Secret tips to growing showstopping dahlias

Dahlia grower Robert Papp calls the Show 'N' Tell class of the flower a 'showstopper'

What is it about dahlias that generates such passion in gardeners?

"Their diversity and the way they make people smile," explains Robert Papp, president of the South Coast Dahlia Society. "There's always something for everybody."

Look for Papp's blooms at the South Coast Dahlia Show Aug. 16-17 at the South Coast Botanic Garden in Palos Verdes. The show will feature a variety of categories for competition. And an added bonus for dahlia lovers: The colorful cut flowers will be given away at the end of the show.

Papp shares some insight, tips and secrets on the popular blooms.

For the uninitiated, what is it about dahlias that endears them to gardeners and plant lovers alike?

There are 20 different forms of dahlias and 10 different sizes. As far as colors go, they can be solid, blends, bicolor and variegated. There are no black or blue dahlias. There are shades of lavender that look blue and shades of purple that look black. There are 7,615 classes. The one I like the best is Show 'N' Tell, a large red and yellow flower with split tips. It grows up to 10 inches. It's a showstopper.

Water is such an issue. Do dahlias require much water?

Dahlias like a deep water. I soak mine twice a week. The two death knells for dahlias are too much water, which will rot the tubers, and cold. You don't want to hand water them. That way, you only get water a couple of inches down and that's not where the roots are. I use a drip irrigation system. It saves most of the water. The soil is the most important thing. Dahlias like a slightly acidic soil, so I'm intent on my soil being organic. Good soil will retain water. I'm also big on vermicomposting. I make worm compost tea and use it for a drench and spray the foliage with it.

Dahlias can grow quite tall. Is staking a must?

You don't have to stake a 4-foot plant. But you have to stake the larger blooms. I like to use a 10-foot conduit cut in half. It's very cheap and very sturdy. I also use tomato baskets and put them over the tubers. Just keep tying them as they grow.

Where is the best place to find dahlias?

Check out, the American Dahlia Society website. It provides a list of commercial growers. I suggest buying locally. I don't like buying them at hardware stores. You're buying a pretty picture. Dahlias come in three categories: show growers, garden variety and cut flower variety. Go shopping at shows and write down what you like.

Any trade secrets?

Even though I live close to the ocean, I have to place a sunscreen over my plants. Come show time, I put umbrellas over them. They can't take full sun full time. They prefer morning sun with a partial shade in the afternoon. Also, I recommend Azomite, a rock dust that adds nutrients to the plant.

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