2010 Dahlia Diary

July 20 . . .Congratulations to those who have ventured into the garden during this run of hot weather.  Heat and humidity raise the question: "fight or flight"? I have fled to the Adirondacks and have left the dahlia plants to more or less fend for themselves.  They will not grow very much when the temperature is +85F.  But the plants will be stressed and more vulnerable to the mites and other critters that are tying on their napkins for a summer buffet. 

If the rains are not regular, it is important to keep watering the plants.  A mulch around the base will help conserve moisture.  Remember, dahlias are now beginning to put our feeder roots near the surface that will extend a foot or more from the base of the plant. So water accordingly.  

July 1 . . . The two weeks of hot weather has finally broken.  Perhaps the dahlias will start growing again.  We had very little rain during June, so it is important to water twice a week.  It is better to water deeply than frequently.  If the plants are growing, this is a good time to sprinkle a tablespoon or two of fertilizer (e.g. 10-10-10 or a time release variety) around each plant.  Sprinkle it about 6-12 inches from the stalk.  The feeder roots grow out from the plant.

It is also useful to mulch the plants.  I have used newspaper and straw; a wood bark will also work to cool the soil and aid it in retaining moisture.  If the plants are slow, do not forget to top and tie when they have formed 4 pairs of leaves.  If they are taller, you can still top them. Taking off the growing tip will stimulate the growth of lateral branches that develop from the point where the leaf and stalk connect.  It will give you a more bloom-filled plant.

June 22 . . .This has been the worse start of the dahlia season in a decade.  Unseasonably hot weather and little rain--although we are having a shower while I write this.  It is hard on the garden and on the gardener.  Last week I stopped planting because it was too hot and dry for me and the tubers.  I have about 20 to go. 

 The tubers planted early need to have their growing tips removed (topped) to encourage laterals to developed and tied.  This makes the plant bushy and it will yield more blooms. I use a soft garden cord to tie. I wrap the cord loosely around the plant and tightly around the stake by crisscrossing the cord after I  put it around the plant. Wrap it around the stake several times and tie it. I use soaker hose for watering and horticultural cloth coverd with straw to cool the soil and keep the weeds down.

Eventually, the weather will cool, and gardening will be a hobby again.

  June 12 . . . The weather is still warm and storms  are threatening.  The U.S. v. England, World Cup match won out this afternoon, so we still have quite a few dahlias to plant.  My frame of mind is that is never too late.  That is how I make peace with the distractions in my life. 

The dahlias we  have planted are thriving.  We have had regular showers, and the temperatures have seldom exceeded  90 degrees.  I am one of those gardeners who do not aspire to prespiring profusely while I work in the garden.  After all it is a hobby and not an obsession.

When the plants get three or four pairs of leaves, nip off the the growing tip and that will encourage shoots to grow at the joint of the leaves and stalk.  Topping is also a good time to tie the plant to the stake.  As my mentor Mark Alger used to say, "loosely around the plant and tightly around the stake."  You accomplish that by criss-crossing the twine between the plant and the stalk.  Use a hemp twine, so you do not garrote the plant when the wind blows.

May 30 . . . The weather has been hot and humid, and this dahlia grower is quickly wilting.  We still have quite a few dahlias to put out--both plants and tubers, as well as about a 100 seedlings.  Hopefully the weather will cool off and the recent rains will become just showers.  

If you have a choice, it is best to put out plants on a coudy day.  It will reduce stress for both you and the dahlias.  Treat the plants like you would any planting.  If it does not rain, water every few days--especially if it is hot. Tubers should be put in the ground with the growing tip facing up--about two or three inches below the surface, giving enough room for the feeder roots. Plant a stake with the tuber.  If you do it later, you might pierce the tuber.  Newly planted tubers can generally take care of themselves.  The plant that grows out of the tuber will live off the tuber for a while.   

May 11 . . .We have just returned from a vacation in Peru--including Machu Picchu--and I am still catching my breath.  The dahlia planting season is in full swing, notwithstanding the thirty-something temperaure on Tuesday morning.  The ground is warm and just waiting for dahlia tubers or plants.

Dahlias are foregiving plants, but need at least a half-day of sun.  Their culture is similar to tomatoes.  The non-bedding types will grow to between 3 and 6 feet and will need to be tied to a stake.  Besides that and an occasional watering during dry weather, Mother Nature will take care of the rest. 

If you buy a dahlia plant, get it used to the outdoors for a week or so before planting.  Tubers should be planted shoot (eye) pointing up about 3-4 inches below the soil level. I could provide several additional pages of detailed instructions, but they are not necessary for bouquets of pretty flowers from August til frost. For those who think they need more help--join the National Capital Dahlia Society by contacting:

Membership - Nancy Mossburg
NCDSmembership@juno.com
National Capital Dahlia Society, PO Box 476, Hamilton, VA 20159

March 28 . . .And they were mostly mush!!  The dahlia clumps that I had not dug before freeze and snow, came out of the ground with some promise.  A number of tubers felt dry and firm.  After two days at room temperature they began to smell and leak.  The insides resembled over-ripe cantelopes. I guess that will answer the perennial question: Will dahlias  winter-over in the ground--not always!!

March 27 . . . I warned you about a frost.  After a warm week, it was 30 degrees this morning, and tender plantings bit the dust. Patience is the watchword.  If you must do something, pot up the tubers and get them started in a sunny place. Make certain that the growing tip of the tuber is near the top of the pot at soil level.

March 17 . . .It is St Patrick's Day and the back- yard is beginning to green up for the holiday. As the temperature reaches the 60s there is a temptation to start planting and to get a jump on the season.  Two cautions:  First we are still likely to get a frost in the Washingron DC area until mid-April.  It will kill off young plants.  Second, until the soil temperature warms up to at least 55 degrees, the tubers will not do much in the way of growth and will be susceptible to whatever microbes are in the ground.  Do not ask me why tubers that successfully over-winter are not bothered by cold, damp soil and newly planted tubers are vulnerable.  I guess it is like the difference between people who live in Maine and those who live in South Florida.

March 8 . . .With the warm weather we put a foot in the patch and sunk at least two inches into the dirt.  The snow melt has soaked the garden beds. Let them dry out; walking in them now will compress the soil and make it less friable and suitable for gardening.

February 25. . . One of our members asked how to start dahlia plants from cuttings.  This technique enables you to grow more than one plant from a single tuber

 I wait until March to start the tubers.  Everything about dahlias speeds up with Spring.  For fun, I would pot up one or two tubers, water lightly and put them in a sunny window.  The eyes should sprout in a week or two.  When two or three pairs of leaves develop cut the stem with a sharp knife or blade just below a leaf node. Fill a  small pot with sand, moisten thoroughly, make a hole in the sand and set in the cutting with a label. Keep away from direct sun for a day or two and water daily--dipping in a rooting hormone is optional.  After about two weeks, you should feel resistance when you tug on the cutting.  Roots have formed!!  I gently lift the cutting with a fork--watch out for the small roots, and transplant in a 4 or 6 inch pot with potting soil.  Thereafter treat normally.

February 20 . . .I guess I could post more pictures of the snow on my dahlia patch.  But they would be redundant.  There is not much to do outside until the last six inches disappears. Many of the commercial growers are posting "sold out" notice on the internet below pictures of their most popular dahlias.  The NCDS will have tubers of many of these dahlias beginning at the April meeting. These tubers have been grown successfully in the area and should perfom well in your gardens.

February 8 . . . There is so much snow in our dahlia patches that the olympic rabbit fence is barely visible.  The only solace is that the tubers still in the ground are well insulated, and are about to receive another !0+" blanket.  An El Nino winter with a southern Low seems to be causing all the snow that is close to a record in our area.

The truth be told, I found of bag of dahlias this fall that I had failed to plant. I put them in a flat and buried them in potting soils.  To my surprise they began to sprout in December. I water the flat periodically and and spray every two weeks with a rotation of insecticides.  One tuber has made a shoot with good growth, the others have modest growth and an orange tint that is a sign of mites. This is an experiment to see if I can keep them alive through the winter.  How I misplaced the bag in the first place remains a mystery.

January 21. . . The ground is still frozen in Falls Church VA.  Hopefully, the clumps that I left in the patch are below the frost line. There has been a lot of discussion about leaving the tubers in the ground over the winter.  This will be a large scale test.  More news when the ground defrosts next month.

The Soil in our area is acidic. The pH is can be as low as 6.4.  About every two years I do a soil  test and apply lime as recommended.  Large garden centers typically provide that service or can recommend a state extension service office. It is hard to collect frozen soil, so wait for the Spring thaw.