Dahlias in North Florida
That’s right, you can grow Dahlias in North Florida. These beautiful tuberous plants are native to the highlands of Mexico and Central America, where warm days in the mid to upper 80’s and relatively cool nights are the norm. The extreme heat & summer rains of North Florida certainly pose challenges when growing these tubers in our agricultural zone 9, but with a little bit of pampering, the very gratifying splendor of these beauties can be realized.
If you decide to start with your own tubers, rather than buying a finished plant from a grower such as yours truly, select a more heat tolerant variety, as well as a modest size plant in the range of 24 inches. This size plant will bear flowers in the range of 4 to 6 inches in diameter, and be much easier to grow than the taller dinner plate style dahlias.
This year we planted our tubers in the second week of February. We used one of our standard potting mixes at the nursery that consists of 60% small aged bark nuggets, and the balance a blend of compost and peat moss, as well as 5% sand. We always top dress fertilizer after planting in the pot, or in the ground applications and feed our plants with our high quality, 6 month slow-release fertilizer. If you choose to mix your own soil blend, I suggest using a combination of any of the following materials to make a hummus rich soil blend. In essence dahlias like a light and organic soil blend around it’s root system. This will also ensure good drainage, whether you are growing them in containers or in the ground. Begin your soil mix with a blend of 50 to 60% combination of peat moss and compost, and supplemented with other course materials such as perlite, partially decomposed leaf litter and/or small aged pine bark nuggets. If planting in the ground, excavate a hole that is 24“ x 24“ and maybe 12 - 14” deep, and fill with soil blend. Also there is no need to dig tubers and store inside for the winter, as is customary for colder climates.
Sunlight exposure: this time of year during the spring, dahlias can handle sun for most of the day as the sun is not that intense yet. However during the summer months and early fall, morning sun will always be fine, but in the afternoon, exposure should be limited to bright indirect, dappled or filtered light.
Regarding moisture levels, this factor has already been addressed in part by selecting the appropriate soil blend. The second moisture factor that is important is to limit the plants exposure to excessive rain in the summertime. If growing in a container, this is easily remedied by shifting your plants around so as to avoid prolonged exposure to hours/days of rain. If planting in the garden, this can be remedied to some extent by employing a creative technique to shield your plants from being bombarded excessively by a lot of
So if you’ve always wanted to grow Dahlias in Florida, don’t be scared to give it a try! Happy growing!