“How and when do you pinch dahlias to encourage fuller growth?” Question from April of Dresden, Tennessee
Answer: Once your dahlias are close to their final height (which depends on the variety) and have ample foliage, you can pinch or trim them back to encourage fuller growth, more branching, and more flowers. Just be sure to wait until they are large and full enough to bounce back nicely.
I always recommend cutting them back just above a branching stem node (see adjacent image). New branching stems will arise from the node. I also recommend using sharp shears to do the job rather than pinching (Corona Flora Scissors work very well). Cleaner cuts help plants heal and revive more quickly.
“I have tried everything to grow Dahlias. They come up sometimes to about 1ft and never bloom.” Question from April of Dresden, Tennessee
Answer: I am sorry to hear that you are having trouble with your dahlias flowering. There are several factors that impact dahlia blooming, including light levels, fertilizer, and dahlia type. First, provide them with full sun–eight or more hours per day is best. Feed your plants with a quality fertilizer formulated to encourage flowering to boost blooms. Finally, choose more compact dahlias with a free-flowering nature. Try varieties in the Gallery Series, which are more compact and flower nonstop. Dahlias in the Happy series are also outstanding when it comes to repeat bloom. Happy Single Flame is especially pretty with its hot pink and yellow single blooms. For more information, I encourage you to read the following blog and watch our video about growing Dahlias to perfection. (Click here to read All About Growing Dahlias.)
Summer is Dahlia time, and my favorites are the supergiants with blooms the size of dinner plates. The grand flowers of dinner plate dahlias are so large that just one is enough to fill a large vase or decorative bowl. They are produced on tall, four and five-foot plants, so staking is required, but when they are grown with success, the results are cut flower heaven.
Dinner plate dahlias, technically classified by the American Dahlia Society as “giant” flowered dahlias, have blooms exceeding 10 inches in diameter. Some can even reach 12 inches or more. They come in a variety of forms and all colors but true blue. Three of my favorite forms are the fully double, wide-petaled blooms of waterlily-forms, quilled incurved-cactus forms, and prickly, puffy laciniated forms.
Planting Dinner Plate Dahlias
Planting time for dahlias is in spring, once the threat of frost has passed. Dahlias are tender to USDA Hardiness Zone 9, which means that they will not live through the winter in most parts of the country. They are sold in spring as tuberous roots. Each root set is topped with a series of buds that are essential for the plant’s success. If the buds are removed, the plant will not grow.
Heavily fortify the soil with Black Gold Garden Compost Blend and Earthworm Castings before planting dahlias. Then add fertilizer formulated for bulbs. (Super garden soil will mean the difference between large and HUGE flowers!) Dig a broad hole to the depth of about 6 inches, amend the soil, and plant the tubers with their roots down (the latter will have unfortunate results). Next, label the spot, and surround it with a low tomato cage to support plants once their tall stems emerge.
Growing Dinner Plate Dahlias
Water regularly, especially when days become hot. Continue feeding the plants through summer for best results. Dahlias aren ative to high altitude regions of Mexico, so they tend to flower best during the cooler months of September and October.
To grow super giant flowers for the show, some tending is required. Competitive Dahlia growers disbud stems to all but the very tippy top bud. The removal of all side buds means that the plant will put all its energy into making the top flower spectacular. This results in blooms the size of your head. It’s a great way to impress the neighbors.
Before I plant my dahlias, I heavily fortify the soil with Black Gold Garden Compost Blend and Earthworm Castings for ample richness. Then I add a fertilizer formulated for bulbs. (Super garden soil will mean the difference between large and HUGE flowers!) Dig a broad hole to the depth of about 6 inches, amend the soil, and plant the tubers with their roots down (the latter will have unfortunate results). Next, label the spot, and surround it with a low tomato cage to support plants once their tall stems emerge.
Regular water is needed, especially when days become hot. It also doesn’t hurt to continue feeding the plants through summer. Dahlias are native to high altitude regions of Mexico, so they tend to flower at their very best during the cooler months of September and October.
Tending is required to grow super giant flowers for show. Competitive Dahlia growers disbud stems to all but the very tip top bud. Side bud removal means that the plant will put all its energy into making the top flower spectacular. This is when dinner plate blooms the size of your head are produced. It’s a great way to impress the neighbors.
There are several nurseries that specialize in spectacularly large dahlias. Swan Island Dahlias is the standby, but there is also Big Dahlias and Corralitos Gardens. Some dinner plates purchased from these companies stood out more than others.
The palest yellow ‘Aitara Majesty’ has perfect semi-cactus blooms that are simply huge, reaching a foot across. They look amazing in a tall vase alongside frothy Queen-Anne’s-Lace. The impressive, two-tone ‘Bodacious’ is a red beauty with petals that curl to show ivory undersides (my children like this one the best.), and the nearly perfect, red, 9-inch flowers of ‘Spartacus’ are just amazing. These are just a few of many spectacular dinner plates to discover.
Give these extra-large garden flowers just a little extra care and you will be rewarded with great results. Provide them with super soil, good sunshine, moderate food, and water, and watch the floral fireworks. If you have a little inclination, you may even want to show one at your local state fair for a certain blue ribbon first prize!