3,226 Garden Web Discussions | Dahlias

I moved mine when they were about that size. They wilted for a few days, but they were okay. Try to keep as much of the root ball as you can, and don't damage the tuber. The main stem near the tuber seemed quite brittle, so be careful of that.

Thank you. My dahlias are always wonderful -- but when I purchase a small potted plant (looking beautiful) - they often wilt, only to return in spring and look great. I was afraid of the same reaction from a move..

For what my 2 cents is worth, here it is.

I have about 25 dahlias in the ground and about 25 in pots. My experience (and most dahlia and rose vets will say the same) is that potted plants NEVER seem to do as well as in- ground plants do. But they can do fine anyway and bloom just fine.

My question would be are you feeding them? And if so, with what?

I made the monumental mistake of withholding Miracle Gro from them last year (even bought 0-20-20 fertilizer) and I had some that looked just as yours are described. They sprouted like weeds and grew to 2-3 feet and then went into hibernation. A couple never bloomed at all. This year, I gave them 4-5 doses of MG so far and some have started blooming already, all are up and growing and it looks like the exact opposite of last year. One of my potted plants last year gave me about 4-5 blooms all year but already it has 2 blooming, 6 waiting to bloom and hopefully many more to come.

Good drainage in pots is key. When the soil never dries out, my dahlias get saggy looking and sometimes die. Then again, potted plants dry out quicker that soil plants so as mentioned above, they may need MORE water.

Many will tell you pot size makes a difference and I don't doubt it does, but I wonder why store bought, already blooming dahlias are doing fine crammed into 1 gallon plastic pots? I suspect they are not grown in pots but I also can't see a 4 ft dahlia with three 8" blooms being transplanted from the ground into tiny pots either. Surely that can't be good for them so which is it? They were transplanted or grown from scratch in 1 gal pots?

The bottom line is they do well in those small pots so maybe smaller is better? (Somehow, I just can't wrap my head around that idea.) Maybe some of the vets on this board can straighten me out about that.

David

My very amateur understanding is that what really matters is that the plant is getting enough water and nutrients. If water and nutrients are abundant, the plant needs less feeder roots than if they're scarce, although there's obviously a physical limit imposed by the maximum capacity of the root system, so you can't grow 4ft tall dahlias in 4 inch pots because the roots physically wouldn't be able to carry enough water to keep the plant fed. Hydroponically grown plants have relatively small root systems for their size because they have a constant supply of water and nutrients in a small space, but they're also very fragile - cut off the water for even a day and they'll be severely stressed. A plant grown in the ground, especially if its not irrigated or fertilized, will have a much larger root system and consequently can take much more abuse.

Container culture is in between. Provided they get a constant supply of water and minerals sufficient for their size, there's no fundamental reason container plants can't do as well as those in the ground, but its hard to keep the supply constant. Its easier with a bigger, well-drained pot than with a smaller one because the mix can hold onto more water without becoming waterlogged and killing the plant's roots. If you're going to grow Dahlias in containers, its also important to note that they need some nitrogen and there almost certainly isn't enough a in store bought mix. From what I've been told, its probably best to give them about 2x as much nitrogren as phosphorus, but I've not tested this with any care.

I've been wondering what's up with the Home Depot dahlias myself. My guess would be that they're grown under carefully controlled lighting with lots of nutrition to get them to grow and bloom quickly, and then repotted into the little 1 gallon pots you see them in in the store. I wouldn't want to leave them in those pots in the conditions I can give them for very long.

Yes. Those are dahlia's

thanks, they better be for 5 bucks per stem:)

Diatomaceous earth used for pool filters has had an extra processing step. It makes it not as effective for insect control. The "Safer" brand DE that I find at any large home improvement store or gardening center works wonderfully.

I have had fantastic results so far this year with Neem oil.
http://www.discoverneem.com/
I sprayed in the early evening/very late afternoon at the first sign of insect damage 3 weeks ago and again yesterday for good measure. Last year I was overrun with small grasshoppers, cucumber beetles and god knows what else that were eating everything and spreading Rust and Bacterial Wilt. I had Dahlia blossoms embedded with beetles.
So far this year no rust, no wilt, no bad bugs! I purchased 100% Neem oil that I store in the fridge and mix as needed. There were some weeds at the edges of my yard that were being eaten by something so I made sure to spray those and not pull them so whatever it was would ingest the Neem.
I'm keeping my fingers crossed that the success so far will continue for the rest of the season.

The link is to a site that provides information only.

Here is a link that might be useful: Neem Oil

I too have used Sluggo Plus with success against earwigs that were ravaging my mulched bed of buddleia and roses. The only downside are the claims of Spinosad, the active ingredient, being deadly to bees. Spinosad, I hear, is the reason why Sluggo Plus isn't OMRI approved. The bees still come to feed on my buddleia and roses but I'm not sure I would want to risk using it again as I have seen some dead bees around my property.

Nothing like the scientific metod: Let us know after you've tested!

Hello, what great advices I find here...I have to try the hot water. Makes me think!

Do I deadhead the little ball that's under the bloom? I don't know if this is another bloom or what it is! They aren't doing anything since the bloom died. As you can tell, these are my first dahlias & they're planted in containers. 1 is Dalina-Midi Sumatra Dahlia, which is doing very poorly & the other is Dalina-Grande Hiva, which has the balls I was speaking of. Neither tag says whether to deadhead or not. HELP!

Absolutely deadhead. It will bring on more flowers!

Go ahead and plant them. You can do a google search on your zone to see if you can leave them in the ground - that wouldn't work in my zone 5, but I just planted the last few tubers I had into containers for the deck. They must have just been waiting for a little soil and water because they were out of the soil in 3 days and coming along. The worst that can happen is they die, 2nd is they grow and stay alive for next yr and best - you get a few blooms off these neglected tubers.

I have purchased dahlia tubers this year, seven of them, I was waiting on beds to go in in my backyard and didn't get them in yet. It is now June 11 and I am wondering if I am too late to get them in. I know that some of the other posts asking the same question were posted in the beginning of July and I wondered since it is the beginning of June if I am still okay. I have never planted dahlias before and I have some beautiful varieties, some of the large dinner plate size, the Maki and others. I would love to see them bloom but am not sure if I am too late, if anyone has any direction they can offer, I would greatly appreciate any advice. Thank you in advance for your knowledge.