The growing season is upon us again and the search is on for the new, the unusual, the plant that will draw the eye. Here are a few for discriminating gardener’s contemplation.

Persian Coneflower
Centaurea dealbata

Consider the Persian coneflower; this plant is a close relative of the blue bachelor button, Centaura montana. The flower is pink and smaller but has the typical scaled calyx.  It opens considerably wider than the one pictured. What is particularly attractive about this plant is its graceful shape, from a narrow base it branches out into an attractive vase shape. The foliage is divided and a fuzzy blue-green with a silvery underside.

A hardy perennial from zone 3-8, this plant will tolerate almost any kind of soil as long as it is well drained. Once it has its taproot down it will tolerate dry conditions but will succumb to lack of drainage especially while dormant. It will accept soil  with a pH of 6.1-7.8.

A very versatile plat for the garden, it will bloom well in full sun or partial sun. It also does well in light shade conditions. Even if blooms are sparse the Persian cone flower is worth growing as a background plant for its beautiful foliage. The normal flowering period is late spring to early summer but it will bloom into mid summer if the plant is deadheaded regularly.

Deadheading is recommended because the Persian coneflower seeds readily. It is closely related to the notorious knapweeds. If you do deadhead religiously and want more plants the root ball is easily divided. . Seeds may be collected and dried in the fall for better control.  Germination takes 10 to 12 days under cool conditions, 60-65 degrees F.

The Persian coneflower reaches a height of 18 to 24 inches and has a spread of 12 inches. It is attractive to birds, bees and butterflies. Goldfinches eat the seeds and it serves as a butterfly host plant.

This plant will be available to all who want it in the spring as I’m letting mine go to seed. The original, I think, came from Aline.

Coral Bells
Heuchera sanguinea

There is a Heuchera series known as ‘Dolce’ that has recently been introduced. I found ‘Peach Melba’ and ‘Key Lime Pie’ last week at Lowe’s and both are exquisite plants. ‘Peach Melba is peach orange in color that according to the tag changes color with the seasons. ‘Key Lime Pie is bright glowing chartreuse. While this series is going to be planted for colorful leave the plants do bear the characteristic “coral bells” both in a creamy white.

 

Other plants in the series are:

• ‘Mocha Mint’ with smaller dark green foliage heavily veined in silver. Bloom color is a rose red.
• ‘Crème Brulee’ has peachy orange to bronze leaves that brighten as the season progresses. The flower scapes are dark red and the flowers are a cream color.
• Crème de Menthe has large silver leaves with dark green veining and a rose underside. Foliage turns red in the fall. Flowers are pink.
• ‘Licorice‘s’ foliage is purple/ black dusted with silver. The flowers are a salmon/coral.

While rated from shade to partial shade, like most coral bells, this series is reportedly more at home in full sun and will tolerate heat and humidity. Many sources suggest that the colors will be brighter in full sun. Since these plats are being grown primarily for their leaves a high nitrogen fertilizer is recommended.
The Dolce series has the typical mounding habits of all Heucheras. They reach a height of 8-16 inches and have a spread of about 12 inches. They are hardy in zone 4-9 and will tolerate temperatures to -25 degrees F.

Huecheras are not fussy as to soil types and thrive in everything from well drained to our heavy clay soil. They grow best with moderate amounts of water but are drought tolerant.  They are deer resistant and the ground hogs don’t seem to like them either. The humming birds however are often seen dipping their beaks into the bell shaped blossoms.

Reblooming Iris

Although some of the beardless irises are now being added to the rebloomer list we are going to be concentrating on the German or bearded irises as they have begun appearing in our local garden centers. The first thing that must be acknowledged is that reblooming is not guaranteed. It is tied to, among other things, climate. Some of the multiple bloomers will send up repeat blooms only in warmer climates that have longer growing seasons. Some will rebloom in zone 5 or colder but they may do so sporadically.  It is possible to check whether a specific iris will rebloom in a planting zone on the web page of the Reblooming Iris Society at http://www.rebloomingiris.com/

The ability to rebloom is apparently due to a number of genetic factors rather than one gene. These irises appear to have recessive genes that allow for blooming without an interceding cold season. Reblooming may also, in part, be due to genetically controlled chemical and hormonal factors that are influenced by the vigorous growth peculiar to hybrids and favorable climactic conditions.

There are 4 types of remontant or reblooming iris. The repeat bloomers go through their bloom cycle then put up another stalk within a month of the normal iris season. Cycle rebloomers have a second blooming season usually in the late summer or fall when temperatures have dropped. The problem with cycle bloomers is that the fall frosts may catch their final flush of blooms.

Ever bloomers are irises that are genetically programmed to bloom any time moisture and temperature conditions are met. ‘Immortality’ is cited as an iris that will bloom almost continuously in southern climates and is a reliable rebloomer to zone 3. Sporadic rebloomers are genetically programmed like the ever bloomers to rebloom when conditions are right but the tendency to rebloom is much weaker. They do not often bloom in northern climates.

Reblooming iris require more fertilization and more water than normal iris, which tend to go progressively dormant as the days shorten. Fertilize them in the early spring and again after they flower, with a low nitrogen high phosphate fertilizer. Supply additional water after they bloom should rainfall be insufficient. It is important to keep these irises separate from the regular bearded irises as extra watering, as their growth slows after blooming will rot a normal German iris.

The rebloomers tend to grow faster and need to be divided more frequently than the normal iris. It is suggested that only half of a clump be lifted and divided at one time as they may not bloom again until they have settled in.

I’ve found ‘Invitation’ and ‘Tiger Honey’ and I know Esther has one as well. We will report any reblooms in the coming years.