3,226 Garden Web Discussions | Dahlias
I bought a plant of "Peaches and Cream" last year, and when I posted my fabulous "Peaches and Cream" bloom on another site, I was told and shown that it was more likely "Seattle" therefore, the big box store did mislabel. It does happen, but . . . all 5? I'm a fan of Duet, but wouldn't want an entire garden of it. I don't generally buy big box store dahlias, I buy my tubers one at a time from either dahlia club sales or from people that specialize in growing dahlias. But even dahlia growers and clubs make mistakes . . . it happens! When I helped package dahlias for my club this year, I learned just how easy it is to mislabel!
And I forgot the link:
Yes, that is a dahlia. I don't know the specific name of it but it is probably one of the bb size. This fall would be a good time to divide it. If it has been in place for many years you might need to just chop it in quarters with an ax and them remove all the damaged pieces. You will still have many tubers left to replant, or you can replant one of the quarters and share the others or plant them elsewhere. You might enjoy adding some other colored dahlias to complement it :-)
Are you sure it's a cutworm, because I am very fond of blaming everything wrong with a dahlia on slugs and this is no exception!
Not sure what kind of cutworms you have in your location, but this dealy below would be awfully tedious on 40 plants. And even worse in my phlox which they invade every year about now...
Here is a link that might be useful: cutworm device
I am raising dahlia plants in raised beds and they were doing so well. Now that they are getting buds they look like they are rotting at the surface. If I touch the plants they fall over. I did not stake the plants in the spring, which I should have, but this seems like either bugs or they are to wet. We have been getting lots of rain but the beds drain very well. I have about 25 plants and I am just sick about it. I have been staking the plants being very carful not to spear a tuber. Help!!!
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.
Don't the packets indicate time from germination to bloom? The two I've purchased did, but I'm not at home to check and see. You must have a lot of garden space to sow that much, or you plan to give a lot as gifts, huh. Nice variety choice, I'd say! Gardening fun, to discover the flower colors and forms in the mixes!!
There have been several reports this year of contaminated compost. Your potting soil may contains some of it. The source is herbicides sprayed on lawns and pastures. Normal composting does not eliminate it. Also, some manure products are contaminated with it as the chemical is not altered by the animal's digestive system. Dahlias are extremely sensitive to it and the symptoms you describe could be attributed to it. There is more information on the Washington State University site. They state that you can test suspected soil by planting garden peas in the soil and as a control, plant some in known good soil. If the peas have twisted leaves and other symptoms at the end of three weeks, the soil is probably contaminated.
I've got some issues that may be the start of what green passion was seeing in 2010. So if you find that you have this problem with contaminated soil, will it still be in the soil in 2012? I read the terminology "sterilize the soil" but what does that mean?
Sorry I'm not much help. Do you have a photo? I would post on the disease forum. I've had luck over there.
Here is a link that might be useful: pests/disease forum
Why not try more?
Digging and dividing dahlias is hard work! If they do freeze, replacements can be easily bought. How much is your time worth?
Some hints: Be sure to mulch the plants with several inches of compost or dry leaves. Make sure they are not in a wet area as they will rot in cold, wet soil. Consider digging them in the Spring every few years and dividing the large clumps. As clumps get too large, they send up too many sprouts and the plants will become too crowded an be spindly. Be sure to control slugs and snails in the Spring as they will lay eggs on the clumps and the hatchlings will eat the sprouts before they come up. By the way, you can easily move clumps around in the Spring and they will do fine when re-planted.