You probably have propagated plants more often than you realize —when you sowed sunflower seeds, for instance, or divided a large perennial. If you’ve tried your hand at a more complex act of propagation and failed, take heart. Trial and error are great teachers.
A gardener’s excitement to do everything at once —or, put another way, nervous anticipation —might seem a problem for a practicing propagator. After all, some of these experiments take a year to deliver results. But it doesn’t feel slow because there is always something going on —the first step of one process, the last of another, a few cuttings to take, rooted ones to pot up.
Over time, gardeners develop a feel for when things have to be done, and with propagation even more so. At the very moment plants are beginning their most active growing period, the gardener seizes the opportunity to divide some perennials or to strike herbaceous cuttings. The announcements of these activities can’t be found on a calendar. To use the example of the Primula again, in 1997, I divided them on April 19. In 1998, following a particularly mild winter, the task was performed on March 21. Some garden books might just call this spring.
On the first day of spring, according to the published calendar, many gardens are still asleep. By March 21 in northwestern New Jersey, the witch hazel has been blooming for a month and the crocuses are on their way. But across the country, in northern California, the saucer magnolia’s flower show is at its peak and the buds on the roses are swelling.
Producing a daily garden guide for one county would be hard; for the country, it’s impossible. So in this book, you will not see dates but rather references to moments in the year, such as “early spring” or “midautumn.” You need to know a bit about your climate and your garden to apply these expressions. Think of the seasons and the conditions of your plants not as days or dates but as events in the life cycle of plants.
The young “Buff Border” was carved from brush and tree stumps and planted with dozens of propagated plants. Gardeners propagate more often than we realize: when we nurture a slip of something special from a friend; discover a branch that has bent to the ground, rooted, and can be removed as an independent plant; scatter seeds of poppies on the snow; or tend seedlings of giant sunflowers. Dividing perennials, alone, is a propagation rite of spring.
If there is a beginning to the year of making more plants then, perhaps it starts as daylight hours lengthen, just after the winter solstice. The houseplants in the window garden begin to sprout new stems, and a few of them set flower buds. At a moment counted backward from when it’s safe to plant outdoors after all danger of frost has passed, it is time for sowing seeds of annual flowers and vegetables indoors.
Later, when underground buds of herbaceous perennials such as phlox are beginning to swell, crowns can be divided. Many perennials need to be renewed to stay healthy. Division time for early-flowering perennials doesn’t last long. Later ones can go on until the growth is too tall and soft to continue, or if flower buds are forming.
When the weather warms, tender tubers and rhizomes are brought up from the dark spot in the cellar where they were kept around 50 degrees F (10 degrees C) for the winter. Some dahlias have already sprouted, and cuttings of their blanched top growth can be taken before their tubers are divided.
In midspring, as the lilac flowers peak, the vegetable seedlings from under lights can move to a cold frame. The rooted cuttings of indoor tender perennials can be potted up. The new growth on some of the herbaceous perennials outside is sufficiently hardened for stem cuttings to be taken, which will root quickly. The very first deciduous softwood cuttings of shrubs can also be taken; beg slips from neighbors for shrubs you’d like to grow.
The first week of summer will be the last chance for taking softwood cuttings, but some of the ones taken earlier may already be rooted and ready to be planted in containers, which can be placed in a protected spot away from bright sunlight and wind.
In midsummer, as seed stalks begin to ripen, certain plants like columbines receive paper-bag hoods to capture their precious harvest. Later, annual fruits like tomatoes and winter squash will have their seeds collected, cleaned, dried, and stored at dinner time.
The houseplants grown from last winter’s cuttings have spent the summer outdoors under the trees and in the shade beneath the porch. They will need to come inside now. Soon a killing frost will blacken the foliage of the cannas and dahlias, and their rhizomes and tubers will be lifted for winter storage. For the next three to four months, cuttings of needle conifers can be taken. Deciduous woody plants, completely dormant in late autumn, will yield twigs for hardwood cuttings and, later, for grafting.
From the time the tree leaves fall to the arrival of the new seed catalogs, there are a few quiet days to rest and reflect on the excitement to come (air-layering a house plant, perhaps). For the propagator, the year is full of opportunities to make more plants.
Sowing of seeds, dividing perennials, and taking cuttings are not difficult operations left exclusively to those schooled in the disciplines of horticulture—they’re just everyday parts of gardening. For example, several of the temporary residents beneath an aged magnolia—tall hollyhocks, blue larkspur, double poppies, golden feverfew—were simply sown in place to be stand-ins while young perennials and flowering woody plants became established.
In the back of the same bed, a rare Franklinia, from a softwood cutting, begins its seasonal foliage display in late summer when the leaves turn scarlet and the camellia-like flowers appear. In autumn, the tropical-looking bronze canna leaves in the foreground will be blackened by the first killing frost. Their harvested rhizomes will be stored in the basement until spring, when each one can be divided into a dozen plants.
There are many books on the subject of propagation (as you can see from the Bibliography). I found a textbook from the 1930s with good ideas that are still included in most modern guides. Other practices, however dubious, are also found in modern publications, such as fungicide drenches and chemical sprays. No book seemed to capture the beauty of plants and their propagation, or to impart the sense of wonder that comes from participating in nature’s schemes.
Real gardeners helped to write this book by sharing wisdom gleaned from experience. Experiments compared accepted recommendations with alternative techniques. For example, cuttings rooted faster and more successfully when perlite, the propagation medium, was tamped down so hard that a hole had to be drilled in with a pencil to insert a cutting.
The chapters that follow begin with an overview of how plants naturally reproduce and then the practices for gardeners are presented, arranged not from the ground up but from the tip of plants themselves —flowers and the seeds they make for us to sow —to the bottom, with methods for propagating even more plants from bits of their roots beneath the soil.
A guide to propagating over 700 genera begins here. When you need to know how to reproduce a particular plant, consult the guide for the possible methods. Annual vegetable seed-sowing instructions are printed on their packets.
The magic of propagation can become habit forming, whether you are performing a simple yearly ritual of starting plants from seeds, or grafting fruit trees in your own backyard. If some of the tasks presented in this book seem beyond your expertise or ability, start small. Try one technique, then another based on the time of year. Your skills will grow, and so will your garden. This book may be your guide throughout your gardening career. And, wonderfully, gardening is something you can do for the rest of your life.
Although the propagator’s calendar has no specific dates, there are daily accomplishments and milestones along the way.
When it is cold outside and most of the garden is fast asleep the appearance of the ribbonlike flowers of the witch hazel is a sign that the outdoor gardening season is on its way.
Indoors, in the sunny south-facing window and under fluorescent lights in the basement, seedlings like the runner beans for the vegetable garden are emerging above the surface of their medium.
By summer, seedlings in pots will be hardened off and some will be ready to go into their permanent homes.
Some of the rooted cuttings of woody plants and herbaceous perennials from from the spring and summer will spend their first winter in the cold frame.
