The Tulsa County OSU Extension Service offers the following horticulture tips for each month. For more information contact the OSU Master Gardeners at 918.746.3701 or browse through the Horticulture or Gardening sections of our website.

January July
February August
March September
April October
May November
June December

January

PLANTING AND TRANSPLANTING:

  • Trees and shrubs in containers and ball and burlap or bare-root fruit and nut trees.
  • Plan now for garden design changes or renovations prior to the spring rush.
  • Vegetable and flower transplants should be started indoors from seed during this month.

PRUNING:

  • Remove dead limbs or tissue from trees and shrubs due to ice or winter storm damage.
  • Prune "bleeder trees" such as Elm, birch, Willow, Maple, and Pines during the month.

INSECT AND DISEASE LOOKOUT:

  • Apply dormant oil sprays to scale prone plants and for control of other over-wintering insects. Do not apply to evergreen trees.
  • Watch for Entomosporium leaf spot on Photinia plantings. Circular, reddish spots indicate this fungal disease. Apply fungicide as needed and avoid wetting the foliage with irrigation water.

GENERAL INFORMATION:

  • Check houseplants indoors to maintain proper watering level. Dry, low-humidity conditions from indoor heating can cause problems. Mist plants periodically with clean water or set up a humidifier near these tropical plants.
  • Have any lawn mower or related equipment repairs taken care of now prior to the busy Spring season. If you wait until spring you may go without your lawn equipment for weeks.

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February

PLANTING AND TRANSPLANTING:

  • Containerized, balled and burlap, or bare-root trees, shrubs, and fruit and nut trees.
  • Asparagus, beets, broccoli, cabbage, carrots, kale, leeks, lettuce, mustard, onions, parsley, radishes, spinach, swiss chard and turnips.

FERTILIZERS:

Base fertility needs on a soil analysis. The Tulsa County OSU Extension office offers soil testing for a $10 fee. When used as a blueprint for growing, the results are invaluable. For maximum growing effectiveness, lawns, gardens, and landscape soil should be tested every two or three years.

INSECT AND DISEASE LOOKOUT:

  • Watch for Bark Aphid populations on Oaks, Yaupon Hollies and others. Heavy infestations can injure or kill entire branches.
  • There is still time for dormant oil applications on scale prone plants.

GENERAL INFORMATION:

  • Pull back mulch around emerging spring bulb plantings.
  • Check now with your local Garden Center for new plant and product selections coming this spring.

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March

PLANTING AND TRANSPLANTING:

  • Plant containerized trees and shrubs. Local nurseries will have excellent selections for the spring season.
  • Complete planting of bare-root trees and shrubs this month.
  • Complete transplanting of native plants, and trees and shrubs requiring moving within your landscape.
  • Divide and transplant summer and fall flowering perennials.

FERTILIZERS:

  • Fertilize cool-season lawns with one pound of nitrogen per 1,000 square feet. Have your soil tested if it has been two years or longer since the last test. Contact the Tulsa County Extension Office at 746.3707 for information on soil testing.
  • Wait until April to feed any warm-season lawn such as Bermuda or Zoysia.

PRUNING:

  • Prune spring-flowering shrubs and vines after they have completed blooming. Examples include forsythia, azaleas, lilacs and others.
  • Complete shade tree pruning as needed. Never top a shade tree!

INSECT, DISEASE AND WEED CONTROL:

  • Apply pre-emergent herbicides to warm-season lawns this month. A good rule of thumb is apply the pre-emergent when the Forsythias are in bloom. Local garden centers have large selections of pre-emergent weed controls available for homeowner application.
    Professional lawn care companies also offer custom applications on a timely basis.
  • Control broadleaf weeds in cool-season turf areas with a carefully applied broadleaf weed killer.

GENERAL INFORMATION:

  • Plan now for landscape design changes or renovations to be made this spring.
  • Aerate cool-season lawns this month. Aeration improves air, water, and nutrient movement to the root-zone of turf and relieves compaction of soil.
  • Contact landscape contractors now for jobs to be completed in spring. Tulsa County
    landscape professionals can help you avoid making costly mistakes in the landscape.

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April

PLANTING AND TRANSPLANTING:

  • Plant containerized trees, shrubs, and groundcovers to enhance your landscape.
  • Begin warm-season lawn planting this month.
  • Plan beds and plant warm-season annuals for color in your landscape all summer. When planting, use masses of single colors together to create a dramatic effect.
  • In sunny areas Marigolds, Firebush, Copper plant, Petunias, Geraniums, Portulauca, Lantana and Verbena work well.
  • Coleus, Caladiums, Lobelia, Impatients and begonias all work well in shady areas.
    Local garden centers should have a supply of healthy, colorful plants for spring planting.
  • Complete transplanting of fall and summer flowering perennials early this month.

FERTILIZERS:

  • Begin warm-season turf fertilization this month. Apply one pound of nitrogen per 1,000 square feet in April, May, June, August and September.
  • The same fertilizer schedule is fine for most trees, shrubs, vines and groundcovers in your landscape.
  • Apply zinc to pecan tree foliage as the first leaves begin to develop.

PRUNING:

  • Remove winter-damaged tissue on plants.
  • Cut back dead foliage on ornamental grasses and groundcovers as needed.
  • Prune spring flowering plants after blooming.

INSECT, DISEASE AND WEED CONTROL:

  • Watch for powdery mildew on roses, crape myrtle, and lilacs. Space and prune plants to increase air flow. Apply a fungicide such as Funginex if needed.
  • Control tent caterpillars on fruit trees and other plants with a Bacillus thuringiensis (B.t.) insecticide. These biological controls are only harmful to certain leaf feeding caterpillars.
  • Circular, dead areas of grass in your bermuda lawn may indicate spring dead spot.
    Do not spray fungicides, but manage damaged areas correctly to minimize the problem.
  • Brown areas of turf with little to no root-system indicates a potential grub worm problem. If you find three or more grubs per square foot of damage then treat with an appropriate insecticide in August.

GENERAL INFORMATION:

  • Wait until all chance of freeze damage has passed before installing warm-season annuals for color.
  • Correctly identify plant problems. Many problems are caused by environmental stress factors as opposed to an actual disease. Contact the Tulsa County OSU Extension Master Gardeners at 746.3701 or a nursery professional for help in correctly diagnosing plant problems.

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May

PLANTING:

  • Install containerized trees, shrubs, vines, and groundcovers to increase your property value and conserve energy.
  • Plant warm-season annuals and perennials to beautify your landscape.
  • Use colorful bedding plants in containers, hanging baskets, and on patios and decks.
    You can enjoy plants this way even if you live in an apartment or zero-lot line home.
  • Seed warm-season grasses from now until later June.

FERTILIZERS:

  • Fertilize warm-season lawns with a quality slow-release nitrogen lawn food.
  • Use timed release fertilizers like Osmocote in new beds and containers used for growing annuals.
  • Gradually increase the frequency of fertilizer applied to houseplants as days get longer.

INSECT, DISEASE, AND WEED CONTROL:

  • Apply the first fungicide treatment for needle blight in pines that are infected.
  • Treat Elm Leaf beetle larvae in late May.
  • Watch for and control bagworms on evergreens such as juniper and arborvitae.
  • Be alert for lace bugs on sycamore, pyracantha, and azaleas. Treat as needed.
  • Treat broadleaf weeds in established turf with a carefully applied broadleaf herbicide.

GENERAL INFORMATION:

  • Use mulch in your garden and landscape beds to conserve moisture, reduce weed populations, moderate soil temperature, and serve as an attractive groundcover.

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June

PLANTING:

  • Still time to plant annual bedding plants for color all summer long.
  • Install container grown trees, shrubs, vines, and groundcovers.
  • Establish warm-season lawns from seed, sod, plugs, and sprigs.

FERTILIZERS:

  • Apply one pound of nitrogen per 1,000 square feet to Bermuda lawns.
  • Feed houseplants and container grown bedding plants with water-soluble plant food or incorporate a timed-release fertilizer.

PRUNING:

  • Remove sucker growth and unwanted limbs on young shade trees.
  • Trim back hedges and evergreen shrubs as needed to maintain a neat appearance.

INSECT, DISEASE, AND WEED CONTROL:

  • Apply fungicide treatment again for pine needle blight on infected pine trees.
  • Treat bagworms with a B.t. insecticide.
  • Stay alert for spider mite infestations on junipers. These tiny insects are worse during the hottest, driest weather of summer. Watch for foliage turning pale, yellowish, and brown.
  • Two-lined spittle bugs are a new pest of many Hollies. Two control treatments in June are normally needed for infested plant material. See your local nursery professional or pest control professional for treatment options.
  • Treat Summer grassy weeds in established lawns with MSMA or DSMA weed control products.
  • Circular, browning areas of turf within cool-season lawns may indicate brown patch disease. Treat with an appropriate fungicide.
  • Dollar Spot disease in turf can be seen in mid-May and June. Avoid applying too much nitrogen to lawns and treat with a fungicide if necessary.

GENERAL INFORMATION:

  • Water lawns deeply, but infrequently to encourage a stronger root system. Apply one inch of water every five to seven days. Avoid frequent, light applications of water and runoff.

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July

PLANTING:

  • Plant container grown trees shrubs and vines. Be careful to monitor plants closely for water needs during this hot time of year.
  • Use high-heat tolerant bedding plants for color such as Lantana, Verbena, Firebush and Copper Plant.

PRUNING:

  • Remove heat damaged tissue on bedding plants to maintain a neat appearance.
  • Trim back Chrysanthemums by mid-July to create a more bushy, compact plant.
  • Remove spent flowers on bedding plants to encourage new bloom production.

INSECT, DISEASE, AND WEED CONTROL:

  • Watch for marginal leaf scorching and lead drop on trees. This is an indication of heat and drought stress and not a problem to actually apply a spray to control.
  • Obscure scale insects become evident in the crawler stage in July and into August on oaks. They are easily controlled with insecticides.
  • Control unwanted Bermuda with one of the newer, grass-only killing weed controls like Vantage.

GENERAL INFORMATION:

  • July can be the hottest and driest month of the season. Watch for signals of drought stress in plants like wilting leaves, leaf margin browning and defoliation.
  • If you go on summer vacation, be sure to have a reliable person check your plants regularly for watering needs.
  • Container grown plants often require watering on a daily basis during summer.

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August

PLANTING:

  • Monitor new plantings daily for water needs. This is our peak of heat and dry weather in Green Country and new plants can easily succumb to the stress.
  • Mulch plants to keep roots cool and moist.
  • Some fall vegetable crops can be planted. See OSU Fact Sheet F-6009 for details.
  • Install container grown plant material at any time of the year. The entire root system is intact and transplantable.
  • Divide and transplant spring blooming perennials such as Day Lillies and Iris.
  • Plant Chrysanthemums for fall color and years of enjoyment. Local nurseries will have excellent supplies of these perennial performers.

FERTILIZERS:

  • Fertilize warm-season lawns if irrigation water is available.
  • Continue to feed warm-season annuals in containers and in-ground with a water-soluble plant food or time-release fertilizer.
  • Use water-soluble plant foods for indoor houseplants and tropicals.

PRUNING:

  • Remove dead limbs or branches in trees and shrubs now while they can still be properly identified before leaf drop.
  • Discontinue dead-heading roses by mid-month to help increase cold-hardiness.

INSECT, DISEASE, AND WEED CONTROL:

  • Rapid death of Scotch or Japanese Pine under extreme drought stress can result from Pine Wilt Nematode attack. No cure at the present time other than using a more resistant plant material.
  • Few disease problems during this dry time of the season unless you tend to over-water and keep plant foliage excessively wet.
  • Water plants in the morning allowing foliage to dry. Wet foliage at night increases disease problems.
  • Apply pre-emergent weed controls to established warm-season lawns late this month.
  • Treat now for grub worms in the lawn. Apply insecticide controls only if you had a grub problem last spring. Control applications made from mid-August to early September will efficiently control these destructive root feeders.

GENERAL INFORMATION:

  • Paying careful attention to watering is critical during this hot and dry period of summer in Green Country.
  • Using mulch and drip irrigation in your landscape beds and garden can drastically reduce water waste and expense.

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September

PLANTING AND TRANSPLANTING:

  • Fall is the ideal time frame for tree planting. Use recommended shade trees for northeastern Oklahoma. The Tulsa County Cooperative Extension office has tree lists available. Local garden centers also have good selections of recommended trees because they know that "Fall is For Planting"!
  • Plant cool-season annuals such as pansies and ornamental kale and cabbage for color all winter in your landscape. Local nurseries and greenhouses will be loaded with these colorful cool-season wonders!
  • Overseed warm-season lawns with rye during this month. Reseed bluegrass, fescue, or rye in shady areas also.
  • Select and purchase spring flowering bulbs now while selections are excellent.

FERTILIZERS:

  • Last fertilizer application on Bermuda lawns for the year.
  • Reduce fertilizer applications to houseplants as days get shorter and light is reduced.

INSECT, DISEASE, AND WEED CONTROL:

  • Apply pre-emergent weed controls by mid-month. Local garden centers have easy-to-apply granular pre-emergent products available. Professional lawn care companies also offer timed, custom applications of pre-emergent weed controls. Do not treat areas you plan to overseed as this will inhibit germination. Also, do not compost grass clippings from pre-emergent treated lawns.
  • Complete treatments for grub control if you had a problem last spring.
  • Watch for insects moving into homes as cooler weather approaches. Treat as needed or hire the services of a pest control operator.

GENERAL INFORMATION:

  • Fall is an excellent time to plant trees and shrubs. See local nurseries for excellent selections of plant material.
  • Mow your lawn at about one inch prior to overseeding for best results. Apply 10 to 20 pounds of rye seed per 1,000 square feet of turf.
  • Perennial Rye has better color, texture, and mowing qualities than Annual Rye.

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October

PLANTING AND TRANSPLANTING:

  • Still an ideal time for tree and shrub planting.
  • Install cool-season color using pansies and other cool-season blooming annuals.
  • Move tender houseplants and tropicals you wish to save indoors prior to any freezing weather conditions.
  • Select trees with fall color attraction now while you can see the intensity of fall foliage coloration. Examples: Chinese Pistache, Ornamental Pears, Red Oak, Sugar Maple and Red Maple among others. Fall color is a genetic trait and within a group of several of the same type of trees we will often see variances in foliage color.
  • Wait until after the first hard freeze to transplant plants that must be moved.

PRUNING:

  • Final opportunity to remove dead limbs in shade trees prior to leaf drop while they can still be identified.
  • Trim foliage and dig tender perennial bulbs like caladiums, elephant ears, and dahlias and store in dry peat or vermiculite in your garage or insulated storage shed.

FERTILIZERS:

  • Fertilize Fescue lawns this month. Apply one pound of nitrogen per 1000 square feet.
  • Reduce concentration and frequency of fertilizer applications to houseplants.

INSECT, DISEASE, AND WEED CONTROL:

  • Treat houseplants for insect infestations prior to moving indoors.
  • Rake and destroy any diseased pine cones or needles form pines which have been infected with Twig Blight.
  • Treat indoors for insect invaders if needed or hire a professional pest control company.
  • Apply a post-emergent broadleaf weed killer to broadleaf lawn weeds if needed.

GENERAL INFORMATION:

  • Clean, repair and winterize lawn equipment at close of this month and store in a secure and protected location.

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November

PLANTING AND TRANSPLANTING:

  • Plant spring flowering bulbs such as Tulips, hyacinth, and daffodils.
  • Plant containerized trees and shrubs.

FERTILIZERS:

  • Fertilize cool-season lawns.
  • Have soil tested if it has been more than two years. Call the Tulsa County Extension office at 746.3701 for more information.

PRUNING:

  • Major tree pruning normally begins in mid-month. Remember; never top a shade tree.

INSECTS, DISEASE, AND WEED CONTROL:

  • Control cool-season weeds like henbit, chickweed and dandelion with a post-emergent herbicide.
  • Apply systemic control products for Pine Tip Moth during this month.
  • Dispose of infected or diseased plant tissue in the landscape.
  • Watch for scale insects on scale prone plants and treat as needed.

GENERAL INFORMATION:

  • Use several inches of mulch beneath plants for winter protection.
  • Plants should not enter the coldest part of winter under drought stress, or freeze damage will be compounded.
  • Disconnect, drain and store garden hoses.

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December

WINTERIZE YOUR LANDSCAPE:

  • Ensure adequate levels of moisture even through the winter months ahead.
  • Plants under the eaves of your home can become quite drought stressed.
  • Water thoroughly all plantings prior to hard, prolonged freezing weather.
  • Water dormant warm-season lawns monthly in the absence of rainfall.

PRUNING:

  • Light shearing of evergreens can yield Christmas time decorations.
  • Remove weakened limbs on trees that could be damaged from ice accumulation.

POINSETTIA AND CHRISTMAS TREE CARE:

  • Keep poinsettias indoors at room temperature in a brightly lighted area. Avoid drafty areas near doors or places near heaters or fireplaces. These are tropical plants.
  • Keep potting soil moist, but not over-watered. Make sure the pot has drain holes. Remove foil wrap to expose drainage holes.
  • Contrary to popular public opinion, Poinsettias are not highly toxic plants, however, the sap within these plants does irritate some individuals eyes and skin. We never know how any one will respond to touching or ingesting a plant. Enjoy the beauty, but do not eat!
  • Make a fresh cut on your cut Christmas tree prior to placing the tree in a sturdy stand capable of holding water. Keep the water level above the cut trunk region at all times. You will be amazed at how much water the tree uptakes the first few days! Preservative solution additives are often available at nurseries and tree lots and can help preserve your tree.
  • Keep trees away from heat and fire sources like heating vents, fireplaces, or furnaces.
    Each year our local Fire Departments respond to home fires caused by improperly managed Christmas trees in the home.
  • Use low-intensity lights for decorating your tree. Do not leave lights on while away from the home or for excessively long periods.
  • Enjoy a peaceful and merry Christmas this year!

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