FYI:
Dahlia Talk
April 23, 2024
There were 31 participants. For those of you have not been on our Zoom meeting there are three levels of participation. Zoom first allows you to be a lurker, a ghost inside the machine who listens and observes the tiny squares of images of the others but hides both your picture and turns off your microphone. You can hear but are not seen and you can observe the others who allow the camera to capture their visage. There are always some people who are in this mode the entire two hours of the meeting. For those who are more outgoing, a typical person will leave their camera turned on but their microphone turned off. Most of us are in this mode. The third level is almost reserved for the exalted leader of the meeting who always has his video and microphone on and is ready to guide us through the meeting. Again, most of us have our video on and the microphone muted(of course you can have only the microphone on and video off and those people make us wonder who is talking now?). If all this sounds complicated, think of this way: It is just like the old TV show called Hollywood Squares and you are now a celebrity.
This meeting had as it's highlight: a true confession from most of the participants, and especially the ones who take dahlia cuttings(the great majority). One after the other confessed they had the same problem: fungus gnats. For those who are not aware, fungus gnats are those really small insects who fly when you disturb them and they seem to be living on the soil in your pot tubers, cutting tubers and even worse, in the soil of your recently rooted dahlia cuttings. The skeptic says: Who cares as those pesky little flying insects are so small they cannot do any harm. The experienced dahlia grower knows that this is not true and yes the flying insects do no harm but they lay eggs in the dahlia soil and the eggs hatch into larvae and they eat the roots of your dahlias. I should end my dissertation here as we discussed the methods to control these vermin and you were not one of the members of Dahlia Talk. But I will list some other subjects we did discuss and give no details on them because I thought most everyone would benefit from the words of wisdom of the Dahlia Talk members.
The first and most common solution is to use those yellow sticky traps that use the yellow color to attract the insects and the sticky stuff to trap them so they cannot move. They are very inexpensive and work very well in trapping the insidious minuscule bugs. I recently found out about them and was amazed how many fungus gnats were living in my cutting area. Of course, when you discuss such things, at least one person has to have a bigger sticky trap than yours and the participant showed off his 8 x 10 inch version of the yellow sticky trap. Thank goodness it was not a used one covered with the vile bugs.
It turns out that sticky traps will not entirely solve your fungus gnat problems as the bugs have already laid their eggs in the dahlia soil and the sticky traps do nothing to control them. And Dahlia Talk comes to the rescue: There are organic solutions that work. One person recommended rosemary oil that kills the larvae. I did some research and found out that 3 tablespoons of neem cake can be soaked in water for a couple of hours and used as soil drench and it kills the larvae. So, there is hope that we can eradicate the deadly fungus gnats using organic methods and we can check our results by continuing to use the sticky traps.
More subjects covered in this meeting:
(1) Genetic decline in dahlias. We discussed the decline of many varieties over time. One person gave as an example an old dahlia called Lilac Time that is no longer a vibrant blue purple but is a dark pink now. I discussed an older dahlia show person who when he needed to replace his show stock would order the older variety from 5 different sources and grow them and select the best one and even then was not always successful in finding good stock. There was lots more discussion of genetic decline and some involved possible virus infections of a type that has no test available. Lots of speculation. Good discussion.
(2) Alpaca manure was toted as being an excellent fertilizer by many show people. Lots of manure talk.
(3) Bat guano was discussed and the various versions are available at Concentrates.
(4) Soil Tests was one of the most discussed items at the two hour meeting. Lots of discussion on pH and the application of lime to correct it in acid soil and the application of sulfur in alkaline soil. It was pointed out that if you have very acid soil, it is not possible to add enough lime in one season to correct it as there is a 100 pound per 1,000 square feet limit for lime application. There was discussion on the use of pH meters that give unreliable results especially as compared to an actual soil test. The A & L company that many people use for soil tests has increased their price to $49.00, and also has moved from Tigard to Sherwood and also have increased the required amount of soil for the test. People in Idaho use a different company called Western Laboratories. Clay soil can be helped by the addition of Calcium Sulfate(gypsum) pellets but in the long run compost at the rate of two inches per year works. Lots of fertilizer discussion.
(5) No till planting of dahlias was discussed and one member explained in detail how he does his no till garden. Very interesting.
(6) We discussed the rotation of crops and dahlias and whether people either rotated crops or let their ground go fallow. Most people do not and continue to grow in the same area every year. Is that best practice? No answer was agreed upon. Lots of discussion.
(7) Vertical planting of dahlia tubers and not planting large or overly long tubers. There was an experienced member who plants his tubers(he said for 30 years now) vertically and the eyes of the tubers are only 2 inches below the soil level. He says this causes the tuber to make easier to divide clumps as the tubers grow evenly from the top of the tuber. He says they do not rot in excessive rain conditions because the water goes down the side of the tuber. He cuts oversized tubers down to about 2 inches in length before planting and does so while planting as he says they need no hardening off after cutting. Again he has been doing this for 30 years.
(8) There was lots of social interaction not directly related to dahlias. Max Ollieu is returning from down South tomorrow is an example.
(9) As usual, I have left most things out and you should take the time to participate in our next Dahlia Talk session on May 28th at 7PM Portland time.
