A hosta trial has been conducted at the LSU AgCenter Hammond Research Station to select hostas adaptive to the climate in southern Louisiana. We evaluated landscape performance and overwinter success of most hostas having H. plantaginea ancestry, which are more heat-tolerant and require less chilling hours, and also selections from H. sieboldians (blue foliage) cultivars that are locally grown and top varieties from the American Hosta Society popularity poll. Two raised beds were established in 2009 with 35 cultivars planted, and more were added over the years for a total of 61 varieties (Table 1). Five plants of each cultivar were planted as a group. The majority of varieties were bare-root divisions at planting. The beds were fertilized every year with Osmocote 14-14-14 (3-4 mo.) at 1 lb N/1,000 ft² in April, and chicken manure (4-2-1) at 1 lb N/1,000 ft² in June. Irrigation was provided with overhead micro sprinklers.

Plants were evaluated for overwinter return (survival %) each spring, and growth (size) and quality (visual rating) each summer. Emergence date, color differences between young and mature leaves, flower scape height, flower color and environmental stress symptoms, i.e. leaf burn and chlorosis, were noted.

Top 10 cultivars selected from this trial include: Iron Gate Delight, Fragrant Bouquet, Guacamole, Stained Glass, Krossa Regal, So Sweet, August Moon, Royal Standard, Albo Marginata and Francee. All of these cultivars established easily and returned reliably every spring for three years. Use these dependable and versatile hostas in your garden with the peace of mind that they will provides color, contrast and texture to the landscape with little care.

1. Iron Gate Delight: one of its parents is H. plantaginea. Introduced in 1981 and has 5-inch-long oval leaves with a very dramatic border that emerges gold and then changes over to cream, this is an improved So Sweet and a vigorous grower that matures into a 3-foot-wide clump, further enhanced with extremely fragrant lavender flowers on 2-foot scapes in midsummer.

2. Fragrant Bouquet: H. plantaginea. Vigorous grower. The wavy, heart-shaped leaves are apple-green variegated with a creamy margin. Large, fragrant, funnel-shaped, near white 3-inch-long flowers appear in summer on scapes rising above the foliage mound. 4 feet wide x 2 feet tall.

3. Guacamole: Reverse variegated sport of Fragrant Bouquet. Leaves are 11 inches long x 8 inches wide, very shiny with chartreuse-gold center and a wide dark green margin. Forms large, dense clumps. In late summer, 3-foot-tall flower stalks emerge, bearing fragrant, large, white blooms. The plant will flourish with some direct sun and is one of the last to go dormant.. Great size and gorgeous contrasting colors with fragrant flowers in August. 4 feet wide x 2 feet tall.

4. Stained Glass: A sport of Guacamole. Heart-shaped, gold-centered leaves with puckered texture. Midsummer blooms are sweetly fragrant. A slower grower, 3 feet wide x 20 inches tall.

5. Krossa Regal: The heavy, leathery, blue-green leaves are slug resistant. It is the most planted large blue hosta. It has continually ranked near the top in U.S. popularity for many years. 6 feet wide x 36 inches tall.

6. So Sweet: Small and upright. Features a vase-shaped clump of flat, glossy, lance-shaped, medium-green leaves with white margins. Racemes of funnel-shaped, fragrant, white flowers show up in midsummer on 14-inch scapes. 2 feet wide x 8 inches tall.

7. August Moon: Heart-shaped, cupped, puckered, pale green leaves provide interesting color and attractive texture. Large and vigorous mounding hosta. Bell-shaped, grayish white flowers are borne on 28-inch-long scapes from mid-July through early August. Can take more direct sun than green leaf hosta. 3 feet to 4 feet wide x 1 ½ feet to 2 feet tall.

8. Royal Standard: A cross between H. plantaginea and H. sieboldiana, patented in 1986. A large hosta that grows into a mound of 5 feet wide x 26 inches tall. Narrow, oval, bright medium green leaves (9 inches by 5 inches) with a satiny sheen and faint marginal undulations, distinctive veining, acute tips and cordate lobes. Highly fragrant, funnel-shaped, white flowers bloom in late summer to fall on leafy, pale green scapes rising well above the foliage mound to more than 3 feet tall. It’s one of the earliest to emerge.

9. Albo-marginata: H. undulata. Bold, large, shield-shaped leaves with a deep green center and creamy-white margins turn white with age. Funnel-shaped mauve flowers borne on leafy scapes 32 inches long appear in midsummer. Plants are medium size, 2 feet wide x 20 inches tall.

10. Francee: The dark green, heart-shaped leaves have a clean white margin. The funnel-shaped flowers are lavender and the scapes are 36 inches tall. This plant makes a choice white-edged hosta for every garden. 51 inches wide x 21 inches tall.

Cultivars that were able to establish and return from winter but grow fairly slow under our summer conditions include Christmas Tree, Eternal Flames, Gold Standard, Hoosier Harmony, June, June Fever, Night Before Christmas, Patriot, and Sum and Substance. They will need additional one or two years to reach the variety-specific mature sizes.

Cultivars exhibiting heat stress (leaf edge turns yellow or brown during summer) include Captain Kirk, Cherish, Frances Williams, Golden Tiara, Last Dance, Minuteman, Paradigm, Paul’s Glory, Sea thunder and Wide Brim. However, Captain Kirk, Cherish, Last Dance, Paradigm, Paul’s Glory,and Frances Williams grew well in containers under a shade structure.

Cultivars that did not return from winter dormancy the second year or died out gradually over three years include Blue Angle, Blue Mouse Ear, Gingko Craig, Hadspan Blue, Mini Blue, Moon River, Samual Blue, Sun Power,and Wheaton Blue. However, Blue Mouse Ear, Gingko Craig and Moon River were able to grow and return when planted in containers.

Table 1. Hosta cultivars that have been evaluated at the LSU AgCenter Hammond Research Station.