting with a mixture of scented geraniums, zonal geraniums, and ivy geraniums. The scented geranium will the the fragrant “thriller” in the pot, growing the largest with striking foliage.
The zonal geraniums will give a punch of color as they fill out the middle of the pot. The ivy geranium will spill down over the edges of the pot as the “spiller.”
When shopping for plants this spring, try to think about buying “associations” of plants rather than just choosing individuals for some quality which strikes you.
Remember to analyze a plant in terms of what it needs to perform well, what it will give you or do for you, and how it will blend into the garden as a whole.
Remember to buy in multiples. In most cases, it is better to buy several of the same plant, and then use the plant again and again to weave a sense of unity through a given space.
This past week I planted 16 Nicotania plants, in three colors, throughout three nearby beds beside the butterfly garden.
A dozen Cayenne pepper plants went into the same beds, along with 16 white marigolds, a dozen cherry Zinnias, four Bronze Fennel, and three Dill plants.
This area is already planted with perennial Echinacea, Monarda, Salvias, Lavenders, culinary Sage, Rosemary, and lots of Iris.
More Zinnias are sprouting and will be planted within the next few weeks, when I add multiple varieties of Basil.
These plants have similiar needs for full sun, drainage, and nutrients. Most are distasteful to the deer, and so offer some protection to the shrub roses planted among them.
The variety works because the same plants are repeated again and again in associations throughout the space.
The last consideration when planning associations of plants is color. Within a particular genus, and even species, there is frequently a choice of color in both flowers and foliage from which to select.
Although flower color is important, I am far more interested in the form and color of foliage when choosing plants.
Foliage is far more of a presence in the garden than flowers both for its relative mass, and for its longevity throughout the season.
Some plants, like Coleus, Heuchera, and Hosta are grown primarily for their foliage. The flowers are incidental for most of the season, and may even be systematically removed .
These bright plants always draw attention to themselves and set the mood of an area in the garden.
Whether you prefer peaceful, monochromatic gardens or bold dramatic ones, the size, form, and color of foliage sets the tone.
It is generally easy to select for color of both flowers and foliage within any given genus or species of plant. Culinary sage alone may be had in golden, tricolor, purple, silver, or green.
Popular flowering annuals like Petunias and Calabrachoas come in an overwhelming number of stunning shades and patterns. New hybrids of patterned leaf Heucheras and Coleus are introduced each season.
All of the many choices of plants for a temperate garden, such as we have in much of the United States, makes it both endlessly interesting and almost overwhelming to select and arrange plants for each season.
Planning for repeating associations of plants, and selecting plants based on specific criteria, helps bring structure and cohesion to the planning process.
I always approach the garden in the spirit of experimentation. I want to know what works well,and what doesn’t.
Repeating associations which work well, season after season, still allows for changing things up with different cultivars of old favorites.
The more plants you come to know personally, through growing them, the more interesting and effective these associations of plants become.
Photos by Woodland Gnome 2013-2014