Yellow Lantern heralds spring

In the waning days of winter, the wonderfully fuzzy buds of Yellow Lantern cucumber magnolia (Magnolia acuminata "Yellow Lantern") flowers become plump, signaling that spring is approaching. But Yellow Lantern bides its time. Its pale yellow flowers don't appear until after the risk of bud-zapping frosts has diminished, making Yellow Lantern a good magnolia for area gardens.

In May or early June, tuliplike flowers 2 to 4 inches long make the wait worthwhile. Sitting upright on twig tips, Yellow Lantern flowers are both pleasantly fragrant and long lasting. While arguably not as showy as the flowers of other magnolia species, its aristocratic charms are undeniable. And because it's a hybrid of a Midwestern native species, Yellow Lantern feels at home in area landscapes.

This spring-flowering tree offers summer and fall features as well. Among its large, dark green leaves are 3-inch green fruits resembling tiny cucumbers, hence its common name: cucumber magnolia (or cucumber tree magnolia). In fall, fruits become pinkish-red and dark red seeds pop to the surface, providing bursts of color in fall's golden foliage.

Yellow Lantern cucumber magnolia grows 25 feet tall, making it a good shade tree for smaller yards. It can be planted in early spring in a location with full sun to partial shade in moist, well-drained soil. Cucumber tree is pH adaptable, but prefers a lower pH, more acidic soil. It has no serious disease or insect problems, but is intolerant of urban air pollution. Yellow Lantern offers its multiseason rewards to patient gardeners. It can take up to 12 years before trees begin blooming. As with all spring-flowering trees, when pruning is needed, do it immediately after flowering. This helps to preserve the maximum number of fuzzy flower buds and pale yellow flowers the following spring.

CAPTURE AND USE, OR LOSE

An important benefit of a green roof is its ability to quickly absorb large amounts of rainwater. This helps to prevent heavy downpours from overloading sewer systems, and puts rainfall to good use watering plants that provide other important benefits. Rooftop soils slowly release excess rainwater over time, when sewers again have capacity.

But what can you do if you don't have a green roof but have problems with runoff from roofs, driveways, patios or slopes? A rain garden just might be the answer. Rain gardens not only help to remedy storm water problems, they cycle rainfall back into the natural system of local groundwater. Rather than flowing away in sewers, water is captured, allowing it to percolate and refill streams, aquifers and wells.

A rain garden can be created in a shallow depression where water naturally collects. Or a depression can be excavated and bermed close to the source of a runoff. To avoid problems with seepage, keep rain gardens at least 10 feet from a house or other built structures.

Line the perimeter of the depression with trees, shrubs and plants that tolerate both flooding and drought, and can cope with heavy flushes of nutrients or other chemicals.

Good plants to consider using are joe-pye weed (Eupatorium maculatum), goldenrod (Solidago spp.) bristly sedge (Carex comosa), river birch (Betula nigra), and arrowwood (Viburnum dentatum). For more recommendations, call the Plant Information Service at (847) 835-0972.

Denise Corkery is a horticultural writer at the Chicago Botanic Garden in Glencoe.

AT THE GARDEN

LECTURE: "The Coming Transformation: American and the Environmental Future," a free lecture with Dr. Gus Speth, dean of Yale University's School of Forestry & Environmental Studies, will take place at 7 p.m. Thursday. Preregistration is required: (847) 835-8261 or www.chicagobotanic.org/ school/symposia/speth.

CLASS: Learn about new varieties and the best choices for Midwestern gardens in a class on flowering Magnolia trees, 1-4 p.m. April 12. To register: (847) 835-5440 or www.chicago-botanic.org/school/class_schedule.

LILIES: Experts will demonstrate how to grow and show lilies, and how to create award-winning floral arrangements at the Wisconsin-Illinois Lily Society lecture, 2 p.m. April 13 in the Regenstein Center. For more information: www.chicago botanic.org/plantshows.

ANTIQUES: Mark your calendars for the Antiques & Garden Fair, April 18-20. For more information and advance ticket sales: www.chicagobotanic.org/antiques.

Color Photo: The Yellow Lantern cucumber magnolia has fuzzy buds that become plump, a signal that spring is around the corner. ; Color Photo: Robin Carlson, Chicago Botanic Garden /Look for the Yellow Lantern's tuliplike flowers to stand 2 to 4 inches in May or early June. ; Color Photo: Learn how to grow and show lilies on April 13 at the Botanic Garden's Regenstein Center. ;