By Denise Seghesio Levine, U.C. Master Gardener of Napa County
A seed packet of Rainbow Floral Strain Mix of coleus is on my table and that is pretty exciting. Better than a box of mixed chocolates, this non-caloric envelope of a potential rainbow of eye candy is waiting to be sown and nurtured. Living foliage kaleidoscopes will be my winter color project.
Coleus (Plectranthus scutellarioides) is actually a member of the mint and dead nettle family. As I look at the shape and texture of the leaves, I can see the resemblance.
Coleus is considered a shade plant, but many darker colors can handle some sun and some varieties are very happy in bright light. Varieties that like sun are called sun coleus and include Premium Sun Crimson Gold, Lime Delight and Chocolate Symphony.
I recently returned from a trip to Louisiana where coleus in lime green, lemon yellow, flamingo pink and chocolate brown in wonderfully varied heights and shapes tumbled over each other in lush beds. They grew in bright, steamy sunlight throughout most of the day.
I do not know if coleus make it through the entire year in Louisiana, but in Napa Valley, coleus should be grown as an annual or dug up when temperatures get cold and brought inside to grow as a houseplant. In protected areas and some of Napa Valley's banana belts, coleus may survive winter outdoors.
You will get the most vibrant color from coleus that receive morning sun and afternoon shade, but there are coleus choices for most light conditions. While most coleus like shade, too much shade can cause plants to become weak and spindly.
Coleus are easy to propagate from cuttings, but I like the grab-bag surprise of planting from mixed seed and seeing what I get. Coleus seeds need light and warmth to germinate. Sow seeds on top of damp soil or seed starting mix, press them gently into the soil and do not cover.
Place the pots on a heating pad, seed-starting mat or cozy window sill to get them started and keep between 70ºF and 75ºF. When your plants get two real leaves, gently transplant them into their own little pots if they are not in individual cells. As plants develop multiple leaves and branches, pinch them right above a branching junction to shape and stimulate growth. Transplant to larger containers as needed.
When I read reviews from other gardeners who have sown these seeds, it seems that one of the hardest tasks is deciding which seedlings to thin out when all the colors and patterns are so enticing. Planting individual seeds in their own cells eliminates the need to toss fragile thinnings.
Put plants near a sunny window for the winter or plug in grow lights if natural light is scarce. Cut coleus back when they begin to bloom to keep them compact. Leaving flowers depletes the energy of the plant, and besides, the foliage is the tar, not the flowers.
If you want to grow coleus outside, grow them through the winter as houseplants or in the greenhouse, harden them off and gradually get them used to outside temperatures. Transplant when the danger of frost is past and nighttime temperature are in the high 50s and 60s.
Coleus grown outdoors enjoy the same conditions as begonias and impatiens.
Because coleus like water and frequent watering can leach nutrients, feed coleus frequently with a water-soluble fertilizer such as fish emulsion. Follow dilution directions on the bottle. Too much fertilizer will suppress vivid colors so pay attention to how your plants look as you care for them.
Use a free-draining potting or soil mix for containers and plant pots or hanging baskets where coleus will be protected from wind. Coleus branches break easily.
Which brings us back to propagating plants from cuttings. Use a clean knife, pruners or scissors or just break off branches to root for cuttings in clean water or a soilless mixture. If you have a choice, choose cuttings from the top of the plant. Hormonal action is strongest there and your chances of a successful rooting will be increased. When roots have formed, pot up the cuttings and grow indoors or harden to transplant outside.
With coleus, there are just so many choices. Coleus can be upright, trailing or rounded. Leaf texture can be lobed, scalloped, frilled, twisted, elongated or duck footed. With a huge palette of colors from deep burgundy, vivid purple, chocolate brown and neon pink to fluorescent chartreuse, coleus provide you the opportunity to design a bed, pot or garden that ranges from subtle to shocking.
If you decide to try your hand at coleus from seed, you can find Rainbow Floral Strain Mix online at Baker Creek Heirloom Seeds and Swallowtail Garden Seeds.
Workshop: U. C. Master Gardeners of Napa County will hold a workshop on “Toxic and Carnivorous Plants” on Saturday, October 27, from 9:30 a.m. to 11:30 a.m., at the University of California Cooperative Extension, 1710 Soscol Avenue, Napa. Foxglove. Lily-of-the-valley. Wisteria. These common plants and many others are toxiix. Who knew? Sundew. Venus flytrap. Pitcher plant. Carnivorous, or so we've heard. Join the UC Master Gardeners and explore the fascinating properties that plants have to protect themselves and survive in inhospitable places.Online registration (credit card only);Mail-in/Walk-in registration (check only or drop off cash payment).
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. U. C. Master Gardeners of Napa County ( http://ucanr.edu/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.
By Denise Seghesio Levine, U.C. Master Gardener of Napa County
To pinch or not to pinch? That is the question. Pinching is a technique that can shape a plant; increase production of herbs, flowers and fruits; determine the size of blooms and fruit and even keep your garden blooming longer. But pinching is not the answer for every plant. So which plants should you pinch, and how?
Pinching is a form of pruning. You can do it with no other tool than your fingertips and fingernails, although if you have a lot of pinching to do, clean scissors or shears will save your manicure. By “pinching,” I mean actually removing the new tender growth at the end of a stem.
Pinch as close to leaf nodes as possible, being careful not to injure the tiny buds beneath. Each time you remove a main stem, your plant will try to grow two new stems beneath the pinch or cut. This easy technique encourages fullness and also helps keep plant size in check. It forces most plants to grow bushier and fuller rather than concentrating their energy on getting taller.
Basil, tarragon, thyme, sage, scented geraniums and marigolds respond well to pinching. Oregano and thyme do best when pinched or cut back to about half their length. Frequent pinching can keep rosemary and lavender to a manageable size during their spring growth spurt and supply you with lots of herbs for cooking. Cut back woody stems by no more than one-third.
With most herbs, the more you pinch, the more you will have. For a summer-long harvest of Genovese or Thai basil, pinch.
Inspect the base of the leaves where they connect to the stem and you will see new leaves forming in tiny pairs. Pinch right above that point and soon each pair of leaves will turn into a new branch. This practice keeps your plant producing leaves rather than going into flower and seed mode. Remember to feed your culinary herbs and keep them watered so they will work hard for you.
Many flowers benefit from pinching or cutting, rewarding you with armloads of blooms. But it's worth getting to know the few flowers that do not like this treatment because an unwelcome pinch can eliminate your entire harvest for the season. Do not pinch campanula, cockscomb, delphinium, dill, stock, larkspur and most sunflowers.
Do pinch annuals such as coleus, impatiens, salvia, most snapdragons and petunias early in the season to encourage bushing and spreading. Pinching encourages more side branches, which means more flowers and color for your garden or pots.
Always pinch at a node but decide how low to pinch depending on how compact you want the plant to be. Sweet peas will branch into a much fuller plant with pinching. When you are happy with your plants' shape, stop pinching and let them grow.
Zinnias and cosmos are especially generous bloomers if pinched. Pinch early to promote branching, then “pinch” by cutting flowers. The more frequently you pick bouquets, the more flowers you will have for your tables and your friends. It is a beautiful thing.
Each time you pinch a plant, you delay its flowering. The result is a plant with more side shoots but smaller flowers. With chrysanthemums you can decide if you want a few large flowers or many smaller ones. If you prefer dinner plate-size blossoms, remove side shoots and laterals early in the season when they are green and succulent, leaving only the few stems you want to bloom.
You can stagger bloom times with some late-flowering plants like Russian sage, phlox and asters by pinching back half of the plants in your flower bed by about one third. The pinched plants will bloom later, giving you a few more weeks of summer beauty.
Remove peony blossoms when they are finished so the plant can focus energy on next year's blossoms instead of producing seed. Clip foxglove after blooming to have healthy flowers next year or forego pinching them and let them self-seed. You will probably have fewer blossoms next year but potentially more plants.
Refrain from pinching if you want blossoms and seeds for local birds and insects. As a compromise position, let the last, late blooms go to seed, or identify a few plants as your seed producers for pollinators, birds and self-seeding.
Workshop: U. C. Master Gardeners of Napa County will conduct a workshop on “Make Room for Salvias” on Saturday, April 21, from 9:30 a.m. to 11:30 a.m., at the University of California Cooperative Extension office, 1710 Soscol Avenue, Napa. Every gardener should be able to find a salvia just right for that little (or big) space. Salvias are long-lasting, attract butterflies and pollinators and have attractive foliage. Learn how to select and care for these versatile plants.Online registration (credit card only);Mail-in/Walk-in registration (cash or check only)
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. U. C. Master Gardeners of Napa County ( http://ucanr.edu/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.
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Bringing some cheery summer color to your garden is fun and easy. Your favorite nursery, garden center or farmers' market can give you a head start with six-packs and four-inch pots of summer annuals and flowering perennials. Healthy, blooming (or almost-blooming) flowers can change the tone of a porch or deck in a moment.
Pair cool pink and warm coral impatiens with deep blue lobelia to brighten up hanging baskets or pots on shady porches. My summer favorite is a solid bed of cobalt-blue lobelia, providing a cool visual oasis on hot days.
For a different look, azure-blue fountain lobelia produces cascades of flowers on bright green foliage for window boxes and pots. The softer ‘Cambridge Blue' lobelia adds to the palette of summer blues. Bright white and deep cherry-colored lobelia offer even more shade choices for our hot Napa Valley summers.
Choose healthy young plants that are not root-bound and still have some unopened blossoms. With good potting soil, an occasional feeding with diluted fish and kelp emulsion, daily watering and regular deadheading or pinching, lobelia and impatiens will provide color until autumn frost.
Consider colorful but flowerless foliage for shady spots. Light-colored coleus, in all its riotous combinations, grows larger leaves in lightly shaded areas. Leaf color ranges from pink and cerise to salmon and chartreuse. Plant a single coleus in a pot for living art, a whole bed in one dramatic leaf color combination, or a chaotic yet harmonious mix of many varieties.
This year I am experimenting with climbing vines. Climbing Black-eyed Susan (Thunbergia alata) has blossoms like regular bushy Black-eyed Susan but grows five to six feet, quickly covering fence posts and pillars. With fuzzy green leaves and bright yellow-orange daisy-like blooms and big black centers, these vines will, I hope, climb up and cover my front-porch pillars. We are dragging the rocking chairs onto the porch and waiting for the show. Another plus: the blossoms are attractive to butterflies and other pollinators.
Another old-fashioned vine I am planting for the first time is cardinal climber (Ipomoea x multifida). This prolific vine can grow up to 20 feet in one season, completely covering a fence or trellis with five-fingered green leaves and deep-throated cardinal-red flowers. My expectation is that cardinal climber will cover a plain fence and tempt our pollinator friends.
In large or small plantings, white, lavender or pink alyssum will soften and blend areas of color while its sweet honey scent attracts bees and other pollinators. Pair velvety deep-purple petunias with knee-high yellow, orange and red butterfly cosmos for a cheerful porch view or walk.
Carnations, Sweet William and the old-fashioned plants known as pinks, all members of the Dianthus family, can be transplanted now for fragrant cut flowers later. You can also sow or transplant sunflowers (Helianthus annuus) this month. They range from knee high to as tall as an elephant's eye, so you have plenty of choice.
If you have a little space and more time, sow seeds of some flowers now, then again in a month or so. This staggered sowing will produce blooms from early summer until the first frost. In a sunny patch, weeded and watered, try some cheery cosmos or warm-toned marigolds (Tagetes). The ethereal blue love-in-a-mist (Nigella) is also a speedy grower; sow it successively to extend the bloom time. Enjoy the whimsical flowers, then the papery pods and flavorful seeds.
For hot, dry areas, four o'clocks (Mirabilis jalapa) are amazing. Also called marvel of Peru, four o'clocks have large, black bead seeds and bright blossoms in deep pink, sunny yellow, snowy white and carnival stripes. These two- to three-foot plants can survive in the cracks between concrete if they get off to a strong start with spring rains or an attentive hose. Four o'clocks hit their stride in the late afternoon and evening, when their distinctive fragrance wafts through the garden.
Zinnias (Zinnia elegans) win for splashy summer color and endless color choices. Tiny ‘Thumbelina' zinnias in soft pink, yellow and orange are perfect for small pots and pathway borders. Consider ‘Moulin Rouge', a selection of three different tall reds; the popular chartreuse-green ‘Envy';' or the mixed circus colors of ‘Cut and Come Again'. And here's the wonderful thing about zinnias and so many summer flowers: the more blossoms you cut, the more they will grow.
Workshops: U. C. Master Gardeners of Napa County will conduct a workshop on “Home Composting” at American Canyon Senior Center, 2185 Elliott Drive, on Wednesday, May 18, from 6:30 p.m. to 8:30 p.m. Learn the basics of backyard composting and how to turn your yard waste and kitchen scraps into a rich soil amendment or mulch. Learn about tools, techniques and bin types. Register online at www.cityofnapa.org/compost. Or pick up a registration form at the Master Gardeners' office (address below). No phone registration. Directions will be sent when your registration is complete.
U. C. Master Gardeners of Napa County will conduct a workshop on “Growing Ornamentals and Flowers” on Saturday, May 21, from 10 a.m. to noon, at Mid-City Nursery, 3635 Broadway, American Canyon. Learn about the maintenance and care of ornamentals. Master Gardeners will discuss hydrozoning, how to plant for seasonal color year round, and how to encourage pollinators in your garden. On-line registration (credit card only);
Mail-in/Walk-in registration (cash or check only).
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. U. C. Master Gardeners of Napa County ( http://ucanr.edu/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.