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The Gardener’s Dirt February 2009

February 2009

 

The Gardener's

 Dirt                               

Information you can dig into.

North Carolina State University
College of Agriculture and Life Sciences
North Carolina Cooperative Extension Service
Johnston County Center
2736 NC 210 Highway * Smithfield, NC 27577
919 989-5380  
 
Shawn Banks
Extension Agent
Agriculture—Consumer Horticulture


In this Issue

Feature Article


Spotlight Plant
 

Announcements


Pest Alert


Gardening To-Do
This newsletter offers timely information for your outdoor living spaces
Addressing the most common questions ranging from container gardening,
tree pruning, wildlife management, to fire ant control, insect
identification and lawn establishment.
 



Feature Story Banner

RAISED BEDS

By Patty Brown
Johnston County Extension Master Gardener

Avid gardeners often spend the winter browsing through seed catalogs, considering changes to their landscapes, and otherwise planning for spring. If you have a problem spot in your yard, especially an area with poor drainage, you may want to consider adding a raised bed to your spring landscape plans.

By definition, a raised bed is an area higher than the surrounding soil level. The higher soil level promotes good drainage, which is essential for the health and optimum growth of almost all vegetables (and most other plants, too). Raised beds should be filled with loose, fast-draining soil that is rich in organic matter and deep enough (generally 8-12”) for plants to develop healthy root systems. Loose, well-drained soil isn’t waterlogged by heavy rains and so doesn’t suffocate plants’ roots. In addition, because air circulates more freely in looser soil, the soil in raised beds warms earlier in the spring, which can lengthen the growing season a bit. Raised beds can be cultivated to provide an increased yield (see Intensive Vegetable Gardening in the Sources section) and have the potential to be an attractive design element in the landscape. Because they don’t require quite so much bending as ground-level plantings, they can also be somewhat easier to maintain and easier on our backs!

Below are guidelines to keep in mind when planning for a raised bed and construction tips.

Location

  • Choose a sunny spot — For most vegetables and flowers, choose a location that gets at least 6 hours of sun daily.
  • Proximity to water and kitchen — Locate the bed near a source of water to provide irrigation. (Soil in a raised bed tends to dry out faster than that at ground level.) It’s helpful to place beds for vegetables and/or herbs near the kitchen, if possible, or at least in a visible and easily accessible spot. This helps ensure that plants aren’t overlooked and makes it easier to harvest at just the right time.

Construction

  • Size and shape — Raised beds can be any shape and size, although square or rectangular beds are often used for vegetables. A height of at least 8-12” deep is recommended. Consider keeping the width of the bed narrow enough so that you can reach across it for planting and weeding; a 4’ wide bed meets these specifications. For free-form beds, try outlining the shape with a garden hose, which can be easily adjusted until the desired result is achieved. Once the bed shape and location is determined, remove all weeds, grass and roots from the area.
  • Materials —To hold the soil in place, raised beds can be framed by materials such as wood, rocks, bricks or cinderblocks. Borderless beds can be formed by raking soil into mounds, then sloping and tamping down the sides of the bed to prevent soil erosion.

To create a simple 4’ x 8’ by 8” high bed with a wood border, you can purchase three 8’-long 2” x 8” boards. Cut one board in half so that you have two 4’-long lengths for the ends of the bed. Use the other two boards for the sides of the bed. Number 12 or 16 common galvanized nails (twisted or ring-shank for better grip) can be used to nail the boards together. To keep the nails from splitting the boards, drill starter holes into the wood before nailing.

  • Bed and soil preparation — If the garden soil is not deep, you can double dig the bed. To do this, remove the top 9-12” of the soil from a small section of the bed and set it aside. Insert a spade or spading fork into the soil and break up the compacted layers. Repeat for the remainder of the bed.

Mix the topsoil that was removed with organic material such as compost or manure. Additional soil can be purchased (or obtained from nearby areas) to fill the bed and should be amended as above. The finished soil mixture should be at least 1/3 organic material. Sand can be added to improve porosity.

Once the bed area is ready, rake the prepared soil into the center of the bed area. If you’re using a frame, install the frame around it. Spread the soil inside the frame until it is 1-2” from the top edge. If you’re not using a border, slope the edges of the bed and tamp them down.

Water the bed, let the soil settle for a few days, then plant.

About using wood to border your raised bed  —

  • Experts recommend that creosote-treated railroad ties not be used as a border. Creosote from these ties can leach into the soil for several years and release vapors even longer. Young seedlings can be killed if planted within 6-10” of newly treated railroad ties.
  • Pressure-treated wood containing chromated copper arsenate (CCA) is now banned for most residential uses. For treating lumber used in the home and garden, the Environmental Protection Agency (EPA) has approved new chemical compounds that do not contain arsenic. When purchasing new lumber, check the tags stapled to the ends of the boards to determine the type of preservative being used and follow all recommendations for safe handling.
  • If you prefer to use untreated wood, rot resistant species such as redwood or cedar are suggested. Using synthetic lumber made from recycled plastic is another option.

Sources:
Gardening Note #11, Making Raised Beds, Cumberland County Master Gardeners
https://www.ces.ncsu.edu/cumberland/hotline/gardenincumb/gardennote11.html

Intensive Vegetable Gardening, NC State University College of Agriculture and Life Sciences, Cooperative Extension, Horticultural Science
https://www.ces.ncsu.edu/depts/hort/consumer/quickref/vegetable/intensive_veg_gardening.html

New generation of pressure-treated wood is safer for home use, Oregon State University Extension Service,
http://extension.oregonstate.edu/news/story.php?S_No=989&storyType=garde

Ortho’s Complete Guide to Successful Gardening, © 1983, Chevron Chemical Company.

The Complete Book of Practical Gardening, Peter McHoy with Susan Berry and Steve Bradley, © Arness Publishing Limited, 1997, 2001.

 Spotlight Plant banner

 

Red Heleborus in flower

Red Heleborus in flower

Helleborus orientalis

Lenten Rose

We were introduced to the Lenten Rose at a snowy birthday celebration one icy January.  The table flowers were Lenten Roses from the host’s yard.  Very beautiful!

Helleborus orientalis, known as Christmas or Lenten Rose, originated in the Alps. The Lenten Rose is not related to the Rose family, but the Buttercup family.  This low growing perennial will reach heights of 18 to 24 inches tall and wide, is very hardy, thriving in the shade or partial shade. Plants prefer a moist, rich organic, well-drained soil.  One advantage is, they are deer resistant.

The leathery leaves are deep green and often hide the buds.  Lovely flowers in endless colors and color combinations of pure white to deep plum are available.  Some varieties have combinations of colors on the same plant.  They bloom in the winter, and blooming in the snow was quite spectacular!

Lenten Rose is certain to be a wonderful addition to the garden.  It is very easy to grow and the foliage makes an excellent ground cover.  The entire plant is poisonous if eaten, so caution is in order with children, pets and adults.
 

Helleborus in the garden


Heleborus in the garden.
Picture by Michelle Wallace.
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Hand holding clipboard          Announcements banner heading            Hand holding clipboard

Tree Pruning Workshop Feb. 7, 10:00am, Johnston County
Agriculture Center, 2736 NC highway 210, Smithfield.  We will be
pleased to have two representatives from the Forest Service here to
teach us how to properly prune dormant shade trees.  After a short
class on the how-to's there will be some time to practice on some of
the trees in the landscape at the Johnston County Agriculture Center. 
For more information contact Shawn Banks at 989-5380.

Grapevine Pruning Demonstration Feb. 21, 10:00am, Hinnant Family Vineyard, 826 Pine Level-Micro Rd, Pine Level. For more information on this class visit http://johnston.ces.ncsu.edu/content/Grapevine_Pruning or contact Shawn Banks at 989-5380..

Fruit Tree Pruning Demonstration March 7, 10:00 am, Central Crops Research Station, 13223 Us Business 70 West, Clayton.  For more information on this class visit http://johnston.ces.ncsu.edu/content/FruitTree-Training or contact Shawn Banks at 989-5380.

2009 Tree and Shrub Sale.  The Johnston County Master Gardeners are holding their annual Tree and Shrub sale.  The list of plants and order form is available as a pdf by clicking this link .  This year there are several plants that are newer plants to the landscape trade.

2nd Annual Film Feastival Feb. 7, 2:00 – 4:00pm, Meredith College Kresge Auditorium.  This year the emphasis is on Community Gardens and local food.  Learn more by visiting their web site at http://www.evite.com/app/publicUrl/QNZWFGMHYPBVNIBRLLIO/filmfeastival

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 Insect Investigator banner  Spider mite damage on a leaf

Southern Red Mite

Tetranychidae, PROSTIGMATA

 

 Spider mite life stages
Southern red mite is a dark red, cool weather mite. They are more closely related to spiders than insects.  With their eight legs spread out they would just cover the period at the end of this sentence. Southern red mites are found in the eastern United States and California and prefer azaleas, hollies and camellias but they have been recorded from a number of shrubs and herbs.

Southern red mites feed on the lower leaf surface, causing the mesophyll (the soft tissue inside a leaf, between the lower epidermis and the upper) to collapse.  Infested leaves turn gray or brown and may fall prematurely.  Heavily infested shrubs may die.

Southern red mites over winter as eggs glued to the lower leaf surface. If the winter is mild, all stages of this mite may survive. As the weather moderates in late winter, southern red mite numbers increase. Most of the feeding damage occurs in early spring. When populations of predaceous insects and mites are active in summer, southern red mites dwindle away so that only the eggs survive in hot weather. If the summer is mild, all stages of this mite may survive. As temperatures cool in autumn, mite populations build up again.

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 Gardening to-do Banner

Lawn Care
  • Cool season grasses should be fertilized mid-month.  If a
    soil sample has not been taken, use a fertilizer of at least 30% slow
    release Nitrogen at the rate of 1 pound of nitrogen per 1000 square
    feet. 
  • Crabgrass usually will start to germinate about the
    same time the Forsythia blooms.  If you have had problems with
    crabgrass in the past, then you may want to apply crabgrass preventer
    when the Forsythia blooms.  
  • Wild Garlic in lawnPulling
    wild onion/wild garlic is the best way to get rid of these pesky bulbs,
    but make sure you get the bulb.  If there are too many to pull, a
    product with 2,4-D works well to help control this weed.  Be sure to
    follow the manufactures directions found on the label.  Complete
    control may take two or more years.  Apply 2,4-D at half the
    recommended rate on centipede lawns otherwise it will damage the grass.
  • For more tips on lawn care visit Turf Files on the internet.
Trees, Shrubs, and Ornamentals
  • Liriope with lavendar flower and variegated leavesCut
    back dormant ornamental grasses before new growth starts to about 10 to
    14 inches above the soil.  Evergreen ornamental grasses (or grass like
    ornamentals) such as Liriope and Mondo Grass should be cut short or
    mowed to remove last year’s unsightly foliage.  If the clumps have
    become too big for the area they can be divided and shared with friends
    or planted in other areas of the yard.
  • Summer blooming shrubs
    bloom on new growth so they can be pruned hard in February to encourage
    new growth and many flowers.  Examples include Abelia, Hibiscus,
    Hydrangea, Beautyberry, Butterfly bush, Althea, Rose of Sharon, and
    bush or Tea Roses.  Shrub Pruning Calendar
  • Spring
    blooming shrubs such as Azaleas, Rhododendrons, Forsythia, Spirea,
    Quince, Weigela, and Climbing Roses bloom on last years growth and
    should not be pruned until after they have flowered.
  • Deciduous trees
    especially those that bloom in the spring should not be pruned this
    time of the year.  Examples being Dogwoods, Red Buds, Maples and
    several others.
  • Four Pansy flowers of different colorsFor many evergreens this is the best time of the year to prune if they haven't been pruned already.  Evergreen Pruning Calendar
  • Summer
    blooming roses can be pruned this time of the year.  Remember not to
    remove more than 1/3 of the growth.  Remove old mulch and leaves from
    around plants, this removes many overwintering fungal spores.  Put down fresh mulch.
  • Bare root roses and trees can be planted this time of the year.  Soak the roots overnight to rehydrate them before planting.
  • Spring
    flowers such as Sweet Williams, Pansy, Viola, Calendula,
    Forget-Me-Nots, English Daisies, Poppy, Alyssum and Dianthus can be
    planted now.  Don't forget to deadhead pansies and fertilize toward the
    end of the month.
Edibles
  • Cauliflower head whiteAsparagus crowns can be planted now through March.
  • Transplant cabbage, broccoli, and cauliflower out into the garden.
  • Strawberry plants can be planted now for spring fruits.
  • Beats, carrots, peas, lettuce, mustard, radish, spinach, irish potatoes, and turnips can be sown outside.
  • Starting
    seeds indoors is easy and economical.  Sometimes it is the only way to
    get the color or variety of the plants you want to grow.  It is not
    necessary to use "grow lights", ordinary florescent tubes will
    usually be enough.  For more information you can read the pamphlet
    "Starting Plants from Seeds", it is on the web at https://www.ces.ncsu.edu/depts/hort/hil/hil-8703.html
  • February and March are good months to prune fruit trees.
  • It is time to start a spray program for peach trees to control the many diseases and insects that attack peaches.
Insects
  • Control overwintering insects such as scale and their eggs by hand picking or using a dormant oil spray (also know as horticultural oil
    ).  Be sure to check for scales before spraying and follow the
    manufactures directions when applying any pesticide.  Do not apply
    dormant oils to broadleaf evergreens when freezing temperatures are
    expected.
  • Cool-weather
    mites are not visible to the naked eye.  Junipers and other needled
    evergreens are a favorite hang out these mites.  If you had some of
    these plants that were an unsightly brown last year, check them with a
    hand held magnifying glass to see if cool season mites are to blame. 
    Horticultural oil or other registered insecticides can improve their
    situation and appearance.
Houseplants
  • Dracena in white potEven
    houseplants need a little rest once in a while, and this is a good time
    to give them a rest.  Keep them watered but give them a break from the
    fertilizer as most houseplants don't do much growing during the short
    days of winter.
  • Turn and prune houseplants regularly to keep them shapely. Pinch back new growth to promote busy plants.
  • While
    this may sound extremely silly, your houseplants will thank you for it.
    When dusting the furniture, also dust the plants. Wipe dust
    from broad-leaf plants at regular intervals using a cloth dampened with
    clean water. If the plant has small leaves, consider placing several in
    the shower to wash the dust off.
  • Keep an eye open for pest on indoor plants.  Most can be treated with insecticidal soaps.

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Need Help

 

 
HELPING PEOPLE PUT KNOWLEDGE TO WORK.

Got Questions? We've got answers!

If you have a gardening issue you would like to see addressed in this
newsletter please let me know I will do what I can to get you the
information you need.  Contact me by e-mail at shawn_banks@ncsu.edu or by phone at (919) 989-5380.

The Johnston County Master Gardener Volunteers are available Monday,
Wednesday, or Friday from 1 to 4 pm to answer questions as well.  They
can also be contacted by phone at (919) 989-5380 or by e-mail at jcemastergardener@gmail.com.


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