The Artist's Landscape: Perennials & Annuals

Color, texture and light. These three words, although synonymous with the painted picture, are a necessity in landscape design.

"I create a work of art when I design a landscape," related Louis Kobus, agronomist, Village Turf, Mt. Vernon, Va. "But instead of using brushes and paints, I use a variety of plant material."

Planting the right perennials and annuals for the right amount of impact on a job can be just as challenging as mixing colors together on a pallet to create the perfect skin color. Although color, texture and light offer a wealth of opportunities for creativity, they aren’t the only factors contractors must consider when incorporating perennials and annuals into the landscape picture. Knowing the differences in bloom time, growth conditions and cost, and taking advantage of this knowledge when using perennials, annuals or a combination of both can turn a crayon drawing of flowers into Monet’s garden.

THE BASICS. Perennials and annuals each have their own advantages and disadvantages, according to contractors.

"Perennials offer color that returns every year and add texture to the landscape," offered Bruce Allentuck, president, Allentuck Landscaping, Gaithersburg, Md. "The biggest disadvantage of perennials is that they have a fairly limited bloom time. Annuals, on the other hand, bloom all season long, presenting bursts of color."

Perennials have an average two- to three-week bloom time, said Greg Fracker, president, Colorscapes by Design, Newark, Ohio, so for season-long color, a contractor may need to install seven to eight different types of perennials, which can hike up the cost.

While using perennials, a client may spend more initially, Fracker explained, but over time perennials are actually less expensive. "A flat of annuals costs $11 to $15 compared to two 1-gallon perennials for $16 in the Ohio market area," Fracker shared. "But while annuals are cheaper, they need to be planted over again every year."

According to Scott Gardner, nursery manager, Barnes Nursery, Huron, Ohio, perennials can be bought for $2.99 per quart size and two to three gallons of perennials are available for $10 to $25.

"When a new variety of perennial comes out on the market, it can cost as much as $5 to $7," Gardner said. "Once the newness of the variety wears off – in about two to four years – the price comes down."

"We tend to use perennials and annuals together in the landscape to get the best of both worlds," Allentuck added. "This does take a serious commitment from the client, though, because re-designing particular areas of a landscape or, in some cases, entire landscapes altogether is often in order. Not every client is willing to make that kind of investment in time and money."

Fracker said he installs more annuals in his commercial clients’ properties because residential clients tend to favor perennials for their lower long-term cost. "Most commercial corporations have money to spend on annuals and want the instant color they bring," Fracker pointed out.

"Perennials should be used when the client wants color and texture and is willing to spend a little more money up front instead of having the on-going expense of having to replace the annuals every season," Allentuck said. "Also, clients who want a somewhat contemporary look may want to use large sweeps of perennials for a variety of textures, whereas annuals should be used when strong color is required."

Charlie Bowers, co-owner and chief executive officer of Garden Gate Landscaping, Silver Spring, Md., said variegated perennial foliage can also add spots of light to shade gardens.

"We use perennials to cover larger areas in broad sweeps to achieve light and texture, making a specific statement at some point during the season," he said. "In the Mid-Atlantic region, we plant annuals in early May and they last until mid-October. Since we are strictly residential, our annual plantings are specifically used to bring season-long color to small spaces in the garden and in containers, both in the front yard and patio garden areas. Container plantings have become a renewed form of garden art and have increased in popularity."

Paul Hubbs, president, Grower Systems, Lancaster, Pa., agreed that container plantings, usually done with annuals, have become more of a trend: "Hanging baskets and patio containers can add visual impact here and there, where the growing conditions are favorable for the plant."

GROWING UP RIGHT. Perennials adapt better to a variety of growing conditions, Hubbs explained, while annuals thrive in direct sunlight.

"Perennials offer more diversity as to what you can do with them as far as environmental factors are concerned," Hubbs explained. "Perennials don’t need as much sunlight. In the meantime, annuals feed off the sunlight and put all their energy into producing seeds and blooms, expending themselves."

Unlike perennials, annuals require a little more maintenance, Gardner said. "If annuals are planted too early in the spring and are hit by a frost, they die," Gardner said. "Contractors need to be patient and wait until the danger of frost has passed to plant annuals."

Certain varieties of annuals also need constant watering, fertilizing and pinching, Allentuck pointed out.

"Because certain varieties of annuals, like geraniums, need a lot of deadheading, we have to be flexible in what we plant, especially on commercial accounts because the property manager is less likely to take care of this maintenance," Gardner said. "Annuals that re-bloom without much maintenance are begonias and impatiens.

"Once perennials are planted, they repeat bloom every year," Gardner continued. "Some perennials need to be dug up and replanted, but in our growing area, 75 percent of the perennials planted will bloom again the following year."

Barnes said that certain perennial varieties, such as the commonly mis-planted hosta, thrive only in shady areas that offer filtered sunlight.

Some perennials also tend to naturalize and enjoy out-of-control growth while others may not look their best all season long.

To prevent a perennial takeover, some plants require division. Some versions need to be separated as frequently as every other year, suggested Ann Hancock, horticulturist/curator, DeLapa Perennial Garden at the Michigan State University Horticultural Demonstration Gardens, East Lansing, Mich.

While constant maintenance is required for certain perennials and annuals, and others need just a little tender loving care, people still tend to expect instant fullness after an installation, Gardner remarked.

"People look at gardens that have been in place for 20 years and want that look," Gardner said. "If annuals and perennials are planted too close together, however, they don’t have adequate spacing to grow. People can’t achieve a ‘flower show’ look unless plants are constantly and carefully maintained and divided. A full garden is not instant and can be a maintenance nightmare."

LOOKING FOR VARIETY. According to Bowers, unique perennials and annuals are in short supply.

"Growers continue to grow the same old plants," Bowers said. "They are not adventurous or inventive. Growers have the philosophy of ‘If we grow it, they will come.’ So what’s popular is driven by what’s available."

"The average residential customer wants the landscape to look good and, honestly, could care less what we use," Bowers said. "We send customers that are picky about variety and/or color to a garden center to buy their own plants and then we’ll install them when we come to their property for a regular visit. There isn’t enough money in residential accounts to search all over for specific plants, especially plants with perfect color. Color is too subjective."

Some of the most popular annuals and perennials Hancock deals with have color that can compliment any other plant partner.

"One of the most popular annuals we deal with now is Purple Fountain Grass," Hancock said. "It can be forced early so that the consumer is able to enjoy a lush plant in full bloom. The plant has deep burgundy foliage and graceful, pendulous flowers. Thus far, we have not had any problems with deer eating it, nor does it seem to be susceptible to any insect or disease problems.

"As for perennials," Hancock continued, "in full sun, Russian sage is popular because its color and texture make it a good companion to other plants. Additionally, it is not attractive to deer or susceptible to insects or disease. One other popular perennial is the purple coneflower. People love it because it is very hardy, and attracts butterflies. This perennial is, however, attractive to rabbits, and sometimes gets a powdery mildew in the late summer."

Bowers said there is a list of bulletproof perennials that perform well in Maryland.

"Some of the old standbys include Black-eyed Susan, hosta and coneflowers – all perennials," Gardner offered. "The Perennial Plant Association named Scabiosa Butterfly Blue the 2000 perennial of the year. Also popular this year are herbs, such as rosemary with its purple blooms and lavender, which provides a great look and scent, but is a plant that doesn’t like wet feet."

Variegated Jacob’s Ladder also looks like a good perennial to try, Allentuck said, and he always relies on coreopsis, Russian sage and Golden Rod. The annuals Allentuck prefers are petunias, salvias and begonias.