Planting Perennials

Posted on October 3, 2013 by tomkarwin

Last Sunday was the Fall Equinox, so autumn is now official and we are heading into the year’s best time for installing trees, shrubs and herbaceous perennials.

When we plant in October, ideally just before the seasonal rains begin, our additions establish their roots during the fall and winter months and prepare for spring’s burst into leaf and blossom.

Many herbaceous perennials could be planted now. We will consider just three arbitrary but good selections:

English Lavender (Lavandula angustifolia). Several good varieties are available for this popular lavender. Small plants can be started now. In the spring, promote a compact mounded form by cutting the plant back to two inches above hard wood., and repeat in the spring of the second year. By the third spring, it will have reached mature size, or close to is, and produced a generous number of fragrant blossoms. With mature plants, a second pruning in late August will help in maintaining a good form. Replace lavender plants that have been allowed to develop a rangy form.

Salvia. Garden centers and mail-order nurseries offer about 100 species of salvia, with many selections and hybrids of most species. These “super shrubs” are native to many parts of the world, principally Central and South America, Central Asia and Mediterranean Basin, and Eastern Asia. California Blue Sage (Salvia clevelandii) is a California native that grows well in the Monterey Bay area; there are many other blossom colors, plant sizes and foliage forms available. The gardener could choose from the local garden center’s inventory or develop specific targets through research in a library or the Internet, or at Cabrillo College, in Aptos, whose salvia collection has been called the worlds largest. Most salvias should be cut back hard in the early spring, when new growth can be seen at the base of the plant.

Penstemon gets its name from a long straight, hairy fifth stamen that gives the blossom the appearance of an open mouth with a fuzzy tongue protruding. This inspires the plant’s common name, beardtongue. This is a large genus native to North America, from Alaska to Guatemala. There are taller-growing species (two-to-four feet) that can be fine additions to the middle of the border, and look best in mass plantings. There are also lower-growing species that are fine for rock gardens or the front of the border. Blossom colors include white, yellow (rare), blue, violet, purple, pink, magenta, and red. A popular selection is P. heterophyllus ‘Margarita BOP’, also called ‘Blue Bedder’. (BOP means “back of porch,” which is where this plant was discovered.)

Prepare to plant perennials in October!

Lavender

Several species of lavender (Lavandula) are available. The most popular garden varieties are English Lavender (see above), French Lavender (L. stoechas or L. dentata) and Spanish Lavender (L. stoechas, L. lanata or L. dentata). There is also Egyptian Lavender (L. multifida). All Lavenders flourish best in dry, well-drained, sandy or gravelly soils in full sun, and require no fertilizer and good air circulation.

Salvia

Visit Cabrillo College’s website of salvia information, and browse through the several pages for the collection, the photos of selected salvias, the chart of several species, and the Cabrillo cultivars.

Another exceptional resource for both information about, and purchases of salvias is the website of Flowers by the Sea, a mail-order nursery in Elk, California (which is about fifteen miles east of Fresno). Owner Kermit Carter tells me that Flowers by the Sea currently offers 369 species and varieties of Salvias, which is extraordinary indeed.

Penstemon

To learn more about Penstemons, start by visiting the website of the American Penstemon Society, which has solid information about cultivating, propagating, and identifying plants in this large genus from North American and East Asia.

Another good source of information is the website of Las Pilitas Gardens (located in Santa Margarita, California), particularly the page titled, California “Penstemons That Grow in DRY Areas.”

The best online information on almost any gardening subject is Wikipedia. Visit its webpage on the genus Penstemon for impressive details including a long list of species, and a list of Penstemon cultivars that the Royal Horticultural Society has honored with its Award of Garden Merit.

Creative Landscaping with Bulbs

Posted on August 26, 2013 by tomkarwin

If you will plant spring bulbs this fall, there is time for design. Brent and Becky Bulbs says the ideal planting time is after the first frost and before the ground freezes. It will be a long time before Monterey Bay gardens freeze over, so you need not rush to planting. They also recommend ordering early and planting when the shipment arrives.

Disclosure: I met Brent and Becky Heath at meetings of the Garden Writers Association, which has named them to its Hall of Fame for their many good works.

Landscaping Ideas

Tentative vs. Bold. Sprinkle bulbs here and there in your garden to good effect, or create large swaths for dramatic impact.

Captive vs. Free. Bulbs are good in containers because they can be moved in and out of the spotlight as needed, but they grow best and look most natural in the ground.

Clones vs. Communities. Both large and small displays of a single cultivar are charming, while mixtures of cultivars of the same plant can offer interesting comparisons and complementary colors and forms.

Big Event vs. Extended Display. Mail-order sources often list the flowering times of spring bulbs, e.g., very early, early, mid, late, and very late. You could plan your display for a garden party or other special event, or orchestrate an extended-season display in a prominent bed.

Monochrome vs. Polychrome. Mass planting of different bulbs that flower in the same color or analogous colors can please; designing color combinations can be challenging but satisfying when the design succeeds. Search the web for “color theory” for color wheels and ideas. The website “Color Matters” is terrific. The web also has demonstrations of many color combinations, which might mix bulbous plants with other types. For example, see the Better Homes & Gardens website:

http://www.bhg.com/gardening/flowers/bulbs/beautiful-bulb-combinations.

Botanical Garden. For an intriguing, educational and satisfying approach, group bulbs by their geographic origin.. There are bulbs from throughout the world, and very good choices from Mediterranean climate regions. South Africa is the home of a large number of bulbs, the Mediterranean Basin has many, and California’s native bulbs include Brodiaea, Calochortus, Triteleia and others.

Many mail order bulb nurseries indicate the origins of their bulbs, and some specialize in exotic choices. Good sources include Telosrarebulbs.com (international), californianative bulbs,com (California), thebulbman.com (South Africa), and www.bulbmania.com (international). Also visit the website of the Pacific Bulb Society (www.pacific bulbsociety.org ) and search for “species bulbs” for a list of suppliers of seeds and bulbs.

Enjoy your spring bulbs!

Bulbs for Next Spring

Posted on August 26, 2013 by tomkarwin

Now that the spring-blooming bulbs have enriched our gardens and faded away, it is time to prepare next spring’s display.

Spring-blooming bulbs should be lifted, divided and replanted every three or four years, so if your existing bulbs could stay in place for another year or two, you can take time off—or attend to other garden priorities that are waiting for attention.

If your garden is still a Spring Bulb Free Zone, or if you wish to bring new or additional bulbs into the picture, now is the time. Let’s review.

The Daffodil (Narcissus) is the most popular spring-blooming bulb. A multitude of great choices is available. The American Daffodil Society advises that there are between 40 and 200 different Daffodil species, subspecies or varieties of species and over 25,000 registered cultivars (named hybrids). These are divided among the thirteen divisions of the official classification system. Visit the ADS website, http://daffodilusa.org/, for full information on the divisions, which are the many delightful forms of the blossom. That website also has good advice on growing this garden favorite.

Visit Wikipedia (search for Narcissus) for fascinating (I think) information on sixteen selected species of Narcissus.

Another very popular spring-blooming bulb is the Tulip, which needs a chill period to grow well. The Monterey Bay area has insufficient cold days for Tulips, so plant pre-chilled bulbs. Most mail-order suppliers offer pre-chilled bulbs, and will ship them at planting time. Order early to be sure to get pre-chilled bulbs of the cultivars you prefer.

There are many beautiful spring-blooming bulbs beyond these favorites, so try other popular choices: Hyacinth, Crocus, Grape Hyacinth, Allium, Siberian Squill, Crown Imperial, Snowdrop, Anemone, and Freesia.

Planting spring-blooming bulbs begins with choosing a location that has full exposure to the sun and is well drained. Build a berm or raised bed to ensure good drainage. If your soil is heavy with clay content, dig in a generous, three or four inch deep layer of organic compost. Bulbs that will remain in place for the next bloom season also will benefit from a top dressing of a good compost material.

Plant the bulbs deeply: three times the height of the bulb. This works out to four-to-six inches to the bottom of the hole for a typical daffodil. Water them in and place mulch on the surface to retain moisture and discourage weeds.

Garden centers are beginning stock spring-blooming bulbs now. As always, the selection is broader when ordering from a catalog or on the Internet.

In next week’s column, we’ll consider opportunities for creative landscaping with spring bulbs.

More – Mail order sources for bulbs

Brent and Becky’s Bulbs – Spring/Fall 2013 Catalog

John Scheepers, Inc. – Beauty from Bulbs

Van Engelen, Inc. – Wholesale Price List

White Flower Farm – Fall 2013 Garden Book

Sizes of Irises

Posted on August 10, 2013 by tomkarwin

We are in iris planting season, made apparent by the annual sales of the Monterey Bay Iris Society and the deluge of catalogs from iris growers.

Iris family (Iridaceae) is huge, with about 2,000 species distributed among 65 genera. The bearded irises, the most popular form, are hybrids based on the German Iris (I. germanica), the Sweet Iris (I. pallida) and the Hungarian Iris (I. variegata). Bearded irises are available in many sizes, colors, color combination and blossom types, thanks to the tireless work of professional and amateur hybridizers.

Today, we review the six horticultural classifications of the bearded iris, both to broaden appreciation of this popular garden plant and to suggest landscaping opportunities.

Miniature Dwarf Bearded Iris (MDB): These are smallest (up to eight inches tall), and earliest to bloom, with the crocus and dwarf daffodil. Each plant produces multiple stems, providing a great display that lasts for weeks.

Tall Bearded (TB): These, the largest and most popular of the bearded irises, grow to 27.5 tall and more. They are the last to bloom.

Medians: there are four “medians,” all created by crossing MDBs and TBs.

Standard Dwarf Bearded Iris (SDB): Eight to sixteen inches tall. Blooms after the MDBs. As edging plants, they make a charming display. Their popularity with gardeners and hybridizers is growing, and new hybrids are appearing in great numbers.
Intermediate Bearded Iris (IDB): Sixteen to 27.5 inches tall. Blooms over a long period, beginning after the SDBs and continuing during the TBs. These provide welcome smaller versions of the TBs for a different look in the garden.
Miniature Tall Bearded (MTB): Also sixteen to 27.5 inches tall; blooms with the BBs and TBs, but produces smaller blooms. The MTB’s smaller flowers are perfect for smaller gardens and a more delicate look.
Border Bearded (BB): Also sixteen to 27.5 inches tall; blooms late, with the TBs. This classification’s name suggests its role: these irises are desirable for the garden bed border, compact and floriferous, with ample colors and color combinations to support creative color effects in the landscape.

This quick review of the several kinds of bearded irises is drawn from Kelly Norris’s new book, “A Guide to Bearded Irises: Cultivating the Rainbow for Beginners and Enthusiasts.”

Last week, I mentioned the Annual Rhizome Sale of the Monterey Bay Iris Society, Saturday, August 10^th (that’s today, from 9:00 to noon!). Visit the sale at Aptos Farmer’s Market, Cabrillo College, Aptos. It’s an exceptional opportunity to add tall bearded irises to your garden at very low cost, and chat with local iris enthusiasts.

Good mail order suppliers of iris rhizomes

Schreiner’s Iris Gardens, near Salem, Oregon

Keith Keppel Iris, Salem, Oregon

Fred Kerr’s Rainbow Acres, North Highlands, California

Aitken’s Salmon Creek Gardens, Vancouver, Washington

Books on Irises (most available through Amazon.com)

The Iris Family: Natural History and Classification, by Peter Goldblatt and John C. Manning 2008

Irises, by James Parry 2006

Classic Irises And the Men And Women Who Created Them, by Clarence Mahan 2006

Irises: A Gardener’s Encyclopedia, by Claire Austin 2005

Wild Lilies, Irises, and Grasses: Gardening with California Monocots, by Nora Harlow, Kristin Jakob 2004

Iris, by Theodore James , with Harry Haralambou 203

Irises, by Sidney Linnegar, Jennifer Hewitt 2003

Iris: The Classic Bearded Varieties, by Claire Austin 2002

The Gardener’s Iris Book, by William Shear 2002

The Siberian Iris, by Currier McEwen, with Jean G. Witt 1996

The World of Irises, by Bee Warburton, Beatrice A. Warburton and Melba Hamblen (Eds.) 1978

The Iris Book, by Molly Price 1972

The genus Iris, by G. I. Rodionenko 1961

Iris culture and Hybridizing for Everyone, by Wilma Vallette 1961

The Iris, by N. Leslie Cave 1959

Iris for Every Garden, by Sydney B. Mitchell 1949

Irises. Their Culture And Selection, by Gwendolyn Anley 1946

The Iris: A Treatise on the History, Development, and Culture of the Iris for the Amateur Gardener, by John Caspar Wister 1930

The genus Iris, by William Rickatson Dykes 1913

Quick and Easy Gardening

Posted on April 15, 2013 by tomkarwin

When selecting a gardening book, look for content that aligns well with your needs and interests. That might seem like advice from Mr. Obvious, but it is easy to be drawn into material that is too specialized or too fundamental in terms of your gardening goals.

Many gardeners share an interest in low-maintenance gardening, so that is has become an inside joke for landscape designers and contractors.

In fact, several factors influence the level of effort that a garden requires. Certainly, landscape size and plant selection are significant contributors to the maintenance task.

Another very important factor that can impact the time and effort required is the gardener’s knowledge of gardening. Simply stated, if you know what to do and when to do it, your efficiency goes up, your error rate goes down and your successes multiply.

So, how does one acquire that knowledge? One way is to spend a lifetime with hands in the dirt and heightened awareness, but there are shorter roads to expertise.

If you regard yourself as a novice, you might enroll in Gardening 101, but such courses can be hard to find and time-consuming.

A good alternative is Sunset Publishing’s 2013 book: The 20-Minute Gardener: Projects, Plants, and Designs for Quick and Easy Gardening, edited by Kathleen Norris Brenzel.

Despite its title, this book does not present a schedule for gardening in 20-minutes a day, but does provide good basic information on many aspects of gardening, so that one could use his or her time efficiently and effectively.

The first 40-plus percent of the book deals with Setting Up Your Space; Quick Fixes; Inspired Ideas, Easy Projects; and Techniques. Many sections within this part of the book begin with an action verb: Choose Easy-Care Plants, Keep Plantings Accessible, Plant Seasonal Containers, etc. This style amounts to setting clear objectives, always a good first step in getting work done.

The next section, which equals nearly half the book’s pages, presents brief descriptions of plants. There are countless gardening books that list and describe plants (gardeners apparently love lists!); the value of this section rests on the shortness of its plant lists in each of several categories. In this way, the book focuses attention on garden-worthy, easy to grow plants, but minimizes the pleasures of discovering and trying less familiar plants.

Such adventures might not be the novice gardener’s highest priority.

The remaining pages provide useful information and a good index.

Overall, the book offers clear and reliable gardening advice that could help the novice gardener establish the knowledge base for low-maintenance gardening, and lead to productive and satisfying gardening experiences. The 20-Minute Gardener is valuable resource for the targeted readers.

Enjoy your garden!

Delightful Dahlias

Posted on March 30, 2013 by tomkarwin

Get ready for the annual tuber and plant sale by The Monterey Bay Dahlia Society, next Saturday, April 6^th, at the Deer Park Shopping Center, in Aptos.

The sale will open at 9:00 a.m., when there likely will be a line of eager dahlia growers looking for the latest hybrid introductions, or particular favorites, or specific colors to complete a landscaping design.

Or all of the above!

The dahlia, a native of Mexico, grows quite well in the Monterey Bay area’s moderate climate.

There are many varieties of dahlias, so selection of plants for your garden is the first task. A good and simple rule of thumb is to select varieties that please your eyes. Other approaches include selecting plants that have won prizes or that have blossoms of the color, form or size that you prefer.

Fortunately, there are excellent plant selection resources on the website of the American Dahlia Society < www.dahlia.org>; click on the link for “Dahlia Resources.” To view photos of dahlia blossoms, conduct a Google search for “dahlia plants” and click on “Images”

Tubers are specialized structures designed to store nutrients during a dormant season. Dahlias are stem tubers, which differ from root tubers, like potatoes. A stem tuber has one or more buds on the end that was attached to the old plant. These buds, called “eyes” are the plant’s growing points, so examine actual tubers to spot an “eye.” Even experienced growers can have difficulty recognizing an eye, but a tuber lacking an eye will not produce new growth, so look closely.

The ADS website also provides information on cultivating dahlias. The basic (and easy) method is to select a spot that enjoys at least six hours of direct sunlight every day, and good drainage. The time to plant is between “right now” and about mid-June. The top of the tuber should four-to-six inches below the surface (larger tubers are planted deeper) with the “eye” facing upwards.

Taller dahlias should be staked to avoid flopping. Install a stake near the tuber at planting time; pushing a stake into the soil later risks damaging the tuber.

If you prefer not decorating your new dahlia bed with bare stakes, install a short piece of plastic pipe next to the tuber, with the top just above soil level. Then, when the plant threatens to flop, insert a thin stake into the plastic pipe and tie the dahlia to the stake.

Snails enjoy snacking on dahlias, so as soon as new growth appears, apply non-toxic snail bait, such as Sluggo or Escargo. Gophers also find the tubers tasty, so plan to monitor for evidence of gopher activity, and have traps ready.

Enjoy your garden!

Fruit Trees in the Garden

Posted on January 5, 2013 by tomkarwin

The New Year marks the season for planting bare root roses and fruit trees. What inspires you to add a fruit tree to your garden? Perhaps you have an excellent location for a tree, plus the need for a visual feature. Or, you have fond memories of fruit tree blossoms in the spring, and want to recreate the scene. Or, best of all, you would enjoy eating a favorite fruit from a tree in your own garden.

These are all good reasons for visiting your local garden center to choose a bare root fruit tree for the New Year. Dwarf varieties are readily available, so just about all gardens will have enough space for a new tree.

Preparations begin with site selection. As the first consideration, the site should have good exposure to sunlight, with eight hours per day being preferred.

Also, consider the appearance of the tree as a feature in the landscape. Visualize it as a full-grown specimen from all angles to confirm that it will always be an asset and not obstruct a viewshed or a pathway. There should be easy access for cultivating and harvesting,

When space is limited, consider an espaliered tree. A side yard with southern exposure could be a great location for an espaliered tree.

The step is choosing the particular fruit for your garden, based on personal preferences. As with many other plants, the Monterey Bay area provides a fine climate for a wide range of fruit trees.

A first priority should be to select a fruit that you will enjoy eating, but as with other garden choices, consider unfamiliar varieties that are not commonly available.

An important issue is the tree’s chill requirement, which is measured by the number of hours of temperatures below forty-five degrees. Apple and pear trees, for example, need more chill hours than peach trees, and fig trees require only a few hours. Garden centers will offer only trees that are suitable for growing in the local area, while mail order nurseries will list trees for all areas.

For more information:

Seminar: All About Fruit Trees, Saturday, February 16, 10:00 – 11:00, Griggs Nursery, 9220 Carmel Valley Road.

Short Course: From Planting to Harvest, February 8–10, UCSC Farm and Garden. For information, visit Brown Paper Tickets.

Book: Fruit Trees in Small Spaces: Abundant Harvests from Your Own Backyard, by Colby Eirman (Timber Press, 2012)

Garden Center. The McShane’s Nursery website offers a detailed list of available trees and other related information.

Non-profit Organization: The California Rare Fruit Growers provides extensive advice on fruit tree selection and cultivation.

Planting a bare-root fruit tree would be a positive step into the New Year, and the beginning of years to enjoy future harvests in your garden.

For details on chill requirements for various fruit trees…and much more…visit the University of California website, The California Backyard Orchard.

What is Blooming Now

Posted on December 29, 2012 by tomkarwin

If today’s walk through your garden yields satisfaction, congratulations!

If it tilts toward disappointment, a good time for seasonal planting would be now.

Many plants need a dormant period to prepare for the spring, but many other plants will bloom while most are dormant. We can’t turn winter into spring, but with a bit of planning we can enjoy color in the garden at any time of the year.

The moderate climate of the Monterey Bay area supports year-round color possibilities that are elusive or non-existent in many other areas.

Here are examples from my garden.

Salvias originate from several parts of the world, and some species from Mexico are in bloom now.

S. wagneriana (Wagner Sage) stands as one of my favorite blossoms, with pink corolla and white calyx. This large shrub does best in partial shade, and tends to sprawl in full shade.

S. karwinskii (Karwinski’s Sage), another large plant, displays pink-coral and green blooms from fall to spring.

S. holwayi (Holway’s Sage), our third example, grows only about three feet high, but spreads to cover an increasingly large area. Its small blooms are red and purple, and prolific.

Aloe arborescens (Torch Aloe) produces numerous vibrant red-orange inflorescences (called racemes) about eight-to-ten inches long. The plant grows easily and can rise to nine feet tall. In South Africa, where it is endemic, it is called called Krantz Aloe. The Afrikaner word ‘krantz’ means a “rocky ridge” or “cliff,” indicating its natural habitat, but it thrives in deep fertile soil.

Helleborus argutifolius (Corsican Hellebore) comes from the Mediterranean islands of Corsica and Sardinia. It grows in sun or shade and produces many seedlings that germinate readily. (I have many plants in a growing swath.) It grows to four feet tall and wide, and produces many pale green flowers from late December to March. After flowering, it can be cut to the ground to stimulate a new cycle of growth.

Daphne odora “Aureo-marginata” (Winter Daphne), which comes from China and Japan, is appreciated for its evergreen, gold-edged foliage, and prized for its beautiful rosy-pink flower buds that open to white, sweetly fragrant flowers in winter and early spring. The flowers grow on the stems, so they are not useful in arrangements, but can be brought indoors to float in water.

Edgeworthia chrysantha (Chinese Paper Bush) is a relative of the Daphne odora (both from the family Thymelaeaceae) and another sweetly fragrant winter bloomer. To be quite honest, both the Daphne and the Edgeworthia in my garden are in bud at the moment, but they will be in flower in January through March.

It is always a pleasure to have flowers in winter. Still, many conifers and succulents provide foliage with much visual appeal.

Enjoy your winter garden.

Several garden writers have listed plants that bloom in each season of the year. One of the better books is The Perennial Garden: Color Harmonies through the Seasons, by Jeff Cox and Marilyn Cox (Rodale Books, 1992).

A book that I refer to often for various purposes is The California Gardener’s Book of Lists, by Catherine Yronwode, with Eileen Smith (Taylor Publishing, 1998). Among its other treasures are lists of “Perennials that Bloom in Winter” and “Shrubs That Provide Winter Interest.”

Growing Gorgeous Geophytes

Posted on September 15, 2012 by tomkarwin

The fall season invites gardeners to plant bulbs to blossom in the spring and create bright swaths of color for the new gardening year.

Right now is an excellent time to design bulb bed(s) and select spring bulbs for the garden. There is a lot to consider.

One strategy is to favor the most familiar bulbs, choosing either old favorites or recent introductions. The most popular bulbs include Daffodils (Narcissus), Tulips (Tulipa), Hyacinths (Hyacinthus) and Dutch Crocuses (Crocus vernus). Garden centers offer many varieties of these plants: the long popularity of daffodils and tulips in particular has motivated hybridizers to develop a range of colors and interesting forms.

The next most familiar bulbous plants include Lilies of the Valley (Convallaria, from rhizomes), Spanish Bluebells (Scillas), Grecian Windflowers (Anemones, from tubers), Snowdrops (Galanthus), Dwarf Irises (Iris reticulata, from bulbs), and Grape Hyacinths (Muscari). There are many appealing options within these genera, as well.

Adventuresome gardeners can explore a long list of less familiar bulbs, each of which brings unique characteristics. Visit my website, ongardening.com, for links to additional options.

A different group of geophytes are summer-bloomers. This group includes Gladioli, Calla Lilies, Dahlias, Tuberous Begonias, and Crocosmias. They are planted in the early spring about the same time we plant tomato seedlings.

Other geophytes we enjoy are fall-bloomers, which are planted in the late summer: Autumn Crocus, Winter Daffodil, Guernsey Lily, Saffron Crocus, and some species of Snowdrops.

With planning, you could enjoy glamorous geophytes during much of the gardening year.

Some spring-blooming bulbs need a chilling period to bloom their best. Winter in the Monterey Bay area rarely provides a chill that is long enough and cold enough for these plants, so schedule six weeks of cold storage. The kitchen refrigerator will suffice except for larger projects, when gardeners will appreciate the luxury of a second refrigerator. Consider organizing a chilling co-op with gardening friends.

Many mail order bulb sellers offer pre-chilled bulbs to be shipped at the right time for local planting. A welcome service!

Here are the basics of planting bulbs. Choose a site that receives all-day sun, and drains well. Select larger bulbs of the preferred genus. Plant the bulbs at a depth that is about three times the bulb’s diameter, and take care to position them with the pointed end up.

Bulbs can be planted very close together and may be arranged in either formal or informal patterns. Fertilizers are not required, but a small amount of bone meal in the planting hole could help. For clay soil, add compost to improve drainage. Water to settle the soil then let the seasonal rains take over.

Prepare now for a spectacular spring.

More.

Information About Uncommon Geophytes

North Carolina State University

The Plant Expert

Pacific Bulb Society Wiki

Mail-order Suppliers of Uncommon Geophytes

Brent and Beck’s Bulbs

Deciding on Dahlias

Posted on August 11, 2012 by tomkarwin

The dahlia counts among our most satisfying and popular ornamental plants. It grows easily, blooms over a long period, reproduces generously and returns anew, year after year.

Spanish explorers brought the dahlia from Mexico and Guatemala to Spain in the early 1800s, where it became popular throughout Europe. The arrival in 1872 of a new variety, Dahlia juarezii, inspired hybridizers to create the wide range of dahlias from which gardeners can choose today.

The dahlia-growing year has three phases: selecting the plants, planting the tubers, and enjoying the blossoms. The planting season begins after the last frost (after April 1^stfor the Monterey Bay area, conservatively) and ends mid-June (earlier is better). The Monterey Bay Dahlia Society schedules its annual sale in early April.

The bloom period begins in mid- to late-July, depending on the cultivar, and continues until frost. In this area, we can leave tubers in the ground to sprout in the spring.

The first phase of the gardener’s annual dahlia-growing plan is to select plants to add to the garden. We might indulge occasionally in impulsive gardening, but planning works!

The time to select plants is now. This may be the dahlia’s greatest challenge. The American Dahlia Society recognizes eighteen forms of the dahlia, fifteen colors or color combinations, and nine blossom size categories. In addition, for each form, hybridizers have produced —and continue to produce—many unique cultivars.

Planning for specific plants also involves choosing a suitable location, which for dahlias means full sun and good drainage. In addition, site selection should consider how the size and color of dahlias would relate to nearby plants. The gardener might visualize a “garden vignette,” a setting in which dahlias would complement other new or existing plants.

There are no compelling rules here, except the tried-and-true “tall plants in back” idea, which concerns only visibility. Many combinations of color and form can be successful, so the individual gardener’s creative and aesthetic senses are most important.

After deciding on a spot for dahlias in your garden, you will have until planting time for site preparation: removing or relocating existing plants, amending the soil, etc.

To choose which dahlias to grow in your garden, know the options. An excellent opportunity for this planning is the Monterey Bay Dahlia Society’s 2012 Annual Dahlia Show, which runs from 1:00 to 5:00 on Saturday, August 25th and from 11:00 to 4:00 on Sunday, August 26th. It will be at Soquel High School, 410 Old San Jose Rd., Soquel, CA. At this free event, local gardeners display hundreds of types of dahlias and compete for awards. Knowledgeable volunteers will offer growing tips and answer questions. Dahlia blooms and plants will be available for purchase as well.

The following information is from the American Dahlia Society.

Blossom Size

AA -(Giant), over 10 inches in diameter
A -(Large), over 8 to 10 inches in diameter
B -(Medium), over 6 to 8 inches in diameter
BB -(Small), over 4 to 6 inches in diameter
M -(Miniature), up to 4 inches in diameter
BA -(Ball), over 3.5 inches in diameter
MB -(Miniature Ball), over 2 to 3.5 inches in diameter
P -(Pompon), up to 2 inches in diameter
MS -(Mignon Single), up to 2 inches in diameter

Form

Formal Decorative – Ray florets (petals) are flat, partially revolute (petal edges roll back), or partially involute (petal edges roll forward). The petals are uniform and regularly arranged, tending to curve toward the stem.
Informal Decorative – Ray florets are twisted, or curled, or wavy creating an affect that the petals are not flat. The petals may be partially revolute with their arrangement appearing irregular.
Semi-Cactus – The ray florets are broad at the base, straight, incurved or recurved and the ray florets revolute for up to one half of their length.
Straight Cactus – The ray florets revolute for more that one half of their length; they also may be pointed, straight, or recurved, radiating in all directions from the center of the flower head.
Incurved Cactus – These dahlias also have ray florets that are curved for more than one half of the length but the pointed petals have a pronounced curvature toward the center of the flower head.
Laciniated – The split or laciniation should be in proportion to the ray floret length. There should be an overall twisting in the area of the split involute or revolute ray florets, to give an overall fringed effect.
Ball – fully double flowers, ball shaped or slightly flattened at the face, and the ray florets are blunt, rounded, or indented, involute for most of their length, fully involute for about one half their length, and normally displayed in a spiral arrangement.
Miniature Ball – Same form as ball dahlia , differing only in size.
Pompon – Fully double flowers similar to ball dahlias but more globular and smaller in size; also, the ray florets involute for their whole length and fully involute for more than half of their length.
Stellar – Fully double, breaking gradually from immature florets to fully developed outer florets. The outer florets should be narrow and involute with a slight recurve to the stem. The less mature florets should possess the same narrow and partially involute characteristic. The depth of the stellar dahlia type should be from one half to two thirds the diameter of the bloom, the greater depth being the ideal.
Waterlily – Fully double and symmetrical blooms with a side view that appears to be flat or saucer shaped. The ray florets are openly faced giving the bloom a delicate appearance. The center is closed and dome shaped breaking gradually to four to seven rows of fully developed outer ray florets which are also broad and slightly cupped.
Peony – An open centered dahlia with two or more rows of ray florets surrounding the disc flowers (small tubular florets which make up the central part of the flower. Each has a pistil and stamens but generally no other conspicuous flower parts). Ray florets adjacent to the disc flowers may be smaller, twisted, and/or curled.
Anemone – Dahlias with one or more rows of ray florets surrounding a center of elongated tubular disc florets. These disc florets should be fully developed and present a domed, pincushion appearance.
Collarette – An opened faced dahlia with a single row of uniform evenly spaced compound ray florets in a flat plane surrounding the disc flowers. The petaloids that surround the disc are less than one-half the length of the ray florets.
Single – An open faced dahlia with a single row of uniform evenly spaced ray florets in a flat plane surrounding the disc flowers.
Mignon Single – Same as single, differing only in size.
Orchid – An open centered dahlia with a single row of evenly spaced ray florets in a flat plane surrounding the disc flowers. The ray florets are involute for 2/3s or more of their length and fully involute for at least 1/3 of their length.
Novelty Open – Dahlias with characteristics differing from the present classifications. These dahlias will have a disc center.
Novelty Fully Double – Dahlias with characteristics differing from the present classifications. These varieties will have a fully double center.

Color

1) White

2) Yellow

3) Orange

4) Pink

5) Dark Pink

6) Red

7) Dark Red

8) Lavender

9) Purple

10) Light Blend – a blending of the lighter tints and tones of pink, yellow,lavender, and other pastels

11) Bronze

12) Flame

13) Dark Blend

14) Variegated – where two or more colors appear on the face of the bloom either in dots, splashes, stripes on narrow lines

15) Bicolor – blooms with two distinctly clear and sharply separated color