Planting summer flowering bulbs is a bright idea

For vibrant cut flowers this season, plant summer flowering bulbs like dahlias, gladiolus and lilies.

These summer blooming bulbs are referred to as tender bulbs. Unlike spring-blooming bulbs such as tulips and daffodils, these tropical plants can be killed by cold temperatures if left outdoors during the winter or planted too early in spring. They need well drained soils but consistent watering.


Dahlias are planted from a tuberous root. For optimal flowering, they should be planted in full sun in spring after the last frost. The taller varieties of dahlias should be planted 6-7 inches deep and shorter varieties to 2-3 inches. Space them 12-18 inches apart, depending upon size of variety. This information is usually located on the package.

Taller varieties need to be staked to support the height and weight. University of Illinois Extension State Master Gardener Specialist Candice Hart loves growing dahlias because of their beautiful and unique colors and shapes. Hart says despite their relatively low maintenance nature, consistent watering is key for blooming. She has lost flower production due to lack of watering during dry periods. Flowers are ready to harvest when fully open.


Gladiolus are planted from a food-storage structure known as a corm. Corms can be planted outside two weeks before the last frost date and every two weeks until the beginning of July for a staggered supply of these beauties.

Plant corms 2-6 inches deep depending on the size of the bulb. Corms may be spaced only 2-3 inches apart for flower production, but 6 inches apart if planted within the landscape. To ensure tall, straight flower spikes, staking is necessary. Gladiolus are harvested when the first few florets at the bottom are open.


Lilies are true bulbs. Grown from bulbs, lilies are perennials and require minimal care. The bulbs can be planted in fall or early spring. Some cut flower growers prefer to grow their lilies in crates.

OT Hybrid or LA Hybrid lilies are the preferred selection for growing cut flowers. OT Hybrid lilies are a cross between Asiatic lilies and Trumpet lilies. Stargazer is one example that combines beauty with heat tolerance. LA Hybrid lilies are a cross between Easter lilies and Asiatic lilies with large flower heads and slight fragrance. Plant bulbs 4-8 inches deep and 8 inches apart. Harvest when the flowers are just starting to show color. Because it is a perennial, do not harvest all the foliage.

Plant care

Hart prefers to use basic bamboo stakes and string for staking her cut flowers and uses a granular slow-release fertilizer on her cut flower beds.

She suggests cutting flowers in late afternoon or evening when the plant’s food has been stored up, or in morning when the stems are full of water. She cuts stems longer than needed and removes all foliage that will be in water and allows warm water uptake for 1-2 hours.

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