Monthly Archive for July, 2012

Is Dichondra Right for You?

Published on July 30, 2012 in Ground Covers. 4 Comments Tags: , , , , , .

One of the questions that has been asked at the Master Gardener help desk is whether or not a lawn substitute called Dichondra is well-suited for the Willamette Valley in Oregon. Being new at managing the help desk, I had to do some research on this ground cover. Today’s blog is information that I discovered in my research, and hopefully, it will help one of my readers make a decision on whether or not Dichondra is right for them.

Photo of Dichondra

Dichondra repens

What is it? Dichondra repens is a warm-season, low-growing (usually 1 – 3 inches in height) perennial ground cover that is often used as a lawn alternative. It is only recommended for USDA Zones 8 – 11. It has nearly round, kidney-shaped leaves that measure 1/2 to 1 ½ inches across and sometimes form a hollow or cup. Dichondra spreads by slender creeping stems that root at the nodes (stolons). It can form a fairly dense carpet of leaves, and looks somewhat like a carpet of lily pads.

 

What are the benefits of Dichondra:

  • Bright green in color and very attractive.
  • Does not require mowing (although many people do mow it).
  • Does well in full sun to partial shade.
  • Tolerates light to moderate foot traffic.
  • Tolerates heat.
  • Establishes very quickly either from seed or plugs.
  • Great for slopes that cannot be mowed.
  • Looks nice growing around stepping stones.

Challenges with Dichondra:

  • Slugs and snails.
  • Flea Beetles, Weevils, Nematodes.
  • Fungus.
  • Not cold tolerant.
  • Has a fairly high requirement for Nitrogen.
  • Not drought tolerant.
  • Needs well-draining soil.

Here are some interesting facts:

  • Dichondra is in the Convolvulaceae family (same family that Morning Glory is in).
  • It produces a small, rather inconspicuous flower.
  • Dichondra is a weed to many people and a lovely groundcover to others. It has several other names such as: Pony Foot, Lawn Leaf, or Kidney Weed.

Care for Dichondra:

  • Water deep and infrequently to maintain Dichondra’s deep root system.
  • Watering too frequently causes weed invasions or disease activity.
  • Mowing regularly to a height of ¾ inch (higher during hot weather to avoid stress) will encourage a small leafed, even Dichondra lawn. Mowing to a height of 1-1/2 to 2 inches can be done less frequently, and this will promote a less consistent texture and leaves of varying sizes.
  • Fertilize lightly each month during the growing season.
  • Hand-pull broad leaf weeds. A pre-emergent can be used to control crab grass and other grasses. Read the label to ensure that the chemical can be used on Dichondra.
  • Watch for signs of disease and insect infestation.

Seeding Dichondra:

  • Soil temperature needs to be 70°F for Dichondra seed to germinate.
  • Prepare a weed free seedbed that is free of clods, loosened 6 inches deep, and is raked even. This is important because herbicides have very limited use on Dichondra and hand-pulling can be very difficult.
  • Broadcast 1 pound of Dichondra seed per 500 square feet and lightly rake the seed in. Cover no more than 1/8 of an inch.
  • Water throughout the day to keep the seed moist but not saturated.
  • Germination is usually within 7 – 14 days.

So, to answer the question: Is Dichondra recommended for the Willamette Valley? In Taylor’s Guides, Encyclopedia of Garden Plants, it states that Dichondra performs best where it rarely frosts, and in Zone 8 it needs frost protection. The Willamette Valley is Zone 7b or 8a depending on which map is being used. The Master Gardener’s desk does not recommend growing Dichondra here … yet I know a few people who have it thriving in their landscape.

Question for the week: Does Dichondra sound like a good choice for your situation?

By Kimberly Bell

Dianthus – They Deserve Recognition!

Published on July 22, 2012 in Garden Flowers and Wildflowers. 3 Comments Tags: , , , , .

Today’s blog post features a flower that many people are familiar with, Dianthus. There is a wide range in colors, with shades of white, red, rose, dark red, lavender and pink, and a variety in form and sizes, but they are all wonderful performers and often sweetly scented. Here in Oregon, they are a flower that reliably blooms by the end of May, and my mom uses them each year in arrangements for Memorial Day. Dianthus deserves some special recognition today!

Photo of Sweet William

Dianthus barbatus ‘Holborn Glory’

There are many common names for Dianthus, including Sweet William, Pinks, Maiden Pink, Gillyflower and Carnation. Dianthus is from the Greek word for ‘flower of the gods.’ Their history goes all the way back to Greek and Roman times, and through the centuries Dianthus made their way from Europe and then to England and finally to colonial America. Many common names were attached along the way, but Dianthus species were an important part of the garden where they were not only charming, but they were also used in flavorings, wine, soups, sauces and jams.

Dianthus plants are versatile and lend themselves to different uses. There are dwarf and mat-forming varieties that are perfect for edging along a border, as a ground cover, or grown in containers. The medium to tall varieties are great grown in a cutting garden with other annuals and perennials, or they look especially nice growing in front of a back-drop of evergreen shrubs.

There are several species of Dianthus that could be high-lighted, but I’ll focus on the two most common:

Dianthus barbatus is the familiar Sweet William. It has been grown in many old-fashioned cottage gardens. It is a short-lived perennial or biennial and some newer varieties are annual. The name Sweet William is not in reference to a person but rather to the flower’s pleasant fragrance. The blooms of the species have a central spot called an eye. This Dianthus is hardy to Zone 4 and can range in height from 5 inches to 24 inches and has single or double flower clusters that form in late spring and into summer. The flowers are not always scented.

Photo of Dianthus

Dianthus chinensis ‘Merry-Go-Round’

Dianthus chinensis is the name for the pinks or China pinks (originally they came from China), and it can be an annual or biennial, but they will flower the first year when grown from seed. The common name, pink, does not refer to the color of the blooms but to the serrated edges of the blooms. To ‘pink’ in sewing means to notch like with pinking shears. The plants can range in size from 6 – 18 inches, and the blooms are not scented and can be single or double. These species will bloom intermittently throughout the summer, and they are very carefree.

Dianthus can easily be grown from seeds. For the earliest blooms, start the seeds indoors about 6 – 8 weeks before the end of frost season and plan on setting them out just before the last frost date. Use a moistened seed-starting mix in trays or pots, and press the Dianthus seeds into the soil, misting the surface to moisten the seeds. Sealing the container in a clear plastic bag is helpful in maintaining moisture. Maintain a temperature of 70°F. When sprouts are seen, remove the plastic and place the containers in a sunny, south-facing window. Water from the bottom and fertilize with water-soluble fertilizer from day 10 of seedling growth and then every 2 weeks until transplanting. Dianthus seeds for annual varieties can also be started directly outdoors in a prepared seedbed after danger of frost has passed.

Here are a few tips for growing Dianthus:

  • Dianthus plants are sun lovers and need at least 6 hours of direct sun each day. If they are grown in shade, they will have few blooms and the plants will be lanky and not as compact and well-shaped.
  • Deadhead the spent blooms to encourage re-blooming and prevent seeds from forming. Using Dianthus flowers for arrangements is a great way to promote new blooms, and the flowers have a long vase-life.
  • Many Dianthus will self-sow. Leaving a few blooms to go to seed will make an annual seem like a perennial.
  • For winter survival, lightly mulch over the roots as Dianthus plants are fairly shallow-rooted.
  • Grow Dianthus in well-drained soil, and either use a slow-release fertilizer when transplanting young plants into the bed, or use a balanced liquid fertilizer each month.
  • Give plants adequate spacing to allow for air movement. Remove any plant part with a sign of disease.

Dianthus flowers have a long history of popularity. They are loved for their ease in growing, low care requirements, and also for the wonderful variety of colors and forms. They definitely deserve some recognition!

Question for the week: How many varieties of Dianthus do you have growing in your yard?

By Kimberly Bell

Coreopsis Will Not Disappoint

Published on July 16, 2012 in Garden Flowers and Wildflowers. 2 Comments Tags: , , , , , .

Not too far from my home, there is a commercially grown field of Coreopsis. I’m not sure exactly what the species is, but what I am sure of is that it is absolutely breathtaking. The color is vivid and bold, and I know that it will continue to bloom for the majority of the summer yet. There are some flowers that must be written about and featured in my blog because of both their beauty and ease of care, and Coreopsis is definitely in that category.

The name Coreopsis comes from the Greek word ‘koris’ which means ‘bug’. Plants in the Coreopsis genus are commonly called Tickseed due to the seeds resembling little ticks. There are some species that are annuals and some that are perennials, and both grow readily from seeds. In general, Coreopsis prefers to live in full sun and tolerates partial shade. The plants are not picky about soils, but a neutral pH and a well-draining soil is best. Instead of producing more blooms, over fertilizing Coreopsis will result with less blooms and floppy plants. Once established, Coreopsis is fairly heat and drought tolerant. The flowers are excellent for cutting and last for most or all of the summer, attracting butterflies and other beneficial insects. Coreopsis is great for flower beds and borders as well as naturalized meadows and prairies, and the plants are usually deer resistant.

Here are some of the most well-known species of Coreopsis:

Photo of Plains Coreopsis

Plains Coreopsis

Coreopsis tinctoria is referred to as Plains Coreopsis. It is an annual that is native to North America, primarily the Great Plains and the Southern United States. It is a marvelous performer giving non-stop color of bright yellow flowers with maroon centers. It has finely divided leaves and handles wet, soggy conditions better other Coreopsis.

Coreopsis lanceolata is commonly known as Lance Leaf Coreopsis. It is a perennial that forms a clump and has short rhizomes, and it is primarily found in the eastern and mid-western portions of the United States. The flowers are 1 – 2 inches, daisy-like and bright yellow with a yellow center, and the leaves are narrow and oval or ‘lance-shaped.’ Lance Leaf Coreopsis is a spring bloomer and will bloom into the summer and longer especially if it is deadheaded.

Coreopsis grandiflora is sometimes called Large-Flowered Tickseed. This species is also perennial that forms clumps and has rhizomes, so it is often found in colonies. As the common name suggests, this Coreopsis has large flowers that measure 2 ½ inches across. They are yellow with a yellow center and somewhat ragged edges on the ends of the petals. The leaves are linear pinnate and occur along the stems, usually in opposite pairs. Blooming usually starts in June and can last into fall.

Coreopsis verticillata goes by the common name of Whorled Tickseed or Threadleaf Coreopsis. It is found mainly in the Southeastern United States. It is also a perennial that forms a clump or rounded plant with yellow, daisy-like flowers, and it has an ultra fine texture. The foliage is extremely fine and needle-like, and it whorls around the thin upright stems.

Photo of Lance Leaf Coreopsis

Lance Leaf Coreopsis

There are many cultivars within each species and the colors (reds and rose shades added), blooms (double and semi-double), and sizes (dwarf and various heights) have been enhanced to make excellent plants for sunny flower gardens or borders. Propagation is by seed (or division for perennials) that can be started directly outside in a prepared seedbed in the early spring after frost season has ended. The Coreopsis seeds can be lightly raked into weed free soil and kept moist until germination. The plants should be watered regularly until they are nicely established. Coreopsis is a marvelous plant with a wide variety of cultivars to fit just perfectly in the landscape, and they will perform and will not disappoint!

 

Question for the weed: What cultivar of Coreopsis are you growing in your garden?

By Kimberly Bell

Coleus – Guaranteed to Thrill!

Published on July 8, 2012 in Foliage Plants. 0 Comments Tags: , , , , .
Photo of Fairway Mix Coleus

Coleus Fairway Mix

In the spring, we often select flowering annuals for planting in our flower beds and containers, and sometimes we overlook annual foliage plants like Coleus. Coleus plants are easy-care, versatile, and their foliage color can only be described as spectacular!  Coleus combines well with flowering annuals to create more texture and interest, or it’s a great stand-alone in a container or bed.

The botanical name for cultivated Coleus is most often Solenostemon scutellarioides. Sometimes it will be listed as Coleus x hybridus and another synonymous name is Coleus blumei. There is also quite a list of common names: Coleus, Flame Nettle, Painted Nettle, Painted Leaf, and Poor Man’s Croton. The name Coleus comes from the Greek “koleos” and it means sheath. The name was probably given due to the fact that the stamens, the male portions of the Coleus flowers, are fused into a tube or sheath.

The Coleus is a member of the mint family, Lamiaceae. Coleus plants have the distinctive stems that are square in cross section and are closely related to peppermint, spearmint, salvia, basil, thyme and oregano. Coleus plants are herbaceous perennials in their native habitat, and that could originally have been Africa to Asia and the Pacific Islands. They are frost tender, so in most climates, they are grown as annuals. Coleus plants have opposite leaves and blue to lilac colored flower spikes (most gardeners pinch out the spikes because they are insignificant compared to the beautiful foliage).

Photo of Chocolate Mint Coleus plant

Coleus Chocolate Mint

So, what’s so great about Coleus? Well, it has the most incredible foliage with colors and color combinations that no other plant species can offer. The colors are brilliant and the range in shades is limitless: dark mahogany, browns, greens, yellows, bronze, reds, and oranges. The leaves are gorgeous with their frilly edges and unique color patterns. The Coleus plants have different growth habits: some are tall and lanky, some branch freely and are compact, and others trail and are beautiful in hanging baskets. There are literally 1000s of forms!

Propagation of Coleus plants is fairly simple. Cuttings that are 3 – 4 inches long will readily root even in a glass of water. Coleus seeds are usually found in mixtures, offering several varieties of colors and sizes in one seed mix. Start Coleus seeds indoors 8 weeks or so before the last expected frost. Using starter trays or pots and pre-moistened sterile potting mix, the seeds should be placed on the surface and gently pressed into the soil. Covering the pots with glass or clear plastic helps to keep the moisture in the seeds. Keep a room temperature of 70°, mist the surface and seeds daily with water,  and place the tray or pots in a sunny location, preferably with indirect light as to not dry out the seeds. Remove the covering once germination has started and set the tray in a sunny window. Watering from the bottom is recommended. The Coleus seedlings can be handled once they have developed 2 sets of true leaves. Harden the seedlings off before planting them outdoors. Coleus plants prefer fertile, evenly moist, well-draining soil, and they do well with a partial shade setting.

When growing Coleus from seeds, it is amazing to watch the genetic expression even in the seedlings. There seems to be an endless variety of color combinations, and the colors are so rich and vibrant. Include some Coleus plants on the yearly list of annuals – they are guaranteed to thrill!

Question for the week: Do you grow Coleus from seeds or cuttings?

By Kimberly Bell

Celebrate Celosia!

Published on July 1, 2012 in Garden Flowers. 0 Comments Tags: , , , , , , .

If you want to add some intense color and exotic looking flowers to your garden, look no farther than Celosia. They are easily one of the most colorful and eye-catching annuals for the garden, and in addition, they are also an excellent choice for cutting. The flower heads are enjoyed in both fresh and dried arrangements. Dried Celosia flowers are often sold as everlasting flowers and for use in potpourri.

photo of red celosia

Celosia plumosa

Celosia is separated into 3 major groups:

Celosia plumosa, sometime commonly called Plume Plant. These flowers look like feathery plumes and the colors are vibrant with reds, oranges and yellows.

Celosia cristata, which is often called Cockscomb. These flowers are called crested, but in my opinion, they look like wrinkled knobs. Again, the colors are vibrant and nearly glow with intensity.

Celosia spicata, which goes by the common name of Wheatstraw or Wheat Celosia, and it is an elongated cone that resembles a wheat head. The colors are in shades of pinks and purples.

The name Celosia is derived from the Greek word ‘kelos.’ It means burning which definitely describes the intense “flame-like” colors and inflorescence (group or cluster of flowers arranged on a stem) of some cultivars. Celosia thrives in hot, humid summers, and they are known for coming through the hottest droughts unscathed. They do not perform as well in areas with cool, wet summers. Celosia is actually a tender perennial, and in frost-free zones, they will grow as trouble-free perennials.

Celosia is propagated from seed, and the seeds are extremely small — 43,000 seeds per ounce. The Celosia seeds need a soil temperature of 60°F or warmer, so for areas with long winters, it’s best to get the seeds started indoors. In general, it is recommended to use sterile seed starting mix as the Celosia seedlings are vulnerable to damping off. Also, their roots are sensitive to transplanting, so it is suggested to sow the seeds into individual peat pots that can be transplanted outdoors without much disturbance. Cover the pots with plastic wrap and mist the soil with water daily to keep the seed mix lightly moist. Once seeds have germinated, move the pots to a sunny south window or under fluorescent lights.

photo of red cockscomb

Celosia cristata

Once nighttime temperatures are 55°F, begin to harden the Celosia seedlings off. Place the seedlings in a protected area outdoors for part of each day. After about 8 days, leave the seedlings out over night. Space the plants the recommended distance apart for the specific cultivar. Remember to tear back any part of the peat pot that is above the soil line. After transplanting, make sure Celosia plants receive 1 inch of water per week for the first few weeks that they are in their new location. To obtain the greatest number of flower heads for crested and plume Celosia, pinch plants 2 weeks after transplanting to promote branching and multiple, small flower heads. Celosia needs nutrition throughout the growing season. Apply an application of a complete fertilizer every few weeks. Celosia blooms for about 8 weeks, from midsummer to fall.

Celosia plumosa varieties are great for houseplants. The potted plants will show color for a month or more under low light conditions. Many gardeners sow seeds in a 10 – 12 inch pot in mid-summer. Within 8 – 10 weeks, the plants will be showing color, and potted Celosia makes a beautiful autumn houseplant.

There is much more that could be written about these lovely, exotic looking flowers! The ideas for decorating with cut and dried Celosia flowers are endless. Celosia is as versatile as it is lovely!

Question for the week: Do you grow Celosia and what is your favorite use for it?

By Kimberly Bell