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Sunday - February 08, 2009

From: Rock Falls, IL
Region: Midwest
Topic: Drought Tolerant, Herbs/Forbs, Wildflowers
Title: Drought and pollution resistant flowers for Rock Falls, IL
Answered by: Barbara Medford


I am looking for hearty flowers for our city planters that are both resistant to drought and auto emissions. We are located in northern Illinois. Planting is done in May.


We're not sure if you are looking just for herbaceous flowering plants, or also for flowering shrubs, so we'll suggest some possibilities for both. At the Lady Bird Johnson Wildflower Center we constantly encourage the use of plants native not only to North America but to the area in which they are being planted. Because they have become accustomed to the climate, rainfall and soil conditions, native plants will require less fertilizer, water and maintenance. We're not sure if there is research available naming some plants more resistant to pollution than others, but all plants, in the process of photosynthesis, are absorbing carbon dioxide and emitting oxygen. It can be a huge tree or a tiny grass, it works the same way, if not on the same scale.

We will go to our Recommended Species section, click on Illinois on the map, NARROW YOUR SEARCH, and select first for "Herbs" (herbaceous plants) and later for "Shrubs" under Habit. Then, we'll take a look at the individual plants and eliminate the ones that call for high water use. Follow the plant links below to the webpage on each plant, where you can establish the size, light requirements and bloom time of each plant. You can go back, using the same procedure, and select also on Light Requirements (sun, part shade, shade), Soil Moisture, etc. and make your own choices. These plants are all commercially available; when you have found some plants you are interested in, if you are having difficulty locating them, go to our Native Plant Suppliers section, type in the name of your town and state in the "Enter Search Location" and you will get a list of native plant nurseries, seed suppliers and landscape and environment consultants in your general area.


Herbaceous Plants 

Campanulastrum americanum (American bellflower) - annual, blooms blue, purple June to August

Coreopsis lanceolata (lanceleaf tickseed) - perennial, blooms yellow April to June

Echinacea purpurea (eastern purple coneflower) - perennial, blooms pink, purple April to September

Geranium maculatum (spotted geranium) - perennial, blooms white, pink, purple March to July

Helianthus strumosus (paleleaf woodland sunflower) - perennial, blooms yellow July to September

Liatris aspera (tall blazing star) - perennial, blooms pink, purple August and September

Lobelia cardinalis (cardinalflower) - perennial, blooms red May to October

Rudbeckia subtomentosa (sweet coneflower) - perennial, blooms yellow July to September


Dasiphora fruticosa ssp. floribunda (shrubby cinquefoil) - 3 to 4 ft. high and wide, may be deciduous or evergreen, blooms yellow June to September

Symphoricarpos orbiculatus (coralberry) - 4 to 6 ft., blooms white, green April to July

Ceanothus americanus (New Jersey tea) - 3 ft. tall, deciduous, blooms white March and April

Diervilla lonicera (northern bush honeysuckle) - 3 ft. tall, deciduous, blooms red, orange, yellow, purple June to August


From the Image Gallery

American bellflower
Campanulastrum americanum

Lanceleaf coreopsis
Coreopsis lanceolata

Eastern purple coneflower
Echinacea purpurea

Spotted geranium
Geranium maculatum

Paleleaf woodland sunflower
Helianthus strumosus

Tall blazing star
Liatris aspera

Cardinal flower
Lobelia cardinalis

Sweet coneflower
Rudbeckia subtomentosa

Shrubby cinquefoil
Dasiphora fruticosa ssp. floribunda

Symphoricarpos orbiculatus

New jersey tea
Ceanothus americanus

Northern bush honeysuckle
Diervilla lonicera

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