DSC eNewsletter

June, 2006
Next Meeting: 13 June at 7:30 at 9^th and Lincoln. Program: Lou Paradise expatiates about dahlia maintenance, good grooming habits, timing blossoms, dahlia bondage and will answer questions. Please bring extra tubers and dahlia plants to share with DSC victims of attrition. Who will bring tempting snacks?
MORE LORE: THWARTING THRIPS & PROTECTING POZIES: Kevin, serving on the American Dahlia Society’s research committee for dahlia disease investigations, translated his extensive experience diagnosing and treating economic crops throughout the Central Valley into practical advice for happy home gardens. Kevin explained that while extensive research has been conducted into viruses of cash crops, not much has been performed on dahlias—yet! Damage control consists of three main processes: Identification, Impact & Intervention. Crinkled leaves? Could be virus. Holes in leaves? Could be insects. Figure out what is causing your damage. Educate yourself about the life cycle of the varmints involved. How bad is the impact? If left unchecked, could it wipe you out? If it’s near show time, could it cost you a blue or higher award? Depending upon the level of impact, you can calculate how much artillery to bring to bear on your problem. Using split slides to show the various life stages, Kevin delineated the purview of several beneficial insects.
The Syrphid fly, minute pirate bug, lacewings, assassin bugs and ladybugs gobble up aphids. Parasitic wasps oviposit eggs into living aphids thereby ensuring a moveable feast for their offspring. Who knew those black and red predatory beetles were the rapacious larvae of ladybugs? Because of our record breaking rain, Kevin predicted an epic year for earwigs, nasty European imports. He recommended deploying diatomaceous earth or traps of rolled newspapers or bamboo with deadly bait inside.
Wire worms, cut worms and symphylan live just below the soil’s surface and feed at night. To detect whether you have symphylan, leave ½ inch slices of potatoes atop the soil. Within 48 hours they could be covered by greedy 1/10” weeny worms. (If you slice it, they will come?) A good soil drench like Bayer Advanced™ All-In-One Rose & Flower Care contains three major chemicals: insecticide, fungicide and fertilizer. The soil drench is systemically taken up by the xylem rendering the entire plant unpalatable to munching marauders, including whiteflies and thrips which cause wrinkled, discolored leaves and leafminers which eat drunken paths through leaves.
Mites thrive in hotter weather, so they plague South Bay growers sooner than the cooler City folks. Be vigilant! Mites reproduce fast. Besides heavy duty AVID or dusting sulfur, Kevin highly recommended P. Persimilis, a predatory mite. These P. Persimilis, tend to stay in one place (unlike wandering preying mantises) and voraciously feast on nasties. The Monterey Bay Dahlia Society will be selling P. Persimilis at their June meeting at bargain prices. Powdery mildew thrives in 54-77 degree weather with high humidity: exactly San Francisco conditions.
Begin treating in June and once a month from then on with a fungicide like All in One, Bayleton or FungiFighter. Neem oil proves a better fungicide than insecticide. Prophylaxis—early and often—is the best solution for mildew control. Cucumber Beetles, the green ladybug look-alikes, multiply in warmer weather and wreak havoc on blooms. Any pyrethrum containing product (derived from chrysanthemums and the active ingredient in products like RAID) works on these menaces. Since white and yellow dahlias constitute their main draw, yellow sticky traps prove fatal attractions. Check www.ipm.ucdavis.edu for pest management guidelines. Spray either early in the morning or late in the day for least wind. Protect yourself: don long sleeves, gloves, hat or bandana, and toss all into the wash immediately afterwards. I strap on a respirator that covers my nose and mouth with removable particulate filters so I don’t inhale “cides.”
WELCOME New Officer and MEMBERS! We welcome Pat to be our new Secretary of the DSC. Looking forward to your contributions. Having experience growing from dahlia seeds in the past, Martha looks forward to the rewards of cloned “pedigreed” dahlias in her future. Christopher anticipates lots of color in his garden. Please introduce yourselves to our new members. VALIANT VOLUNTEERS: Dirty thanks to Manny who helped tie all the labels and chart up all the cultivars when Deborah planted the Dell. Thanks to Rose for multiple times planting and watering. Thanks to Diana for the fertilizing and ripping asunder milk cartons. Congratulations to Tinnee and Frank for a great start on the Hillside. Lou and the Juuls are way ahead of the rest of us. Looks like a great season has started again! Hope to see some of you some Saturday mornings.
BLOOMERATI SLUMMING? What a wonderful surprise to have the president of John E Stowell Dahlia Society, Jeff Minor, join us. Coming down from Oregon, we welcome Jeff, a sunstone miner. Utililizing 3 public plots in San Leandro, Guy Chibante also checked out our DSC meeting. So glad you all visited us.
SHOULD GOLDEN GATE PARK BE CLOSED ON SATURDAYS, TOO? President Tinnee circulated a petition against closing GG Park on Saturdays. She cited the difficulty it would present to volunteers helping with the dahlias, the impossibility for the handicapped to enjoy our beauties, the loss of revenue from the Conservatory and museums, as well as the parking pressure this would put on the neighborhoods immediately around the park. Ultimately Mayor Newsom listened to the people of San Francisco who had voted against the proposal twice before and vetoed the bill. So you can still volunteer at the Dell, still celebrate our August picnic, and still drive in your friends to admire the official City Flower.
JUNE JUBILATION: So now that you’re all planted, what’s next? If you have tubers which have not come up after more than a month underground, it’s time to GENTLY disinter the laggards, being mindful not to knock off any emerging sprouts. If you discover a mushy mess, toss it out and replace it with one of your back ups. Protect your tender lovelies against snails, slugs and earwigs. Swash on a soil drench like Bayer’s All in One or serve up your first cocktail of fertilizer, insecticide, fungicide and “sticker” of liquid soap. I have spotted green aphids already, so en garde! I have begun pinching out my centers. When you see the first bud with its two buddies, pinch them all out down to the next set of leaves. This puts more energy into nascent plants; as much as we long for the first blooms of the summer, the central one would probably be horribly crotch-bound on a negligible stem. When the next set of buds emerge, disbud the two attendant buddettes leaving only the central one; this will result in a bigger, stronger flower on a sturdier longer stem. To protect my emerging “sophomores,” from my kitty, I use wire plant hanger domes. Cut the top and bottom off half gallon milk cartons to act as tower tubes protecting the newly planted from the wind. Give a couple sprouted tubers to unsuspecting friends—imagine what you could start!
Looking ahead on what you might need to do in the coming months? Check out the Monthly Calendar.

Dahlia Society of California, Inc., San Francisco, CA -- Copyrighted Chief Editor: Deborah Dietz eNewsletter Editor: Ted Marr Acknowledgement: Photos in this issue by Deborah and Ted. Web research by Rose.