Are Dahlias Hard to Grow?

February 5, 2024

As a cut flower farmer growing 1,000+ dahlias in our field, two questions I am often asked are whether dahlias are hard to grow, and if dahlias are worth the effort in time and money. I want to explore this common predicament and I aim to give you my honest opinion.

My wholehearted answers in short, are:

Are Dahlias hard to grow?
It can be hard to grow beautiful, productive dahlias if you don’t have the correct growing conditions in place (I’ll help you with that below)
Are Dahlias worth the money and effort?
If you are a gardener who loves growing gorgeous flowers, then yes. Always. Dahlias make up the most impressive, rewarding flowers in our field (and home garden) and I personally can’t imagine life without them, even in years where some varieties don’t do as well as I’d hoped (every year is different). On the other hand, if you don’t really care about dahlias and aren’t all that curious about them, then you won’t spend the time to get to know their needs, and your dahlias may suffer from lack of proper growing conditions.

how can we make growing dahlias effortless?

I recently finished reading Effortless: Make it Easier to Do What Matters Most by Greg McKeown. From this book, I’ve been inspired to highlight which of our gardening systems cause us the most trouble (spoiler alert, it’s weeding), and then figure out what it would take to make that pain point easier and more enjoyable.

Growing productive, beautiful dahlias is a pain point for a lot of people. The most important thing to understand when growing anything though, is that a good foundation is necessary to produce a beautiful result.

A necessary foundation for growing dahlias consists of these four elements:

Full sun exposure (the sunniest spot in your yard)
Healthy, loose soil with lots of organic matter
Mulch on top of the soil
Adequate water supply

How to Improve Your Dahlia Growing Space, Pretty Effortlessly

Maximize Sun Exposure for dahlias

This is the most simple fix. Literally look around and make sure you are choosing to plant dahlias in the sunniest spot in your yard. There should not be any trees nearby. Trees (and tall shrubs) will not only shade the dahlias but will also suck up water and nutrients with their massive root systems. Planting a garden against your house on a South or West-facing exterior wall will help insulate the plants on cool nights later in the season.

If the sunniest spot in your yard is your lawn, consider starting a Sheet Mulch Garden, which is an effortless way to start a new dahlia planting bed.

What happens if dahlias aren’t planted in full sun?

If you plant your dahlias in a shady spot, they will not flower. If you plant dahlias in a partly sunny spot, they will flower but will become “leggy,” producing long, weak stems with minimal flowers. This may still be enjoyable and worth it to you — if part sun is all you have to work with, then plant away in a partly sunny spot!

Improve your soil with simple tools and organic fertilizer

There is a very simple, no-till method to prep your backyard garden soil and it involves nothing but your body and a garden fork.

To aerate your soil without tilling and using heavy, expensive machinery, simply sink your garden fork down into the soil and pull it back so you “crack open” the soil. Then pull the fork out. You are not picking soil up and flopping it over, or moving any soil around whatsoever. You are simply using the fork to crack open your soil to allow air pockets in.

Before cracking your soil with the garden fork, you should put down some organic fertilizers and compost. I like adding these amendments first because when you use the garden fork, some of the amendments will go down into the soil.

Recommended Soil Amendments for Dahlias:

Organic Compost - Add a 1-2 inch layer on top of the planting area. We use a hard rake to rake it out flat.
Kelp Meal - Add to top of soil according to package directions.
Bone Meal - You will add a handful of bone meal inside the dahlia hole during planting.
Mycorrhizal Fungi Inoculant - You will add to dahlia hole during planting (follow package instructions). Learn more about mycorrhizal fungi, and how amazing it is, here!
If this list is too much for you to purchase, skip the kelp meal and mycorrhizal fungi, but make sure you use leaf mulch (which takes me to my next point…)

mulch your dahlia planting beds

Using mulch on your planting beds is perhaps the most important thing you can do in the garden, no matter what you’re growing.

Mulch will hold soil moisture in, provide a protective barrier from heat/cold for soil microbes, provides food and nutrient exchange for soil microbes, and breaks down over time to provide a constant supply of organic matter. For a better explanation, read this post about Gardening like a Forest and The Law of Return.

My favorite type of mulch to use is free and abundant — shredded leaves. In the fall, once trees have shed their leaves, I gather my and my neighbors’ leaves and top off all of my garden beds with a thick layer of shredded leaves. To shred leaves, you can get a leaf shredder or simply mow them up with your lawnmower and catch them in the mower bag.

If you don’t have access to leaves during planting, you could break apart straw bales and use the straw as mulch in the meantime.

set up automatic watering for dahlias

If you think you’ll have time to water your dahlia garden everyday during a drought, you might be kicking yourself later. It’s simple to set up an automatic watering system on a timer and you will never have to worry about watering your dahlia plants.

Dahlias require a lot of water (1 inch per week minimum) to produce big, beautiful blooms. If you have a backyard dahlia patch with less than 100 plants at 12-15 inch spacing, you could lay a soaker hose and attach it to an automatic timer (I prefer the Melnor brand). To automatically water dahlias, set the timer for every morning before sunrise for 10 minutes, then again in the evening for 10 minutes. The cool thing about these timers is that if rain is in the forecast, you can set a rain delay on the timer and water will not go off (overwatering is bad, too).

in conclusion: growing Dahlias is in everyone’s wheelhouse

If you’ve struggled with growing dahlias in the past, then try fixing all of the issues above. ALL of the growing conditions have to be in place — not just one or two of them. For instance, if you had beautiful soil but weren’t watering during a drought, your dahlias are going to suffer from lack of water. If you plant dahlias in a full-sun exposure garden but did nothing to add nutrition or mulch the soil, your dahlias will be more susceptible to disease and will grow weakly and with nutrient deficiencies.

Growing dahlias effortlessly does take effort up front, but the rewards come in endless buckets of beauty.

I hope this post may have shed some light on struggles you’ve had in the past with your dahlias, and maybe I’ve even convinced you to give it a go again, or to try growing dahlias for the first time!

Here are more helpful dahlia growing posts…

How to Plant Dahlia Tubers & Maintain Dahlias Organically

When to Dig Dahlia Tubers

When to Split Dahlia Tubers - Now or Later?

The #1 Mistake Not to Make When Splitting Dahlia Tubers

Storing Dahlia Tubers in Wood Pine Shavings

How to Deal with Crown Gall or Leafy Gall on Dahlias

Will Deer Eat My Field of Dahlias?

How to Store Dahlias Over Winter & Get Rid of Mold

I Skipped Drip Irrigation on the Dahlias; Here’s What Happened

Our Favorite Dahlias for Wedding Designs

Dahlia Tubers for Sale in 2023: Preview