How to Grow Dahlias

Dahlias are spectacular flowers that come in a variety of rich colors. When planted in a border, the shape and form of these flowers contrasts with that of the other flowers in the border and creates visual interest. Learn how to grow dahlias in this P. Allen Smith video:

Dahlias are a very good value. They’re grown from a tuber, and there are lots of different varieties both in terms of the shape of the flower and the size of plant. There are the lowest dwarf varieties that will grow up to 12-18 inches tall, all the way up to big dinner plate dahlias that grow over 4 feet and even up to 6-7 feet. There are shaggy cactus-like blooms to more compact pompoms. Dahlias also make great cut flowers, so go ahead and bring a touch of the garden indoors.

To ensure frequent beautiful blooms, use a fertilizer with more phosphorus. Don’t fertilize with too much nitrogen because it will make the stems weak and cut down on flower production. After the first blooms, when the flowers start to fade, deadhead them off so the plant will produce more buds and bloom throughout the summer and into the fall up to the first hard freeze.

Dwarf varieties are excellent for growing in containers. Whether in containers or in the garden, dahlias love full hot sun, so you want to make sure they’re planted in well-drained soil and that they get consistent moisture. They can tolerate some periods of dryness because they have a tuber that stores moisture, but it’s really better for blooming if you keep the soil moist. Give them a good deep soaking about one a week.

If you live in a warmer part of the country, dahlias will come back year after year, but if you live in a colder area, you will have to bring them indoors and replant them each spring.