Tips for Growing Beautiful Dahlias
Over the past couple of years I have found my passion in growing cut flowers. Learning to grow cut flowers connects me to my background in flower design and I love being able to grow what I am using in arrangements. Each year I have thrown myself into learning to grow a new cut flower in my backyard. I feel like taking the time to do my research and learn everything I can has been really helpful. A couple of years ago I started growing Zinnias and had huge success, so last year I was ready for a new challenge and fell into the opportunity to purchase and grow Dahlias.
I love Dahlias, they are such a beautiful cut flower. But, I never had success growing them the past couple of years when I bought them at a garden center. I did a lot of research about them over the winter and when I saw a local farm offer some of her tubers for sale I decided to buy some and try growing them myself. While it took a lot of patience and I babied them probably a little more than necessary the payoff was huge! I harvested probably a minimum of 30-50 Dahlia flowers a week from late August through the middle of October. This was such a rewarding growing experience for me and I want to share what I learned this past year. Hope it helps anyone else looking for more information and tips on growing dahlias!
First a little info about Dahlias...
Dahlias are a flowering plant that grows from a tuber. A tuber is actually a short and thickened part of the plant root. It is used by the plant for storing nutrients and new growth in the spring. Dahlia tubers multiply during the growing season and can be divided in the off season. Each tuber will produce their own plant the next year if they have an eye. The tubers are very cold sensitive, so in growing zones 1-7 they need to be dug up every fall and carefully stored for the winter. Then the new tubers are planted again in the spring when the ground is warm enough. Zones 8-10 can might be able to be left in the ground to grow again the next season. If you don't know your hardiness zone you can do a quick search online to find it.
The Dahlia plants that grow from the tubers can produce beautiful blooms from late summer through early fall. With the right pruning and care plants will produce tons of flowers that can be cut for use in bouquets or flower arrangements. This past year my house was filled with dahlia arrangements from August through October!
My Tips for Growing Dahlias...
Wait to plant the tubers...
Once I had the tubers in my hands in late April I was so excited to plant them. We had some warm weather and a beautiful weekend and we decided to go ahead and plant them. A little more than a week later the temperatures dropped significantly and we were expecting some hard frosts. Dahlia tubers may not survive low temperatures so I ended up covering the dahlia garden bed with heavy tarps to try and protect the soil and tubers. Luckily almost all of the tubers did survive and the plants emerged not long after the temperatures warmed up.
Lesson learned for me was to wait to plant dahlia tubers until the ground temperature is at least 60 degrees and is going to stay that warm. I live in zone 6A in Southwest Ohio so a more optimal planting time would have been the middle of May.
Water and Fertilize Regularly Once Plants Emerge...
Waiting to water until the plants emerge is really important. Watering tubers in warm soil could cause them to rot. Once plants emerge begin to water regularly. Once the plants are larger and more established a watering regimen of about 30-60 minutes every 2-3 days works well. I watered mine every 3 days for 30 minutes. In a hotter climate more may be necessary, especially as they mature. I used sprinkler hose (pictured above) to water which was really helpful in making sure the plants got plenty of water.
Once plants were 1-2 feet tall I began using Flower- tone fertilizer. It's important to use a low nitrogen fertilizer (high nitrogen encourages leaf growth instead of flowers). Simply sprinkle the fertilizer on the soil around the plants before watering at the rates recommended on the package. I only fertilized once every 30 days.
Prune the Plants Back...
Through a lot of research I learned that pruning dahlia plants would be essential to encourage the plant to branch out and produce a lot more blooms. I had done this before with my Zinnias and it worked like a charm, so I was pretty confident in using this process with the Dahlias.
When the plants are 12-18 inches tall it is time to prune them. Using clean, sharp shears cut the center stem of the plant back about 4 inches. Be sure to cut just above a set of leaves as I am showing in the picture above. This is something that is so hard to do, cutting a healthy growing plant feels so wrong. But, I can promise you it is worth it and you will have so many more branches and longer stems on your dahlias.
Stake the Plants...
I did not stake my plants this summer and it was a big mistake! I read so many places that it was important to stake dahlia plants before they get too big. Looking at my dahlia plants I figured they weren't too big and would probably be fine. Come late August the plants were huge with thick stems and so many fell over. My husband and I were then trying to find ways to stake these huge plants back up without breaking them. I really regretted not staking them earlier in the year. This winter I plan to do some research and find a staking method that will work for our garden.
Be Patient...
This is a really hard skill to master with dahlias. You plant them in May and then they slowly emerge and grow. Honestly, all you see is a whole bunch of foliage for most of the summer. But trust me it is worth the wait! When those first dahlia buds finally bloom in August it is so exciting! Continue to care for, harvest and water them regularly and you will have blooms through late September or early October.
Harvest Flowers 1-2 times a week...
Just like other flowers and vegetables it is really important to spend time harvesting dahlias once or twice a week. Cutting flowers that are ready off of the stem will encourage the plant to put it's energy into the new buds.
When harvesting dahlias follow the stem from the bloom as far down as you can before cutting. This may be as far as the main stem or where the stem branches off from other stems or buds. Sometimes when cutting to get a long enough stem you will end up cutting a bud as well. Do not worry too much about a couple of buds coming off with the flowers, as sometimes it is unavoidable. While the buds will not open once cut from the stem, they still look great in a flower arrangement.
Enjoy Your Dahlia Garden!
I hope that my tips were helpful to anyone new to dahlia growing. If you are on the fence about growing some my advice would be go for it! I grow mine in a little suburban backyard, so even with just a little bit of garden space you could grow them! Plus, they are so beautiful and fun to learn to grow.
