May Stepping Stones

May Stepping Stones to Gardening Success

April can be pretty frantic; May should be more relaxed. Typically, we have passed the time of our last freeze for this growing season. Hopefully, we won’t be surprised this year. It is still spring, which means the weather still has a certain volatility to it – vacillating between cool and rainy and hot, windy and cold all in one week! But one thing we do know, after Memorial Day, it will be hot.
May 2, 2005 was no exception to spring surprises. A late freeze was forecast for the last 2 days in April. I covered as many plants as I could with row covers and sheets. Our low temperature fell to 35º. Happy that a freeze didn’t occur, I removed the covers. On May 2nd, we woke up to see snow covering the ground, to reach a 2” accumulation, high temperature of 41º, low temperature of about 32º. Visually disturbing, but still minimal damage. By May 10th we reached a high temperature of 90º. The temperature roller coaster continued!
For optimum success of cold hardy perennials, the April 1st – May 15th is the best spring planting period. Young tender plants with limited root zones need time for the root zone to grow and expand prior to the onset of summer’s day and nighttime heat, which usually begins prior to June 1st. I noticed the percentage of survivors planted after May 15th decreased dramatically, and most planted into June failed to survive at all. By May, all the heavy garden work could be completed and all that’s left is dropping new plants into the planting hole and applying mulch.

The garden really bursts into bloom in May with all our favorite traditional plants finishing or continuing. Our wonderful natives, many of them warm season plants, begin with many of them continuing throughout the summer. May is a glorious month in the garden!

Hail weather note: Although hail can occur in any month when the conditions are right, hail occurs most often during the growing months. The most probable time for hail to fall in the Texas Panhandle is mid-April through mid-July, with the peak happening at the end of May to early June  (Weather in Texas: the Essential Handbook, by George Bomar), Panhandle gardens can be battered by serious hail during May and June when the weather is transitioning from spring to summer. After plants take their beating, prune back the damaged leaves, stems and branches, as needed. Depending on the plant and season, the garden may loose that season's flower display. In most cases, new growth will emerge quickly. Boost plants with compost tea, liquid humate or other organic foliar spray for disaster relief. Plants need special emergency care to quickly spring back and look their best during the remainder of the growing season.

Stepping Stones is arranged in most cases on a week to week basis within the months with gardening tasks described by order of the Seven Principles of Gardening, as needed, namely:
1. Plan and Design
2. Analyze and Improve the Soil
3. Create Practical Turf Areas
4, Choose Appropriate Plants
5. Efficient Use of Water
6. Use Organic or Inorganic Mulch
7. Practice Appropriate Maintenance

Following the weeks' tasks, I've included suggestions under the headings "Keep it Up",  "Extras", "Be a Plant Explorer" and "Oops! and/or Don't" -- extra tips I practice and have found to be important or interesting. If you've been gardening for several years, there will be fewer tasks each week for each principle. Included in the sidebar at the right are QuickSteps -- a summary or outline of tasks to do each month. Feel free to copy and print out to refer to during the month.

Don't worry if you can't get to the task in the first week suggested. These times are when I've noticed the earliest most likely success achievable. Naturally, each and every year will be different. Some years will be warmer, some cooler. Adjust and stay tuned to the weather.

Week One and Two


The first of May is a good time to start warm season turf prep. The warm season turf grasses should be up and growing. Look it over and decide if re-seeding is necessary. To seed or re-seed warm season turf areas, follow the same guidelines as for cool season turf grasses. Warm season grasses best suited are buffalo grass and Bermuda grass. Both these grass genera have many different varieties that produce desirable turf. Two of the newest and highly rated buffalo grass varieties are Turffalo®, and Legacy®. Warm season turf areas can be seeded, sprigged, plugged or sodded, depending on the variety. If you are faced with maximizing use of available water, lay sod. Someone else has already used the water to grow the turf sod to this size.

Buffalo grass is a slow and irregular germinating grass. That is, it germinates sporadically over a longer period of time than other turf grasses, in fact, up to 3 years. When seeding buffalo grass, tamp down the seeds, mimicking the action of buffalos stampeding across the plains. In creating a wildscape area, add 1/3 mixture of blue grama grass. For a wilder scape, add sideoats and black grama, little blue stem and low-growing native wildflowers. A wildscape, and wilder scape landscape will fill in faster than just buffalo grass, as the seeds of the other plants germinate quicker.

Appropriate Plants

Non-cold hardy annuals and perennials for containers are best set out after May 1st (recall the 2” snowfall Amarillo received on May 2, 2005). Plants in containers are more sensitive to environmental changes than plants rooted direct in the ground. Even nighttime temperatures in the low 50º’s are too low for tropicals. The minimum chill threshold for subtropicals is 33º – 40º. To be safe, this means the nighttime lows must be above 40 degrees for subtropicals, and above 55 degrees for tropicals to safely leave them outside. The chill threshold varies from genus to genus, species to species, and variety to different variety. Even minimum exposures of 4 – 6 hours are enough for irreversible damage to occur in the cell membranes in young, tender plants such as tomatoes, peppers , eggplants and ornamentals. These temperatures may damage their tissue and stunt their growth that will not be able to be overcome. Damage to the plant includes slowed and delayed growth, delayed or no flowering, blackened and death of leaves and reduced water and nutrient absorption. If you have subtropical and tropical plants, monitor the temperatures closely and plan to move then back and forth, inside and out, or wait until May 15th.

Non-cold hardy annuals such as the begonias, impatiens, petunias, pelargoniums can be purchased. It is usually safe to plant them now. Plant the summer bulbs and tubers of cannas, caladiums, colocasias, alocasias, and any other non-cold hardy perennial bulbs you might fancy. Diversity is good!

Spring Vegetables

  • Plant warm season vegetables after the average date of the last frost (ADLF), which was April 20th.
  • Plant 1 – 4 weeks after ADLF your beans, pumpkin, and squash.
  • Plant cucumbers, cantaloupe, and mustard greens, 1 to 6 weeks after ADLF.
  • Plant tomatoes 1 – 8 weeks after ADLF. Wrap cages for temperature wind and pest protection.
  • Eggplant, okra, and peppers should be planted 2 – 6 weeks after ADLF.


Clean up any areas of the garden that’s been neglected for a number of years. Some years we are overwhelmed with life’s activities and can’t attend to every nook and cranny of our landscape. Take a step back, glass of ice tea in hand, and decide what will be tackled next. Then do it.

Extra -- Horticultural Therapy

Mother’s Day is on the agenda. Offer to clean out her flower beds, amend the soil, do some plantings, and top it off with mulch. A completed flower bed makes a rare, but welcome gift. Include the gift of a summer’s maintenance. Drop by weekly to observe its growth and weed. As with most great gifts, the giver may receive more in the giving than the receiver. This flower bed gift can be given to anyone, including an institution, such as the Veteran’s Hospital, Women’s Shelter, nursing home, school or church. Volunteering to tend to the entire landscape isn't necessary, maybe just a small bed, or even container. Start small; work your way through the landscape through the years if time permits.

Volunteer work doesn’t always have to be hospital visits to the patients, rather, visits to where the patients might go for inner healing, the garden. There are many acts of horticultural therapy we as gardeners can give. Each person can contribute individually. We don’t all have to organize full-blown programs. Perhaps the small, individual acts will coalesce into something larger, but it doesn’t have to. The world is improved one small act at a time, by one person at a time.

Be a Plant Explorer

Baseball isn’t the only activity that has double headers. Do a botanic double header and visit the Fort Worth Botanic Garden and the Dallas Arboretum. It’s as American as baseball, apple pie and gardening. For a triple-header, add the Texas Discovery Garden, Texas’ first certified organic public garden, located at Fair Park in Dallas. (Photo at left is of the Rose Garden at the Ft. Worth Botanic Garden, in June.)

Another garden to visit is the Native Plant Garden at the Heard Natural Science Museum and Wildlife Sanctuary southeast of McKinney, Texas.

More in tune with our ecological community are the Comanche National Grasslands near La Junta, Colorado, where mixed and shortgrass prairie areas can be viewed. Penstemons, calylophus, evening primrose and prickly pear cactus burst into bloom in May and June. Close by near Boise City, Oklahoma; drop by the Black Mesa State Park for similar flora. On the way from Amarillo, drive through the Rita Blanca National Grasslands. Be sure to stop and look closely at what’s blooming and how plant communities are arranged in a naturalistic setting. You might pick up a tip for a future bed design. Don't forget GardenFest at the Amarillo Botanical Gardens.

Weeks Three and Four

Amend the Soil

If on an organic program, apply alfalfa meal, pellets, worm castings or cottonseed meal to turf and rose beds. Traditional turf grasses and roses are heavy feeders. Give the landscape a boost going into the hot summer months by spraying with liquid humate, liquid seaweed/kelp and/or mineral blend, horticultural molasses, compost tea or aerobically activated compost tea.

Add organic matter to your vegetable beds, they are heavy feeders as well. Insure that any compost or organic amendment is free from residues of persistent synthetic herbicides (see Maintenance, Composting, Killer Compost).

Review the sections on Replenishing the Soil for tips on amending the soil (feeding the plants), and on Maintenance, Feeding.


Review the tips for having a healthy lawn.

Mulch-mow turf as needed, rather than by a set schedule, possibly every 4-5 days. Cut off no more than 1/3 the blade length. The proper mowing height for turf type tall fescue and bluegrass is 3 – 4 ½ inches, cutting off only about 1-1 1/3rd inches. Fescue does better in our hot climate when kept at a higher height, by shading and promoting deeper root growth. Proper mowing height for Bermuda grass is 1 ½ - 2 ¼ inches, cutting off ½ - ¾ inch. Mow hybrid Bermuda grass in the lower range, common Bermuda grass in the upper height.

If you’ve already cut your Buffalo grass turf once, that’s it for May. Head out to the mall or ballgame instead.

Appropriate Plants

My usual last spring and summer planting date is May 15th. From May 15th on, we could be propelled directly into summer with a heat wave of 90º to 95º+ temperatures and a long-term period of little rainfall. New plants from small containers (2” size) have a very limited, undeveloped root ball. For greatest plant survival, at least a two week period is needed for the roots to begin development in the soil to be able to survive the gardener’s harshest season – summer. By June 1st, even the nighttime temperatures offer little respite for the plants to recoup from the day’s trials. If the soil has not been prepared properly for drainage and organic matter and beds mulched, they might still wither. To withstand the searing sun, unrelenting wind, high heat and low humidity, be sure plants have every advantage you can give them to be able to not just survive, but thrive.

It should be safe to set tender perennials, tropicals and non-cold hardy annuals outside in containers for the growing season, without undue worry. Many people have success with prepared soil mixes purchased at home improvement centers and nurseries. Plants thrive better with good drainage. Success can also be achieved by making container soil mixes yourself. For my own use, I do not use “sterile soil less mixes” and have not since 1996. I combine 1/3 good vegetable garden soil (well amended for a period of years), with 1/3 compost and 1/3 coarse sand, gravel or lava sand. Depending on individual plant material, you may decide to include inorganic amendments for better water and nutrient retention and drainage. In pots devoted to drought tolerant plants, I increase the inorganic amendment and decrease the soil and compost. Drainage is a more critical factor than organic matter for xeric plants.

We usually harden off plants to acclimatize them to colder temperatures after buying them from warmer greenhouses. The last two May's of 2011 and 2012, it was necessary to harden them off to the hotter temperatures, sun and wind conditions. Adjust your practices to new weather conditions.

Summer Vegetables

Plant warm season vegetables of okra, tomatoes, peppers, cucumbers, corn squash and beans, if not already done.


Add mulch to container plantings with either organic or inorganic materials, depending on the plants chosen. Generally, high feed and water users benefit from organic mulches and xeric container plants benefit more from inorganic mulches.


Prune and/or deadhead any spring flowering shrubs after it’s bloomed, if necessary. In a low maintenance landscape, have a reason for pruning or just enjoy the natural shape of the shrub.

Snip the top of the stem of spring bulbs or remove the stems that have already flowered so the plant can send it's energy to the bulb for building it up for next year's flower. Continue to wait for the leaves to yellow and wither before removing.

If you've planted larkspur, keep up on deadheading for continued blooms and to avoid scattering thousands of seeds -- larkspur is prolific!


  • Plant amaryllis bulbs that you’ve gotten for last winter’s holiday season outside. Either plant in a sunny location directly in the soil or bury the pot as well. Keep them well fed and watered during the growing season.
  • Also plant paperwhites, hyacinths or other forced bulbs outside. Many of these are cold hardy for our climate, and may re-bloom next year, depending on the variety.
  • If you are thinking of planting fall blooming bulbs, April and May is the time to order them for best selection. Fall blooming bulbs haven’t caught on like spring bloomers, but if you’re a bulb enthusiast, order early for the best selection. Fall blooming bulbs include fall blooming crocus’, Crocus speciosus, C. pulchellus, C. medius, C. cartwrightianus, C. goulimyi, and the saffron crocus C. sativus, are some species to consider. Other fall blooming bulbs are the colchicums, specifically Colchicum autumnale, Lycoris squamigera, the surprise lily, and Zehyranthes (rain lilies). Pay attention to whether the varieties choosen are cold hardy.
  • Enjoy a Memorial Day picnic with friends and family, you deserve to relax. Take time to smell the roses and notice the beauty of the landscape you’ve contributed to.

Keep it Up

  • Water as needed, paying attention to rainfall and ET rates.
  • Replenish mulch as needed.
  • Add plant debris to the compost pile and turn it every two weeks. Moisten it if necessary.
  • Weed, weed, weed. Weeds that have not seeded out and weeds without invasive rhizomes can be tossed in the compost bin.
  • Check roses often and other susceptible plants for aphids and spray them off with a jet of water. Watch your vegetables closely for insects and manage any problems starting with the least harmful technique (IPM).
  • Keep up the garden journal entries.

Oop! or Don't

  • Don't roll up the leaves of daffodils and tulips in an effort to hide them after blooming. Allow them to be exposed to the sun to soak up energy for next year's flower.

Angie Hanna, Updated February 7, 2018

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