Dahlia Dahlias for the Pacific Northwest Garden

Dahlias are available in dozens of shapes and in sizes ranging from petite mignons and poms little more than an inch across to giant decoratives over a foot in diameter.  They come in a dazzling array of colors – reds, pinks, yellows, oranges, lavenders-complementing just about any garden setting.

Although dahlias are native to the highland areas of Mexico and Central America, they are particularly fond of our cool-summer Northwest Coast climate in Washington State, and it’s easy for anyone to grow them to perfection with very little care.

How to Plant

You can safely plant sometime between April 15 and June 1.  Check your soil; it is better to plant when the soil is slightly moist.  Place the tuber flat with the eye upward.  The tuber should be about five inches below the ground. The tubers should be planted shallower in heavy soil.  You will need to be weary of slugs.


You should water about every two weeks.  Certainly more frequently during very hot weather, and when buds begin to form.  Deep watering is better than frequent light watering.


You will increase the number of blooms and the length of the bloom time by deadheading. 

Cut Flowers

Blooms should last several days.  You will get the best results if you take cuttings early in the morning or late at night. Display flowers in a cooler area of the home. If you mist regularly and change the water every other day you will get your blooms to last several days.


Around November 1 you need to cut down the dahlias and then dig around the root so you can carefully lift the entire plant from the hole.  The stalk should be trimmed at root level, washed, and then soaked in fungicide.  The roots will keep best if the storage area is cool and above freezing. Line a box with plastic and put in alternate layers of vermiculite and dahlia roots. Be certain to check the dahlia roots on a regular schedule.  Dahlia roots can be left in the ground and will survive cold winter days if kept from freezing.  Good drainage is essential for roots to be kept successfully in this manner.

Annual Dahlia Tuber & Plant Sale

The Seattle Dahlia Society holds its annual tuber and plant sale each April that is open to the public.  Dahlia experts will be on hand to answer any and all questions.


Country Village (Map)
23718 Bothell Everett Hwy,
Bothell, WA 98021-9363


Saturday April 20th, 10am to 6pm
Sunday, April 21st, 11am to 5pm


  1. One of the easiest flowers to grow, as long as they get plenty of sunshine.

  2. We have to lift them in fall, so I plant few. I like them a lot, but so do the slugs.
    Donna recently posted..Buzzing a Crocus Says Spring is HereMy Profile

  3. Thank you, Charlie, for reminding me of when I can replant my dahlias. For the first time I overwintered mine successfully by keeping them in my husband’s workshop rather than the potting shed – which was too damp…

    Blessings ~ Wendy
    Wendy recently posted..Bees and Blooms MedleyMy Profile

  4. Thank you so much for this information, Charlie.
    I love dahlias, but for some reason do not have very much luck with them.
    I planted a variety called “Dinner Plate Dahlias” last year, but surely they were not dinner plate size. A couple of them actually bloomed though! 🙂

    I hope you’ve had a wonderful weekend, and i wish you a bright week ahead!

  5. I had simple dumb luck with Dahlias for years, lately, not so much…so thanks for this tutorial. I’ll see what happens when I follow the rules.
    ricki recently posted..out like a lambMy Profile

  6. It is amazing how many varieties there are!

  7. Such pretty flowers, aren’t they?
    ladyfi recently posted..La lumiere d’oreeMy Profile

  8. Thank you for the wonderful information! Happy Sunday, Charlie!

  9. Pingback: Annual Dahlia Show | Seattle Trekker

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