Tips for Growing Dahlias

Have you ever wanted to grow your own dinner plate sized dahlias? Well, me too! These bright and colorful beauties are both fun to grow and care for, so here are a few tips and tricks to ensure you grow the biggest and best dahlias every year!

Dahlias can be planted by seed or by tuber, but today we will focus mainly on tubers.

Planting

If you are planting new dahlia tubers like me this year, you’ll want to wait until the last risk of frost has passed and the soil reaches 60 degrees Fahrenheit or warmer to put them in the ground. Dahlias do best in well draining soil, with a minimum of 6 hours of sunlight each day. Dahlias also do better in soil that is higher in acidity. Tubers should be planted on their side 4-6 inches deep in the soil with the eye (first growth point) facing up. If you plant multiple tubers, (because why wouldn't you??) they can be placed as close as 14 inches apart, but ideally a little further apart so each plant has enough space to grow.

Watering and Fertilizing

You don’t want to water your dahlias until the first set of leaves pop up to ensure the tuber does not rot. If you're like me, being patient in the garden is so hard. I know we all want our flowers to come up as fast as they can, but don’t water until you see leaves!! They take their time sometimes, but when you finally see leaves, you can start watering/ fertilizing your babies! Depending on how well your soil drains, you can water and fertilize your dahlias deeply at least once a week. When choosing a fertilizer, you want to make sure the middle number (which represents phosphorus) is the highest. Jacks Blossom Booster 10-30-20 is a good, organic, water soluble fertilizer to use for your plants. Always choose the best for our babies, right?

Dahlia Care

When your dahlias begin to mature and reach around 12-18 inches tall, you will want to pinch and thin the stems. That sounds scary but trust the process! Thinning can be done by cutting off all of the small, weak stalks leaving you with 2-3 of the tallest, strongest stalks. Pinching can be done on the 2-3 strongest stems by cutting off 3-4 inches of the top sprouts. This part is the hardest, no one wants to snip away the amazing growth so far, but doing this encourages the plant to branch out, grow more side stems, and produce longer flower stems. The sneaky slugs love to come in and munch on all of our hard work when we're not looking, so using a slug deterrent is also recommended.

Your dahlias can get full and heavy, so it is best to stake and tie up your plants to ensure they grow upright and have all the support they need to give you the biggest flowers ever. As they begin to produce blooms, you can remove lateral buds to send all of the plant's energy into producing a bigger bloom. Deadheading your dahlias is also recommended to encourage the plants to keep blooming. The more flowers you cut, the more flowers the plant will produce, so don’t be shy in cutting all you want!  Dahlias will actually bloom up until the first frost of the year blessing you with beauty through the summer and fall.

In our region, they can usually be left in the ground through the winter and will come to life again the next spring. On occasion, the don’t make it through the winter, so just be prepared to shop for more in the spring if any of yours didn’t make it. For the ones that do survive, the mother tuber can multiply by 5-20 tubers over the season making propagating easy. Just dig and divide!

By following some of these tips and tricks, your dahlias are guaranteed to be the talk of the town! Just be patient and kind with your tubers and watch them produce some of the most beautiful colors you’ve ever seen.

-Elin Willard