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

The last several weeks have been extremely hot and dry for most of Oklahoma. Many of our trees, shrubs and flowers are under severe heat and drought stress, literally facing the plant world version of heat stroke. I am seeing many 2 and 3 year old tree plantings where folks were diligent in watering the first year, even using Tree Gators or similar watering devices but appear to think the trees can survive and thrive on their own now. It is true that the more established trees and shrubs with a more comprehensive root system that goes deeper into the earth can better survive this intense summer heat and access moisture deeper in the soils. But younger trees and shrubs, even in their second or third years still need your help and support when we face these extreme heat conditions.

Take time to observe your conditions. Be aware that open, well drained sandy soils dry out more quickly than tighter, slow draining clay soils so require more human watering support in these extreme dry conditions. Remember that shallow rooted plants like annuals, vegetables and even perennials and lawns will dry out and stress even quicker than trees and shrubs since their roots, (the plant’s soda straws to suck up water) don’t go as deep and the surface soil dries out more quickly than soil further under the surface that isn’t dried out by winds and the hot sun.

Assist your plants with additional water using drip irrigation, soaker hoses, sprinklers or at least hand watering. Most plants need the equivalent of at least 1” of water weekly to deal with this heat and drought. It is best to really soak your plants, getting water deeper into the earth, instead of just squirting the flowers and wetting the dust.

Mulched plants are in much better shape to face the stress of an Oklahoma August inferno and reduces amount of water your trees, shrubs and flowers need to help them through this hot spot so they can rebound with new growth and energy as September eventually delivers cooler nights and some natural rainfall.

Please make time to walk your yard and observe and “listen” to your plants. Are they wilting? Is the foliage a grayish green instead of the usual bright or glossy green? Are your trees and plants dropping many leaves, a natural survival effort to shed part of the canopy and reduce the plant size to the conditions and what the roots can support.

If you observe any of these conditions, don’t just stand there, grab the waterhose and start soaking your plants. Their very survival may depend on the water you can provide. Remember that trees or plants already stressed out from surviving an extreme winter, ice storm damage, and extreme insect or disease damage are more vulnerable to this extreme heat stress as they were already “wounded, tired or stressed”.

We have been cruising along in full summer conditions the last couple of weeks repeating the 96° high, 74º low pattern almost daily. Most plants will still do well as long as they have access to the right amount of moisture. Many sunny area plants may wilt some even with moist soil in the middle of the day but will often perk up as temperatures cool in the evening and remain turgid into our pleasant mornings.

Most established plants need the equivalent of 1 to 2 inches of rainfall per week so it is good to soak them 2 or 3 times per week to deliver this needed moisture evenly. Mulching with natural bark or hull mulches will be of great benefit as it reduces the soil temperature, moderates moisture levels in the soil, reduces evaporation loss and cuts watering. Drip watering with emitters is the most efficient watering technique or you can use soaker hoses, sprinklers or water by hand to get water to your lawn, trees, shrubs and flowers.

The hot dry weather has many insects and pests at their peak and attacking our gardens. Bagworms seem to be everywhere this year and can literally destroy junipers, arbor vitae, cedars and other shrubs. You can control them using the pick, stomp and trash method or spray with a product containing permethrin, acephate, spinosad, bacillus thuringensis or cyfluthrin.

This is the time to attack white grubs if you see them in your lawn. They are the larval stage of beetles. If you have a lot of gophers or moles, they are probably there to feed on grubs, one of their favorite delicacies.

You can control them by spreading granules of carbaryl or thrichlorfon applied right about now which is 30 to 40 days after the flight of the beetles and should be after their eggs have hatched and produced very young grubs. You have a bigger control window if you apply and spread granules of a systemic insecticide with residual action like imidacloprid or halofenozide. You should irrigate or water in these products after application to activate the product and to move it into the “grub zone”.

We are also seeing lots of red spider mites, webworms and voracious grasshoppers this summer. Consult with your local nurseryman for help in solving these or other pest and disease problems.

Many new gardeners have been asking how and when to pick melons. Muskmelons are the easiest. As the melon ripens, a group of cells around the stem softens so the melons literally slip free of the stem with just a very little hand pressure when ripe. This leaves a clean dish shaped scar at the melon and the melon gives off a pleasant, musky aroma at room temperature.

Watermelons are trickier and folks use many techniques before using a knife to cut the melons from the vine.  Listen for a hollow sound when thumping the melon, look for “sugar bumps”, a surface roughness on the melon near the base of the fruit. Observe a yellow coloration on the “ground spot” where the melon has laid on the ground or look for the tendril or stem to the melon to dry and turn brown then enjoy fresh melons after cooling.

As I  flew back into Oklahoma City on a crisp clear summer evening this last week from a few days in Columbus, Ohio at the national greenhouse growers conference it was stunning to see how green everything is here in Oklahoma in the middle of summer. There are a few crops that don’t like such “wet feet” so some vegetable crops and a few other plants are battling disease issues or just running behind from receiving too much water.  Most flowers, lawns, shrubs and trees are celebrating the extra moisture with tremendous new growth and branching and intense green color. Many of our beautiful summer flowering shrubs like crape myrtle, vitex, buddleia and the ever blooming landscape roses have been producing their best flower shows in many years creating a colorful backdrop for all of our beautiful blooming annuals and perennials.

It is shaping up as a remarkable and memorable year for most all of the flowering plants.  If you want to add more color to your yard, you still have time to plant and enjoy more hanging baskets and container gardens for this year. You can add new trees, shrubs and perennials to your permanent landscape, even in this summer heat, if you will be responsible in watering those new plantings the rest of this growing season.

The national grower’s conference is a great opportunity to see all the new crops and varieties to be released for 2011 and to visit with growers from around the country about what crops did well this year, while discussing sales and style trends. After the big surge in new vegetable gardeners last year, vegetable gardening is up again this year as more folks get involved in growing some of their own food.

The tree and shrub industry continues to be experiencing smaller markets as both commercial and home construction remains limited. Since these tree and shrub crops often take several years to grow for market, the nurserymen planned and planted for a larger market than we now have, so there is an oversupply that makes this a great time to buy more trees and shrubs or larger trees and shrubs then you normally could afford.  I would strongly encourage you take advantage of this opportunity to add trees to your yard.  Trees can add to your property values, adds shade, cooling, beauty and even energy savings, while removing carbon dioxide and pollutants and adding oxygen to your environment.

Color or flower gardening grew slightly from last year. The flower seed and cutting growers are adding new varieties, new colors and breeding for longer flowering seasons and better growth habits at an unprecedented rate.  Each year it feels a little more like the fashion business with the unveiling of the styles and colors for the new year.  Visit local gardens and get to know you local nurseryman to help you select the right plants for your yard. Don’t forget to mulch your gardens. Water as needed and enjoy this amazing stretch of lush summer gardens.

Hope you had a great 4^th of July weekend and got to celebrate the birth of our country with family, fireworks and some time to reflect on the many sacrifices made to create and maintain our great country. We just returned from Washington D.C. and got to see Arlington Cemetery, the Declaration of Independence, Constitution and the Bill of Rights and feel renewed in our commitment to this country, the responsibilities of citizenship and the many opportunities we enjoy as Americans.

We also witnessed many beautiful gardens around the capitol including the magnificent National Conservatory, the beautiful blooming lotus and water lilies at Kenilworth Aquatic Gardens and amazing container gardens everywhere we looked. This is a neat time of year because we can really enjoy the many flowers and plants we planted earlier this season that have now grown significantly and are making a real impact. We can still plant most all container grown trees, shrubs and flowers even in our most intense summer heat as long as we commit to thorough and regular watering of newly transplanted plants. We are over 10 weeks past our last freeze and have about 16 or 17 weeks to go until out next freeze so you have about 4 months of great outdoor annual gardening left this season.

If you plant perennials, shrubs or trees you not only have 4 months but hopefully will be adding to your landscape for many years or decades of future enjoyment and beauty. Those crape myrtles that are in such spectacular flower around our state right now have to get planted some time and then they just get better each year so the sooner you plant the crape myrtles or other plants you desire the sooner they start making an impact in your yard and life. Just soak them well after planting and water again as needed until they are well established.

Mulching your new plantings and established gardens with a bark or hull mulch will dramatically reduce watering and protect your plants from temperature extremes so that they will be more prolific and productive. Mulching also dramatically reduces weed pressure and will allow more time for planting, harvesting and enjoying your garden and less time weeding.

Warm summer conditions also produce our greatest insect pressure. Be on the lookout for bagworms and webworms on your junipers and trees. The hornworms and other worms are really munching on the tomatoes, squash bugs are dinning on the squash and red spider mites are attacking many annuals and vegetables. Be prepared to take action. Take a sample of the pest or your problem to your local nurseryman for a diagnosis and they will help you select the right control for your application. Make time to enjoy the mornings and evenings in your garden as they are truly special at this time of year.

Oklahoma gardening is always exciting when we push 100° with hot, dry winds and get record rainfalls with flash floods in the same week.Hopefully your garden held up well through this smorgasbord of weather. Except for washouts and extreme erosion caused by the flooding or damage from sustained time under water most of your plants have probably bounced back from these weather tests and are back in growth mode.

We normally have limited fungus issues of blackspot and mildew in the hot dry summer in Oklahoma but with this much water we are seeing an unusual amount of disease issues as the standing water and high humidity with hot temperatures creates a perfect incubator for many fungus, molds and diseases.

Be on the lookout for rotting or mushy plant tissue, white powdery mildew and dusty spores on leaves or flowers. Pick off and destroy damaged plant tissue and be prepared to use fungicides if needed to control these problems.

For disease and insect problems collect a sample of the problem plant material in a paper bag and take it to your nurseryman for diagnosis and suggested treatment. They can often recommend chemical and organic solutions for most problems. In most cases the chemical solution is faster acting but we are adding more natural or organic solutions to our gardening options all the time. The organic solutions are often slower to respond but can be effective over time when combined with a mindset of accepting a little less yield  and being willing to share more of your crop with nature.

These warm, moist conditions not only create more fungus and disease challenges for our plants but the warm weather is the high season for pest problems. Most of the insects produce many more eggs in each batch and much more often in warm weather so insects can appear to explode in population.

I have seen a surge in worm damage to many of the vegetables and annuals in my yard as they eat holes, whole leaves or even significant parts of young plants. Bagworms are growing on the junipers and cedars. Red spider mites are just getting started on the tomatoes and marigolds.

A good time to study your plants and watch for these insect and disease problems is as you are watering your flowers, lawn and trees. That time while you are soaking the plants is a good time to observe and enjoy their growth and to watch for pest or disease problems, to pick off or “dead head” old flowers and to pinch or prune your plants.

This is still a great time to plant container grown plants in your yard and plant new container gardens as long as you are diligent in your watering after planting. Sometimes at this time of the season you can buy many plants at a discount allowing you to try new species and experiment in your garden.