3,226 Garden Web Discussions | Dahlias
Hi roxborough & all, from my experience growth is dependent on temperature, by this I mean when temps., remains low then the tubers will remain dormant.
If the temps., are raised to minimum 10 oC with max temp., 15 oC + then the tubers will initiate growth, untill green foliage appears the presence of fertilizer will have minimal effect.
The use of a temperature dependent fertilizer (here in Australia we use 6month Osmocote exact) which as the temps., rise the fertilizer starts to be released, hence starts feeding the shooting tuber when they have green leaves.
I tend not to feed most tubers, until they have shown green shoots (this is when I use 6month Osmocote exact). Once the foliage has developed sufficiently I use stronger fertilizers.
Dahlias can be kept in flower during winter, by adding lights in the middle of the night for approx., one hour, as this sends false signals to the plant that the season is summer instead of winter. This is the reverse process to flowering poinsettia.
Am still curious how the US snow storms are going? as I do not watch TV often, hence tend to miss the news which would show images & give reports on the extent & severity?
From what I have seen, it looks very stressful (if not terrifying?) to say the least for many people. The forum is very quiet gives me the impression people are occupied else where? would like a quick summery if any one has the energy & inclination thank you allan
You should treat the plants as though they were growing in a greenhouse. If they are growing and it is warm enough to get them to grow, you should feed them with 20-20-20 soluble green house fertilizer after they have sprouted. It should be used at half the normal rate and done a couple of times a week. Sun and heat plus water and fertilizer is what grows plants. If there is enough light and it is warm enough, the addition of the fertilizer will give them a real kick start. Here in my garden, I have noticed that the earliest blooms come from the cuttings I take in early Spring and grow to about 12 to 18 inches tall before planting in the garden. I do not bother to to replant them into larger pots and they are in 2.5 inch pots. They are root bound and somewhat tall but have stiff stalks because of the fertilizer. Since they have such a developed root system, they can grow very quickly when planted. If I plant a tuber in the ground on the same day I plant the root bound cutting, the cutting blooms a full month before the tuber. At a trial garden for dahlias, they accept both rooted cuttings and tubers to trial. They plant the rooted cutting 3 weeks after they plant the tubers and the cuttings still bloom well before the tuber grown plants.
Dahlias are self regulating about their growth. In your area where there is no possibility of frost now, the dahlias will grow at their own rate depending on the weather. Remember they are native to the mountainous regions of Southern Mexico and they over winter just fine there. I would just let them grow and they will do just fine. Worst case would be that several weeks of totally wet weather sets them back in April or May. You have the advantage in your climate that you could cut the plants down to the ground in any month between February and June and still have lots of growing season to have flowers in August through October and maybe later.
I'm on a Yahoo Group. Go to the Colorado Dahlia Society web page for tons of information, including forums. I also think some of the individual societies around the world have their own chat groups.
If you can get to a dahlia meeting you will learn all you need to know, at least a lot of information.
You might also look at Dave's Garden, although I think you have to pay to post messages.
Ginny
Here is a link that might be useful: Colorado Dahlia Society
Why the "nevermind?" Did you just trash them or find information on the web about what to do with them? I've been growing dahlias for 20+ years. I love them!! I almost never divide them, but when I do I take a shovel and chop them into 4 parts, or so, and replant those.
One year I helped divide tubers by looking for the eye, etc. I did it under supervision but decided very quickly that it was easier to divide by shovel or buy new ones rather than take a chance on cutting my fingers.
Ginny
Flickr is owned by Yahoo and it has a dahlia picture group with several thousand pictures of dahlias in it. The pictures vary from superb contest winning types to more average ones. They have a comment section for the pictures and if the picture is especially nice, it can win an award from various people and groups. Lots of fun to look at the pictures during the cold winter.
Thank you for the replys, livsauntieshel & teddahlia have opened a picas folder & am not sure how to insert image code?
Only placed a link to the folder at bottom of this post.
The flowers in this folder were taken today & are not as good as unusual, as this is the last of a week of hot humid weather with day temps 22 oC min up to 35 oC max each day.
Will try Flickr next, if I find picas difficult to post images from?
cheers allan
Here is a link that might be useful: Dahlia Images taken today 7th February 2011
Growing dahlias from seed is lot like trying to grow potatoes from seed. I do not believe you would generally want to eat that potato because they do not breed true from seeds. Both the potato and the dahlia have tubers that give you superior plants every year. Breeders of dahlias grow about 1000 seeds to get one really nice one. About 800 are really ugly or just not healthy or vigorous. The 199 or so are inferior to named varieties and the one is very nice.
The dahlia seeds that seed companies sell are nothing like real dahlias. They have been bred them to grow only 2 feet tall and to have semi double flowers that are not much to look at. If you like short plants with randomly colored, partly open centered flowers then grow some from seeds. If you want real dahlias that grow 3 to 5 feet tall and look just like the picture, buy named tubers.
I did a quick search on "The big list"
Check out homestead dahlias. http://www.homestead.grimloc.net/
Thank you Steve, though am more envious of the fantastic selection available in the US, If I lived there would check up with any local grower to get their recommendations? am sure they would be fantastic. cheers allan Oz.
Right now I am just about finishing cleaning up my re-bar stakes. I use a power wire brush to remove rust and repaint with rustoleum. Last year I tried some of the tomato cage supports but did not particularly care for them. Seemed to get in the way for weeding etc. Steve in Baltimore County.
I second the advice on ordering early. I started my shopping in January and was surprised to see how much had sold out. Thanks for the suggestions ted. I had already decided on AC Rooster also. I was only able to find a couple photos of it online; but the ones that I have found are stunning. Lot's of good "AC" dahlias that have originated in the last couple year. I'm also adding 'golden nickels' , 'darkhorse' and 'ben' to my list for next year. I'm afraid I might need to dig up some of my last remaining grass to make room for it all!!
I believe that your dahlia plants are suffering from virus and will never grow properly.
(1) Throw all stock away and start over
(2) Order new stock from a reputable nursery or get stock from the San Francisco Dahlia Society.
(3) Grow them in the ground if possible
(4) In the pots use Miracle grow but each month give them some weak epsom salts, so that the plants can take up the iron. Miracle grow has too much phosphorus and the magnesium will displace the phosporus and in turn the iron will be made available for the plants.
(5) In the ground, make sure they get lots of sun and fertilize with a fertilizer that has plenty of nitrogen. There is myth out there that dahlias need less nitrogen. It has been proven wrong over and over by reputable growers.
Many thanks Ted(dahlia)
I agree - they may have gotten a virus (which is an answer I was looking for originally). So I have already accomplished 1 and 2.
3 is a problem - I have limited ground space available in my yard which is why I have twice as many container dahlias (and roses) as ground dwellers.
4 is a great point. I use Epson Salts for my roses (growers and old time gardeners say it makes the colors more vivid) so I will try it this year on the dahlias. Never heard that iron angle before so that is interesting.
5 is a BIG problem. Can't control how sunny it will be this or any year in SF so I can only do my best and hope for the best. (I realize that is NOT what you meant but believe me,I have a dahlia in every area of my yard). What gets me is a blooming dahlia in the sunniest spot can be next to another dahlia that MAY or MAY NOT bloom well. That is the maddening aspect that I suspect we all share.
I was one of those that heard nitrogen was bad for dahlias because of advice like this from a well known grower: "Dahlias require a low nitrogen fertilizer, such as used for vegetables". Somewhere else I read you shouldn't use (high? a lot?) of nitrogen either and I always thought it was the nitro that made Miracle Gro such a miracle! As I wrote elsewhere in the forum yesterday, I am going to go back to MG this year though, in part because of advice like yours.
The saddest part is I rent an in-law and in Sept. the owner moved back in (above) and informed me that he wants to build a deck from their unit (I have the only access to the yard) so he and his sons can plant vegetables! (Now that I made his weed patch into a Butchart Gardens.) Building a deck will put about 30% of my BEST sunniest growing space in shade and I will obviously lose more space to beans and peas apparently.
It only figures that by the time I get this growing thing down right, I'll lose half my dahlias/roses/yard. :>(
I agree with you. I did 10 potted last year and they grew to about one foot and stopped!!! Now I have a garden that has bout 75 tubers in it and everything was fine there. I can't blaime water or soil. They just didn't like the pot. I will try again with a different shape pot. The smaller azeala type. Getting ready for old age with just a patio for 2 plants!!!
Any veterans of this forum may recall my dilemma with a container dahlia from last year so you'll know I have about 10 dahlias in soil but twice that many in pots. I have grown them for 4 years now and while it is true the larger ones do much better in the ground, I have good 4-8" blooms on my container dahlias as a rule.
2010 was also an odd year here in SF. A couple pot growing dahlias came up but never bloomed - a couple gave me only 2-3 blooms. But that was equally true of a couple of the ground dahlias as well. What I have noticed though is most of my good container bloomers are first year dahlias and if I am honest about it, the potted dahlias from years 2,3,4 were not as robust as the first year they were in pots. Not sure if anyone else ever commented on this or noticed it on their dahlias.
But on this forum I learned that my thought processes in 2010 were probably wrong. I had read that excess or 'early' nitrogen was to be avoided so I took that to mean none and I never gave them miracle gro, though I did feed them 0-10-10. What I have since learned is the word excess didn't mean NO nitrogen and apparently that admonition applies to before they start growing anyway. Once they are a foot tall or so, it is apparently OK to use nitro on them so this year I am going BACK to my use of MG on them and hopefully they will all bloom this year.
I am anticipating a troubling crop though this year. We had 80 degree weather in November for a short spell followed by 40 degree weather for much of Dec and Jan. Now it is approaching 70 this weekend for 4-5 days and then we MAY go back to rain, so all this cold-hot-cold-hot-cold may wreak havoc on the tubers. Will have to wait and see.
Loved your beautiful blooms. What is the height of plants? Please post more. Wish I knew the variety.
Sorry for a late reply, the height is variable the shortest being 18" and the tallest is 3.5'.