Growth Habit

• Tulips with large flowers soon deplete the bulb.tulip image by Henryk Olszewski from Fotolia.com
  
  Tulips store their energy in the fleshy bulb, feeding that bulb with springtime foliage before going dormant in the summer and fall. Winter brings the necessary chill period for tulips, without which they will not bloom the following spring. After a season or two, however, the tulip's energy stores are low and the plant may not flower. Additionally, the tulip begins to spend what energy it has left into producing bulblets, which will take several years to produce their own bloom. For this reason, many gardeners treat tulips as annuals, replacing old bulbs with new ones. This law of diminishing returns, fortunately, can be prevented with a little planning.
  
  

Tulip Variety

• Botanical tulips often open wide when blooming.tulip 2 image by Igor Pashin from Fotolia.com
  
  Although those big double blooms or peony tulips are beautiful, the size of these blooms quickly expends what energy the tulip may have stored in its bulb. To ensure returning flowers, choose tulips that are close to the species rather than showy but energy-consuming varieties. University of Minnesota Extension suggests keeping things simple when trying to perennialize tulips by planting varieties such as Tulipa turkestanica, a white star-shaped tulip with multiple blooms, or T. clusiana, a red and white tulip also known as the candy tulip. These botanical tulips, which are varieties closer in form and bloom to wild tulips, will become long-lived perennials easily with the right care. Once a variety has been chosen, always choose the largest bulbs available. Bulbs should be firm, with no signs of rot, mildew or other diseases.
  
  

Planting

• Tulip bulbs are susceptible to rot in wet soils.amstertulip15 image by Jaume Felipe from Fotolia.com
  
  Tulips, like other plants that grow from bulbs, require excellent drainage. Standing water or slow-draining clay soils will encourage rot that will soon kill the bulb. Many gardeners forget the tulips lying dormant under summer plants and continue to unintentionally water the bulbs. To prevent this, tulip beds should be clearly marked and overplanted with low-water perennials. Tulips also need six to eight hours of sun, and will only serve as an annual if planted in shade, even if given the best care. Mulch tulip beds to retain moisture in the summertime as well as prevent frost-heaved tulips from surfacing in winter.
  
  

After Bloom

• Never cut down perennial tulip leaves.tulip bud image by Alison Bowden from Fotolia.com
  
  The strap-like leaves should be left on the plant until they mature on their own. Never trim green leaves from a tulip unless disease is present; only yellow leaves should be removed. In spring, the valuable tulip foliage can be a tasty snack for hungry deer--if deer are a problem, plant tulips in protected areas or with bitter-tasting daffodils. Planting drought-resistant perennials over tulips will camouflage the yellowing leaves as well as add additional color. Keep in mind that even the best bulbs will only produce blooms for a few seasons, even if foliage is left on the plant, when a showy, large-blooming variety is planted.
  
  

Fertilize

• Elegant imperial tulips do not perennialize well.tulips image by Alison Bowden from Fotolia.com
  
  Bone meal was once the fertilizer of choice for tulip bulbs. This is no longer true; modern bone meal has little nutritional value for a growing tulip, and in some cases can attract burrowing animals that will feed on the bulb. Simply top-dress the tulip bed with a slow-release fertilizer or good-quality compost in spring, when the tulip leaves first emerge. If the soil is below average, fertilize the bed again in fall.
  
  

Pests

• Most browsing animals dislike daffodils.Daffodil image by azzzh from Fotolia.com
  
  Gophers, voles, mice and other burrowing animals will readily eat a vulnerable tulip. Protect perennial tulip bulbs from these pests by planting the bulbs in wire baskets or by interplanting tulips with daffodils. Squirrels, the neighbor's dog and other digging pests can be thwarted by laying chicken wire over the bed and covering it with mulch.