SUCCESSION PLANTING

A great many gardeners, pressed for time and space, have come to the sensible conclusion that it's possible to keep one garden looking good throughout the growing season rather than trying to keep up with several beds, each of which has a stunning but ephemeral peak after which things begin to look a little sad.

Christopher Lloyd, whose gardens at Great Dixter in Sussex, England, are visited by thousands every year, is perhaps the best known of gardeners who employ succession planting in order to have continuously blooming and ever-changing displays. His book Succession Planting for year-round pleasure is the source of many of the ideas we will discuss today.

A full-season garden needs anchor plants, which can be provided by small trees, shrubs, and ornamentals. Leaves have great advantages. The larger ones create a sculptured effect, providing many shapes, colors, and textures. Using slow growers which take a long time to become trees and require little pruning allows your garden to mature through the years with an often-changing effect.  Consider Cornus alternifolia or pagoda dogwood, Acer palmatum or Japanese maple, and Thuja occidentalis or American Arborvitae. Depending on the size of your garden, you may want to include ornamental grasses or small shrubs such as laurel, boxwood, golden spirea, aucuba, and virburnam. Think creatively!  Include some of your favorites and do a little research to find new friends that will grow well in our area.

Continuous bloom from mid-April to Halloween can't be achieved with a single cast of characters, no matter how sophisticated and wide ranging your plant selection may be. Early bloomers and cool-temperature plants need to give up, or at least share, their space with later-flowering plants that are more tolerant of heat, drought, and searing sun.

To assure a sequence of interesting plants, some planning is required. More important, a little attention and effort is needed to get the job done.  Realize that this apparently "labor intensive" approach may spook those who are trying to squeeze some gardening into an otherwise full life; but if you have a garden, and enjoy it, you are around when it is blooming and probably enjoy doing a little primping and fussing anyhow.

Lloyd constructed his gardens in five layers:  anchor plants and key perennials, bulbs, self-sowers, early summer bedding, and summer bedding. We have discussed anchor plants so let’s turn to key perennials. Pick ones that you enjoy!  A good way to discover new ones is to look around during the summer and see what is growing well in other people’s gardens. A plant that looks lovely at the nursery may prove difficult to grow in your conditions. Consider peonies, daylilies, hydrangea, oriental poppies, daisies, tall phlox, yarrow, Baptisia, money plant, and coneflowers. Don’t be seduced by lupine and delphinium, which are difficult to grow here.

Bulbs are a key part of our succession garden. .  Position them among the perennials. Select from early blooming snowdrops, followed by crocus, narcissi, bluebell, tulips, and hyacinths.  Next come later-blooming alliums, Asiatic and oriental lilies, crocosmia, and liatris.  Fall blooming crocus and daffodils are available to finish out the season.

The middle layer is made up of self-sowers.  For these to work, you sure not use mulch   in your garden as the seeds need bare earth to germinate. Self-sowers plug gaps and help keep the show going as long as you treat them as allies that need to be controlled.  Try forget-me-nots, cosmos, bachelor’s buttons, larkspur, hollyhocks, daisies, evening primrose, and rudbeckia.  They will sow themselves into combinations you would never have considered, appear in places you would never have planted them, and add a certain charm. On the downside, make sure they don’t overpower their neighbors, become too messy and chaotic, or appear in too large a mass.

Layers four and five are early and late bedding plants – annuals that you get at the nursery or grow from seed. They are used to fill the gaps and provide extra color and excitement. For spring planting among tulips Lloyd favors Cheiranthus cheiri or wallflowers. If you want to experiment with these, you can grow them from seed or order them from one of several nurseries. Siberian wallflowers are bright orange and will self-sow. We all have found salvia to be a good filler for the summer months.

Coleus, especially now that many have been hybridized to be sun-loving, makes a wonderful addition to the garden.  In early spring, buy a six-pack of them and plant each in a pot. As they grow, pinch off the sprouts, root them in a glass of water, and plant in additional pots– by July you will have a lovely clutch of plants to put out in the border as your early blooming perennials have finished their show.  Dianthus, both annual and perennial, comes in many shades of pink from pale to luscious raspberry. If curly parsley is seeded in the spring, by summer you can have bushy plants to add color and texture to the scene – try it with marigolds for a bold look. It will also attract black swallowtail butterflies!

As summer wears on it is time for the zinnias to come into their prime. Planted among verbena or lantana, they provide color and flowers for cutting. Be sure to deadhead them daily to keep them blooming well into the fall.

Dahlias from simple to showy to dinner plate size will spruce up any sunny spot as they reach their peak in late summer. Cannas come in a rainbow of colors and add structure and height to your garden.

Climbers are an invaluable adjunct that intensify the main display and sometimes take over completely.  Lloyd says, “Whereas most gardeners think of climbers as clothing for walls and trellises, which is essential, to the adventurous minded this is a ridiculously limited assessment of their possibilities.  Clematis are naturally adapted to grow through other vegetation.” Plant them alongside rhododendrons and peonies; here they are ready to take over when blooms have faded. Plant them with a climbing rose for a stunning display, Plant nasturtiums along a hedge, Crimson Gloryvine, which turns a beautiful red in the fall, with small evergreens. Don’t neglect the wonderful autumn clematis, Clematis paniculata. Whether climbing on a fence or up a string trellis, it is a sure show stopper.

While Lloyd is famous for his spectacular large gardens, his methods work equally well on a smaller scale – all gardens don’t need five layers, but they all benefit from planning.  Start planning now as the bulb catalogues are arriving – if you have a lot of squirrels be aware that they love tulips and crocus but will not touch a narcissus. By looking at the blooming times, you can decide on a variety of bulbs and iris for a long-blooming display. Then as the winter wears on and the nursery catalogues start arriving, take time to dream and select a few new plants to add where color or texture is needed. Many catalogues offer collections of plants that grow well together. Now is also a good time to draw sketches of your beds so that, come February, you will know what you have and where it is. If your soil has not been tested in the last few years, take soil samples the local Extension Office for analysis and advice about fertilizer and soil amendment needs. This is also a good time to start a garden journal, so that, as the seasons  progress, you can make note of when each cultivar blooms, which ones do especially well, and which ones should be moved or divided.

Here are some ideas for a small bed that you can easily incorporate in your landscape or around a mailbox or lamppost. In a three by six foot space in the sun begin by planting spring blooming bulbs as well as later blooming Asiatic and oriental lilies. Next put in a dozen daylilies.  If you plant a dozen pansies in the fall, they will thrive and bloom well into June when the daylilies and Asiatic lilies begin their display. You can add some coleus for late summer color in the spots where the pansies were or try some dwarf marigolds. Salvia or cannas planted between the daylilies give color and height.

Not interested in doing a whole bed?  How about some interesting new plants in your existing garden? Gunnera manicata, giant rhubarb, with its three-foot leaves is a great space filler for a dampish spot; Japanese anemones bloom in late summer; campanula or bellflower is available in many hues; foxgloves can be spectacular in the early summer followed by hollyhocks planted in the same area.

While we have concentrated on sunny garden ideas, these principles can also be used in planning a shade garden.  Snowdrops and miniature narcissi can be the first flowers to bloom, followed by tulips and by bleeding hearts and toad lilies; or you could go with hellebores, sweet woodruff, and Erythronium Pagoda or trout lily for early spring, following with hostas and ferns for a cool summer look.

Having something in bloom all the time is a wonderful thing; enjoy your garden in all seasons!