Dead head tulips in the Indiana garden

Dead heading tulips and keeping petals out of the leaf axis will help them bloom next year in the Indiana garden. (C) Jo Ellen Meyers Sharp

Indiana gardeners struggle with tulips that don’t come back year after year. There are a few things we can do to help the spring blooms.

Tulips do best when allowed to go through a hot, dry period in summer to process nutrients into energy for blooming in spring, said Frans Roozen, technical expert with the International Flower Bulb Centre in the Netherlands. He discourages summer irrigation where tulips are planted to allow the soil to heat up and bolster the tulip’s staying power.

Indiana gardeners and others should remove the spent flowers as soon as the flowers fade, called deadheading. Snipping off the spent flowers directs the plant’s energy into replenishing the bulb rather than setting seed. Deadheading also keeps the petals from falling into the leaf axis, Roozen said

When the petals land where the leaf meets the stem, they block sunlight and clog the plant’s ability to take up water, he said. The result is smaller and smaller flowers until the tulips just disappear. This is particularly true for the larger types of tulip hybrids.

Here are other tips he provided to me and nearly 30 other garden writers from throughout the world during our April visit to the Netherlands to learn more about tulips and other Dutch bulbs.

• Apply an all purpose fertilizer around the tulips as soon as their leaves break ground in spring.
• Do not remove the foliage until it turns brown or yellow and falls flat, a process called ripening. The leaves carry the nutrients needed for next year’s flowers.

When working with landscape designer Piet Oudolf’s master plant for Battery Park in New York City, Roozen wanted tulips that returned year after year in the Garden of Remembrance and other key sections. His selections:  ‘Spring Green,’ (Tulipa viridflora), ‘Little Wonder’ (Tulipa bakeri) and the species, Turkestan tulip (Tulipa turkestanica). I have each of these and can attest they return every spring with minimal care.