Rather than let this scented geranium (Pelargonium ‘Lady Plymouth’) die outside during cold New England winters, I keep it alive in my living room.
Although a wild world of variety occurs within the plant kingdom, most plants live and die by a few general rules. Use these lifecycle categories to help identify, accommodate, propagate, and manage the growth of the best plants for your garden:
• Annuals go through their entire lifecycle of growing, flowering, setting seed, and dying in a single season.
• Biennials spend one season growing roots and foliage. During their second season they flower, set seed, and die.
• Perennials cycle through growth, flowering, seed setting, and either stasis or full dormancy, annually, sometimes for many, many years. During dormancy—which usually occurs when light levels and/or temperatures decrease toward winter—plants may die back to the ground, sending up fresh growth the following growing season.
• Shrubs and trees go through the same yearly cycle as perennials but usually live longer. Shrubs retain a woody, multi-stemmed or low-branching structure, while trees branch higher from a single trunk. Shrubs and trees may be deciduous or evergreen during dormancy.
Plants in each lifecycle category are adapted to survive their native habitat’s weather extremes, and to follow its seasonal cues to optimize growth and reproduction. (Hybrids and cultivars generally follow in the cultural footsteps of their parent species.) And quite a few—more than we could ever hope to possess—are amazingly easy to accommodate. Given a close approximation of the soil fertility and drainage, light, and climate conditions they require, they thrive.
Reproduction
When it comes right down to it, plants want to live—regardless of whether they’re growing as their ancestors did on their home ground, or in your garden. They are heavily invested in the survival of their own species and they have some very clever ways to ensure generations of success.
For starters, sex sells. (Any gardener who has fallen in love—or lust—with a particular flower knows that.) DNA-laden pollen must be transferred from anther to stigma, one blossom to another, and in many cases, from one parent plant to another in order to keep the gene pool viable and healthy. So showy flowers are specifically engineered to seduce whichever pollinators can help them get it on. They offer their assistants gifts of high-caloric nectar and surplus nutrient-rich pollen in exchange for promiscuity.
In addition to making possible new generations of showy self-sown volunteers and surprising hybrid variations, pollinators enliven the garden and give us a close personal view of nature at work. You can put out the welcome mat by refusing pesticides and by planting pollen-heavy and nectar-rich flowers like poppies, sea holly, mountain mint, and dahlias.
Pollinators also need water and places to live. A birdbath, plant saucer, or small fountain will do if you don’t have space for a frog pond. Providing habitat is as easy as allowing bumblebees to nest under plants or leaf litter near a sheltering wall (while remembering to avoid that spot with your bare feet and trowel) and as cool as constructing an insect condo for several different species using found objects.
To keep butterflies in the garden, make sure their caterpillars have something to eat. Monarch butterfly caterpillars only feed on milkweed family plants (Apocynaceae) while swallowtail butterfly caterpillars prefer plants in the parsley or carrot family (Apiaceae). Send out an invitation to hummingbirds by filling a feeder with diluted simple syrup (four parts water, boiled to dissolve one part sugar). Hang the feeder near a patch of their favorite flowers and replace the liquid every two or three days to prevent fermentation. You can quit filling the feeder when the birds find the flowers and have added your garden to their daily rounds.
Hollow bamboo tubes, drilled wood, piles of pottery shards, and tangles of grass and fiber offer habitat to a variety of beneficial insect and pollinator species. If you build it, they will come.
After being fertilized by pollen dusted on a stigma and transported down the style, the flower’s ovule becomes a seed. Like flowers, seeds are also designed to take advantage of the conditions in their native ecosystem. They will drop like stones, scatter, blow, be carried away, or eaten (and shat back out) depending on whatever method is most likely to result in a seedling with a good chance for survival.
If sexual reproduction ever fails, some plants fall back on asexual means of populating the earth. Plants are capable of generating clones because they are as hormonal and susceptible to influence as teenagers. The rapidly dividing cells within the leaf nodes (the point of attachment along the stem) of growing tips are especially full of growth regulators that stimulate the plant to make constant adjustments to light levels and gravity, and determine whether those versatile cells should grow into roots and a new plant, instead of leaves.
Also, when genetics place restrictions on vertical growth, allowances are sometimes made for horizontal growth. Plants then use their competitive energy to increase ranks sideways by creeping outward in ever-enlarging clumps, sending up suckers, flinging stolons in all directions, and by a slightly stealthier rhizomatous march. From our perspective as gardeners, the ways plants advance through—and over—the soil look very similar. A cheat sheet helps to recall their differences:
Honeybees and syrphid flies work a peony-flowering opium poppy (Papaver somniferum).
• Suckers are new plants that arise from a horizontal
root. This is a particularly common self-propagation
method for colonizing trees and shrubs.
• Stolons or runners are horizontal aboveground stems capable of forming adventitious roots (meaning any roots that form elsewhere than the plant’s actual root system) and new plants or “plantlets” at the tips and nodes. Picture strawberries.
• Rhizomes are underground stems, which often look more like roots, capable of sprouting new plants. Pieces of rhizomes broken off the parent plant are usually also sufficiently hormonal to become new plants.