The Karl Switzer Rose Circle at Deering Oaks has been fully planted with new dwarf and compact roses that will require a lot less maintenance than the All American Rose Selections that had been growing there for the past few decades.

While the garden shows a lot more bare soil than it has had in past years, all of the roses that have been planted — and there are some the city has not been able to locate yet — are looking healthy and ready to go through a Maine winter.

Jeff Tarling, the Portland city arborist who is in charge of the project, said all of the new roses were planted by the end of June, a little bit later than would be ideal. Most of them had an early bloom, and some of them were just coming into a second bloom in early September.

The Rose Circle is now a test garden for Earth Kind Roses, and three of each variety were planted except for one: Lemon Fizz, for which the city received only two plants. He said Lemon Fizz is a gorgeous, yellow-flowering rose.

“We give them no special treatment,” Tarling said of the new roses. “No pesticides and no fungicides.”

He said city crews are watering the roses for the first year, but beginning next year, the roses will get only the water from natural rainfall.

The Earth Kind program was begun at Texas A&M University about 15 years ago, and the person Portland has been dealing with most in Texas is Kim Benton.

“The program is based on the premise of following Mother Nature, in the way the plants are fed naturally,” Benton said in a telephone interview.

Tarling and his crew added a lot of compost to the soil before the roses were planted, and put mulch on top of the soil after they were planted.

More mulch will be added each year, imitating leaves and other material falling on a forest floor. As it breaks down it becomes soil humus, which will feed the plants.

Benton said the previous Earth Kind trial gardens have been on full-sized roses. The Portland test is the first one for dwarf and compact roses.

“Not everyone’s yard can support a 6-by-6-foot rose,” Benton said, “and that was the premise behind this trial I set up. A lot of people have patios, and need smaller roses or container roses that can be used in a smaller environment.”

So far, Portland is the test garden that is farthest north, but there is one planned for Washington state as well.

The roses are tested in a variety of climates, Benton said, so the study will determine how the roses react to high humidity, drought, heat and cold.

And the study is being done by an independent group, not a nursery that may be biased toward the roses they are testing.

“Just because someone is selling a rose does not mean it will grow,” Benton said. “We don’t want roses that will just survive. We want ones that will knock your socks off despite adversity.”

She said the trial will run for three years, and the roses that die obviously will not get high grades. But there will be ratings from city staff as well as the public.

Right now, all of the roses are marked with plastic tags provided by the nursery. Sometime next year, each rose will be marked by an easily visible sign.

Tarling said that eventually — probably on a Saturday when the Farmers Market is being held at Deering Oaks — there will be a public vote on which roses are best.

For the city of Portland, Tarling said, one of the main benefits of the Earth Kind test is that the city has to spend a lot less time caring for the rose circle, which saves the city money.

The two roses that looked best when I visited were Peach Drift and Raspberry Vigoro, but that was just one day at the end of August.

ON ANOTHER TOPIC, Tarling said the city has been hit by more pests and invasive species of animal and plants.

Hemlock Woolly Adelgid was seen in several places in Portland this summer, on the mainland as well as on the islands. He said swallowwort is getting a good hold on the islands, and it is spreading.

Tom Atwell has been writing the Maine Gardener column since 2004. He is a freelance writer gardening in Cape Elizabeth and can be contacted at 767-2297 or at:

tomatwell@me.com