Rodd's Seeds of Wisdom Horticultural tips and tricks from Rodd Moesel

The weather is clearly changing as we have nighttime lows down in the 40’s and the tree leaves are starting to color and get ready for their autumn dance to earth. You can smell the cooler fall weather and the weathermen are talking about wind chill temperatures again. The first frost and then the first freeze normally arrive in the next two or three weeks on the calendar. Now is the time to start planning on any tropicals or annual plants you want to save and bring inside for the winter. Some plants may be too large to save but you may want to take some stem cuttings to root and carry over to next spring. Most tropicals need to be kept near windows in good light if you are going to try to overwinter them in the house.

Many people look at the killing fall freeze as the end of a special season or memory and a chance for a fresh start or clean palette to start their garden anew next spring. Others can’t bear to lose their beloved plants, large porch or patio gardens or special plant collections. You can save a few plants in your house but space, limited light and family relations often limit the amount of plants you can bring in the house and make a hobby greenhouse the best option. A hobby greenhouse can also be a lot of fun to produce your own vegetables through the winter, to grow your own seeds and cuttings, to start your own transplants for next spring or to start your own collection of orchids, begonias, bonsai or the special plants of your choice. 

You can buy a kit greenhouse at local stores or over the internet or you can build your own greenhouse frame and cover it with a number of good greenhouse skins or glazings.  Decent kit greenhouses start at around one thousand dollars and go to as high as twenty thousand dollars for houses in the 60 to 180 square feet range depending on the strength of the frame and type of glazing. Most of the inexpensive kits are made of light weight galvanized metal or polycarbonate extrusions and are covered with either plastic film or single wall polycarbonate panels. The frames go up in cost as the metal frame gets heavier, you switch to aluminum frames or painted frames. There are a few kits that use redwood or cedar wood as the frame but over 85% of the kits sold use metal frames which probably offer the best value of strength for the money.

The earliest greenhouses were glazed with panes of glass and glass is still available but not used as often because of glazing cost and the fact that it takes more structure to support the glass. Glass is available in 1/8” thick tempered glass and in energy saving insulated glass panels. The most popular glazings these days are single wall corrugated clear polycarbonate panels or the energy saving twinwall polycarbonate in 6 or 8 millimeter thick panels. Some kits still use corrugated fiberglass and some newer kits use the more expensive corrugated or twinwall acrylic panels that will stay clear much longer.  The greenhouse grade ultraviolet resistant polycarbonate panels probably offer the most strength, durability and light transmission for the money. The twinwall panels save almost 30 to 35% in energy. Greenhouse copolymer plastic film with either one or four year life based on UV resistance is the least expensive glazing. When you install two layers and blow air between the layers as you see on many commercial quonset or barrel roof structures greenhouse plastic film is one of the most energy efficient choices. If you build your own wood or metal frame or convert a garage, shop or other building you can buy good greenhouse glazing to put on your frame. You can use 4’ wide corrugated polycarbonate panels that install by overlapping the panels and screwing to the frame. The twinwall panels that look like a sheet of square soda straws in a row install with “U” extrusions to cap the ends and sides of the 4’ or 6’ wide panels and “H” extrusions to go between the panels.

You will also need heat in your greenhouse and a unit heater is usually the best choice. Natural gas, if available, is generally the cheapest commercial fuel, followed by propane. Electric heat is the cheapest to install but costs the most to operate. Even if you are only using the greenhouse for the fall, winter and spring you will need some ventilation as all greenhouse owners very quickly appreciate the power of solar energy. You can provide winter cooling with side and roof vents or with a motorized shutter on one end and an exhaust fan on the opposite end. It is usually best to automate the ventilation on a thermostat as we often need some cooling near the middle of the day even in the winter.  It is not unusual to have the fan come on to ventilate on a 40 or 45 degree day if it is clear and sunny outside as it is possible for the greenhouse temperature to rise to over 100 degrees with solar radiation if you are not ventilating. Next summer you will probably need to add shade cloth and an evaporative cooler if you want to use the greenhouse through the summer months.

Although you can buy hobby greenhouses from mail-order catalogs or over the internet I would encourage you to buy this specialized equipment locally for the best advice on frames, glazing materials, sizing heating and cooling equipment and shade percentages for this area. There are several good suppliers in both Oklahoma City and Tulsa that would be familiar with our conditions to help you select the right hobby greenhouse for your application and crops.

Now is the time to be planting your pansies, viola, ornamental kale and cabbage and selecting and planting your spring flowering bulbs like Tulips, Crocus and Daffodils. This is also a great time to mulch your more tender hardy plants to help insulate their roots and protect them for the winter ahead.

Oklahoma hospitality is really something very special. We often forget or take for granted just how wonderful our state and its people are, until we get to spend time here in our state with people visiting from all over the country. It is a real joy to hear visitors bragging about this great state we call home. Since our last visit the National Garden Writers held their national conference in Oklahoma City with side trips to gardens here, in Stillwater and Tulsa. Over 500 garden writers were here from major magazines like Better Homes and Gardens, Horticulture, American Gardener and Fine Gardening as well as most of the major newspapers in the country. We also hosted many garden book publishers and writers. Most were from large cities and many from the two coasts.

To hear them talk many were not excited about coming to Oklahoma before their arrival. It is amazing to this day how many folks that have never been here still expect cowboys and Indians or the wild west. Amongst garden writers many expected the dust bowl and very limited horticulture or gardening. I had numerous visits with folks like the Philadelphia writer that told me she really had not wanted to come to Oklahoma City because she expected a gardening wasteland still dealing with the dust bowl. She said a writer at another paper who had been here previously talked her into coming saying she would love the people and be surprised by the gardening. By the end of the conference she was telling me it was the best meeting she had ever attended and the people she met at the hotel, on the streets and on the garden tours were the friendliest she had ever met and the gardens were amazing.

The garden writers probably only agreed to come because of our state’s centennial and the leadership of Steve Dobbs, a former writer of this column who just finished a two year term as National President of the garden writers. The enthusiasm of the local host committee helped attract them to our state as well. Once here it is the regular folks our visitors meet at the airport, in cabs or busses, at hotels, restaurants, shops and on the street that really sets our state apart. The local arrangements committee led by John Fluitt, Linda Horn and Patrick Bones put together an amazing set of seminars and special events. Hundreds of Okie volunteers pitched in to make each event special.

The Myriad Gardens is a special treat anytime but is almost magical on a perfect fall evening for dinner among the beautiful outdoor gardens followed by a special Route 66 story telling program under the stars. Another evening had 10 tour busses going out to visit the new Route 66 “Pops” gas station with 400 kinds of pop from all over the country and hay wagon tours through the impressive new wholesale Deep Fork Tree Farm. The surrounding Arcadia Farms is a magnificent showplace of natural plains and wildlife habitat that hosted special Oklahoma food and beverage stops along the way. The final night was at the beautiful Cowboy Hall of Fame with its pretty grounds and magnificent art and western collections.

The star attraction besides the warmth of our people was beautiful landscaping and gardens. Many visited the Bricktown Canal, Arts Museum, Zoo and other public attractions on their own but the private gardens stole the show. Many of the tour stops will show up in future months in national magazines and you heard repeatedly from folks that they could not believe they were finding these gardens in Oklahoma. When you get a chance to see any of these yards on neighborhood garden tours from time to time, buy a ticket and go to enjoy these remarkable gardens.

Hugh and Jennifer Stout, national leaders in the daylily and iris societies were one of the most photographed stops and have a lot of fun plantings and artwork incorporated into their gardens. OSU Oklahoma City was a big hit with their beautiful gardens, All American Trials, greenhouses and Farmers Market where many peanut eating writers got to see and take pictures of their first actual peanut plant loaded with below ground nuts. The Kenneth and Nova Minick water gardens were spectacular and the impressive Express Ranch gardens with their “Dallas” style mansion overlooking the gorgeous river valley full of cattle and an oil well or two was a special sight and just would not all fit in a single picture.

The Bombing Memorial has a powerful but solemn impact on our visitors and this group was especially touched by the endurance and persistence of the survivor elm. Two small yards in Crown Heights had a significant impact beginning with the beautiful English style Vater family garden topped off with a colorful cutting garden hidden behind her studio. The MacMayhill and Baker garden featured one of the most imaginative and relaxing outdoor living areas I have ever seen literally nestled in a beautiful oasis.

The final garden tour to Nichols Hills featured the magnificent Italian gardens of Christian Keesee and the beautiful yard and great kitchen garden of Don and Fanny Bolen. The new gardens of Jackie and Barbara Cooper are less than 2 years old but already look like a great European style estate garden while the David and Kirsten Griffin Gardens feature some beautiful formal boxwood plantings and another impressive and comfortable outdoor living area. Two of the biggest hits were the Guilford gardens of Kamela Gamble where she grows many of her own vegetables, herbs, edible and cut flowers for her Kam’s Kookery. The Japanese inspired gardens of Jerry and Sherry Cash are absolutely stunning and feature incredible ponds, bridges, rockwork, koi fish, over 20 varieties of bamboo, water lilies and other impressive plantings.

We have a great state, a great city and wonderful people. We all need to believe in ourselves, be a little prouder of our state and keep showing that great hospitality to everyone whether they are here for business, for pleasure, for horse shows or the garden writers national conference. This next weekend the National Zoo horticulturists are going to be in Tulsa and Oklahoma City. Lets make the same great impression on them.

Now is the time to plant hardy mums, pansies, ornamental kale and cabbage. You can also select and plant your spring flowering bulbs to make your garden a special Oklahoma treat.

Fall officially began last Sunday and it even feels a little like fall now as we enjoy slightly cooler 80 degree days and 60 degree nights. The days are getting shorter with the arrival of fall and now is the time to engage in full scale fall gardening. This is one of the most pleasant times of year to be outside in the yard to enjoy the annuals you planted this spring and the perennials you have planted over the years. Besides enjoying your existing gardens this is an excellent time to plant new trees and shrubs in your landscape.

Container grown trees and shrubs can be planted most anytime of the year but fall plantings often have the highest success rate as they can get well established and rooted into their new soil home before having to endure our hot and dry summer weather next year. New plantings always need to be watered but there is not as much pressure to water fall plantings as often. The fall and winter weather is not as hot and does not cause as much evaporation and dehydration. If you have been wanting to add more trees or shrubs to your yard this is a good time to get some healthy garden exercise to dig holes and plant more trees in your yard. Remember to dig a hole about twice as large as needed and amend the soil by mixing about one third sphagnum peat moss or other good organic matter with the natural soil. Then place some of the amended soil back in the hole to the proper depth. Do not plant the trees too deep. Plant it so that the top of the soil matches the top of the existing ball of soil.  Put your new tree or shrub in the hole and back fill with the amended soil. Water the new plantings thoroughly to soak the rootball and surrounding backfill. Water periodically this fall and winter when the soil is dry and get ready for years of enjoyment from your new trees and shrubs. I am getting ready to plant several new bald cypress and caddo maple trees in my yard this next week. Trees are one of the greatest things we can do to improve our home and the environment and to leave as a legacy. Each tree helps clean up the environment by absorbing carbon dioxide and air pollutants and produces large quantities of clean filtered oxygen. Well placed trees and shrubs can also reduce our energy use by providing natural windbreaks and natural cooling to reduce home air conditioning and heating costs. As an extra bonus they can transform the appearance and beauty of your house, improve the resale value and make outdoor living much more pleasant and inviting.

The use of fall color plants has really grown over the years and we have many great choices to add an exciting splash of seasonal color to your yard. Hardy mums have been the star attraction of the fall garden for years. There are hundreds of varieties and colors to choose from with many new varieties introduced each year. Some varieties are already in full flower while other varieties are just showing their first color. They will be quite showy up through our first hard freeze although the flowers may be bronzed or slightly burned with the first light frosts in late October. If you are entertaining during the next few weeks or just want a special burst of fall color nothing can compare with the mounds of colorful flowers from fall chrysanthemums or hardy mums. Hardy mums bloom naturally with short days and are perennials that usually come back year after year. They will bloom naturally in future fall seasons as long as they are not planted under street lights or security lights that extend the daylength.

The early pansy crops are now ready and on display at most all the nurseries and garden centers. Unlike the hardy mums which freeze back and die for the season with the first hard freeze the pansies will keep growing and flowering all through the winter. These are available in lots of bright colors so you can plant the color pattern of your choice. I especially enjoy the varieties that have two distinct colors on their flower face, yellow with black, purple with yellow or other fun combinations. Fall planted pansies do best planted in the full sun or mostly sunny locations. With regular watering and an occasional feeding they will grow and produce flowers throughout the winter and into mid spring when the extended daylength and warmer temperatures will start to wear them out. Next spring it is best to replace them with new spring annuals to give you spring and summer color. I especially enjoy pansies in full bloom peeking through light winter snows or looking cheerful during depressing winter cold spells.

When you are at the garden center don’t forget to select some spring flowering bulbs to plant this fall so your can enjoy tulips, hyacinths and my favorites, crocus and daffodils next spring.  We offer a special Oklahoma welcome to over four hundred garden writers from all over the United States that are here in Oklahoma City the next four days for their national meeting. A special thank you to all the Oklahomans who are sharing their yards and gardens and hospitality to welcome these good folks to our state for this national event as we celebrate our state’s centennial and Oklahoma gardening.

The football season is in full swing, schools are all back in session, the first few “cold” fronts have passed through and the state fair is starting so we know that means fall has arrived in Oklahoma. Fall is a great season in the yard or garden to enjoy all your annuals as they get re-energized with the cooler weather and produce another round of beautiful flowers. The tomatoes, peppers and other vegetables often bounce back to life after the summer heat and produce a bumper crop of fresh food. Many of your trees, shrubs and perennials produce another flush of growth before they prepare for the first freezes of the fall in late October or early November.

In addition to enjoying another round of flowers on your lovely crepe myrtles, altheas and roses and the bright colors of all your annuals, now is the time to enjoy the special flowers of fall. Probably no other plant is so associated with autumn as the chrysanthemum or hardy mum. You can buy them already in bud or flower and enjoy them throughout your yard up until the first hard freeze. They do great in the full sun in your front flowerbeds, in beds around your patio or in large container gardens. Hardy mums are heavy drinkers and will need more water than most other plants yet good drainage is still important. There are hundreds of hardy varieties well suited to our state in all tones of red, burgundy, yellow, purple, bronze, pink and white. They are available in the traditional cushion mums and the new large mound Belgian varieties. They also come in many flower styles including traditional, daisy and spoon shaped mums. Hardy mums will freeze back to the ground after the first hard freeze but the perennial or hardy varieties will sprout out from the roots next spring and bloom again next fall. Some folks like to plant asters for fall color to complement or in place of hardy mums. It is still a little early for pansies, ornamental kale and cabbage but they are very special plants great for providing late fall and even winter color. Pansies will survive light or moderate freezes and keep flowering and producing color right through the winter. We will talk more about them in our next column after it has cooled down a tad more.

This is the season to shop for your spring flowering bulbs like tulips, hyacinths, crocus, daffodils, Dutch iris and the many specialty bulb crops. Shop early to get the biggest, firmest bulbs in the varieties and colors you want. They should be planted over the next two months for best results next spring. Plant them with a little bit of bulb food, bone meal or blood meal and the roots will grow all winter. They will sprout from the ground early next spring to deliver the first exciting splash of color after our long cold winter. Daffodils are especially good to add to your landscape in Oklahoma as they will often naturalize and come back year after year where tulips usually need to be replaced every year or two with new bulbs.

This is the time to do your final feeding for this growing season on your trees, shrubs and lawn. This feeding can help with root growth to prepare your trees and shrubs for winter. As we discussed in our last visit we are nearing the end of the prime time to apply a fall weed and feed fertilizer with a pre-emergence herbicide or weed killer to your lawn to kill winter weeds before they germinate. I prefer products containing Barricade or Dimension but there are many good herbicides to choose from. The sooner you apply this product the more effective it will be since a pre-emergent can not kill weeds like henbit and chickweed once they have sprouted.

If you want to seed a tall fescue or perennial ryegrass lawn in order to have a green lawn this winter you should sow that seed over the next few weeks. Tall fescue seed germinates in 8 to 12 days after sowing and watering. You can plant fescue in the shade or partial shade for year round turf or over-seed in sunny turf areas to get green winter color for your lawn. You can plant a blended seed mix that includes several fescue varieties well adapted to our area or a single proven variety like Crossfire II or Wolfpack at a rate of eight to ten pounds of seed per 1000 square feet. 

This is one of the best times of the year to plant container grown trees and shrubs. “Fall is for Planting” was an industry campaign promoted for many years to encourage more trees and shrub planting in the fall. Fall plantings allow the roots to get well established before the heat and extra water requirements of our Oklahoma summers. Fall tree and shrub plantings often experience the highest success rate as they adapt and get established quicker in their new home. Take time from your busy schedule to get outside and enjoy your fall garden and the many wonders of nature at this special time of year.

Henbit, chickweed, annual bluegrass, smooth brome and shepherd purse winter weeds have not sprouted in your lawn yet but now is the time to prevent them. The best time to control these winter weeds is between mid August and the end of September each year with a pre-emergent herbicide. Think of the pre-emergent herbicide as birth control for your winter weeds. The seed is still there but the herbicide creates a barrier at the soil surface. This barrier prevents most of the weed seeds from germinating. Once the seeds have germinated the pre-emergent herbicide will not be effective so that is why it is important to apply it early enough to stop the seeds from sprouting. We have been so moist this year that some of these seeds may sprout earlier than normal. This year it is probably a good idea to apply the pre-emergent as soon as possible. Once the seeds have germinated the pre-emergent herbicide will no longer be effective and you will have to use a post-emergent to burn back and control these cool season weeds.

Herbicide, by the way, is a term descended from latin that means to kill herbs or weeds. Most of these winter weeds germinate when the temperatures start to cool and there is sufficient moisture for sprouting. The cool season weeds don’t grow real fast in the early winter but get well rooted and surge in growth in late winter and early spring when the temperatures start to rise again. In the early spring when winter weeds are well established they actually can compete with your desired lawn grasses for space, light, moisture and food. This can weaken your bermuda or chosen turf grass and can result in bare spots, stunting or leave your lawn more susceptible to invasions by crabgrass or summer weeds.

Your pre-emergent will be most effective if you mow the lawn before applying and remove debris and lawn clippings if very thick. The goal is to get the herbicide granules or spray through the turf foliage and to the surface of the soil. The pre-emergent works best if you get a half inch or more of rain within forty-eight hours of application. If it doesn’t rain within two days you should soak the lawn by hand or with a sprinkler to deliver the equivalent of a half inch of rain to water the herbicide into the soil where the weed seeds are laying and waiting to sprout. Most pre-emergent herbicides remain active for sixty to one hundred twenty days or two to four months. In some more severe cases you may want to make a second application in six to eight weeks for full control to next spring. There are many good herbicides on the market and it is always a good idea to divide the labeled amount into two batches and apply half going north /south and the other half in an east/west pattern to insure good even overlapping coverage. Most of the fall pre-emergent herbicides we apply in this area are available with a fall fertilizer and are marketed as weed and feed products. This is a good time to do the last lawn feeding of the season while applying your pre-emergent weed killer to prevent cool season weeds. Ask for a pre-emergent weed killer containing Dimension, Balan, Treflan, Barricade, Sulfentrazone or Simazine for best results.

This is also a good season to fertilize your trees and shrubs. Use a well balanced food where the three fertilizer numbers for nitrogen, phosphorus and potash add up to over twenty. This is a good time to lightly prune or shape your hedges and shrubs. Be on the lookout for fall webworms on your trees and shrubs and spray with carbaryl (Sevin) or bacillus thuringiensis (Dipel) for control if you are not able to just cut off and throw away the webbed branches. If you plan to sow tall fescue lawn seed in mid September to late October you can go ahead and spray that area with a glyphosate (Round Up) product to kill the competing grasses and to get ready for your winter fescue.

For those of you doing fall vegetable gardens we are in the last phase of the fall vegetable planting season where you can still plant cool season vegetables cabbage, cauliflower, collards, garlic. kale, kohlrabi, leek, onions, peas, radish, rutabaga, swiss chard and turnips of the semi hardy vegetables that will survive several light frosts. You can still plant a few tender vegetables and still get a crop before our first serious freeze. That group includes bush beans, lima beans, cucumbers and summer squash.

As the temperatures start cooling later in September we enter the prime season for planting trees, shrubs, hardy mums, pansies, ornamental kale and cabbage. It seems like this year we have been zigging and zagging between a barrage of heavy rains and hot humid days. Celebrate the pretty days to get out in the yard and get some exercise while   growing some fresh food and beautifying your yard.