What could be better than a giant pot stuffed to overflowing with nicotiana? OK, probably plenty of things, but no doubt I am a big fan of the nicotianas. There are a number of ornamental tobaccos suitable for cultivation in our area. The species nicotiana alata pictured above grows strongly to 30″ or better. It has a loose, rangy, and unstructured habit of growth. Sporting clusters of big leaves at the base, the flowers appear all along thin soft stems. They are indeterminate bloomers; a stalk will continue to elongate and produce flowers for months. Once a stalk blooms out, and starts setting seed, I trim it back.
The species nicotiana alata is very fragrant in the evening, but my favorite part is the simple star shaped flowers. Individually, they have the same impact common to any simple flower. I favor hellebores, single roses such as Sally Holmes, mandevilleas and Japaense anemones for this reason. Single flowers are swell. The individual florets make a graceful mass; I like the looks of the from the sides and the back, as much as from the front. In the box pictured above, Nicotiana Alata white, Nicotiana alata lime, and Nicotiana Perfume white-the shortest of the group.
Nicotiana alata lime is a brilliant lime. The petals are thin eough to permit light to shine through. Their color makes every other color look good, and they are equally as effective if a combination of greens is your idea of beautiful. I always have them close by my deck, as hummingbirds visit regularly. I would much rather grow nicotianas and fuchsias, than deal with a hummingbird feeder.
A pairing with Panicum Virgatum Dallas Blues makes that grass all the more icy blue in appearance. Grasses can be difficult to do well in a container, as they are stiff, or awkwardly floppy. Nicotiana makes for a graceful ruff here. They are not without their problems, however. The sticky soft succulent stems are a magnet for aphids. Their giant basil leaves sometimes need pruning back when they threaten to smother something else growing at ground level.
Some nicotiana hybrids are short, stodgy and airless in appearance; I do not grow the Avalon series for this reason. Of all the shorter growing hybrids, the Perfume series seems the most graceful. Perfume purple is a most unusual and intense red purple; true to its name, the smell is divine.
But by far and away my favorite is Nicotiana Mutabilis. It grows tall, and billows out over any edge with a cloud of small flowers that dance in the slightest breeze. Can you tell I like it? The flowers range from white to cream to pale pink to rose pink. This big thing requires secure staking from the beginning. It will pick up speed, and send out new growth from the base of the plant as the night temperatures start to cool.
They are a nuisance to keep deadheaded-I don’t fuss so much with that. Its hard to spot which stems need headling back, and every part of the plant is sticky. This seems a fairly minor problem to me; a well grow stand of mutabilis is enchanting.
You can see the new growth pushing from the base of this pot on both sides; all of this came on strong in September, and will continue until a hard freeze. They also seem much more aphid-resistant than other nicotianas.
The individual flowers are so small and so delicate; the overall picture is delightfully meadow like. All of these nicotianas are a staple of my summer garden.
Topiary is the art of pruning, and training a plant to grow in whatever shape you might fancy. Plenty of plant species lend themselves to this kind of treatment. The above pictured lantana is seven years old. It began as a small plant, whose side branches were removed until the primary trunk was about four feet tall. A devoted grower then pinched back the main leader-the first step in the formation of the top. As I like slightly flattened spherical shapes in topiary, we keep the top pruned, and grow the side shoots wide. Lantana flowers profusely in hot weather, it makes a strikingly statuesque topiary plant. In the fall, I cut the head of the plant back by two-thirds,, strip all the remaining leaves off, and stash it in the greenhouse. I strip the leaves off, as lantana is a magnet for whitefly-and they multiply like lightening in a green house environment. What they require is plenty of trouble, but it is glorious in form and flower.
Well grown large topiary plants are expensive. It takes a lot of time to grow them on-sometimes years go by before a plant can be sold. This dwarf variegated euonymus with a batch of leaves atop a stem tells the story. In ten years, this plant will not be much taller-just much stockier, with a full head of leafy branches. As euonymus is a hardy shrub, they like to be wintered in a cool light place.
Bay Laurel is not hardy here, unfortunately-so a greenhouse is a necessity in the winter. This plant is 14 years old. This single ball topiary suckered at the base so persistently, I finally just let it grow. The formal shape is easy to keep up; you can see it needs a little haircut right now. There are many kinds of topiary shears available-I like short bladed snips, so I can cut branches without slicing into the leaves. Any leaf that is cut will show that telltale browing on that cut edge within days. �
Coleus makes a great topiary, but the growing process is different. As it is a short lived annual plant, they need to be grown fast. Coleus, irisine, geraniums and the like are given a push with a growth hormone. The specific hormone causes the cells of the plant to elongate; the stem develops fast. One crop of 50 tree geraniums I grew 20 years ago got treated five times before they reached their four foot finished height. Topiaries grown from non-woody plants need careful staking of the stem-that stem will never be as strong as a branch. I usually stake with a pair of bamboo stakes, for extra insurance. A beautiful topiary-its head snapped off in a wind- this is enough to make you fall to the ground and weep.
Some woody plants have such a tight habit of growth that you might suspect they were topiaries from the beginning. Dwarf Alberta Spruce is one such tree that lends itself to the pruning process with ease. An Alberta Spruce of this gorgeous shape and size is expensive; many many years has gone into the growing and shaping process. As they are hardy, they can make a big statement as a centerpiece in a formal garden.
Gardenmeister fuchsias are vigorous growers and bloomers; they make an ideal subject for an informally shaped topiary. They are easy to winter over, and bloom continuously from spring to fall. This topiary is supported on the interior by a column of heavy grade wire fencing. Once the multiple stems and flowering shoots grow in, that support fades from view. Big fuchsias make good subjects for topiary in general-but I like the vigor of this particular variety.
Ivy can be readily be trained over a wire form. This makes it an ideal subject for fast growing. The vines are tied to the form to provide completely coverage, and the vines are clipped as needed. Hedera algeriensis ” Gloire de Marengo”, or variegated Algerian ivy, has large glossy leaves, and a prominent white variegation; old topiaries grown from this plant are striking. A bonus-it is possible to winter ivy topiaries over in the house.
The coleus topiary I let go after two seasons-they seem to loose vigor. The minute you decide to grow a plant in any form which is not its natural form, there will be maintenance problems down the road. Plants tolerate being fooled with by people-they rarely love it. Plants that naturally lend themselves to this treatment are easier to look after.
For all their trouble, a well grown topiary plant can instantly provide large scale to a new planting. Handsome, this. Should you be the patient sort, try growing one of your own. Lacking patience, the nursery industry offers many different species of trained to shape plants. I admire any pair of hands that can make them grow.
On my top ten list of frequently asked questions, the culture of evergreens in pots ranks right up there. In theory it sounds great. You invest in an evergreen which will provide you with a center of interest that looks great no matter the season. Perhaps there will be room on the edges for a few seasonal annuals. The work and expense up front is considerably more than planting smaller and less expensive plants, but then you are done. Redoing one’s pots with new plants every new season no doubt is a lot of work and expense. But as with everything connected to growing a garden, one is rarely “done”. The Italian cypress in the pot pictured above is not hardy in Michigan, nor can one leave a terra cotta pot such as this one outdoors during the winter. The cypress has to be wintered in a greenhouse cold storage area, and replanted every spring. The pot is put away. There is time and trouble hauling it back to the greenhouse in late fall.
This 25 year old rosemary has spent 25 winters in a glass house. It is an evergreen-should you live in Greece or Italy, or California. Michigan winters are fiercely cold. However unfair it seems, rosemary is just not hardy here. In return for the extraordinary pleasure of owning an old rosemary such as this one, my client is willing to weather what it takes to keep it alive and healthy.
Junipers on the other hand are ruggedly hardy. But key to the successful culture of evergreens in pots is to understand that at best, they tolerate this treatment. Growing a plant in a pot is actually about growing a plant with its roots above ground. No plant likes this-they may or may not put up with it. Siting is the first crucial issue. Evergreens must survive the winter and stay green without being able to take up water. A windy location can dessicate the needles-thus the term, winter burn. A winter burned plant is still alive, but it’s not a good look. It will take time to grow out of the scorched needle phase.
Mugho pines, both the shrubby and the topiary forms, have the reputation of good survivability in pots. Critical to that survival is proper watering. Should you quit watering this evergreen when your geraniums go down from frost, you are almost certain to loose it. Judicious watering right up until the soil ball is frozen solid is a must. If this evergreen were to unfreeze in a January thaw, a watering might be in order. When the soil thaws in the spring, the watering should be resumed-even if this is long before you plant your other pots. What evergreens in containers require is not for the faint of heart.
This grand old myrtle topiary was beautifully maintained, for 11 summers. The 12th winter in the greenhouse, a furnace went out, and it froze. It has been in the greenhouse for the past two years; we are trying to coax it back to health. Owning plants like this is a big committment with little in the way of any guarantee. Just because you have provided next to perfect care for a long time does not mean you cannot loose it. Evergreens in containers are for gardeners who relish risk.
These mugho pines on standard have lived in these orangery boxes for 6 years. At some point, they should be taken out, root pruned, and reset in fresh soil. They will most certainly decline without this maintenance. No plant stays the same, just because its container stays the same. Plants will prosper and grow, or sulk and decline-one or the other.
Boxwood is a good choice for a container. As this French terra cotta pot cannot be left out, I wheel this entire assembly into the garage for the winter. This species, Buxus Microphylla, is very tough; my hedge on the southside of my building never winter burns. In the same spirit, it tolerates a mostly dark and unheated garage from November until March. At the first sign of moderating temperatures, I take it back outside. A garage can get too warm for holding plants dormant long before the outside temperatures moderate.
Waxleaf privets are an aristocratic cousin of our hardy privet. The large leaves are lustrous and juicy looking. They are hardy in zone 7, so they can be wintered in an indoor spot without much in the way of heat. They grow slowly, and are available in big sizes; there is demand for the topiary forms from gardeners in more temperate regions. They take well to pruning and shaping.
These giant scotch pine on standard are breathtakingly beautiful. I kept them in equally giant wood barrels for the better part of two years, before I sold them. Evergreens need big rootballs to insure successful transplanting-so pots for evergreens need to be large. Boxwood balls are usually larger than their foliage diameter. A well-grown evergreen in a gorgeous container is hard to beat; most likely I will keep on trying to grow them.
Deborah Silver is a landscape and garden designer whose firm, Deborah Silver and Co Inc, opened its doors in 1986. She opened Detroit Garden Works, a retail store devoted to fine and unusual garden ornament and specialty plants, in 1996. In 2004, she opened the Branch studio, a subsidiary of the landscape company which designs and manufactures garden ornament in a variety of media. Though her formal education is in English literature and biology, she worked as a fine artist in watercolor and pastel from 1972-1983. A job in a nursery, to help support herself as an artist in the early 80′s evolved into a career in landscape and garden design. Her landscape design and installation projects combine a thorough knowledge of horticulture with an artist’s eye for design. Her three companies provide a wide range of products and services to the serious gardener. She has been writing this journal style blog since April of 2009.