• These bright perennials are the national flower of Mexico, the dahlia's country of origin.dahlia image by Luc FLANDROIT from Fotolia.com
  
  Dahlias are beautiful, bushy tuberous perennials that bloom summer through fall with big, brightly colored flowers. Dahlias planted April through May in a sunny location produce the best results. These flowers require a water regimen appropriate to their stage of development. Overwatering will drown them, so avoid planting dahlias in areas where soggy conditions may occur.
  
  

Soil Preparation

• Proper soil preparation is essential to grow dahlias from seed because of their moderate watering requirements. The soil should be warm--about 60 degrees Fahrenheit--well-drained and in a sunny location to prevent oversaturation. No mulch or other ground cover is required. That extra material may hinder the growth of sprouts and hold more water than is necessary for the dahlias' growth.
  
  

Initial Planting

• After you've planted the seeds, water only once so that the soil is damp. Don't water again until after sprouts have appeared above ground. This typically takes between seven and 10 days. In hotter climates, the dahlia seeds may need some watering before the sprouts appear. During the initial sprouting phase, lightly water dahlias periodically to dampen the soil, but be careful not to overwater.
  
  If you intend to transplant juvenile dahlias into flowerbeds, however, liberally water them until the young roots are established. This process takes one to two weeks.
  
  

Established Flowers

• When their sprouts become young flowers, the dahlias' need for water quickly increases. Once the dahlias have established themselves and their root systems have matured, the flowers require deep watering several times a week for at least 30 minutes with a sprinkler. In hotter conditions, more frequent watering is necessary. Without enough water, the dahlias will not bloom successfully.