3,226 Garden Web Discussions | Dahlias
Looks like Thrips damage to me. They bite the plant in the summer than leave a virus which only appears many months later in some cases esp. bulbs and tubers. Try cutting back all the foliage and keep the tubers cold for several months if you don't already live in a cold winter area. As soon as new leaves appear in spring spray with Neem to stop the critturs coming back. Good luck - ian.
We get this type of occurence (possibly the same pest), every year with various perennials and shrubs, such as Philadelphus, Phlox and Rudbeckia.
We never see what causes it, but at a certain stage of growth (or time of the year), the leaves get twisted and distorted. After some time, new growth appears, which is unaffected, but we never get around to actually spraying the plants.
don't know your climate, whether Dahlias like it. July could be somewhat too early,
I plant mine mid- late May, in July they just about start flowering (need to check my fotografs)
apart from that: you would`t bother with seedling Dahlias, as they are of mixed parentage and will show all kind of different colors.
and it could ruin your timing, assuming that you don't have a greenhouse at your disposal?
The Dahlia seeds sold in garden centers are often from short ones (perhaps additional filler flowers) but nothing really amazing.
Do you know what kind of colors you need/ want?
I would decide on the colors, then pick some named cultivars.
I gather that growers like Swan Island (did I get that right?) have recommendations for cut flower cultivars (long stems, long vase life).
quantity is tricky,
mine (mostly water lily types) produced about 2-5 flowers when harvesting about once a week.
you could ask on the cut flower forum about quantities, lots of people selling theirs on the market so they could give you a better guess/ calculation.
did you grow Dahlias before?
Well, best of luck,
bye, Lin
I am in zone 5/6 Pennsylvania, and the earliest I've gotten dahlias that we're suitable for cutting was July 15... But that was also starting them from tubers mid-march so they were 12-18 inches tall before setting them out. Even so, most of mine were blooming mid August.
Remember, if you are thinking of purchasing tubers, that typically the larger the flower, the later the bloom.
The vendor Lin mentioned also sends dahlias all over the US at decent rates. If you choose to try growing your own dahlias,that is great! You'll have lots of fun learning about them! BUT have a backup plan in case that cute bunny over in the neighbor's yard comes over for a dahlia snack before the plants can fend for themselves!
Best of luck!
CC
Lin, thanks for posting this! I watched/listened to most of the thirty-five minute presentation while my furnace was being repaired.
Wish the poster of the 'video' had asked to use his slides, as it was frustrating to not see what he was talking about. For those not wanting to watch but want the general ideas, this is what I got out of it...
-Look for dahlia varieties that have constant flowers with blooms above the foliage (many competition varieties do not make good garden varieties)
-when pairing dahlias with other garden plants, blend lacy leaves with broad leaves, light with dark, pastel with vivid colors
Anyone else got another good pointer from the presentation to share here?
flipping through youtube, I came across that snippet of film.
Is at least 12 years old, when the tropical garden (that Fergus Garrett talks about, they use the Dahlias for that spot) is in its third season and Christopher Lloyd still alive.
Amazing.
Still need to listen through that talk again and take notes about plant combinations.
take care, bye, Lin
Here is a link that might be useful: garden for which Dahlias are used: Great Dixter
You might ask Teresa of Cowlitz River Dahlias via email if she grows it. She imports from overseas often, but doesn't offer for sale to the general public until she has plenty of stock. If she doesn't grow it, you might pique her interest to get it in the future.
So variegation and bicolor is not created from recessive genes, but from unstable genes... That's gotta sit a while on my skull before absorbing! Time to Google transposons and McClintock.
A very experienced dahlia grower has said that multiple attempts to grow Harvey Koop with variegation has failed, and the grower blames the soil for it. The grower claims that when the reverted Harvey Koop tubers are given to other growers with different soil, the variegation comes back. I suppose unstable genes makes more sense, if the theory about the soil is accurate. Your thoughts, Ted?
Transposons are DNA sequences within a gene that cause genes to to turn on and off in a somewhat random pattern. They cause the red pigment formation to turn on and off, creating variegation. Because they are unstable, they can sometimes "jump too far" or some such thing and affect another portion of the DNA and stay there for awhile. Later they may relocate back to the pigment producing area and again the flower would be variegated. I do not know what environmental factors affect transposons but have heard of this happening over and over to variegated flowers. Many times the variegation never again appears. I doubt that it is soil related but it may be related to excess heat.
And dahlias do not have "recessive genes" in the diploid sense because dahlias are octaploid, For a dahlia to be homozygous for a recessive trait 8 genes must be the same whereas in diploid plants only 2 are the same. It is nearly impossible to breed dahlias with all 8 genes being the same. If you know how to do it let me know.
Yes, CC, the vary pale pink stellar is V's DF. The "Pink Cactus" is an end of the season HH Cotton Candy. Not sure about the "Red WL" It might be an end of the season HH Black Widow, or something that is usually deep purple like Fremont;s Memory.
Hard to tell at the end of the season just before frost! Just below the dark red is a HH Butterscotch and I think the last of the Hart's Pink Tickled Pink. Right below it are a few very pale, fading away Verrone's Rosalyn.
Hollyhill Court Jester's most outstanding trait is the variability of the flowers. Nearly all of them have some white on them. Here at Hollyhill, we have found that Court Jester is not as vigorous as most dahlias and is a bit below average tuber maker. At it's best, it is a great flower. But you have treat it well to get nice flowers. It's parent Hollyhill Jester is much more vigorous and easy to grow and it makes lots of tubers. However, most of it's flowers are solid red and just a few have the white blotches. The parent of Hollyhill Jester was Hollyhill Jokers Wild. It has very consistent white splotches on nearly every flower. It is still sold by a few nurseries and is worth trying if you like this type of flower.
From what one grower in Gainsville told me, the dahlias start blooming Feb/march, slow down in midsummer, and take off again when it cools down in the fall/early winter. Effectively, there are two growing seasons in a given year.
There is no dahlia society in Florida, but Georgia's website has a list of the top heat-tolerant varieties and other goodies.
www.dahliasocietyofgeorgia.com
Here is a link that might be useful: Southern Growing Guide
Here's the most comprehensive list out there, complete with hotlinks to sites.
Here is a link that might be useful: Dahlia vendor and variety list
I've noticed that, once dug up, a clump of tubers gets colonised by mould etc within 2 or 3 weeks, especially in a shed which, although having some ventilation, the weather is damp. As for dividing them, if only tubers could be divided as easily as a bunch of Bananas!
If they've been grown in a pot, you're looking at a tightly congested mass, having a mulititude of thin stems where you just don't know where to start.
It's not so bad when they've had the extra space of open ground, as the individual tubers are larger and spread out, and have a thicker, main stem. I think that the loose 'floppy' tubers, which have a very thin neck, can be detached, but others are bonded onto the main stem, which makes any knifework a daunting prospect.
Tubers grown early on in a pot are compressed and contorted. This includes especially, plants grown from rooted cuttings. I divide hundreds of such clumps each year and get an average about 3 viable sections. They may not look like tubers but each section has at least one viable eye and they store well. In the UK it is common practice to store clumps or partially divided clumps over the winter and then they are used to produce sprouts to make rooted cuttings. While many growers may not do this, the commercial sellers do so and then sell the rooted cuttings to the back yard gardener. The prices of such rooted cuttings is less than what we pay here in the USA for tubers or rooted cuttings.
Yes, when I dug up my Dahlias, there were many in the soil between those bulb parts. I guess they like the soil and mulch stuff (cut stems and bits) to feed on.
I tried to wash them off with a hose,
Not wanting them or nasty cutworm things in the boxes while storing the bulbs.
Bye, Lin
From Dr. Saar's website called wild dahlias:
Dahlias are plants of the uplands and mountains, most frequently at elevations between 1,500 and 3,700 m (4,900-12,100âÂÂ), where frost usually occurs during the winter months but the ground does not freeze. They frequently grow in a vegetation zone described by Leopold (1950) as a âÂÂpine-oak woodland,â where open, scattered stands may be dominated by pines in some places and oaks in others. These woodlands are usually situated between the oak scrub and high pine forests, and Arbutus is a frequent associate. In a few instances, Dahlias such as D. tenuicaulis occur in a zone of Pinus and Abies at elevations near 3,000 m (9,800âÂÂ). The habitat for D. macdougallii is a cloud forest of epiphyte-covered tropical hardwoods in southern Mexico south of the 18th parallel. On a collecting trip in 1995, D. foeniculifolia was observed growing along road cuts through oaks and mimosoid scrub at elevations as low as 950 m (2,800âÂÂ) (Saar, 1999
HI
Dahlia foeniculifolia Sherff, American journal of Botany 38:70. 1951
This is in the section Entemophyllon which includes dissecta, scapigerioides, rupicola, and linearis.
Most of these have long lived stems giving them a similar appearance to the "Caudiciform" xerophytes of South Africa and Madagascar. Cultivation is similar also in that they need Summer moisture and a dry rest over Winter. Not frost hardy and so far difficult to root from cuttings.
Thanks for taking the time to answer, and for the advice!
I have not had good results from Touché. For me they rarely came out fully double so after trying it for several seasons I have now trashed it. My climate is also hot and dry in summer which tends to make dahlias open up in the center. Some varieties are more susceptible to this problem than others. You may want to consider varieties that are listed as being more heat tolerant. Check out the link below.
Here is a link that might be useful: Heat Tolerant Dahlias