How To Grow Dahlias

Dahlias are vibrant, versatile flowers that can enhance any garden with their stunning blooms from mid-summer through fall. Growing dahlias from tubers is a rewarding process that, with proper care and attention, yields beautiful results. Here's a comprehensive guide to help you cultivate healthy dahlia plants:

1. Selecting the Right Location

Choose a sunny spot in your garden that receives at least 6 to 8 hours of direct sunlight daily. Adequate sunlight ensures robust growth and abundant flowering. Ensure the soil is well-draining to prevent tuber rot, as dahlias do not thrive in waterlogged conditions. If you have heavy clay soil I would advise you to plant Dahlia Tubers in raised beds or grow bags. 

2. Soil Preparation

Dahlias flourish in rich, loamy soil with a pH between 6.0 and 7.0. Before planting if at all possible, conduct a soil test to determine its pH and nutrient content. Amend the soil with compost or well-rotted manure to enhance its fertility and structure.

3. Choosing Tuber Varieties

Dahlias come in various types, including decorative, cactus, pompon, dinnerplate, novelty, ball, and waterlily forms. Select tubers from reputable sources, ensuring they are healthy and free from disease. Checkout our Dahlia page on our website to see what varieties we offer. We start our first sale in January of each year! 

4. Planting Tubers

• Timing: Plant dahlia tubers in the spring after the last frost, when soil temperatures reach at least 60°F. This timing ensures optimal growth conditions.

• Depth and Spacing: Dig holes approximately 4 to 6 inches deep and 12-18 inches apart. Place the tubers horizontally, with the "eyes" facing up, and cover them with soil.

5. Watering Practices

After planting, water the tubers lightly. Overwatering before sprouts appear can lead to rot, as tubers are susceptible to excessive moisture. Once the plants are about 8 to 12 inches tall, water them deeply 1 to 2 times per week, depending on rainfall and soil conditions. Do not let the plants get too dry, however do not over water the plants as well. 

6. Fertilization

Apply a balanced fertilizer every 4 to 6 weeks during the growing season. A fertilizer with a higher phosphorus content (middle number) promotes robust blooms. Avoid high-nitrogen fertilizers once timing gets closer to blooming, as they encourage excessive foliage at the expense of flowers. 

7. Supporting Your Plants

Tall dahlia varieties often require support to prevent stems from bending or breaking. Install stakes or use a support system at planting time to guide growth and maintain plant structure. We use Hortonova Horizontal Trellis netting to support our Dahlias and many other cut flowers on the farm. 

8. Pinching and Deadheading

When plants reach about 12 inches in height or have at least 4 sets of leaves, pinch off the top 3 to 4 inches of the central stem. This practice, known as pinching, encourages bushier growth and more blooms. Once your Dahlias start to bloom try to regularly remove spent flowers (deadheading) to promote continuous flowering throughout the season. Try to cut deep if you are wanting blooms on longer stems for the perfect vase cute flowers. 

9. Pest and Disease Management

Monitor your dahlias for common pests such as aphids, slugs, and spider mites. Employ organic pest control methods, like introducing beneficial insects or using insecticidal soaps. Ensure proper spacing and air circulation to minimize the risk of fungal diseases. defoliate any lower leaves as your dahlias grow to help with better air flow in between the plants. This is especially important if you have your Dahlias close together. 

10. Overwintering Tubers

In regions with freezing temperatures, dig up dahlia tubers after the first frost blackens the foliage. Cut back the stems, gently remove soil from the tubers with either a brush or with water, and allow them to dry for up to 24 hours. Store the tubers in a cool, dark, frost-free location in peat moss, vermiculite, or in saran wrap in a fridge with temps under 50 degrees and mild humidity, until replanting in the spring. I have another Blog on different storing methods that I recommend to read as well. Due to so many different micro climates, there are many ways to store tubers and some of those ways might or might not work for your specific climate or area. I have tried a few different methods and what works for me might not work for you. Keep this in mind when researching the best storage methods for your tubers.