Questions and Answers…

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First Light Freeze of the Fall Garden Season!

Most of the Oklahoma City area got a killing freeze last week.  It was a light freeze so it killed many of the unprotected warm season annuals and vegetables and did not bother many hardier plants.  Many of the perennials and more cold tolerant annuals survived the soft freeze and will live on until knocked back by harder freezes to come as the calendar marches towards winter.  It was a hard freeze north and west at places like Woodward and Ponca City but in the metro area we saw mostly 29 to 31 degree temperatures which would often freeze the top growth and outer canopy of foliage but the lower, bottom foliage may have survived on many plants.  Plants under a tree or shrub or larger plant or in a micro climate may have had enough protection to survive the light freeze unprotected and may continue blooming or growing through some milder Indian summer weather until hit by a harder freeze.  Surviving with just a little protection indicates the value of using frost blankets, hot kaps, old sheets, or other light frost protection to extend the fall growing season when we experience light freezes and just a few degrees makes the difference between life and death.

Folks often think outside gardening is over for the year after we experience a killing frost but there are actually many crops we can still plant at this season for immediate and future enjoyment.  For immediate color plant pansies to cheer you up most all winter.  There are literally hundreds of pansy varieties that do great in Oklahoma offering a multitude of colors and bright cheerful faces that display their personality.  Pansies are one of the real highlights of the winter garden in Oklahoma.  Pansies greet you with color and life even on the darkest and most dreary winter days or by poking up through a light cover of snow with yellow, blue, red, pink, purple and countless multicolored flower faces.  Add a little blood meal to the planting holes as you plant them to feed them for the winter.  We are at the tail end of the season to plant tall fescue grass seed if you want to have a green lawn this winter or to establish cover on open soil to prevent blowing and erosion.  These cool grasses will germinate within days and grow throughout the winter until worn down by our heat late next spring.

This is the prime season for planting spring flowering bulbs.  Shop for good firm bulbs of daffodils, crocus, tulips, hyacinths and the dozens of other unique bulb crops to plant now.  They can root in through the winter and be ready to shoot from the ground next spring with a burst of color to announce spring.  The blooming season will start with many of the smaller spring bulbs like crocus, snow drops and grape hyacinths then progresses through daffodils, hyacinths and tulips.  Some of these bulbs, like most of the daffodils, will naturalize and come back year after year while other bulb crops, like the tulips, are usually a one year flowering spectacular and need to be replanted for future years.

This is a great time to add trees to your landscape.  Container grown trees can be transplanted most any time the ground is not frozen but field grown trees transplant and handle best while dormant at this time of year.  If you plan to plant larger trees that are hand dug and balled and burlapped or spade dug trees this is a great time to move the trees with the least stress to the trees.  Spend time and money to properly prepare the planting hole, then transplant the tree or shrub.  This will give the tree a chance to get rooted in and established before they leaf out next spring.  Fall and winter transplanted trees have a chance to get established before facing our hot summers and the challenges of summer drought.

Plant pansies for immediate joy and excitement and plant bulbs to liven up spring.  Plant trees and shrubs to change your yard and create a landscape and habitat for decades and generations to come.

Enjoy All The Colors of Autumn and Fall!

It is sinking in that fall is here and all around us.  A few pretty cool nights make it clear that the first freeze for central Oklahoma could be close at hand.  Our friends at Woodward and throughout the Oklahoma Panhandle got a light freeze earlier this week so our time is coming.  It could be in the next week or it could be a month but the clock is ticking on all of our pretty annuals, the warm season vegetables and the foliage on our deciduous trees.  This is one of my favorite times of year as we enjoy the last hurrah of the warm season crops and their flower colors get more intense with the cool night temperatures.  We enjoy the fall decorations of hardy mums, pumpkins, hay bales and corn stalks.  We enjoy the colors of the fall and winter crops that can be planted now including ornamental kale, ornamental cabbage and the charming pansies, which are the leading stars of the Oklahoma winter garden.  This is the season to sow your tall fescue or ryegrass seed if you want a green winter lawn.

One of the best things about fall that complements the football games, time by the crackling fire pit and the pretty fall flower shows is the annual dance of fall color on our deciduous trees and shrubs.  This show is never the same from year to year because it depends on the temperature and weather patterns, day length and moisture in the ground.  The fall color is triggered by day length as the days get shorter and the sunlight less intense so that the deciduous trees and shrubs know that winter is coming and start to prepare for winter hibernation.  The timing and amount of color and intensity of fall color all depend on the weather patterns – how early we get cold fronts, how cold, for how long and by how much moisture is in the root zone.  Fall color will be different in a drought year than in a year with good moisture.  If we get a really hard freeze early we will jump to leaf drop and miss much of the fall color show which is best in years with good sunlight, decent soil moisture and gradually declining night temperatures which allow the symphony of leaf color change to go through their full fall song and dance.

As autumn progresses the trees start pulling extra sugars and carbohydrates down into the branches and roots to store for winter.  Three pigments are involved in autumn color.  Chlorophyll is the green color we see throughout the growing season and it is the building block that converts sunlight and water into sugars for food for our plants.  Carotenoids are pigments that produce the yellow, orange and brown tones we see in carrots, corn, bananas and daffodils and are present in all plant cells all year but are concealed or masked by chlorophyll for most of the year.  Anthocyanins produce the reds and blues we see in grapes, red apples, blueberries, cherries, plums and strawberries.  They are produced in most plant cells only in the cooler weather of fall by the excess plant sugars in the leaf cells and bright fall sunlight.  Chlorophyll production slows down and then stops as fall progresses.  As the green chlorophyll disappears from the leaf we get to see the carotenoids or anthocyanins that are still in the leaf cells and give us the yellow, orange and red colors that announce autumn to us.   Poplar trees give us bright yellow leaves before they drop and Oaks give us red leaves and brown colored leaves.  Maples give us yellow, orange – red or brilliant red depending on the species. These leaves will eventually fall where they can provide natural mulch to your yard, be collected and composted to add to your soil and help continue the circle of life.  We hope the hard freezes are delayed and we get to enjoy a long and colorful fall.

Getting Ready for Fall!

It feels like fall with moderate days, cool evenings, football, fairs, lots of color on our spring plants and time to think about hardy mums. These are pleasant days and evenings to garden and enjoy our yards and our neighborhoods. We still have to water when nature does not provide well spaced rains but we don’t face the watering pressure of the long triple digit days of summer.

There is a lot we can do with our lawns at this season. If you want to control winter weeds you should apply weed and feed or pre-emergent weed killers over the next couple of weeks to achieve the best control of henbit, chickweed and their other winter weed friends. This is also the time to apply your last nitrogen fertilizer of the growing season. It can be applied with the weed and feed product or apply a good general fertilizer by itself. This will help strengthen your lawn as it wraps up this growing season and prepares to go dormant this winter. If you plan to overseed your lawn with a winter cool season grass like tall fescue or ryegrass broadcast the seed in late September through October so you can enjoy a green winter lawn. Do not treat those areas to be seeded with a herbicide or weed and feed product as they will inhibit germination of your desired winter lawn.

We enjoyed such a mild and moist August that our spring annuals from penta, petunias and periwinkle to begonias, geraniums, zinnias, marigolds, lantana and sweet potatoes are generally doing quite well. Their flower color will intensify as we get cooler nights.
Enjoy this fall color from your spring and summer plants but start to think about adding fall color.

Hardy mums will lead the fall color show and are now available at your local nurseries and garden centers. They are widely available in one gallon, three gallon and many styles of large decorative containers. Hardy mums look great in the ground in flower beds and are perennials that will usually come back next year when planted in the ground. They look fabulous in decorative pots and will make a big color show until the first hard freeze. There are many styles of hardy mums from smaller more compact cushion mums to the larger mounds of Belgian mums. They come in many color combinations of white, yellow, orange, lavender, purple, red and burgundy to allow you to decorate your patio, porch or gardens to show your own style. Many folks will combine the mums with displays of pumpkins, gourds, hay bales and corn stalks as fall progresses to create the perfect fall ambiance. Remember that chrysanthemums or hardy mums are heavy drinkers and will require water more often than most of your established plants. They wilt fairly dramatically to advise you when you are behind on watering them but they perk up quickly after you water them well. Try not to drought stress them out too many times or it will effect or reduce your fall flower display. The hardy mums are close relatives of the pot mums you may enjoy throughout the year but these varieties are hardy perennials and although they will freeze down to the ground this winter they will usually sprout back up next spring ready for another year of action. The mums in pots are less likely to over winter as they will freeze harder and are more likely to be dry when it freezes which can dehydrate them. Mums are day length sensitive and that is why they bloom reliably each fall as the days get shorter after their growing season. Occasionally there will be mums under a street or security light that don’t re-flower well in future years because they don’t get these natural short days to initiate flowering.

Enjoy this gorgeous weather and the beautiful plants all around us as you get ready to plant new trees, shrubs and hardy mums this fall.

BREEDING PLANTS: WHERE OUR NEW & IMPROVED PLANT MATERIALS COME FROM!

We are enjoying some remarkable mild summer temperatures and have even been blessed with periodic rains.  As a result most of our plant materials are looking great and we are enjoying some nice vegetable harvests and beautiful flowers.  You can be planting for fall as you enjoy your current plantings and keep a close eye on your watering to keep your plants properly hydrated between rains.

Earlier this week I made a quick trip to Raleigh, North Carolina for CARET, the Council on Agricultural Research, Extension and Teaching.  The trip included a couple of stops that got me thinking about where our new and improved plant materials come from.  The first stop was the JC Ralston Arboretum which was started by the famous modern plant explorer who grew up in the Oklahoma panhandle and graduated from Oklahoma State University.  He had few trees and shrubs in the panhandle but loved them and longed for more.  He led plant expeditions around the world as a professor at North Carolina State University and discovered many new plants he and his students brought back to the United States where many were introduced into the American nursery trade.  There have been many other great plant explorers like Alfred Graf of Roehrs Nurseries, John Creech of the U. S. National Arboretum and many more with the United States Department of Agriculture.  We have two prominent active explorers in our state today including Steve Bieberich of Sunshine Nursery in Clinton and Steve Owens of Bustani Farms in Stillwater.  These explorers find new plant varieties and genetics from all over the world to enrich our plant choices and to expand cold hardiness, drought tolerance and other important plant traits.

The second stop was the plant breeding program at North Carolina State University.  Breeding of the most significant agronomy or field crops is done by the big seed companies and our land grant colleges.  The breeding of specialty crops is done by smaller seed companies, land grant universities and even a few amateur breeders.  This is a very important process to stay ahead of diseases, viruses, pest problems and environmental conditions. North Carolina State University has been a national leader in breeding sweet potatoes for the food market that resist wireworms, have thicker skins for digging and storage and better uniformity for harvesting and marketing.  Sweet potatoes are the seventh most important crop to deliver nutrition and calories to humans in the world and this one breeding program evaluates 65,000 new seedlings from breeding crosses each year in the quest for a better sweet potato.  Many of these selections did not prove out for food production but some have been introduced as the beautiful ornamental varieties we use in our summer landscapes that explode with new multicolor, chartreuse or burgundy foliage.  North Carolina also has important breeding programs in cucumbers, stevia for sweeteners, redbud trees, blackberries, gourds, cantaloupe, watermelon, tomatoes, azaleas, peaches and raspberries.

Closer to home, the University of Arkansas features a spinach breeding program that achieved mildew resistance and that is now used on most every American spinach variety and most spinach around the world.  Dr. John Clark has led the nation for decades in breeding blackberries and his varieties are built on the thirty-three years of work by his predecessor, Dr. James Moore. Their work has led to over a dozen varieties now grown on every continent except Antarctica as these innovations have extended the harvest season and dramatically expanded the geography for blackberry production.  Arkansas has also been a leader in raspberry, blueberry, peach and strawberry breeding and plant introductions.  Here in Oklahoma our most famous plant breeding program is by the Oklahoma State University wheat team lead by Dr. Brett Carver.  Over half the wheat grown in our state the last few years are Cowboy varieties bred by Dr. Carver and his amazing wheat team which has introduced over twenty varieties well suited for production in the plains states and is now grown on over three million acres just in Oklahoma each year.

Oklahoma horticulture breeding is led by two former Oklahoma State University professors who have stayed active breeding since their college days.  Dr. Jim Motes is one of the top hot pepper breeders in the world and his varieties are grown on many acres in the Southwest including thousands of acres at the Hinton/Hydro area for use as food additives, as a safe replacement for food dye and for pepper spray personal protection and deer repellents.  Very brave people actually eat some of his hot peppers.  Dr. Carl Whitcomb has several breeding programs underway at Lacebark in Stillwater including hardy hibiscus, desert willow, lacebark elms, river birch and his many amazing varieties of crapemyrtles.  You can find many of his pink, raspberry and red crapemyrtles at nurseries and garden centers all across the southern half of the United States and his breeding fields outside Stillwater are breathtakingly beautiful at this time of year.

It is important we use and save native and heirloom plants but these plant discoveries, introductions and new plant breeding are critical to expand our plant choices, to extend flowering and fruiting seasons, to deal with wetter or drier locations and to achieve insect, virus and disease resistance.  There are lots of great stories about plant explorers and breeders available in books or magazine articles so you can learn more about the rest of the story on your favorite plants.

Oklahoma Summer Gardening & Watering!

We are definitely in the high heat of our Oklahoma summer season and watering continues to dominate our garden and landscape priority lists.  Please make certain you walk your yard regularly and soak or water thoroughly your trees, shrubs, perennials, vegetables, color plants and lawn to avoid extreme stress.  The shallower a plant is rooted in, like color plants and vegetables, they will need water more often than deep rooted plants like trees and shrubs that can pull moisture from deeper in the soil.  The soil closer to the surface gets hotter, has surface evaporation and is supporting more plant roots so it will dry out quicker and more often.  You can help cool the soil and reduce surface evaporation and drying by mulching the soil surface with two to four inches of bark mulch or hulls like cottonseed hulls, pecan hulls, cocoa hulls or pine straw.  Soaking style watering replenishes moisture deeper into the soil and is more effective and long lasting than squirting or syringing and just wetting the surface which inspires shallow roots instead of deeper roots.

Even as we enjoy the harvest and beauty of our spring and prior year plantings it is time to plant ahead for our fall vegetable gardens.  Gardening is a good metaphor for life in that we are rewarded for thinking ahead and taking action to get what we want or dream of.  This is the time to get your plants of tomatoes, tomatillo, peppers, eggplant and cucumbers planted if you want a fall harvest before our first freeze which is usually in early November. These crops need sixty to ninety days from planting to harvest so fall vegetable plants should be planted at once.  We usually say to plant from July fifteenth to August tenth.

You can plant seeds of cowpeas, bush beans, pole beans, or Lima beans to get a harvest in fifty to eighty days after seeding.  You can plant seeds of sweet corn, pumpkins, summer squash, winter squash or cilantro to get a fall harvest.  All these should be planted this weekend or next week to assure plenty of time to raise and harvest your crop before the winter freeze, that seems so distant as we deal with the triple digit temperatures of summer.

These fall garden crops are usually grown in the ground but you can grow limited amounts of most all these crops in container gardens on your patio, porch or even setting in flowerbeds.  Remember all of these young plants and seedlings will need careful attention to watering as they will have a small root system and can dehydrate quickly.  They will become more tolerant as they grow and get bigger and deeper root systems.

You can reduce your water use and get more even and efficient water to your vegetable garden and flowerbeds by using drip irrigation.  Next best is the use of soaker hoses.  If you have a automatic sprinkler system consider upgrading to smart irrigation by adding a soil sensor and rain sensor to your controller so you will not waste water by watering when we do get blessed with rain.  The soil sensors can measure moisture tension in the soil and only water when dry to conserve our precious water while still caring for your plants water needs.  You can use hose end water sprinklers or water your crops by hand as you evaluate and enjoy your garden.  It is much more pleasant to do your summer gardening activities, including watering or planting your fall garden, early in the morning or in early evening as the temperatures moderate.  Enjoy your garden meditation as you water and remember fall will be here soon.

Summer in Oklahoma Garden Means Lots of Heat, Water and Mulch!

It feels like summer has really arrived in Oklahoma this week.  We have been very blessed so far this growing season with periodic breaks in the heat thanks to clouds, cool fronts and even some rain showers.  This was the first week of pretty much full time, unfiltered bright sun and temperatures in the mid to high nineties every day.  It looks like more of the same in the weeks ahead.  Our early spring plantings have had time to get rooted in and have grown a nice plant canopy and many of our flowering annuals and perennials have been and are blooming nicely this season.  Folks are harvesting their first big tomatoes, cantaloupes and even a few early pumpkins.  This summer weather is a real test for many of our plants as they deal with the extreme heat and dehydration.  Just like we humans need to drink more water and stay hydrated in the heat, so do our plants.  Deeper rooted and more established plants like trees, shrubs and many perennials and native plants can handle the heat and water stress better as they have a larger and deeper root system that can draw in water from deeper in the ground and using a bigger network of roots as “soda straws”.

Annuals and newer plantings that have shallow roots or don’t have as well established of a root system will show the stress of the heat and dry conditions quicker and more often.  We can grow lots of types of plants if we are faithful to take care of their watering needs.  They can grow great corn not just in Iowa, but in Guymon, Oklahoma and even the Arizona desert as long as the growers are prepared to irrigate and provide adequate water to keep the corn from too much stress.  Many plants will tolerate the high light and intense heat as long as they receive adequate water at the right times and don’t become too stressed.  Some plants will visibly wilt, some turn grayish green instead of bright or dark green, and most all will begin to yellow and drop leaves so they have less plant to support if they are under too much heat or drought stress.  Plants under stress become much more vulnerable to pest problems, like bagworms on needle evergreens, red spider mite on tomatoes and marigolds, webworms on pecans, walnuts and other trees.  As soon as you notice these pest problems, get them identified and decide on a course of action.

Help keep your plants summer strong by mulching the soil surface around them 2” or more deep with a good bark or hull mulch.  Water deeply and regularly between rains using drip irrigation, soaker hoses, sprinklers or your water hose.  Every time your plants go to the wilted stage or come under heavy heat or drought stress it saps some of their energy and momentum and acts like a growth regulator.  You surely don’t want to overwater your plants but you don’t want to get them “wilted” dry either.  Some good gardener judgment is involved to know your soil type and water accordingly.   Sandy, well drained soil will dry out more often while clay, tight soils will dry out less often.  One key reason to add sphagnum peat and organic matter to our garden soils over time is that soils with more organic matter will hold more moisture and need less regular or extra watering.  Don’t forget that above ground hanging baskets and container plantings will dry out quicker and will need to be watered more often.

You can still plant in this heat as long as you will be faithful in watering these new plantings.  Like the stories of the cobbler’s kids being the last to get shod we horticulturists are often the last to get our own gardens planted because of being so busy serving others in spring.  Dona and I have done most of our plantings the last two weeks and there may be a little sunburn and extra “heat wilting” for the first few days or even weeks as they adjust to their new home but with adequate water they will adapt well and look great as the season progresses.  You can still plant as long as you will water and mulch!

Midway Point of Our Gardening Calendar!

We have arrived at the midway point of the 2017 calendar and are a little over a third of the way through this growing season.  Time marches on without pause and we are at a point in the growing season where many of our spring plantings are really starting to make a show.  The summer flowering shrubs are producing waves of colorful flowers.  The vitex or butterfly bush is covered with blue flowers.  The crapemyrtles are impressive this year dressed in all tones of pink and red, purple and white flowers.  Crapemyrtles not only produce one wave of flowers but often will bloom repeatedly throughout the hot summer months they love into early fall.  They are available in dwarf varieties that only grow a few feet tall to varieties that make large shrubs or even small trees at 20’ tall or more.  There is a lot of active breeding and variety selection growing on now for new crapemyrtles.  The most prolific breeders are the National Arboretum in Washington D. C. and Lacebark Publications operated by Dr. Carl Whitcomb, right here in Oklahoma at Stillwater.  Gardeners all over the south half of the country are growing new varieties bred and grown right here in Oklahoma.

Other summer flowers putting on a show include the lovely cannas, started from a tuber or purchased as a plant.  These large leaf plants produce impressive flower stalks of red, pink, yellow or orange cannas with either green or reddish foliage.  Many of our perennials bloom now as we enjoy our longest days of the year including white Shasta daisies, Echinacea, gazania, and the impressive Rudbeckia also known as Gloriosa daisy or coneflowers with their exciting yellow and orange flower petals spiraling off the black or brown flower center.  Rudbeckia were first named by Linnaeus and recent breeding has produced lots of stunning choices for your summer garden.

Those of you that are vegetable gardening are now digging your early crops of potatoes and onions.  The tomato plants have really grown over the last few weeks and you should have quite a bit of fruit showing on your tomatoes and may have already had a few fruit  turn red.  Many more tomatoes should start turning red over the next week or two. Green beans and squash are producing their crops while the cantaloupe and watermelon fruit is visible under their canopy of foliage and just needs time and water to product their tender, thirst quenching melons.

Many of the annuals that love the heat are now exploding with color.  Look for lantana, penta, periwinkle, marigolds, zinnia, rose moss, sweet potato vine, copper leaf plant and many other warm blooded crops to respond well to our summer heat.  Even the plants that love the heat the most still need regular and adequate watering to perform well.  Remember your plants can’t turn on or operate the water hose yet so please remember to check your watering regularly and water and mulch your plantings to keep them healthy, happy and growing through our hot and dry summers.  You can still plant container grown annuals, perennials, vegetables, herbs, trees and shrubs as long as you will commit to provide adequate water to get them established.

We continue to be blessed with mild, even beautiful mornings and evenings so this really is a good time to get outside and smell the roses and all your other pretty and amazing flowers and vegetables.  Don’t forget to enjoy the cooling natural shade of your trees in the heat of the day.