Dahlia Diary


March 22: It is too early to plant dahlias. The soil is damp, and tubers may rot. Plants will succumb to a late frost Our tubers have been slow to show eyes, even with bottom heat and periodic sprinklings. Patience is the name of the game. Have the patch tested before fertilizing.

Dahlia Diary 2016

June 15:  We are having trouble with the software for the website. Be sure to make a map of your planted dahlias in case the tags disappear.

April 26:  Question, Can I put the dahlia pots in the rain? Answer, Yes, if the pots drain.

April 2016: The tubers are finally sprouting. But it is still too early to plant. I would wait until early May for the tubers, and mid to late May for dahlia plants from cuttings. If you have only a few, put them in pots with a good potting soil. Keep the pots moist, but do not soak it. The idea is for the tubers to develop roots. Initially, the shoot feeds off the tuber. If the plant is to grow well , it will need to form roots, as soon as possible. I have some tubers that are just sitting there. In a couple of weeks, if there are no roots, I will discard them. I have a small garden, and need vigorous plants.

March 2016: The last entry disappeared. I was a victim of cyber theft. The baskets worked pretty well. I shaved off the tubers that grew outside the baskets and was left with what appeared to be healthy “pot roots.” They went into flats with a damp potting soil. Now if they put out eyes and shoots all will be well. This afternoon 5 of the 60 clumps have shown signs of life.

Check the soil pH in your patch. It should be between 6.5 and 7 (neutral). For the past 3 years my patch has been above 7 (alkaline). I c cannot figure out why.

The National Dahlia Society in the UK has enhanced it website. The photos and comments in the discussion thread are very informative.

December 31: It is New Years Eve, and we are between seasons. I have a new knee, and I am still adjusting. Most of the commercial dahlia growers have websites. See the ADS Bulletin for details. If you are interested in the 2016 new introductions, get going as soon as possible. Do not wait for the paper catalogues. HAPPY NEW YEAR.

October 26: We are approaching the end of the dahlia, season. The stems are getting weak and the blooms and bees are hard at work. Underground, tubers are maturing. In the Washington DC area it is risky to leave the tubers in the ground. It is mostly a problem with moisture retention in clay soil. There are a variety of instructions on line and on You-Tube for digging and storing tubers. It is permissible to treat them as an annual and to buy new plants or tubers next Spring.

Happy Holidays

August 29: The heat continues and powdery mildew is appearing. A spray of Neem Oil is an organic remedy. The internet reports many home remedies such as baking soda.

July 23: The unusual heat in the Washington DC area has slowed down growth, and is rushing bloom development. Have patience! It will become easier to work in the garden

JUNE 9: The August issue of Fine Gardening has an interesting article comparing water-soluble fertilizers. Authors Jeff Gillman and Lin Plummer tested three organic and two synthetic fertilizers. The test was applied to marigolds and tomatoes. They concluded that the marigolds that were fertilized produced flowers later than the marigolds that received no fertilizer. The latter immediately devoted their energy to reproduction. At the end of the experiment the fertilized plants were flowering more actively.

A small amount of phosphorous is enough. More adds nothing, except runoff. Generally, plants need much less fertilizer than is called for on the label. No difference was found between organic and synthetic fertilizers sampled. The former tend to release more slowly and may contain micronutrients. Fine Gardening is a consistently informative magazine.

June 8: The dahlias have been planted and the weather is getting hotter. It is time to mulch the dahlia patch. The June issue of Virginia Gardener has an excellent article on mulching by Garry McDonald PhD. He observes that any mulch is better than no mulch. The article discusses bark and hardwood mulch, compost, and pine straw mulch. In some areas ground tree trimmings are available for free from the local government. He makes the point that for most gardens bagged mulch costs the same a bulk mulch and is easier to apply.

In our dahlia gardens all sorts of mulches are use. One grower uses carpet remnants. Others use mushroom compost. I lay permeable horticultural cloth with straw on top.

Do not apply whatever mulch you use too thickly. The rain has to get through to the root area. A lot is going on underground. The mulch should not become a roof suffocating the root area..

May 26:  June can be windy. Tie the plants when they are tall enough to blow over.

  • Make a map of the patch. Tags can disappear over the summer.
  • As June becomes July, mulch the plants to keep the ground cooler and to retain moisture. I use permeable horticultural cloth and straw. Do not use a dense mulch. It will retard oxygen getting to the roots.

Whether you are growing for cut flowers, garden beauty or for dahlia shows, top the plants by removing the growing tip. As a general rule top when there are 4-6 pairs of leaves. This will lower the center of gravity of the plant when the lateral shoots develop. To get larger blooms, reduce the number of laterals when they can be pricked out. It is a matter of preference

May 5: Tomorrow is the moment of truth. If a division (tuber) does not have an eye it will be tossed. I now have about 100 seedlings in various stages of development. They will need to be moved to 4 inch pots. There are about about a dozen rooted cuttings in sand. I keep forgetting to bring a fork to lift them out and transplant them.

April 26: Do not be fooled by spurts of hot weather. We can still have another frost. Rooted cuttings and seedling will not recover. Tubers will develop another shoot.

April 12:   What a difference a week makes. The tubers are eying up, and seed is germinating. Even cuttings will root more quickly. Absent intense technological intervention, nature dictates the tempo of life.

April 5: The commercial orders have begun to arrive. Les & Viv Connell’s tubers were firm with good eyes. I think I have ordered more than I need. My eyes are bigger than my patch.

April 1:  Don’t be fooled by the warm weather. We can have frosts in the Washington, DC area into the third week of April. The biggest threat to early-planted tubers is cold, soggy soil.

March 31:  I am still opening bags and putting tubers on beds of vermiculite in half-sized flats . I have opened about 50 bags so far. Most are small trash bags and some 1-gallon zip locks. The tubers are in good shape. There is little rotting or shriveling. Still, the eyes have been slow. The exceptions are Honka, a yellow orchid, and the Verrone originations. The eyes on the latter tubers are thick and clearly poised to create shoots.

March 25:  I opened some more bags and found some tubers with eyes. One bag of Verrone’s Pink Giraffe had good shoots. On punctured the plastic bag. Now that is vigor. A good day.

March 22:  If you want to take cuttings, the tubers need some warmth. If you use a heat pad, make certain there is a thermostat. Several years ago I melted a plastic flat and baked the tubers.

March 20:  Spring has sprung, and it came with snow flurries this morning This is a good time to take a soil sample and have it analyzed. I use A&L Laboratories near Richmond. www.al-labs-eastern.com/. Send them an email and they will provide boxes and


March 3:  I just received the Winter Bulletin of the National Dahlia Society (Britain). Once again I enjoyed seeing the the frequent references to American originations, both old and new. The dahlia does not know national boundaries. Kudos to Les and Viv Connell on winning the NDS John Brown Medal with Tahoma Lady Oh at the Wisley Trials. Congrats to the Parshalls for the Silver award for Clearview Sundance at the 2014 Exhibition Trials

March 1:  The American Dahlia Society announced today that the dahlia, Edna C has been selected as the Best Dahlia of the Past 50 Years. The designation is part of the American Dahlia Society’s centennial celebration.
Edna C is a large, bright yellow dahlia in the decorative class. Its overall appearance creates a “bouffant” effect.
Originated in 1968 by the renowned California hybridizer Paul Comstock, Edna C has been widely grown and has been successful in dahlia shows throughout North America. In 1997, it was awarded the coveted Stanley Johnson Medal for overall exhibition success. The criteria used by the ADS included popularity, dahlia show success and longevity.
In 1964, the dahlia variety Jersey Beauty was acclaimed as the best dahlia for the prior 50 years. The American Dahlia Socie  ty was formed in 1915 and has over 2,000 members.A yellow medium semi-cactus, Hamari Accord was the runner up. Inland Dynasty, a yellow giant cactus finished in third place.

February 25:  Who was Paul Comstock?

February 24: This is the season for being unrealistically optimistic.

February 23:  For those of us starved for dahlia images, the Giant Foods “Floral Tissue” box has a striking picture of a white cactus dahlia on a blue background with glitter.

February 21:  Snow, ice and cold. If your tubers are in a unheated area, make sure they do not freeze. Snow insulates the ground below.

February 8:  We’ve had a couple of nice days, and I opened some of the storage bags. The tubers were nice and firm, but the crown tissue was a bit iffy. In a week or two I will try to get them eying up.

Dahlias are beginning to pop up like crocuses. Our garden shops, hardware stores and the big boxes in the area, like Home Depot and Cost all have packages and boxes of dahlias. The tubers almost all come from Holland and most places have the same varieties. To be frank, most of the dahlias gown in the gardens of this area, come from such places.

If you are reading this you are ready for a step up. Come to the NCDS tuber sales starting in March

January 21:  I was going to open some of the bags of tuberous roots, then it began to snow. All I need is an excuse.

I ordered some dahlias by internet. A number of new introductions are sold out. I received Brent and Becky’s catalogue yesterday. They are supporters of the American Horticultural Society, so I like to support them. They have six pages of dahlias. There are a number of border dahlias including the Gallery and Karma families. A lot of the images had open centers. There is a single with a dark center and dark foliage. Is is called Dracula

January 9:  January is the time for new resolutions. Mine is to be more faithful to the diary. If you are interested in acquiring dahlias introduced this year. Open the website of your favorite dahlia dealer and place your order ASAP. Think of it as a late Holiday present –a dahlia-selfie.

November 9:  You will have to give me a pass this season. In mid-July I broke my leg and spent eight weeks away from my dahlias. They grew with the help of Nature and a little tying to keep the plants upright. The experience confirmed that you can grow beautiful dahlias with minimal work if you do not care about top-size blooms. In 2015 we will start again.

Our serious growers in the NCDS agree that this was one of the best growing seasons in memory.

I also have been sharing tubers with gardeners in the Adirondacks. How to grow our plant in the 85 days between frosts.

Remember, 2015 Is the Centennial of the American Dahlia Society.

May 26:  I have no idea how the fonts work with this application Perhaps the bold is appropriate because everything is proceeding at warp speed. Spring was short-lived, and we seem to be into summer. The tubers have sprouted and are ready to put in the ground. Some are more tun a foot tall. One has a bud. Make sure you tie these tall ones to a stake when you plant them out. If the tubers have been kept indoors, give the shoots some time to “harden-off” by putting them in the shade before subjecting them to the patch.

The seedlings will be potted and also hardened off, by putting them outside and in the shade for a few days.

Some of the tubers are more than foot tall. I will remove the lower pair of leaves and plant them so that the stem where the leaves were attached is buried. This is likely to support the plant more effectively and generate additional users in the fall.

If you are applying a time-release fertilizer, spread it on the surface and not in the hole with the tubers. The dahlias create roots just below the surface of the patch.

Aphids seem to be around. Be observant. If you see them spray with a general insecticide or wash them off.

The big surprise of the spring is the appearance of five plants, the tubers of which were left in the ground last fall. After a harsh winter that killed all sorts of “hardy” plants, these tubers survived. Wonders never cease!!

April 24:  The experts tell us that we are two weeks behind this Spring. They also predict the last frost date to be May 6. A drive around Falls Church bears this out. The tulips and some daffodils are still in bloom. The azaleas and dogwood are just coming out.

Somehow, my dahlias have gotten the word. They are slow to eye up and grow shoots. I have opened the bags and slightly moistened the vermiculite. This and warmer weather should wake them up.

I store by dividing each clump and bagging the tubers in vermiculite. I cannot see eyes, so some of the divisions in the bags will not have latent eyes (they are called blind).

I have begun potting up tubers with eyes, and will plant during the second week in May. This will allow them to get established before the real heat begins. Other growers wait until late May or early June. They will be growing to get their first flush of blooms on the large-size cultivars for the Philadelphia and NCDS Shows in September.

Some growers plant in 6″- 8″ pots. In the Fall they will just lift the pots and save the clump in the pot. This practice limits the spread of feeder roots, and may limit the large dahlias from reaching maximum size. It will work well for BBs and smaller.

February 11:   In the dahlia world there is the equivalent of Spring training. For me it is cleaning the small greenhouse where I start the dahlias and making sure the flats and containers are clean. I use a Lestoil solution. You can also use a 10% bleach solution or even soap and water. Make sure you have a stiff brush.

To lower the pH of the soil to make it less acidic (6.5-7) use agricultural lime in amounts recommended by the garden center or the laboratory that did the soil test. Make sure it is a slow acting type, and scratch it into the soil apply as soon as the patch is sufficiently dry to work. It will need some time to do its job. Hydrated lime (used on playing fields)works more quickly but is can burn the plants and is not recommended.