Beautify – May 2017

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On The Radar: May

Meeting Notes: March 7, Proven Winners

To Dahlia or Not to Dahlia

On The Radar: May

Cheryl Gross, Advanced Master Gardener, Vice President MGANM, President Plant It Wild

By the end of the month, flower gardens will be set for the season.  May is when annuals shine.  Rules of thumb for annuals in the garden and in containers begin with the color wheel!  Make things pop with opposites… blues and oranges, yellow and reds…or go for a classy monochromatic look by layering the same color in different flowers and leaf textures. 

Keep in mind the ‘filler, spiller, thriller’ rhyme in your pots and hanging baskets.

Use annuals to fill beds as you await the spread of perennials and shrubs.

Photo from Proven Winners

Meeting Notes: March 7, Proven Winners

Nancy Denison, Advanced Master Gardener

MGANM met on March 7 at the Botanical Garden Visitor Center for a joint presentation on new plants for 2017. Our guest speaker was Heidi Grasman from Garden Crossings in Zeeland, MI. Heidi, and husband Rod, grow and sell many plant varieties in their greenhouses, provide products to area landscapers, and run a retail garden center as well.

Heidi and Rod brought along some plants to give-away as well as photos of some of the newest “Proven Winners” offerings for this year.  Several that caught my eye were the Rose of Sharon which grows in a 3-4 ft. mound with deep green foliage; the “Summerific  Ballet Slipper” hardy hibiscus which grows to just  4ft; and a compact hydrangea, “Invincible Limetta or Wee White”, with smooth leaf foliage and large flowers.

Heidi also invited us all to the Grand Garden Show on Mackinac Island, August 27-29 for tours of private gardens on the island, seminars and more. Opening day for Garden Crossings is April 17.  Thanks so much to the Grasmans for a fun, informative night.

7 month old Dahlia tubers, Coastal NC

To Dahlia or Not to Dahlia

Nancy Denison, Advanced Master Gardener

A late September trip to Seattle included the famous Pike’s Peak Market and a jaw dropping ogle at the vendor table of dahlias. The colors, the petal designs, the sizes made me drool every time we cruised through the market. I’ve since tried to grow various types with little success. Here’s what I’ve discovered that may help those of us who need it.

Dahlias are a “genus of bushy tuberous, herbaceous, perennial plants native to Mexico.” Spaniards reported finding the plants growing in 1525. (Wikipedia) The tubers were grown as a food crop by the Aztecs but this ended after the Spanish Conquest in the early 1500s. There are 42 species, 1000 cultivars, and 14 flower group types. These range from group 1, single flowered, to group 4, water lily, to group 8, cactus, to group 14, peony flowered. The dahlia was named after the botanist Anders Dahl born on March 17, 1751.

Dahlias grow best in zones 7-11. They need full sun, except in the Deep South where some shade is preferred. Of course for us in zones 4 and 5, dahlia growth requires a few modifications in planting.  Jerry Baker (“America’s Master Gardener”) recommends planting the bulbs after the last threat of frost has passed.  Or at least when the soil temperature is about 60F. The soil should be well draining, whether in a planter or the ground. One reference suggests digging a hole 12” in diameter and 12” deep, filling half the hole with compost mixed with bone meal. Another suggests digging a hole 4-5’ deep. Make sure tubers are not wrinkled or rotten, and a bit of green growth is a good sign. Do not break tubers, but plant the whole section with the “eye” or sprout pointing up and cover with composted soil.  Do not fertilize or water right away to decrease possibility of tubers rotting. If planting in a bed, space tubers between 12”and 36” apart depending on flower size.  Smaller flowering can be 24” apart while the larger flowering should be 36”. Do not cover with mulch or bark to avoid pests.

Dahlias begin blooming about eight weeks after planting, usually in mid-July, however some gardeners may want to start the tubers indoors to get a jump on the season.

Pinching the first buds will encourage strength and fullness. Fertilize with a low nitrogen product within a month of planting and then regularly during the season but don’t over fertilize, especially with nitrogen, as you may end up with no blooms and weak tubers. 

Dead head spent blooms for new growth.  Dahlias are attractive to snails, slugs, earwigs, spider mites, aphids and rabbits. For taller varieties, stake at the time of planting to avoid piercing the tubers.

Tubers must be dug up and safely stored for use the following year.  When foliage has been blackened by frost, cut tops down to within a few inches of the ground. Carefully lift out the tubers, separate, shake off soil, cut rotten sections off and leave upside down to dry naturally. Pack each tuber in loose fluffy material such as dry sand, peat, vermiculite, or packing peanuts. Store in a well-ventilated, frost-free spot where temps are at best 40-45F or at least between 35 and 50F. In the spring, if all has gone well, you can begin anew.  If not, just go buy some new ones and try again!


Jerry Baker, Great Garden Tips and Tonics. American Master Products Inc. 2003.

Farmer’s Almanac:

Fine Gardening Magazine, Taunton Press; p22-29 by Alastair Gunn.


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