Meets second Tuesday of the month at Rose City Park
United Methodist Church, 5830 N.E. Alameda
Editor: Mike Riordan (503) 256-0425
|Next meeting July 14th, 2009 @ 7:30 PM
Editor: Mike Riordan (503)256-0425 Contacts: Teresa Bergman (360) 274-8292, Jeanette Benson (503) 649-4118
Next meeting Tuesday, July 14th, 2009 @ 7:30 PM
COOKIES FOR JULY
Cookie host for July is Larry Sawyer.
PROGRAM FOR JULY
Our program for July will feature a presentation on the ins and outs of making prize-winning basket arrangements.
Jeanette Benson and Gordon Jackman will be the presenters.
We encourage members to bring in blooms to the July meeting so others can admire and enjoy. We know it’s still very
early, so anything we can feast our eyes on is much appreciated.
In preparation for our annual show Labor Day Weekend, we need to ask for volunteers to help with some of the show
functions. Thursday afternoon, September 3rd, we need members to help with the set up of the exhibit hall. This includes
assembly of the head table, draping the tables and setting out the size/form/division markers.
Friday night we need a few to help with classification as blooms are entered. Both Saturday and Sunday we need
volunteers to help with hospitality and answer general questions from the public.
HOW DO I FERTILIZE MY DAHLIAS
By Ted Kennedy
Sometimes the shortest, most basic questions are the most difficult to answer. Rather than just saying how I do it, here
are some ideas from other growers.
One club member got a soil analysis to determine what his garden needed. He has always used a lot of organic compost
and a bit of sheep manure on his garden. In addition he has used commercial garden fertilizers such as 10-20-20 and 16-
16-16 in the past. His soil report indicated that he needed only nitrogen and he decided to buy a time release product that
only has nitrogen. I believe he bought a product called Nitroform and it is 38% nitrogen
Another member of the club is strictly an organic gardener who uses lots of compost along with such products as bat
guano, blood meal and green sand. Such products are available at Concentrates on SE 8th Avenue between Powell and
Division in Portland. Peruse their offerings and prices at http://spreadsheets.google.com/pub?
key=pJrWEmwyrO76JtBhzIRWDcQ Other organic choices include alfalfa and chicken manure. An English grower
swore by cow manure and added a full six inches to his garden every year. The dahlias grew wonderfully, but in the long
run the high nitrogen content and probably high levels of bacteria and soil fungi caused the tubers to rot in storage. That
did not deter him and he kept pot tubers of all his dahlia varieties and planted rooted cuttings from them.
One grower in the Seattle area who has won very many best in show awards uses the very best Osmocote fertilizer. I
was told that she uses the product that has an 8 to 9 month dissipation rate and an analysis of 13-13-13 and includes
micronutrients. There are numerous choices in the Osmocote line but the biggest drawback is the expense. I have been
told it runs about $1.00 per pound, even in the 50 pound bags. Osmocote releases all of the plant nutrients slowly along
with all of the trace nutrients throughout the entire growing season. This should not be confused with come cheaper
products that release only the nitrogen slowly and really over-dose the plants with phosphorus and potassium when first
One grower now deceased grew dahlias on the coast in sandy soil. She swore by chicken manure and a product derived
from seaweed (probably no longer available). That seaweed product probably provided micro-nutrients and some
potassium. By the way, the word potassium derives from potash and that was produced by burning seaweed to produce
a nutrient laden ash. Later, chemists determined that the potash was mostly one chemical element and named it potassium.
Another grower in Washington swore by the liquid fish products that he sprayed on the plants. Fish fertilizer used to be
very popular but its downfall was that it smelled so bad. There are fish pellets being sold as a time release fertilizer for
organic gardeners. Their drawback is that dogs and other animals like to eat them and will dig them out of the soil.
In our area it is necessary to add lime to the soil to maintain proper pH. Lime is not technically a fertilizer but it sure works
to make your flowers grow. If the soil has the proper pH, the plants can utilize the nutrients in the soil. One needs to test
the pH of your garden and lime regularly to keep the pH at proper levels. If should be noted that commercial fertilizers
tend to make the soil more acid. If you have been adding only fertilizer and no lime to your garden, you have probably
made the soil acid (reduced the pH number, over 6.0 is needed for dahlias and 6.5 is considered ideal). There is a chart
on a university web page that showed how much each fertilizer component acidified the soil. For example, for every 100
pounds of urea (46% nitrogen, very common ingredient in fertilizer), you add to your soil, you need to add 71 pounds of
lime to keep the soil pH the same. Here is a link to that chart: http://extension.oregonstate.edu/catalog/html/fg/fg52-
Many dahlia growers like to use the water soluble products such as Miracle Grow to fertilize their dahlias. These
products can be applied with a hose end sprayer and the product is sprayed on the foliage on a weekly basis. A more
economical alternative to Miracle Grow is the use of commercial greenhouse fertilizers such as Peters or Plant Marvel 20-
20-20 that cost about $25 for a 25 pound bag. All of these products have the advantage of giving the plants a feeding of
fertilizer that takes effect almost immediately. These products are very useful in hot weather, when dahlias seem to have
problems getting enough fertilizer from the soil.
JULY IN THE GARDEN
Besides fertilizing, spraying, tying, topping, disbranching, disbudding, and irrigating (my, we are a busy lot!), one needs to
consider the benefits of mulching and with what type mulching of material. Mulching benefits plants in three ways. By
shading the soil, mulch keeps the soil cooler and reduces moisture evaporation. Thick mulch discourages weed growth.
And finally, most organic mulches provide some plant nutrients and over time improve the texture and water retention
capacity of the soil. A nearly ideal mulch is screened compost available from your local yard debris recycler. The Portland
Dex Yellow Pages has 13 listings for compost purveyors. If you are considering having it delivered (as opposed to
hauling it yourself), keep in mind that transportation costs can add up quickly. So look for suppliers close to your
Another thought for mulch would be grass clippings (sans Weed and Feed only). When applying any mulch be careful not
to smother the dahlia stalks. Remember it is a soil blanket, not a plant blanket. One grower down in the valley had a
rabbit farmer contact. The rabbit farm used mint silage as litter for the rabbits. So not only did the mulch smell like
Doublemint, it had the rabbit manure kick. Some growers have used straw or stable bedding mixed with manure. With
the manure think light dressing (see Ted’s previous discussion). Other growers have used spoiled silage or spoiled or
unspoiled bales of Alfalfa. Your local Feed and Seed store would most likely be able to direct you to nearby sources.
Another type of mulch is the in-organic type. Here I’m thinking of “landscape fabric”. The landscape fabric is porous
enough to let water, nutrients and air through and yet forms an effective weed barrier. It is sold by the lineal foot at most
garden centers. Other types of barriers; e.g., layers of newspapers or black plastic are not recommended since they
generally don’t allow good moisture and air exchange with the soil.
Side dressing the plants with fertilizer is generally done in June or early July. Be sure to place the fertilizer no closer than
around the drip line of the plants and in all instances at least 6” away from the dahlia stalk. Growers that continue to side
dress later than mid July run the risk of causing an increased incidence of oblong, double, misshapen or “bull” centers.
Into every garden a little rain must fall.
This is great for plant growth, but sadly promotes some fungus diseases. Powdery Mildew (as well as other fungus
diseases) is much easier to prevent than to cure. Organic preventatives include 1 Tbs. Baking Soda with 1 tsp. Ivory
Liquid in 1 gallon water sprayed on the garden weekly. Another is skim milk with the same spreader-sticker (Ivory).
Home garden approved chemicals include Daconil and Funginex which are available at most garden centers. Good
garden sanitation seems to help. Also take a look at other vegetation around the dahlia plot. Does it show evidence of
mildew? If so, consider treating it along with the dahlias. Dahlia Smut seems more active this year. It starts out as lighter
discolorations in round circles on the leaves, looking almost like mosaic virus. Later, these circles in the leaves completely
rot through leaving a “shot hole” perforation in the leaves. Daconil seems to be the best control. Best photo I could find
on the net is at the below link. Be sure to scroll down to find the two photos of early and advanced infection.
Some growers like to combine insecticides and fungicides. This is a great timesaver and a good idea as long as both
labels say this is permissible. Still others have been known to combine liquid fertilizer with insecticides or fungicides. My
experience has been this combination sometimes will cause some leaf burn. Saying this another way…if you are
experiencing leaf burn with a combination fertilizer spray, you might want to try applying your liquid feeding separately
from your other garden chemicals. For years I was kidding myself and blaming the burning on relatively high daytime
temperatures. Applying separately solved the leaf burn problem. Be sure to thoroughly shower after using garden
by Ted J. Kennedy
I remember the first dahlia show my wife and I went to in about 1989. We were aware that dahlia fanatics conducted a
show where they displayed their best blooms to win ribbons but we were not caught up in dahlia fever in those days. We
went because we sold some cut flowers from our newly purchased acreage and we wanted to see the dahlia varieties that
may have been suitable for cut flower sales. We had little interest in Giant sized dahlias but that was the year that the dark
giant called Zorro hit the show scene. Seeing the huge flowers staged in single and triple entries was really impressive. We
wrote down numerous dahlia varieties to try the next year and remarked that those dahlia fanatics were way over the top.
Flower shows seem to be an American and British tradition. For some reason, rose people have rose shows; orchid
people, orchid shows; and iris and chrysanthemum and undoubtedly many others, all seem to enjoy the competition
involved in showing off their spectacular blooms. And then there are the Fairs where fruits, vegetables and flowers
compete for prizes. Dahlias shows fill the need for the dahlia aficionados to display and share the flowers that they have
enjoyed in their yard and to compete for prizes and awards.
If you have never attended or entered a dahlia show the first and most important fact is that attendance and entry in the
show is FREE. Let me repeat that important fact: you can see our dahlia show and park for FREE. In fact, if you come on
the second day, when the show is being taken down, you may even get some free flowers to take home with you. So if
you have never attended a dahlia show, “free is a very good price” to quote the appliance huckster Tom Peterson.
And entry of blooms in the show is FREE. And if you win at the show you get ribbons and in many cases, cash prizes and
perhaps other prizes like dahlia medals or vases or gift certificates. In fact, I have seen some of the more successful
exhibitors take home as much as $200- in cash prizes along with a bunch of ribbons. You may ask: Where does the
money come from to support the awards? Our Portland Dahlia Society has two major dahlia tuber sales each year where
we sell donated tubers. These fund raisers finance all of the clubs activities. Also, the whole purpose of our non profit club
is to promote and share the growing and appreciation of our favorite flower, the dahlia. Traditionally, the flower shows
have filled the need of displaying our favorite flower in the best of all circumstances in a place where anyone can come and
So, please come to our annual show that is held on Labor Day week end at the Clackamas County fairgrounds. You will
not be disappointed. And if you enjoy a little competition, why not enter some blooms?
The society has placed its order for black ADS vases. If you have pre-ordered, we may have the vases available at the
July meeting, if they shipped on time. Bring your method of payment along , just in case.
We have set the date for our annual tour of Dahlia Gardens for Sunday, August 16th. We experimented last year with this
earlier tour date and found better weather and viewing conditions. We will have the tour itinerary published with the
August Bulletin. See some photos of last year's tour at our society's website, portlanddahlia.com
Teresa Bergman has pricing information for custom Portland Dahlia Society T-Shirts, etc. as follows:
With regards to the t-shirts, I'm going to keep the prices the same as they were when first offered so, hopefully more
people will order.
T-shirts(Hanes 50/50 heavyweight) - Small - XL - $11 XXL $12
Youth sizes: XS (2-4), S (6-8), M(10-12), L(14-16), XL(18-20) -- $10
Golf shirts - S - XL - $17 XXL $18
Youth sizes: $6
Crewneck sweatshirt - S - XL $17 XXL $19
Youth sizes: $16
Colors for all of above: Purple, Black, Navy, Forest Green, Ash, White, Royal
1/4 zip sweatshirt - S - XL - $25 XXL - $27
Birch, Forest Green, Jet Black, Maroon, Navy
Sorry, no youth sizes in 1/4 zips.
If someone would like a color or style that is not listed, they could contact me and I can probably get it for them.
I am going to get an order form to Ted that hopefully he can put on the website. The order deadline will be July 20th so
we can get them back in time for the August meeting, and possibly sooner. I'll have order forms at the meeting.
If you have any questions, just give me a shout.
|Embrace BB SC Bronze
Top winning dahlia variety. Needs some disbudding, and disbranching and some shading to achieve it's full
potential. In much of the USA it is classified as yellow but as you can see from this picture it is bronze here
in the Northwest.
Nick Sr. AA ID R