Dinner plate dahlias
GARDENING
Coming home from a summer holiday can be a bit of a letdown, unless there is a special treat to look forward to at home.
For a gardener, it can be as simple as a border reaching its potential or the anticipated flowering of a new plant.
I came home to find my seed grown annuals had finally come into flower: florist zinnias in Crayola-crayon shades of red, yellow, orange and white; orange and straw-coloured calendulas, and the first of the gloriosa daisies.
Container plantings were brimming with colour, our first crop of container-grown tomatoes are ready for tasting, and we’ve suddenly got a bumper crop of dahlias. Thank you to my special garden angels who kept a watchful eye on the garden while we were away.
Last summer, I started three dahlia tubers in our little greenhouse, then moved them to the south facing border in early June. They came into bloom some time in late August and then flowered well into early November. The tubers were harvested, cleaned and stored in our wine cellar for the winter — all in all, a successful crop.
This spring, I split the clumps of tubers, making sure each clump had one or two eyes (swelled buds that will shoot), and planted them up in gallon containers the greenhouse in April. I had doubled my stock from last year — that’s more than I can say for any money I had tucked away in the bank last fall.
I also planted a sample decorative dahlia, from simplepleasurebulbs.com, tucked in the label and hoped for the best. With the cool, damp spring, the tubers developed slowly in our little unheated greenhouse; when leaves finally appeared I started to feed them with liquid fish emulsion, the same organic fertilizer that I was using on my tomato seedlings.
In early June, the dahlias were transplanted into the garden, they should be planted in the garden when the ground is warm, the same time you plant out tomatoes and other tender vegetables. As a side note, dahlia tubers can also be planted directly in the garden — it is not necessary to give them a head start in a greenhouse. In terms of ongoing care, the planting bed was top dressed with compost at planting time and the plants were treated to a deep drink of water laced with water soluble fertilizer every second week.
Dahlias have simple, but very specific, needs in terms of feeding. Fertilizers labelled for ‘bloom’ or ‘vegetable’ plants is ideal, the first component on the label should be half of the other two numbers (510-10 or 10-20-20 for example). High nitrogen fertilizers promote weak stems, huge leaves and small blooms, and should never be used on dahlias. Growers recommend feeding dahlias once a month during their growing cycle. Anticipating the July garden walk, I fed my dahlias biweekly, using half the recommended dose of water-soluble food.
Dahlias need full sun (at least eight hours a day) and plenty of water to produce an abundant crop of flowers. Water deeply two or three times a week: 30 minutes or more with a sprinkler or a good soaking with a hand-held watering wand; water daily if the temperatures soar. Once the plants are established, a thick blanket of bark mulch will help retain moisture.
Dahlias that reach 90 centimetres or more in height should be staked to keep the stems upright. I did not stake my plants at planting time (they’ve grown perfectly without stakes … until this week), and now several top-heavy stems have collapsed in the rain. Tomato cages, metal rods or bamboo stakes will help to support the heavy stems.
To promote bushy plants, with longer stems for cutting, pinch or cut out the centre shoot just above the third set of leaves when the plant reaches 45 cm tall.
Dahlias are one of my favourite flowers for cutting, and they reward me with more flowers the more I cut them — it’s as if they want to be cut and shared. Cut dahlias early in the morning if possible. Condition the stems by placing them in a bucket filled with 10 cm of very hot water, then put them in a cool, dark room for at least one hour. This step helps to set the bloom; conditioned flowers will last up to week in the vase. After conditioning, arrange the stems in a vase, the use of Floralife will help to preserve the flowers, change the water every second day.
So where does the surprise factor come in to play, you might be wondering. Yesterday morning on my garden walkabout, I spied a huge red bloom in the dahlia patch. I thought it was a mass of flowers, but it was a single dinner-platesized dahlia — the first bloom on my sample plant. Dahlia ‘Nick Sr.’ is a real show stopper, with long fire-engine red petals that twist and turn to reveal pale yellow undersides. I pulled out a measuring tape, and the flower measure 25 cm across, literally the size of a dinner plate. The stems are very sturdy as well. Dinner-plate dahlias take a little longer to flower (they are about two weeks behind my standard dahlias) but they are worth the wait.
I grabbed my pruners and cut the prize-sized flower for my desk — now that’s the way to return to work with a smile. — Theresa Forte is a local garden writer, photographer and speaker. You can reach her by calling 905-351-7540 or by email at theresa_forte@sympatico.ca.