House Grail is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

How and When To Plant Dahlias? What You Need to Know!

pink dahlia

Dahlia is a favorite garden flower for many—its attractive flowers have different colors and shapes and are the main reason this plant is adored by gardeners worldwide. There are thousands of species of dahlias, and each species offers a rich and luxurious look.

This article will go over ways to develop a healthy dahlia plant. Make sure to follow our step-by-step guide on how to grow dahlias, and you will have a rich and sophisticated garden in no time!

garden flower dividerWhen To Plant Dahlias?

Do not rush with planting because dahlias will get sick in cold soil. Planting dahlias should start when the soil temperature is around 60°F. Wait until all the dangers of spring frosts have passed and choose a well-lit place for planting. Dahlias will have more flowers if they are exposed to direct sunlight for at least 6 to 8 hours a day.

They like the morning sun the most but are also susceptible to wind, so for growing dahlias, choose a somewhat sheltered area. What is nice about growing dahlias is that they start to bloom about 8 weeks after planting, sometime in mid-July.

Dahlia
Image Credit: Pixabay

How To Plant Dahlias?

Large dahlias and those grown as cuttings are best grown in special beds in rows and individually, without competing with other plants. Dahlias of medium and low height are perfectly combined with other summer flowers. If you only have a vegetable garden, it is an ideal place to plant a row of dahlias for cuttings—you will also have something beautiful to look at while weeding the rest of the garden.

1. Choose the right soil type

Dahlias thrive in soil that is fertile and well-drained. If you have soil that is not loose, add a little sand, peat, or burnt manure to loosen the ground for better drainage. The soil should have a pH value between 6.5 and 7, which should be slightly acidic.


2. Placing a preferred variety

close up yellow dahlia
Image Credit: minka2507, Pixabay

Place the dahlia tubers in a funnel at a distance of 9 to 12 inches. Arrange smaller varieties, which usually grow up to 40 inches in height, at a distance of 24 inches. Planting greater varieties with larger flowers should be in spaces 40 inches apart. You should plant dahlias in a hole that is a little bigger than the tubers, and you should add a little compost or peat. It can also be helpful to put a handful of bone meal in the planting hole but do not use any fertilizer when planting. Plant the whole tuber, with buds facing up at a depth of 6 to 8 inches. The crown should be just above ground level.


3. Secure the plants

For most varieties of dahlias, place support stakes at the time of planting. Tall cultivars with large flowers need support. Place pegs of about 59–79 inches high around the plants at the time of planting and tie the stems to the plants as they grow.


4. Properly watering

red dahlia close up
Image Credit: Veronika_Andrews, Pixabay

Do not water the tubers immediately after planting, as this may cause rot. Start watering when the first shoots appear above the ground. When dahlias are germinating, provide them with water by soaking them 2 to 3 times a week. Spray the plant frequently, and do not let it dry. Make sure to spray the water regularly for 30 minutes, and in the summer or the warmer-climate zones, use the sprayer more often.


5. Feeding the plant

Dahlias will do well with liquid fertilizer with a low nitrogen content—similar to the one used for vegetables. Feed them after germination, and after that, every 3 to 4 weeks from mid-summer to early autumn. Make sure not to overdo it with top dressing, especially with nitrogen, because you will risk the flowers being either small or non-existent and weak or rotten tubers. Do not cover further with mulch or bark, as sprouting will be difficult.


6. Trim the plant

orange dahlia flowers in the garden
Image Credit: Sve_M, Shutterstock

Trim the top of the shoot to encourage the shrubs’ formation and remove overblown flowers. Tear off the central shoot above the third row of leaves. Moderately pluck shoots, branches, buds, and overblown flowers to get a luscious look out of the plant for 3 months or more. Cutting flowers for a vase and removing overblown flowers further stimulates the formation of new buds.

garden flower dividerHow to store a dahlia plant over winter

If you want to preserve the plants in colder climates, you have to dig up the tubers in early autumn and store them over the winter. Store in a well-ventilated, frost-free area—from 39.2°F to 44.6°F is ideal, and from 34.7°F to 50°F is acceptable. In the spring, take out the tubers, separate them from the parent web and start growing dahlias from scratch.

Common Pests and Diseases

Dahlia cultivation can be hindered by pests and diseases characteristic of other garden flowers.

  • Slugs and snails: 2 weeks after planting, start setting snail baits and continue to do so throughout the season.
  • Cobwebs: If you think you can avoid them, start spraying at the end of July and continue throughout September. Ask at the agricultural pharmacy which product is best to use.
  • Aphids: Aphids are small sap-sucking insects that spread incredibly quickly, and sometimes without the possibility of the plant recovering.

garden flower dividerFinal Thoughts

In addition to Dahlias in all rainbow colors, its flowers can range from small flowers of 2 inches to huge flowers the size of a plate at 15 inches. What is interesting about this plant is that the more you cut it, the more it will bloom. Follow our advice if you are fascinated by dahlias and want to grow them to become luscious and healthy. Dahlias are pretty easy to grow, so you will have a spectacular breath-taking garden decorated with dahlias in no time.


Featured Image Credit: AnnaER, Pixabay

Related posts

OUR categories

Project ideas

Hand & power tools

woodworking

Garden

Automotive