When it comes to fertilizing plants, you can usually find your tree, shrub, and garden fertilizers at any nursery or hardware store, each one specified for all sorts of potential uses and purposes. But for many reasons, turf fertilizer is much less clearly understood by the general populace. What makes turf fertilizer different from other fertilizers, if anything?
Fertilizer Types
Fertilizers, at the most basic level, are collections of nutrients that plants need in addition to water, sunlight, and carbon dioxide, in order to thrive. A “complete” fertilizer is one that contains each of the three most important elements for healthy plants: nitrogen, phosphorous, and potassium. Most of the liquid and granular fertilizer for trees, shrubs, and herbs will be some formula of a complete fertilizer. The ratio, typically written as (Nitrogen %) – (Phosphorous %) – (Potassium %), is important to note on any container, because different regions have soils with different amounts of each of these compounds. Additionally, every species of plant uses up its mineral supply at a different rate.
The Needs of Arizona Grass
The Arizona soil found in the Valley is known for being almost completely void of natural Nitrogen, and it just so happens that Nitrogen is the nutrient that grasses tend to use up extremely quickly. If your grass is looking sad, with patches of thinning or discolored foliage, there’s a high chance that your turf is running out of usable Nitrogen.
In order to ensure a good supply of Nitrogen for your grass, ELS typically recommends the use of Ammonium Sulfate. Ammonium Sulfate is a chemical compound that is not a “complete” fertilizer, but rather a nutrient that supplies exclusively nitrogen to the soil with the fertilizer ratio 21-0-0. We follow the Maricopa County Cooperative Extension’s recommendation of applying ½ – 1 pound of Ammonium Sulfate per 1,000 square feet of turf space, depending on how deficient the grass appears to be. The same ratio is recommended for your personal backyard spaces as well. For example, if you have 500 square feet of turf in your backyard, apply 0.25-0.5 pounds of 21-0-0 Ammonium Sulfate across the space, depending on how healthy your grass is looking.
How Often Do I Fertilize Arizona Turf?
Every yard space is different. Some yards have very poor soil drainage, some have more or less shade than others, some have more nitrogen in the soil than others. Because of this, you’ll have to adjust for how your grass behaves over the course of a year. The general recommendations, however, range from every four weeks to every eight weeks. The Maricopa County Cooperative Extension website with the University of Arizona offers a series of charts explaining the best fertilizing frequencies for different varieties and combinations of grass. Go to extension.arizona.edu/sites/extension.arizona.edu/files/pubs/az1817-2020.pdf to read the full explanation.
The most common grasses that follow rules for the examples provided are Winter Rye for the winter and Bermudagrass for the summer. Other, less common grass varieties may have slightly different fertilizer preferences, though these general rules pertain throughout most grasses.
Other Nutrients and Practices
While Nitrogen is the most important element to get into your grass, it’s not the only nutrient that could use an occasional boost. Sometimes, grass becomes deficient in iron, which leads to pale foliage and an overall sad look. To solve this, use iron chelate or other iron-filled supplements. The Arizona soil (and water supply) is often high in salts, which can clog up soil and hurt grass. For this, apply gypsum and “aerate” the soil using a tool called a “lawn aerator.” If you’ve recently overseeded, we recommend using a fertilizer that contains both Nitrogen and Phosphorous.
The ELS Maintenance Division is a group of experts who have been keeping turf spaces looking great around the Valley for nearly 50 years. If you have any questions or manage a community or commercial property that could use a new landscaping company, email us at [email protected] and we can get started.
Citrus trees have strong wood that requires minimal pruning. A healthy tree can bear the load of heavy fruit. A common misconception is that a heavily pruned citrus tree will result in new growth and improved fruit quality. In fact, the opposite is true; minimally pruned citrus trees can produce fruit that is of better quality than heavily pruned trees.
Spring is Citrus Pruning Season
If your citrus tree requires pruning, the best months in Arizona are February to April. Best is after the danger of frost has passed but before the tree flowers. Pruning between April and October can expose the tree to sunburn damage, and November to February exposes the tree to potential frost damage.
Regular Maintenance with Minimal Pruning
Citrus trees produce the least fruit in areas of the tree canopy that are most shaded. Thus, your citrus tree may only need to be pruned in the spring to thin out those deeply shaded sections inside the tree canopy, opening them up to sunlight for fruit production.
Year-round maintenance of citrus trees involves regularly snipping off suckers and removing branches that are weak, diseased or dead. As with other trees, a limb that crosses another should also be removed to prevent damage to and consequent disease in the other limbs it touches.
Citrus trees, like roses, are most often grafted varieties onto a base rootstock. Shoots growing up around the base of the trunk or in nearby soil are rootstock suckers that should be removed. They are characteristically thorny and will not produce the desired citrus variety.
Thorny, unproductive varietal branches higher up in the tree can also be removed as part of regular maintenance.
Protect Cuts with Paint
Especially for large cuts, protect the exposed citrus wood by painting it with a 50%/50% mix of latex paint and water. Never use an oil-based paint on citrus.
Want to know more about how you can maintain the investment in your landscape and improve its value? Call ELS at any time at (602)-243-1106 or fill out a request a bid form on our website at www.elslandscapeaz.com
Most of us grow up hearing our parents yell at us that money doesn’t grow on trees. The sassiest of us called them liars because money is paper, and paper comes from trees. What is indisputable, however, is that trees are tangible assets in the urban landscape that increase in value over time. Generally, the bigger and older the tree, the more valuable it is.
Economic and Ecological Worth
To assess the value of a tree, let’s first ask whether we are after its economic or ecologic worth. Economically speaking, one measure is a tree’s perceived contribution to the value of the property on which it is located. Other economic benefits of well-placed trees include providing protection from the weather. Tree canopies provide shade from the sun, and evapotranspiration cools the surrounding air. Tree canopies can slow down winds and reduce the amount of heat a building loses, particularly through its windows. For a homeowner, that sun and wind protection can add up to real savings from lower cooling and heating costs.
A tree’s worth in ecologic terms is even more interesting. Arborists and other scientists geek out on measures that include stormwater runoff interception, energy savings, air quality improvement and CO2 reductions. Trees serve to control urban pollution by reducing stormwater runoff and are considered a rainwater harvesting technique. They intercept and hold rain on their leaves, branches and bark, increasing soil infiltration and storage of rainwater through their roots. They also reduce soil erosion under their canopies by diverting and slowing rainfall before it strikes the soil.
How Trees Work For You
Trees phytoremediate water, taking in trace amounts of otherwise harmful chemicals from the soil and transforming them into less harmful substances that they use as nutrients or store in their tissues. Trees can reduce the level of air particulates and ozone because their leaves absorb ozone, nitrogen dioxide and sulfur dioxide and generate oxygen during photosynthesis. They can also reduce atmospheric carbon by sequestering CO2 in their roots, trunks, stems and leaves while they grow, and in wood products after they are harvested.
i-Tree Design
To quantify and predict the economic and ecological value of one or more trees, use the clever modeling tool from i-Tree Design. This tool uses the tree’s location, species, diameter and condition to let you model your built structures and predict the value of specific tree species over a 1 to 99-year period.
Still, we humans usually plant trees for far simpler reasons—reasons that are rooted in neither economic nor ecologic value. We simply like how they look. They add curb appeal, design interest and sometimes privacy to our yards. We like them for bearing fruit, seeds or nuts. We like how they flower or change color with the seasons. We enjoy them as a source of recreation, like for a tree house, a rope swing or a hammock. And we admire how they are the simplest of homes, supporting local ecosystems of bees, birds and squirrels.
Whatever the value you desire or derive, invest in your landscape and property through proper tree selection, placement, pruning and nourishment.
Reach us at [email protected] to request a custom bid for your commercial landscape.
Soil testing is a good way to assess the health of your soil and make any necessary improvements to soil fertility for more productive plants. Soil testing provides a snapshot of your soil’s current nutritional and material composition.
A big factor in your test will be the pH (acidity/alkalinity) level of your soil, which affects whether or not nutrients already present in your soil are available to your plants. Search the web for “soil pH and nutrient availability” images, which illustrate how pH corrections can improve what your plants access.
There are basic self-test kits available in garden centers and home improvement stores that can be helpful in measuring pH and for identifying nitrogen, phosphorous or potassium (NPK) deficiencies. Or, you can submit a sample to an independent laboratory for a more detailed report that can including other micro- and macronutrients, as well as cation exchange capacity (CEC), organic matter content, and soil structure. Here are the basic soil sampling steps to get your soil analyzed.
Collect a representative sample
From the area you wish to sample, like a planter bed, vegetable garden, lawn, or even a single pot, create a composite sample of the area’s soil. Use a professional soil probe or dig down 6-8 inches into the root zone to collect several small soil samples. Deeper samples are useful for measuring salt buildup. Collect the samples when the soil is the driest and mix them together. Then, per your specific lab’s instructions, use a clean, dry bag or container to package up the consolidated sample, minus any plant roots or rocks.
Submit your consolidated sample for analysis
There are many choices for soil testing: home test kits from garden centers, test-by-mail services, cooperative extension services, or independent laboratories, which cater to agronomy industry professionals and whose reports can seem highly technical.
The lab you choose will give you specific instructions for submitting your sample for analysis. Follow the instructions carefully to ensure the accuracy of your results.
Understand your results
For many homeowners, this is sometimes the most intimidating step in the soil testing process. For most self-test kits, a color chart will help you read whether your pH and NPK levels are over, under or within range. Mail-order services generally include results together with written reports that help to explain the nutrient levels and advice for why and how to correct. Testing laboratories catering to industry often test for a broader range of micro- and macronutrients, but the reports may list numeric results with little interpretation. A good beginners’ resource for understanding soil test results is at https://extension.psu.edu/soil-test-results-whats-next-guide-for-homeowners.
Amend your soil
There are so many possible variations for what your soil remediation may involve that we cannot cover them here. Still, no matter your soil test results, adding organic matter to your soil is the best remedy for poor soil. The process may take several years to improve your soil, so start now by adding compost or top-layering with various organic matter like mulch, manure, grass clippings and leaf debris to decompose into your soil. You can even start making your own compost from kitchen peelings and plant debris. A good sign your soil is improving is an increase in earthworms and beneficial funghi, microbes and nematodes.
For immediate corrections to macronutrient NPK deficiencies, look to common fertilizers to correct for the levels you need. You will find the amendments you need at local garden centers. Follow package instructions carefully for proportions and mixing.
Everything is coming up roses. Here in the Valley, January is the ideal month for pruning roses. It’s also time to get your bare-root roses into the ground and to relocate any established roses planted in an unfavorable location.
Rose pruning season begins once the danger of frost has passed, when daytime temperatures are below 70 degrees Fahrenheit, and while roses have ceased blooming. Prune roses before Valentine’s Day, when temperatures rise and bud eyes swell with new growth.
Know your rose
The purpose of pruning roses is to stimulate new spring growth and to achieve the greatest number of quality blooms. Most roses respond best to drastic pruning, so don’t be nervous. It’s always best to first confirm the types of roses you have—hybrid tea, floribunda, miniature, climbing, rambling, groundcover, etc.—so you can prune your rose to its best potential shape and size. This article focuses on pruning bush roses like hybrid teas and floribundas.
Cut for shape
Begin by using sharp, clean loppers and pruning shears/secateurs sterilized with isopropyl (rubbing) alcohol to prevent spreading plant pathogens. For bush roses, the objective is to achieve a vase-shaped plant (open in the center) and to have 5-12 remaining canes that are roughly knee height, 18-24 inches tall; more vigorous, established plants may have more canes.
While you are cutting, take note of discolored or diseased leaves or insects present to properly address any problems. Seal cuts with commercial cut sealant or school glue. Lastly, clear all clippings from underneath the rose to prevent mildew and disease.
What to prune in winter
Here are general rules of thumb for what to remove in the pruning process:
At least one quarter to one third, but no more than one half, of the previous year’s growth
Dead or diseased canes
Crossing, rubbing canes
Limbs less than the thickness of a pencil
Old, unproductive canes
Suckers below the graft union (on hybrid teas)
What to prune in other seasons
At other times of the year, keep your roses in shape by snipping off spent blooms just above the next lowest leaflet of five leaves (i.e., deadheading) and by removing any dead or diseased canes.
Rose care annual calendar
For more tips about caring for your roses year-round, download the Arizona Rose Societies’ calendar on https://rosegarden.mesacc.edu/documents/azrosesocietiesrosecarecalendar.pdf. The links to Arizona rose societies at the end of the document will help you connect with other rose enthusiasts in your area.
Reach us at [email protected] to request a custom bid for your commercial landscape.
Love trees but hate the mess they make? In this month’s post, we are featuring desert-adapted evergreen trees you can enjoy in your Arizona landscape, with minimal maintenance. Although it’s rare for trees to produce zero litter, you can count on non-deciduous trees to produce minimal debris.
As always, match the right tree to the right location to maximize your enjoyment of the trees you select.
To help you select the most suitable trees for your landscape, we have listed the main characteristics of some of our favorite low-litter species, followed by more detailed descriptions.
Willow acacia (Acaciasalicina): 30’ high, 20’ wide; shade tree for narrow spaces
Detailed Descriptions of Low-Litter Trees for Arizona Landscapes
African sumac
The African sumac (Rhus lancea) is an evergreen tree with a wide, rounded canopy that spreads to 20-30 feet high and wide. It features dark brown, cracked bark and 4-inch-long leaves that are dark green on top and silver underneath. On female trees, its yellow spring flowers produce green berries that many bird species enjoy. It tolerates heat and poor, dry, salty soil.
Arizona rosewood
Arizona rosewood (Vauquelinia californica) trees are slow-growing shrubby evergreens that grow to about 10 feet tall. They feature dull, dark green serrated leaves and clusters of short-blooming white flowers between late April and early May. Performing best above 2,500 feet in elevation, Arizona rosewood grows in partial or full sun but yellows in the hottest Valley temperatures.
Brazilian pepper
The Brazilian pepper tree (Schinus terebinthifolius) is a dense shrub that can be pruned into a small tree that can reach 30-40 feet high and 20-30 feet wide. The Brazilian pepper features clusters of flowers 2-3 inches long in a long flowering season, September to November, with glossy fruits that ripen to red clusters of peppery edible berries.
Cypress, Arizona
Blue Arizona cypress (Hesperocyparis arizonica, formerly Cupressus arizonica) trees are native to the southwestern U.S. but do not always perform well below 6,000 feet in elevation. They are fast-growing, reaching 40 feet in height and 30 feet in width. Planted together, they can form a windbreak or a privacy screen along fence lines.
Cypress, Italian
Italian cypress (Cupressus sempervirens) trees require direct sunlight and are drought-tolerant. Their vertical, conical shape makes a strong, vertical focal point, reaching 30-50 feet high and 5-8 feet wide. Cypress trees shed small amounts when the old, interior growth ages. They can be planted in a row to provide an imposing wind break or natural barrier.
Carob
The carob or locust bean tree (Ceratonia siliqua) is an evergreen native to the Mediterranean and the Middle East. Reaching 30-40 feet tall and 30-40 feet at maturity after 20-50 years, it features a broad, hemispherical crown, sturdy branches, and a deep taproot. Female and some bisexual varieties produce summer flowers and 6-inch-long edible seed pods that taste like chocolate.
Cascalote
Cascalote (Caesalpinia cacalaco) or Mexican bushbird is a native Mexican evergreen tree that likes full sun and grows in a vase-shaped form to 20 feet tall and 15 feet wide. It grows in full sun in well-drained soil and has bright green leaves and seed pods. It attracts hummingbirds with its very showy yellow flower spikes, winter through spring.
Cherry laurel
Cherry laurel (Prunus laurocerasus) is an evergreen shrub or small tree is useful as a privacy screen. It attracts butterflies and bees with its fragrant, cream-colored flowers, followed by red berries that attract many bird species. It grows 20-25 feet tall and 20-30 feet wide but can be trained into any shape. The cherry laurel tolerates full sun and full shade but performs best in part shade.
Chinese pistache
Chinese pistache (Pistacia chinensis) is a large tree with showy orange and red leaves in late fall which it drops all at once, once a year. Chinese pistache is dioecious, which means each tree is either a male that produces pollen that has little or no allergenic qualities, or a female that produces inedible berries that are attractive to birds. It is fast-growing and enjoys full sun and fast-draining soil. At maturity, it reaches 30-35 feet in height and 20-30 feet in width and is very drought-, wind-, and heat-tolerant.
Indian laurel fig
Indian laurel fig (Ficus nitida), also called Chinese banyan, is a fast-growing, medium-sized evergreen, native to Asia and Hawaii. It features tropical-looking foliage that is glossy and dense. Its spring flowers are inconspicuous. It tolerates air pollution and grows 20-30 feet high and wide.
Ironwood
Desert ironwood (Olneya tesota) is native Sonoran Desert evergreens. The oldest know specimen is over 2,000 years old. It features green leaves and lavender flowers in late spring that mature into bright red berries. Ironwood can reach 15-30 feet tall, 15-20 feet wide, and can grow in rocky, infertile soil, but it requires full sun and 6 inches or more of annual rainfall. Its wood contains compounds known to have anti-inflammatory properties.
Leather leaf acacia
Leather leaf acacia (Acacia craspedocarpa) is a dense evergreen shrub that can be pruned to a small tree that grows slowly to 10-13 feet. Its rounded leaf petioles are silver and leathery. Native to Australia, it grows in full or reflected sun and blooms with yellow puffy flowers, spring to summer. It tolerates poor, dry, rocky soil and is frost resistant to 18 degrees Fahrenheit.
Live oak
The live oak (Quercus virginiana) tree is a broad, evergreen shade tree. It differs from typical oaks in that it is a medium-fast grower that is drought tolerant once established. It grows in full sun, 40-80 feet tall, spreading 60-100 feet wide. It features large, dense foliage for deep shade. It has subtle green flowers in spring.
Mastic
The mastic tree (Pistacia lentiscus) grows as a large shrub or small tree that is 15-20 feet high and 20-30 feet wide. It can be pruned into topiary shapes, and its resin can be chewed to clean teeth. It tolerates poor soil and hot, dry growing conditions. Spring flowers develop into small, red berries that ripen to black.
Mulga
The mulga acacia tree (Acacia aneura) is native to Africa, Asia, Australia and North America. With silver, needle-like foliage and gold flowers in mid- to late summer, the mulga is great for color contrast. Mulgas are slow growers but reach 15-30 feet in height and 15-20 feet in width and have roots that grow to 35 feet. Mulgas lose their leaves only in extreme drought conditions.
Neem
Neem tree (Azadirachta indica) is an evergreen tree native to the Indian subcontinent. It is widely used for medicinal properties and in cosmetics, producing white or yellow flowers in spring that develop into vibrant yellow fruit that attract birds and insects. It grows 30-40 feet tall and 10-20 feet wide. A neem tree is sensitive to frost and needs frost protection.
Red cap gum
Red cap gum (Eucalyptus erythrocorys) is a fast-growing Australian-native evergreen that likes full sun. It has 4-inch-long silver-blue leaves and grows to 30 feet high and 25 feet wide, serving as an effective screen. It features red buds followed by yellow clusters in the summer.
Silk floss
Silk floss tree (Chorisia speciosa) is a lush, dense tree, native to Brazil and Argentina. It likes full sun and grows to 30-60 feet in height and 20-30 feet in width. It features an eye-catching spiny trunk and deep green 5-inch-wide leaves. In the fall, the tree drops its leaves and produces showy, pink, lily-like flowers, and then produces seeds and cotton-like fibers in the seed capsules.
Texas mountain laurel
Texas mountain laurel (Dermatophyllum secundiflorum, formerly Sophora secundiflora) is a small, shrubby evergreen native to the Chihuahuan Desert. It features dark green leaves and beautiful hanging clusters of purple flowers in spring. It is frost-tolerant and grows in full sun to 8 feet tall and 6 feet wide.
Texas olive
The Texas olive (Cordia boisseri) is a medium-sized evergreen that features multiple trunks and a growing size of 40 feet high and 25 feet wide. It has narrow green leaves and produces white blossoms from February to April that attract hummingbirds. Its fruits are edible, but the seeds have been known to cause serious illness in humans. It prefers moderate summer temperatures but can withstand freezing winter temperatures.
Weeping myall
The weeping myall (Acacia pendula) is an Australian native evergreen that resembles a weeping willow, with graceful, draping grey-green foliage. It creates dense shade and features pale yellow balls in spring and winter. Frost- and drought-tolerant, the weeping myall needs full sun and is slow-growing, reaching 15-30 feet in height and 15-25 feet in width at maturity.
Willow acacia
The willow acacia (Acaciasalicina), an evergreen native to Australia, is an excellent shade tree for narrow spaces. It likes full sun and grows to 30 feet high and 20 feet wide. Its spring blossoms are puffy and cream-colored.
With a little knowledge and planning, you can protect your landscape plants—and your investment—from frost damage. In Arizona, we can get frosts from about Thanksgiving to Valentine’s Day.
As a rule of thumb, it’s important to know that younger, dehydrated and actively growing or flowering plants are most at risk for frost damage.
As the weather cools, plants naturally “harden off” by slowing their new growth and ceasing blooms. Therefore, it’s important to protect landscape plants both from frost and from budding or blooming too soon before the danger of frost has passed. Still, the faster the drop in temperature, the lower the temperature and the longer the exposure, the more at risk any plant is to frost damage.
Select frost-tolerant plants. Native plants will fare the best in all temperatures, whereas tropical plants may suffer in the cold. To find a plant’s temperature hardiness, search https://www.amwua.org/plants, AMWUA’s Plants for the Arizona Desert
Keep soil appropriately moist. Although water requirements for different plant species vary year-round, it’s important to know that frost damage can be more severe in dehydrated plants. And, although it seems counterintuitive, it’s beneficial to water plants before a predicted frost because water releases energy in the form of heat when it cools, thereby warming the foliage above ground.
Cover at night. Each night a frost is predicted, drape over sensitive plants a cloth that touches the ground, allowing warmth from the ground to fill the resulting dome structure. Remove the cover in the morning so the ground warms up again the next day. If you need to keep plants covered for multiple days, look for purpose-designed frost cloths or frost blankets. Do not use plastic because it freezes.
Choose warm locations. Frost-sensitive plants will be better protected when they are sheltered, when they are exposed to full daytime sun (south and west sun are best) or when they are located near rocks, walls or benches, which radiate daytime warmth.
Resist pruning. Pruning stimulates new plant growth, which can be even more susceptible to frost. Do not prune frost-damaged plants until spring, after the danger of frost has passed.
Wrap tree trunks. For young citrus and other frost-sensitive trees, loosely wrap the trunk from the lowest foliage down to the ground using multiple layers. Leave wrapped for the winter.
Add heat. Add incandescent lights or string lights below the foliage because their heat radiates upward. LED lights do not generate sufficient heat for this purpose.
If the weather forecast shows low nighttime temperatures, refer back to these 7 tips to prevent frost damage to your sensitive plants. You’ll be protecting their shape and giving them a head start on budding and blooming when spring comes.
Plant beautiful new rose plants this winter from among the many varieties that thrive in the Arizona sun. Visit some of the lovely rose gardens in our state, like the Encanto Rose Garden in Phoenix, or Mesa Community College to see which blooms catch your eye.
Because they are the most affordable, this article focuses on buying and planting bare root roses. Bare root roses arrive in commercial nurseries in December, but you will want to buy your selections early, because they sell out quickly. Sun exposure can cause your bare root rose plants to begin leafing out, so keep them in a cool dark place, wrapped in their packaging, until planting time.
Prepare the Planting Locations
Planting time in the Arizona low desert is January to mid-February, when the danger of hard frost has passed. The day before you plant your new rose, carefully unwrap it and remove all the packing material from the roots. Submerge the bare plant roots overnight in a bucket of clean water and plant the next day.
Choose a location where your new rose will get at least 6 hours of full sun per day and is 3-5 feet apart from other plants to allow for air circulation to avoid diseases. Dig a hole no less than 18 inches wide and deep, which will break up native soil and allow room for new roots to spread.
Amend the native soil you dug out of the hole by mixing 1:1 equal parts native soil and mulch, or 1:1:1 equal parts native soil, compost, and sand or perlite. At the bottom of the hole, sprinkle around 1 cup sulfur, and then pour 1 cup triple superphosphate (0-45-0) into a pile. Over the superphosphate, start adding the amended soil mixture back into the hole to form a cone-shaped mound.
Planting and Caring for Your New Roses
Place the bare root rose on top of the cone, watching carefully that the plant’s bud union stays 2 inches above the soil line. Cover with the remaining soil and press to make firm. Spread a layer of mulch around the top of the new hole, leaving the soil surface bare in a ring directly under the plant to serve as a water well.
Water in the new rose by saturating the surrounding soil to remove pockets of trapped air. Water deeply and generously once per day for the next week, and then once per week into spring. Follow package directions when fertilizing your roses throughout the blooming season and watch for common pests that can damage your blooms or plants.
As the summer grass fades and we wait for the winter grass to grow in, you may notice our maintenance crews sprinkling grass clippings from our mowers across the grass. Some mowers are even made to spit out grass clippings. Why do we do this? In short, grass clippings are a great mulch that provides the next batch of grass with good nutrients to give it a head start!
When mowers cut lawns, the blades of grass cut off contain lots of nutrients. This is great for the existing grass and for the seedlings of future grass. The reason for this? Grass cuttings are a perfect fertilizer for grass, since they are made of… well, grass! If the lawn was healthy, chances are that using its own lawn clippings as fertilizer will make for a healthy next batch of grass.
The only thing to really look out for is the quantity of grass. While small, well-spread clumps or a thin even coating are great for fomenting future grass growth, if there’s a spot covered with way too much of the lawn clippings, then that may inhibit the development of seedlings or new grass.
Overall, there’s no need for concern when you see lawn clippings gradually decomposing over the existing lawn. It’s there to help the grass of the future!
If you’re looking for community maintenance from ELS, call 602-243-1106 or visit elslandscapeaz.com.
By Northeastern U.S. standards, fall tree color comes to Arizona late in the season. Here in the Sonoran Desert, we might see our deciduous trees change to the iconic reds, oranges and yellows of autumn between October and sometimes January. Think of it this way—Arizonans get to enjoy an even longer leaf peeping season.
Detail of Yellow Fremont Cottonwood Leaves in Autumn Stream
The Science Behind the Colors
Getting a little scientific for a moment, leaves change color on deciduous trees, trees that shed their leaves in the winter, as opposed to evergreen trees, which tend to keep their leaves on their branches throughout the year. In the warm months, trees are busy producing food to grow. That process is called photosynthesis and produces chlorophyll, which creates the green color in leaves. When seasonal temperatures cool and the amount of daylight shortens, most trees slow down their growth and photosynthesize less. As chlorophyll production declines, other pigments that are always present in leaves gradually dominate over the green. In trees where the leaves turn yellow and orange in the fall, carotenoids are the pigments you see showing through in the leaves. In leaves that turn red to purple in the fall, you see the anthocyanin pigments come through.
Leaf Peeping in Arizona
To leaf peep in Arizona, look along our many waterways and riparian areas. You’ll spot fall color dotting our lower elevation cities, but the most showy fall tree varieties tend to be very large and generally aren’t suitable for urban landscapes. So head for the hills, where you are likely to see a preponderance of native trees that change color in autumn.
Easy to spot where there’s flowing water, Fremont Cottonwood (Populus fremontii) trees turn a gorgeous yellow in fall. Deep red leaves characterize tall Texas red oak (Quercus texana or Quercus buckleyi), the oak variety that is more common in urban landscapes and at lower elevations, while the shorter Gambel oak (Quercus gambelii) grows at higher elevations and shows in bright yellow and orange. At higher elevations, look along streams for the orange fall leaves of Arizona sycamore (Plantanus racemosa var. wrightii), for gold on quaking aspen (Populus tremuloides) and for light yellow on the Arizona walnut (Juglans rupestris var. major).
Add Showy Trees at Home
Want to add some fall color to your home landscape? This author is partial to the shape and color of the non-native Chinese pistache (Pistacia chinensis) tree, whose red and orange anthocyanins and carotenoids burst through in fall. Another tree for urban landscapes is the Arizona ash (Fraxinus velutina), and cultivar ‘Modesto’ is known for particularly splendid yellows. The boxelder (Acer negundo) ‘Sensation’ cultivar turns light pink in fall. In smaller spaces like patios, Pomegranates (Punica granatum) are excellent choices, with stunning reds and oranges, plus edible fruit in autumn. (Note, however, that dwarf varieties of pomegranate will give you a colorful autumn show but produce inedible fruits.)
This is by no means a comprehensive list of native or desert-adapted plants that change colors in autumn in Arizona, but now you have a little bit of the science behind the transformation in leaf color and a lot of pointers on what to look for on your leaf peeping escapades between now and January.
