Dazzling Dahlias

by Lynn Hunt

Someone once wrote that the best things in life are worth a little extra
effort. The author may well have been talking about dahlias. Hybridized by
Aztec gardeners, dahlias don’t like freezing weather. In areas north of Zone
8 the tuberous roots must be lifted and stored during the winter. Sure, it
might take an hour or two, but what reward do you get for your trouble? How
about a spectacular array of blooms from July until frost?  How about flowers
as small as a pincushion or large as a dinner plate? How about colors in
every imaginable shade except blue? Like the hair color commercial,
delightful dahlias declare, "I’m worth it."

Preparing for the show

Dahlias are a versatile addition to the landscape because they offer a
wide height range from 1 to 6 feet and a variety of flower sizes from 2 to 12
inches. You can choose from short-growing single-flowering varieties to the
breathtaking double-flowered giants. No matter which varieties you plant,
your dahlias will require full sun, well-drained soil and steady moisture. 

Plant dahlia tubers after all danger of frost has passed. About a month
before planting, work a fertilizer such as 5-20-20 into the soil. Tubers need
to be planted deep enough to protect them from drying out, but not so deep
that they become waterlogged. A good rule of thumb is to plant them 4-6" deep
in sandy soil and 2-3" deep in rich soil.  If in doubt, ask your Growise
expert for advice.  Smaller varieties can be planted 2 feet apart,
large-flowering dahlias should be spaced 3 to 4 feet apart. In the planting
hole be sure to set the tuberous root on its side with the "eyes" facing
upwards.

Summer care

After planting your dahlias, cover the beds with a 3- inch layer of
mulch. Watch for slugs and snails snacking on young shoots and apply bait if
necessary. When plants have 3 to 4 pairs of leaves, pinch out the terminal
bud to encourage branching. Make plans to stake your taller varieties –
dahlia stems are hollow and brittle and will require support. Fertilize
monthly through August and be sure the soil is moist but not saturated.

As the season progresses, you will discover why dahlias are the darlings
of summer. Each plant should produce 40 or more showy blossoms. Flowers
should be cut when fully opened -- those cut early in the day will last
longest.

Tuber storage

Sadly, fall signals the end of the show. After the first killing frost in
your area cut foliage back to about 4 inches. Attach name labels to the base
of each main stem so you’ll know which plant is which next year. Then lift
out each tuberous clump with a spading fork. Spread the clumps in a shaded
area for a few days. Discard any tubers that are damaged or diseased and dust
with sulfur.  Pack clumps in a ventilated box or basket filled with slightly
damp vermiculite or peat moss. Store in an area where temperatures remain
between 35 and 50 degrees.

Some experts say dahlias should be cut and divided after the eyes have
sprouted in the spring. Others say let the tubers dry out a bit, shake the
clumps and they will separately naturally. Whichever method you try, get
ready to enjoy another dazzling dahlia performance.