MARCH 11, 2020BEGINNER’S GUIDE TO GROWING DAHLIAS

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It’s hard for me to believe how much dahlias have changed our lives in the last few years…

You can read more about it here, but long story short, my husband came home from work one day and declared that he wanted to start growing dahlias.

As our love for dahlias grew, we read everything we could get our hands on… and my husband even joined the West Michigan Dahlia Association so he could soak up knowledge from dahlia experts and enthusiasts. 

In the past few years, we have gained so much experience and currently we grow about 1000 dahlias each season on our small farm. 

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Below, I’ve compiled a list of some of the most common questions we receive about dahlias. Hopefully this helps you feel more clear and confident about growing dahlias yourself!


Dahlia FAQ’s

1. I HEARD THAT DAHLIAS ARE HARD TO GROW. IS THAT TRUE?

  • Yes. No. Maybe? While I would say they are NOT difficult to grow, they ARE one of the most labor intensive flowers grown for cutting. So, yes, they are “easy to grow” but require some special care.
  • They require careful planting, staking, pinching (more about that later) and the tubers must be dug up each fall.
  • If provided with proper growing conditions, they will perform beautifully and provide you with many blooms over the summer!
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2. WHAT IS A “TUBER”? IS THAT LIKE A “BULB”?

  • Dahlia tubers are sometimes called a “bulb”, but they are technically a tuber, similar to a potato. Similar to a potato, the tuber sends up a shoot that becomes the plant, which produces leaves and flowers. Underground, the tubers multiply each year (again, like a potato).
  • You only need one tuber with one “eye” to successfully grow a vigorous dahlia plant. Ever left a potato in the pantry too long and noticed “eyes” sprouting? Same thing with a dahlia tuber.
  • Watch the short video below to get an overview of dahlia tubers.
https://youtube.com/watch?v=MTbPPezNlpg%3Fwmode%3Dopaque%26enablejsapi%3D1

Tubers come in all sorts of shapes and sizes! Some are long and skinny, some are short and stubby, some are huge (up to 10” long!) and some are tiny (the size of your pinky).

It’s a common misconception that “Bigger Tuber = Bigger Plant”. This is not true.

The tuber is simply the food source for the plant until they have about 3-4 sets of leaves. After that, the root system growing from the tuber is responsible for health of the plant.

According to Michael Genovese of Summer Dreams Dahlia Farm, a tuber the size of a AA battery or larger is considered usable. All three of the tubers pictured below are acceptable, but the two tubers on the right are considered ideal sized.

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So if tuber size doesn’t matter, what DOES matter?

Two things are necessary for a viable tuber:


1. The tuber MUST have 1 eye. The eye is where the sprout will grow (similar to a potato left too long in the pantry).


2. The neck MUST be intact. If the neck is broken or damaged, the tuber is worthless.

Tuber Diagram.jpg

3. PINCHING? WHAT DOES THAT MEAN?

  • If you want your plant to produce multiple blooms, you must “pinch” or cut back the plant early on, when it has reached 12-16″ tall. Find the center stalk, count down about 1-2 sets of leaves and make a cut with clean clippers, removing the top inch or two of the center stalk. This signals the plant to “branch out” and put it’s energy into creating more branches and more blooms.
  • If you want bigger blooms (but less flowers in total), then do nothing.
https://youtube.com/watch?v=yzYps7X4vSw%3Fwmode%3Dopaque%26enablejsapi%3D1

4. DO I NEED TO STAKE DAHLIAS?

  • Yes, most varieties will need to be staked, otherwise the wind may flatten and ruin the whole plant. Gently tie the plant to a sturdy wooden or metal stake. A tomato cage would also work!
  • We use netting stretched between posts, hovering about 12-18″ from the ground. The plants grow right up into the netting, which keeps them in place.
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5. WOW! SOME DAHLIA TUBERS COST OVER $10… FOR JUST ONE TUBER! WHY DO THEY COST SO MUCH?

  • Remember in Question #1 when I said they are labor intensive? Dahlia tubers are not cold hardy and will not survive over the winter in most climates. They must be dug up. By hand!
  • Dahlia tubers are quite fragile. and break very easily. If they break, they are worthless! As of yet, no one has been able to successfully mechanize the dahlia tuber digging process without suffering major losses. Hand digging is the most gentle method resulting in MUCH less breakage… but it is HARD MANUAL LABOR… hence the high cost of tubers.
  • Once the tuber clumps have been dug up, they must be divided into individual tubers… yet another extremely labor intensive job, that cannot be mechanized. It’s all done by hand!
  • Keep reading… Question #6 may ease your mind…
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6. YOU SAID IN THE VIDEO THAT THE TUBERS MULTIPLY EACH YEAR. DOES THAT MEAN I’LL BE ABLE TO PLANT EVEN MORE OF THEM NEXT YEAR? 

  • YES! If you dig up the tubers in the fall, properly store them and divide them, you can easily triple or quadruple your stock in 1 year. Once you factor that into the price of buying a tuber, they don’t seem so expensive anymore!
  • See the photo below? I planted ONE tuber in the spring… now I have more than I can count! Yes, all of those grew from one tuber.
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7. SO… DO I HAVE TO DIG UP THE TUBERS EVERY FALL? WHAT DO I DO WITH THEM?

  • No, you don’t HAVE to… but then you will have to by new tubers each spring, which gets expensive!
  • Wait to dig up your tubers until a few days AFTER a hard killing frost. This signals the tubers to go into “storage mode” and you’ll have better success storing the tubers over the winter.
  • After killing frost, tubers can stay in the ground for a while, so there is no huge rush… but do dig them up before the ground freezes!
  • Tubers are best stored in a cool, dark location – not too warm (they will rot) and not too cold (freezing will ruin them). A root cellar is perfect.
https://youtube.com/watch?v=VQNfDjCDZqQ%3Fwmode%3Dopaque%26enablejsapi%3D1

8. UMMM… HOW DO I DIVIDE THEM? THAT SOUNDS HARD.

  • I’ll admit it takes practice and you will make a lot of mistakes at first, but it gets easier with time.
  • Want to see how to do it? Watch this short video!
https://youtube.com/watch?v=q4yKfpXZOLk%3Fwmode%3Dopaque%26enablejsapi%3D1

9. HELP! I DIVIDED MY TUBERS AND NOW THEY HAVE BLUE MOLD WHERE I CUT THEM!

No worries! This type of mold is generally just a surface mold and does not penetrate the tuber. Double check to make sure the tuber is not mushy. If it’s still solid, simply wipe off the mold with damp towel or brush it off.

See the “Before” and “After” photos below:

10. MY DAHLIA TUBERS ARRIVED IN THE MAIL BUT IT’S TOO EARLY TO PLANT THEM! WHAT DO I DO WITH THEM WHILE I’M WAITING?

No worries, friend! You have 2 options:

1. Leave them right in the bag they arrived in. Be sure to open up the bag to let them “breath” a bit and regulate humidity. Store the bags of tubers in a cool, dark, dry location, such as a basement or garage. Do NOT store them in a place that dips below freezing.

2. Pot them up! You can fill a small pot with potting soil and pop the tuber in there. Be sure to “plant” it tail down, and head up (look for the “eye” or sprout on the head of the tuber). Water the pot sparingly (not too wet, not too dry) and place in a warm, sunny spot. The tuber will send up shoots and leave above the soil and roots into the soil. Simply transplant outside when the weather warms up, being sure to cover the crown of the tuber. https://www.youtube.com/embed/gHC9KdRQmlE?feature=youtu.be&wmode=opaque&enablejsapi=1


Ok, feeling a little more confident now? Read on for instructions on how to grow these beauties! 


How to Grow Dahlias

1. Choose a location with at least 6 hours of direct sun (the more sun, the better!) and well drained, fertile soil. Compost and all-purpose fertilizer worked into the soil before planting will help. 

2. Plant AFTER the threat of frost has passed (about May 15, here in West Michigan). The soil should be warm and well drained.

3. Space tubers about 18” apart. Dig a hole about 4-6″ deep and wide enough to accommodate the tuber. Place tuber in the hole with the “eyes” at the top (or lay it on it’s side) and back-fill the hole gently, covering the tuber completely with a few inches of soil.

4. DO NOT WATER after planting, unless the soil is super dry. You want the soil to be just slightly damp. Too much water can cause the tuber to rot. REPEAT: DO NOT WATER. It’s also wise to check the weather and avoid planting right before a huge rain storm. 

5. Once the plants have sprouted, you may begin watering regularly. When plants reach about 8″, begin fertilizing with all purpose liquid fertilizer about twice a month.

6. Pinch the plants when they reach about 12-16″, to signal the plant to produce more branches (and more blooms).

7. Plants begin to bloom in late July and produce heavily until the first killing frost of the season. 

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Questions? Comments? Just let us know.

Happy planting!

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COMMENTS (286)

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Amy B. 2 weeks ago · 0 Likes  

I planted a couple of Dahlias from seed in pots. They seem to be doing well and one is about to bloom. Can I just bring the pots in over winter?

Lori Hernandez 3 days ago · 0 Likes  

Hi Amy, yes, you could try that. Just make sure the tubers are never exposed to any freezing temperatures.

Lori Hernandez A week ago · 0 Likes  

Give it a try and see what happens!

Natalie 3 weeks ago · 0 Likes  

I have a couple questions. First one is- I accidentally planted my dahlias too close together. They are doing ok so far, one in the back isnt as tall as the others but one of the two that have started to bloom are sagging. The flowers are not open yet amd just hanging as if they are top heavy. Is this because the plant is stressed? Also I had a tuber fall apart, all the food storage things fell off. I’ve been researching as much as possible but I’m confused because from what I’ve read- the eye can only form at the crown. The little pieces that fell from the tuber do have some sprouts or what looks like eyes but my husband has told me it isnt possible. I just checked them again a few minutes ago and it looks like a potato that is sprouting. Is it possible for a single tuber food storage root to form an eye and sprout? I guess I’ll have my answer soon but I was curious on your opinion

Ragini 4 weeks ago · 0 Likes  

Hi,
This was a very detailed info on Dahlias. This is my first time growing them. I have rooftop and I have these potted in containers. I have beautiful buds and many as well, however, as soon as my buds starts to bloom in couple of days or so, they are browning. I have only fertilized them once they were potted and water them daily as these are in containers. Any suggestions on why my blooms are browning and what kind of liquid fertilizer should I be using?

Thanks,
First time Dahlia Grower.

Lori Hernandez 3 weeks ago · 0 Likes  

Hi there,
Hmmm, I’ve never heard of this and I’m not sure what to advise. The blooms do only last a few days after they open up.
I like to use a “Fruiting and Flowering” type of liquid fertilizer for plants that are in bloom.

Ragini 3 weeks ago · 0 Likes  

Thanks, Lori. I have used fish emulsion liquid fertilizer couple of days ago. I will keep an eye and see how this does.

Note: I can understand if the flowers brown after they bloom, but my buds are browning as well. I am hoping this liquid fertilizer should fix it.

Lori Hernandez 2 weeks ago · 0 Likes  

Ragini,
I’ve talked to a few people growing in pots this year that having issues with rotting. We had a very wet 2-3 weeks and I suspect the plants got a type of fungal disease. I wonder if that’s what’s going on with yours as well? I wish I had some advice, but I’ve never grown them in pots before!

Lynne Gibb A month ago · 0 Likes  

This has been hugely helpful. We’re in N Ireland and are dahlia beginners but love these plants. Thank you again

Lori Hernandez A month ago · 0 Likes  

You’re welcome! Best of luck 🙂

Judy 2 months ago · 0 Likes  

Thanks so much for such an informative post and videos! Very useful information.

I am growing dahlias for the first time this year. I started them indoors in pots in April. They are all sprouting. Some of them are quite tall (close to 19 inches) but they are quite leggy as I have kept them indoors by my south facing window. I was waiting for the weather to get warmer.

The sets of leaves are about 4 inches apart up the stalk. I was waiting for the weather to get warmer to plant outdoors. Should I pinch these dahlias since they are so leggy? If so, how far do I pinch? The majority of the leaves are on the upper part of the stalk (about 13 inches from the bottom), whereas the bottom is mostly stem.

Any advice would be really appreciated 🙂

Desiree Clayton 2 months ago · 0 Likes  

I live on Florida and want to know what the growing season would be since our soil dose not freeze.

Lori Hernandez 2 months ago · 0 Likes  

Hi Desiree,
I only have experience growing in Michigan, so I can’t answer your question!

Abbey Dee C. 2 months ago · 0 Likes  

I live in Orange County, Southern California. We have no frosts here. So does that mean I can plant the Dahlias at any time of the year? And when do I dig up the tubers?

Lori Hernandez 2 months ago · 0 Likes  

Hi Abbey,
I only have experience growing in Michigan, so I don’t know the answer to that question. Perhaps there are other growers in CA that could help you out!

Marissa 3 months ago · 0 Likes  

Hi there! I have started growing my tubers in pots and because I live in an apartment, I was hoping to keep in pots on my patio. In your opinion, can dahlias be successful in pots? Also, I have a bunch of 16” pots, should there only be on tuber per pot? Thanks in advance, your site is very helpful!

Lori Hernandez 3 months ago · 0 Likes  

Hi Marissa,
Yes, dahlias can be grown in pots, one plant per pot. Use the largest, sturdiest pots you can find or they might tip over. Please note that some varieties are only 2′ tall and others can reach 6′!!! The larger types will need support. I recommend using a tomato cage. Best of luck!

Marissa A week ago · 0 Likes  

Hi Lori! Thanks for the response!! I’ve had great luck with my dahlia plants, they are just now beginning to bloom. I did notice, however that the stem right below the bud is short and thick. It only goes a few inches before the two side buds start (I hope this makes sense!) I can’t imagine how I can cut for a vase, have you heard of or experienced this? Am I doing something wrong?

Lori Hernandez 3 days ago · 0 Likes  

Hi Marissa,
Did you watch the video on Q#3 in this blog post? Sounds like the plants were not pinched back. Watch the video and learn how to do it. Without being pinched, the plant will send up a bloom on a ridiculously thick and unusable stem.

It’s too late to pinch it now, so you will need to cut back that thick stem way into the plant, in encourage the plant to send out slimmer side shoots.

Lori Hernandez A week ago · 0 Likes  

Marissa,
My guess is the plants were not pinched/cut back when they were about 12″ high? No problem, it just means the first bloom will have a ridiculously thick stem.

You will have to cut very deep into the plant to remove that stem when it’s ready to be harvested. The subsequent stems won’t be as thick and more useable in arrangements.

Debbie P 3 months ago · 0 Likes  

My local garden center is advertising a beautiful dahlia I’m thinking about buying. I love to have cut flowers in the house. I grow several roses but would like to try some new flowers in a small cutting garden. I live in zone 10a and frosts are rare. Do I still need to dig and replant the tubers each year? What special care do I give them if they stay in the ground all year?

Lori Hernandez 3 months ago · 0 Likes  

Hi Debbie,
Lucky you! In your Zone, you’d treat them as a perennial, which means you would divide them every 2-3 years to multiply your stock. They likely need no special care over the winter, other than perhaps covering them with a bit of mulch.

Chelsea Dufresne 3 months ago · 0 Likes  

So you don’t water them until they start growing?

Lori Hernandez 3 months ago · 0 Likes  

Chelsea,
That’s correct. If you plant them as a tuber, then you should not water them until you see the green foliage begin to peek out of the ground. After that, they can be watered normally.

BUT…. if you potted them up and grew them indoors for a couple weeks , and they are an established plant with roots and sprouts, then you should water them when you transplant them.

C 3 months ago · 0 Likes  

Love dahlias! What kind of fertilizer do you recommend?

Lori Hernandez 3 months ago · 0 Likes  

A fish emulsion type fertilizer works great!

Dolores 3 months ago · 0 Likes  

Love the info you give- I planted dahlias indoors about 3 weeks ago- they came up very well, they are about 5-6” tall now with leaves- do I cut back the leaves to plant out side ?. Live in Ontario zone 6 so not real warm nights yet. Can I move these to a building outside without shocking too much

Lori Hernandez 3 months ago · 0 Likes  

Hi Dolores.
There is no need to cut back the plants. When it’s warm enough to plant them outdoors, simply make sure the planting hole is deep enough that the head of the tuber is buried 4-6 inches BELOW the surface of the soil. That might mean you end up burying most of the sprout too, and that is totally fine.

You can move them outdoors slowly. Start with 1 hour per day, then increase it by an hour or two each day until they are hardened off properly. Of course, don’t let them freeze at night.

Best wishes!

Timmi Hagen 3 months ago · 0 Likes  

I love your info! I am curious to know, if one does not have an irrigation system set up, how should one water? I have sprouting dahlia’s (I’m on the peninsula of Washington state) and all I find on watering is drip irrigation. Ahhhh!! What is your recommendation? Thank you for your time!

Lori Hernandez 3 months ago · 0 Likes  

Yes, it’s recommended to water flowers at the base of the plant, as this helps to discourage disease problems and is a more efficient method of watering.

If you don’t have irrigation, you’ll have to hand water with a hose or watering can, doing your best to direct the water at the base of the plant, not the foliage and blooms.

Sarah 3 months ago · 0 Likes  

Hi Lori,
I really do enjoy your blog as well as everyone else – I absolutely love gardening but this year is my first Dahlia year. For a garden bed that is beside your home but has other flowers growing between such as hibiscus, lilies, hydrangeas and such – how would you setup your netting to ensure stability or would you do a wooden stake as you have mentioned? If a stake any height suggestion and how much into the ground? Thank you for taking the time to share this information with everyone!

Lori Hernandez 3 months ago · 0 Likes  

Hi Sarah,
Thanks for your kind words!

In your case, I feel a sturdy stake or tomato cage would be the best solution.

The height depends on what type of dahlias you are growing. Some varieties only reach 1-2 feet, while others can easily reach 6 feet or more!

For larger varieties, be sure to sink the stake at least 12-18″ in the ground, which means you’ll need a 4-5′ long stake to provide good support.

jeff 3 months ago · 0 Likes  

Hi. I have a question. I can’t seem to find any info on thinning Dahlia. If multiple sprouts come up from the tuber, is it better to thin to a single sprout? It seems like one big plant would do better than multiple plants squeezed together.

Lori Hernandez 3 months ago · 0 Likes  

Hi Jeff, if it has a couple eyes/sprouts, I would leave them. If you try to break them off, the tuber will actually send up more to replace the ones you removed.

If the tuber has LOTS of spouts/eyes (like more than 10 on one tuber), I’d suspect the tuber is diseased and it should be thrown out. Do an online search for “Dahlia Leafy Gall Disease” and take a look at that.

Mary Heine 3 months ago · 0 Likes  

Loved your videos. Yes, that dividing up the tubers (looking for great-looking eyes) looked very time-consuming. I hope you play classical music as you snip away in your basement. I am thinking of all the years I have dug up mounds of dahlia tubers, and just threw them away. After ordering $350+ worth, which are the size of fingers, I won’t be so eager to just throw them away this Fall. Thanks for the informative “how to store over winter”. I’ve kept them in my garage in bins with a lot of peat moss, with some occasional misting. They were all dried and shriveled up. Fail. Is keeping them in brown paper bags the secret? I also invite people to just clip away at my lovely farmette. I do not charge, I just enjoy sharing with people. The looks of happiness are payment enough for me. Just wish I were in my 20s again, as being 62 years old, it gets more tiring to have my 60×60 plot for farming. I had it all fenced in, and keep chickens in a separate run, and their squawking keep my entertained outside. Best of luck to your dahlia enterprise. It’s HARD work, and I do not mind paying $$$$ for the back-breaking work.

Lori Hernandez 3 months ago · 0 Likes  

Hi Mary,
Yes, dahlias a beautiful, but I true labor of love. Sometimes I think I’ve gone crazy to invest so much time and work into these plants!

Sorry about your struggles with storing them. Unfortunately, there is no secret trick to successful storage of dahlia tubers. Mostly, it depends on WHERE you’re storing them, more than HOW. Sounds like the garage was too dry, despite the peat moss and misting 🙁

Carolyn Gilman 3 months ago · 0 Likes  

Hello! I’m planting tubers that I started in pots, so they’ve already sprouted. Would you recommend putting bone meal or anything in the hole with them as I plant? Or just wait until they get bigger to fertilize?

Lori Hernandez 3 months ago · 0 Likes  

Hi Carolyn,
When we plant our tubers, we dig the hole, then add a scoop of well composted manure and a handful of bone meal. That seems to help!

Once they start growing, we do fertilize them weekly though our irrigation system.

Dr s kazmi 3 months ago · 0 Likes  

Very helpful information trying first time to grow dehelia
I was going to plant as soon as I get them
Now I have good advice from you
Thanks
Dr kazmi

Lori Hernandez 3 months ago · 0 Likes  

You’re welcome! Best of luck!

Claire Lamb 3 months ago · 0 Likes  

Thank you! What a great article

Lori Hernandez 3 months ago · 0 Likes  

Claire,
You’re welcome! Glad it was helpful!

Jes 3 months ago · 0 Likes  

Lovely site and great videos. Enjoyed reading all your helpful info.
To Laura in sunny Florida. I plant my dahlias the first of March in full sun and they do quite well.
They are now blooming and bringing joy to the garden.

Lori Hernandez 3 months ago · 0 Likes  

Jes,
This is great info! Thanks for sharing!

Laura Gilmer 4 months ago · 0 Likes  

First year trying to plant Dahlia’s. I live in hot sunny Florida. I’m hoping I do it right. Great information you provided. Thank you!!

Lori Hernandez 4 months ago · 0 Likes  

Hi Laura,
I wish I could give you some advice, but I have no experience growing them in Florida! Best of luck!

Katie mccaffery 4 months ago · 0 Likes  

I live in the very North of Scotland , guess what !!!? we have Snow over the past week and there’s more to come . My Dalhias are in a shed , I’ve checked them so they ok , but I’m still worried in case they go mushy and die , I have 5 and they weren’t cheap , it’s the first time I’ve bought them . I just love your videos very helpful . From Katie

Lori Hernandez 4 months ago · 0 Likes  

Katie,
Sounds like Michigan! We’ve had snow storms on April 15ish the last 3 years. You just never know! Hope your tubers are ok!

Luna 4 months ago · 0 Likes  

Hello, this is my first time planting dahlia tubers , in fact my first time planting. I’ve planted my tubers in pots but I’ve notice tiny flies in my pots, please any advice on what to do without harming my tubers. Thank you so much for your wonderful information!

Lori Hernandez 4 months ago · 0 Likes  

Hi Luna, not sure exactly what is going on but perhaps fungus gnats? They can show up when the soil is too wet. Let the soil dry out between waterings and that may help.

Frankie 4 months ago · 0 Likes  

Really loved the videos and the info! Thank you 🙂

Lori Hernandez 4 months ago · 0 Likes  

Frankie,
You’re welcome!

Carol 4 months ago · 0 Likes  

This was fantastic!! Thank you for the information. I live in Ontario & received an email that my dahlias are on their way!!! I am so excited. Loved the videos. I am also growing other flowers & veg from seed hence the mini greenhouse in the kitchen. First time growing dahlias though & wanted to thank you for all the info.
Carol 🌸

Lori Hernandez 4 months ago · 0 Likes  

Carol, you’re welcome! Glad to hear this was helpful!

Bianca Beale 4 months ago · 0 Likes  

I had stored my dahlia tubers in a dark closet inside my home last year since I didn’t have time to plant them. It appears that they have sprouted…a few of them have a long white vine that has grown out of them. Is the tuber bad? Do I cut the vine and attempt to plant them? Any help you can provide would be greatly appreciated! 🙂

Krystle 4 months ago · 0 Likes  

Hi –

I had great luck last year and dug up my dahlias. I pulled them out to get ready to replant and some of the tubers are shriveled up. Are they still ok to use?
Thank you!

Donna Marshall 4 months ago · 0 Likes  

Good Morning, I’d love your advise on fertilizing dahlias. I’ve read so many conflicting ways from others but would like to know from a real grower.
Thank you for your time💜

Lori Hernandez 4 months ago · 0 Likes  

Hi Donna,
Ha! The reason you hear so much conflicting advice is because everyone’s soil is different and has different fertility requirements. 😉 Does that make sense? There is no “one size fits all”.

For starters, getting a soil test will help you figure out what your soil needs and how to best feed your plants.

On our farm, we fill the planting hole with well rotted composted manure and a handful of bone meal. Over the growing season, we try to fertilize once a week (we inject the fertilizer into our irrigation system) with a higher nitrogen type fertilizer as the plants are establishing, then switch to a higher phosphorus fertilizer as they get ready to bloom.

We have very sandy soil that doesn’t hold onto nutrients very well. People with different soil types may need to fertilize much less often.

Moral of the story… get a soil test! 😉

elaine rakoczy 4 months ago · 0 Likes  

Hi, My twin sis purchased seeds not knowing I’d prefer tubers. What should I do? BTW, your blog is absolutely awesome!!!!

Lori Hernandez 4 months ago · 0 Likes  

Hi Elaine,
Thanks for the feedback about the blog!

I’ve never grown dahlias from seed, so I can’t share any tips! What I do know is that most dahlia growers say out of every 1000 dahlia seeds, there are usually only a handful of plants that produce good blooms. You never know what kind of plant you’ll get growing from seed.

Growing from tubers is a much more reliable way to get beautiful blooms.

I’d say go ahead and try growing them from seed as an experiment, but you may also want to grow some from tubers.

anissa 4 months ago · 0 Likes  

I found this site to be one of the most helpful I have found thus far.
I have a few questions actually, after you divide the tubers how soon do you need to plant them? I mean can they sit in the root cellar for weeks, months?
I have heard two seasons are optional for digging the tubers up. I am in zone 7. I’m debating on which would be easier. Someone said that you can see the eyes better in the Spring?
What do you sterilize your tools with? I know it’s important before cutting the tubers to avoid diseases, maybe its also best to go a step further and re-sterlize before starting the next group of tubers?
If I have clay soil with some rock, would adding Soil Perfector be the best additive?
I have more questions, but I’m blanking at the moment. Long day. 🙂
And thanks….

Lori Hernandez 4 months ago · 0 Likes  

Anissa,
Thank you! I’m grateful to hear this has been helpful.

  1. Yes, they can sit for months after being divided. Some people divide their tuber clumps in the fall and store them over the entire winter as individual tubers. We prefer to divide in the spring. It’s personal preference.
  2. We prefer to divide in the spring, because the tubers begin to “eye up” and it’s easier to tell which tubers are viable. If you divide in the fall, it’s much harder to see the eyes.
  3. I sterilize with rubbing alcohol between varieties.
  4. I’m not sure what Soil Perfector is? Many people with clay soil choose to create raised beds instead and plant in those instead.

Hope this helps!

Lindsey 5 months ago · 0 Likes  

Thank you for this information. Can dahlias be grown from seeds in West Michigan? I’m guessing not?

Thank you,
Lindsey

Lori Hernandez 4 months ago · 0 Likes  

Hi Lindsey,
Yes, I believe they can, but I have no first hand experience with it. I might try it this year, but I was told by dahlia growers that out of every 1,000 dahlias plants grown from seed, there are usually only 1-2 worth trying to keep and propagate. I don’t have room for that kind of experimentation 😉

Tara 5 months ago · 0 Likes  

This is the most helpful blog I have found on planting dahlias. Thank you. The two areas on our property that I would like to attempt to grow dahlias for the first time have an automatic sprinkler system in which other plants / flowers depend on every 3 days. If I plant the tubers in this area, will the sprinkler water rot the tubers? If so, what would your suggestion be here? Perhaps start them in small pots until they sprout and then transplant them into the ground?

Lori Hernandez 5 months ago · 0 Likes  

Hi Tara,
Thanks for letting me know this! I’m grateful the blog post is helpful!

Regarding the rotting in areas with sprinklers…. if it’s clay/dense soil, I’d be wary of planting them there. But if it’s sandy, well drained soil, then I wouldn’t be too concerned.

Your idea of starting them in pots and transplanting them there is a great idea. Once they are growing plants, with leaves and roots, regular watering is ideal!

Manuel Gomez 5 months ago · 0 Likes  

Hello, I’m new to planting dahlias. What do the multiple white little roots coming out of the neck region of the tuber mean? What way should they face, up or down?

Lori Hernandez 5 months ago · 0 Likes  

Hi Manuel,
If you can see the little sprouts coming up, that’s good news! It’s means your tubers alive and ready to grow. Those are called “eyes” and a tuber only needs to have 1 eye to grow a new plant.

Once the soil is warm enough to plant them (needs to be after your last spring frost date), you can plant the tubers in a hole 4-6″ deep. It’s really doesn’t matter if they are up, down or sideways. They will grow! We usually lay them sideways in the hole.

Best wishes!

Ann Regan 5 months ago · 0 Likes  

Very Informative and well explained,

Thanks from Ann in Ireland

Lori Hernandez 5 months ago · 0 Likes  

You’re welcome, Ann!

Cheryl 5 months ago · 0 Likes  

I volunteer at a garden in my area. Per the instructions provided me by the garden managers, I’ve planted my tubers in pots and have them in a dark room in my home. I’m told I shouldn’t water them until they begin to sprout at which time I’m to move them to a sunny area of my home. No where do I find this method being used. Can you comment on this?

Lori Hernandez 5 months ago · 0 Likes  

Cheryl,
Yes, this is a viable method for growing dahlias! The soil can be a little bit damp, but you don’t water them regularly until they send up sprouts. They will also send out roots from the bottom of the tuber as well.
You can find more info and some photos of this process in my blog post called “All About Dahlia Tubers”.

We don’t have space to start all our dahlias this way, as we plant over 1,000 of them, but I do pot up a few each year.

Jennifer Dahill 5 months ago · 0 Likes  

I am in the process on building raised garden beds (18” high) I think I’m going to use stakes with the crisscross netting method. But after pinching them back what is your suggestion on keeping lower leaves trimmed back? Last year I noticed they flopped and sometimes had small flowers near the base. Is it recommended to trim the bottom? And if you could show a photo how it should look. Thank you

Lori Hernandez 5 months ago · 0 Likes  

Hi Jennifer,
I’m not exactly sure what you mean by leaves flopping? We do not trim the leaves on our dahlia plants.

What kind of dahlias were you growing? From tubers? From potted plants from a nursery?

Ann Paris 5 months ago · 0 Likes  

Hi! I dug up my dahlias last year, but I did not separate the tubers, I followed instructions to put them in peat moss in a paper bag over the winter and I am ready to plant them indoors in pots to start them. Since I didn’t separate the tubers what should I do now ? Thanks

Lori Hernandez 5 months ago · 0 Likes  

Hi Ann,
You should divide the clumps into individual tubers and pot them up. Be sure that every tuber has an eye or else they will not grow.

I have another blog post called “All About Dahlia Tubers” that has more info about tubers!

Best wishes!

Tia 5 months ago · 0 Likes  

Hi I’m entirely new to this, my boyfriend bought me six dahlia bulbs thinking they would come as flowers by accident, can I plant them as they are? They’re still attached to the little stalk thing and they are very big.

Lori Hernandez 5 months ago · 0 Likes  

Hi Tia,
Yes, if the bulbs are still viable, they will begin to “eye up”, which means they will sprout like potatoes do when they are left in the pantry for too long.

They cannot be planted outside until after your last spring frost date. You can find that by Googling it.

Jon B. 6 months ago · 0 Likes  

Hi,

I had lifted my dahlias last fall (michigan zone 6a), i put them in peat moss in a 5 gallon bucket in my stone walled michigan basement. I sits about 60 degrees. I noticed today that they had begun growing significantly. If i trim off the growth and keep them in the basement will they still grow properly in the spring when the weather warms enough to plant them?

Lori Hernandez 5 months ago · 0 Likes  

Jon,
Love this! Those plants are ready to grow!
Yes, you can trim off or break off the growth (like eyes/sprouts on a potato) and they will send up new sprouts later.
Or you can pot them up in small pots and start growing them under lights or a warm place until it’s time to plant them out.

Tracy 6 months ago · 0 Likes  

Do you have a video on planting/growing dahlias in containers? What size pot do you recommend if keeping them in all summer?

Lori Hernandez 6 months ago · 0 Likes  

Hi Tracy,
No, I do not have a video of growing them in pots, as I’ve never personally tried this method! But many of my customers have. They grow them in the largest pots they can find and usually support the plant with a tomato cage. The larger the pot, the more the tubers can grow and you’ll have to water it less. I’d say at least around the size of a 5 gallon bucket…

Charla 6 months ago · 0 Likes  

Hello there.
Will pinching the dahlia plant sacrifice bloom size considerably? Will I only get one bloom per plant if I do not pinch?
I want some whopper flowers, but would also like to have enough blooms to sell.

Lori Hernandez 6 months ago · 0 Likes  

Charla,
Generally speaking, people who are growing dahlias as “show quality specimens” will leave their plants unpinched, so they get larger blooms.

But we’re not talking inches here (usually…), it’s more like centimeters. While large blooms are fun to look at in the field or at a dahlia show, for floral work/arrangements, slightly smaller blooms are more desirable and easier to work with.

You can certainly leave some unpinched, harvest that first big bloom, then severely cut back the plant to encourage smaller subsequent blooms.

Best of luck!

MONIQUE MAILLOUX 6 months ago · 0 Likes  

Hello hello, We live in Greece on an island where it never freezes. Can I leave the tubers in the ground over winter or is it best to dig them up. Thanks very much , really appreciating all of your advice, Monique

Lori Hernandez 6 months ago · 0 Likes  

Hi Monique,
Ah, you’re one of the lucky ones! Yes, you should be able to treat them as a perennial and leave them in the ground. Like most perennials, every 2-3 years, you’ll want to dig them up and divide them. Best of luck!

Sara 6 months ago · 0 Likes  

Hi Lori,
What size netting (hole size) do you use in your beds?
Thanks!

Lori Hernandez 6 months ago · 0 Likes  

Hi Sara,
The netting Hortnova trellis netting and I believe it’s a 6″ spacing?

NC 6 months ago · 0 Likes  

Wonderful! Thanks 🙂

Lori Hernandez 6 months ago · 0 Likes  

You’re welcome!

Christina 6 months ago · 0 Likes  

Hi! Love the blog!!
I am starting a garden in Northern California. Zone 9. Am I able to keep planted each year to regrow as the weather isn’t freezing or do I need to dig up? Thank you for all the great tips & tricks!!

Lori Hernandez 6 months ago · 0 Likes  

Hi Christina,
Thanks for being here! I have zero experience growing in Zone 9, but I suspect you’d be able to grow dahlias as a perennial, leaving them in the ground all year long.

Like all perennials, they should be divided every 2-3 years. So perhaps every other spring, you dig them up, divided them to multiply your stock, then replant them.

Not going to lie… a little jealous you don’t have to dig them up. Ha!

Samantha 6 months ago · 0 Likes  

Hi Lori, this year will be my first season planting Dahlias and in your video “How to pinch dahlias”, I see you have a black plastic tarp of sorts on each side of your dahlia rows. Is this to deter weeds, or can you elaborate why you prefer to use this?

Lori Hernandez 6 months ago · 0 Likes  

Hi Samantha,
Yes, it’s a type of landscape fabric/weed blocker that comes in big rolls. We order it in the 3′ size and use it as pathways to significantly reduce weed pressure in our dahlia field.

Todd 6 months ago · 0 Likes  

Assuming I have done a decent job of amending my soil, pinching and keeping my dahlias properly hydrated how many stems should I be able to cut each week from each plant?

Thanks so much for your help!

Lori Hernandez 6 months ago · 0 Likes  

Hi Todd,
This is a hard question to answer, as some varieties are much more productive that others.

Some of the Dinnerplate types will produce maybe 1-3 useable stems per week, while smaller Ball types may produce 5-12 per week.

Best of luck!

Paige 6 months ago · 0 Likes  

Hi, thanks for your post! If I wanted Dahlias for Fall, do I cut the flowers back in Summer? Will more grow?

Lori Hernandez 6 months ago · 0 Likes  

Hi Paige,
Dahlias are a fall blooming flower and are at their best in September. Here in Michigan, they generally don’t start blooming until August.

In order to keep them looking their best, you should always “dead head” or remove the old blooms. This signals the plant to keep producing blooms.

P.S. This is true for most flowers! “Dead heading” and sometimes even major pruning/cutting back is necessary for continued blooms.

Madeleine H. 7 months ago · 0 Likes  

Hi! Thank you for all your wonderful info on dahlia growing.
I am going to be planting dahlias in Washington state. Since the heavy rain season ends around June, and the weather in general is better for dahlias after that, should I postpone putting my tubers in the ground until then? Or should I do greenhouse growing?
Lastly, my goal is to get a decent amount of blooms from each plant in the second week of September. The weather is usually great around then (average 70’s -80’s with full sun daily). How would you manage your dahlias to ensure heavier blooms at the desired time? When would the last trim be before the desired blooming period?

Lori Hernandez 7 months ago · 0 Likes  

Hi Madeline, thanks for the kind words! Glad to be of help!
We usually try to get ours in the ground by Memorial Day, at the end of May. Their growth really depends on warm soil, so planting them earlier in cold soil is quite pointless and could even cause rot.

You may want to try raised beds with good drainage or possibly even greenhouse growing. But if you can’t get them in the ground into early June, that’s no reason to fret.

Here in our climate, dahlias are usually at their best and more productive in mid September. The best way to encourage blooming is to keep harvesting all the blooms and making deep cuts into the plants to encourage branching to produce MORE blooms. We cut our stems deep, usually getting stem length of 18-24″.

Amanda K. 7 months ago · 0 Likes  

Hi! Very informative site. Thank you, this will be my first year trying a dahlia garden.

I am going to build a raised bed for a small dahlia garden off the side of my vegetable garden structure. It will be about 10 x 3 feet. How many tubers do you suggest planting my first year?

Also, there is a lot of wildlife around. I read that planting sage will help. I thought that I could plant that along the edges of the bed. How far from the tubers should I plant the sage?
Thank you!!

Lori Hernandez 7 months ago · 0 Likes  

Hi Amanda,
If you have lots of wildlife, I strongly urge you to fence in the raised bed. Sage and other herbs/plants will not effectively deter hungry critters… and almost critter likes to eat dahlias. Only a physical barrier, like a fence, is effective.

You could likely fit about 10-12 plants in that space, 2 rows of 5-6 plants.

Happy planting!Load More CommentsNewer PostToo Soon to Plant Your Dahlia Tubers? Here’s What to DoOlder PostMy Top 10 Favorite Cut Flowers

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