As a young gardener, I bought and cared for individual plants I liked. I still remember a beautiful, red-leafed Begonia in a hanging basket that I bought at a Richmond farmer’s market in the early 80’s. I happily brought it home to my little apartment and hung it on the screened in porch. It brought tremendous joy as it bloomed and stretched and succeeded in that humble little space.
Many of us may spend our entire gardening lives focusing on single plants. There are orchid enthusiasts, African violet enthusiasts, rose enthusiasts and Begonia enthusiasts; and we can remain quite happy with our special plants in special little pots doing their beautiful genus specific ‘thing.’
But at some point, some of us experiment with putting several different types of plants, together, into a single pot or basket. You may have seen ‘how-to’ articles in gardening magazines that offer recipes for container gardens of 3, 5, 7, maybe 9 or more plants. When plants are grown together in a community like this, we call it an ‘association.’
It takes a little more understanding of the chosen plants to create a successful association. In addition to considerations of the various colors of the flowers and leaves, we also consider each plant’s form. What will grow tall? What will droop or drape down the pot? What will grow thick and dense? What will reach out of the arrangement for the sun, or what will creep across the soil as a groundcover? When will the flowers bloom, and for how long?
To create a good association, we also need to know what is happening in the soil. How deep do each plants roots want to grow? Do any have taproots? Will there be bulbs dividing and expanding? Rhizomes creeping?
And of course, we need to consider the amount of sun each plant needs to thrive, and which plants might die back with too much or too little light. Does the plant want the soil to dry between waterings, or should the soil remain moist? Or ever waterlogged? Most of us learn these things through our mistakes as much as through our study.
It may be simpler to use a recipe from a magazine, but experienced gardeners develop their own ideas of favorite associations that suit their own microclimate. A simple potted arrangement also allows us to learn about new plants, watching them carefully through a season or two to learn more about how they perform. We can decide whether to grow more, or move on to something else.
A good association of plants can carry a pot or basket with something of interest every month of the year. Winter blooming annuals, bulbs that begin their growth during the cold weeks of winter, and good strong foliage plants can bridge the awkward times when nothing else much may bloom. Annuals may be popped in and out of a grouping anchored by a shrub or an evergreen perennial.
Pots are a great way to try out new associations of plants. Some will work beautifully, and maybe others, not so much. Nothing ventured, nothing gained, right? Pots are portable, allowing a gardener to easily move the grouping into different light, and to control the water more reliably.
Those of us blessed with a bit of ground where we can dig, and plant, will eventually create associations in our garden beds and borders. That is how great designs develop, as we get a good feel for which plants make good neighbors and stunning displays together.
I have been reading, lately, about how our gardens can function as complete ecosystems. More and more researchers into forest and prairie habitats have published proof of the many ways that plants work together, cooperatively.
Plants tend to communicate through various chemical signals. Quite often, those chemical signals pass from one plant to others through the network of roots, and fungal mycelium growing in the soil. Roots of different plants mingle and interact deep in the soil. They are also interacting with a variety of microorganisms, fungi, bacteria, insects and invertebrates that each play their own part in enriching the soil and aiding the growth of plants. The nature and qualities of these interactions determine the health of our garden.
For example, now we know that a ‘mother tree’ can share the sugar she has made high in her canopy, through photosynthesis, with the seedlings growing in her shade below. The mycelium help with this transfer of sugars from the parent tree’s roots to the roots of growing seedlings.
Nitrogen ‘fixed’ in the soil on the roots of my wax myrtle shrubs may be ‘shared’ with plants growing many feet away, through this underground network of roots and mycelium. Plants that fix nitrogen, like common clovers and members of the pea family, help to naturally fertilize large areas of the garden.
Comfrey has extremely deep roots which spread out and absorb minerals from deep in the garden soil. The minerals find their way into the comfrey’s leaves. The leaves may be brewed into a fertilizer tea by letting them steep in a bucket of water over several days. They can also be cut from the plant and dropped on the ground, as an impromptu mulch, to fertilize the soil as they decay. Comfrey plants live for many years, improving the soil and feeding pollinators each summer. Some of those same pollinators will also visit the apple and pear trees, elsewhere in the garden.
Gardens are amazingly intricate communities. Plants help and harm one another in fascinating ways. Beyond the aesthetics of an attractive combination of plants, or an association that allows each plant full expression of its own beauty and form, we can select and combine plants to benefit from their unique properties.
This, in turn, benefits the rich community of animal life attracted to our garden, and ultimately benefits us. The more we understand the plants we grow, the richer the associations, and relationships, we can nurture.
For example, knowing that every part of a Narcissus is poisonous allows us to use those poisonous bulbs and roots to protect the roots of other plants from moles and voles. Simply plant Narcissus around areas you want to protect from underground tunneling and around plants whose roots might otherwise be eaten.
Knowing which ground cover plants grow very shallow roots, allows us to plant them under shrubs and trees as a living mulch that won’t compete with the tree for resources. Knowing which trees and shrubs host certain butterflies, allows us to increase butterfly traffic in our garden as new broods of cats grow and transform into butterflies throughout the season.
Last fall, I collected acorns. I watched for them to sprout, and then planted them into small pots with commercial potting soil. Some did better than others, and some eventually fell prey to hungry squirrels.
Most of the acorns under an oak tree will be eaten by squirrels or birds or deer, anyway, I suppose. But for those few that survive to sprout and grow, what a richer environment for their roots to sink into the native soil beneath their mother tree, fed by the mother tree’s roots, through the mycelium in the soil. This is a relationship most of us would never understand without some study, because it is invisible to our layman’s eye. My potted seedlings may get better light than those growing in the shade of a mother tree, but they will never have the benefit of the mother tree’s chemical nurturing.
The more we learn about how our plants function as a community, the better gardeners, and stewards of the Earth, we become. Let’s expand our own horizons from our sometimes very narrow focus on a favorite plant or genus, to a greater understanding of the ecosystems where we live and grow.