Desert friendly xeriscapes are a great way to replace high-water-use turf grass with something beautiful, low-water-use and wildlife-friendly. Many Albuquerque area homeowners are taking their conversion projects a step further and choosing wood chip mulch over gravel or other aggregate, which can get hot and allow weeds to pop up.
Our featured homeowner replaced 2,000 square feet of high-water-use grass lawn with a xeriscape filled with a variety of local native plants. Their lawn had become too high maintenance to keep up, and they were interested in a more water efficient yard that was pollinator friendly and low maintenance. The shrubs they chose include chamisa, cherry sage and catmint. Flowering plants include Mexican primrose, dwarf plumbago, desert marigold, creeping germander and penstemon. A mix of ornamental grasses such as Karl Forester, blue avena and muhly grass as well as a native desert willow tree round out the landscape.
Additional Facts on Mulches:
Wood chip mulch insulates plant roots from both heat and cold, reducing moisture loss from the soil by evaporation, feeding beneficial soil microorganisms that enhance plant growth and improving soil health. This makes the soil more sponge-like and better able to hold water. By installing 3-4 inches of mulch over bare dirt, weeds are reduced, the soil is enriched and new plants retain more moisture.
Another benefit of organic mulches is that they can visually accommodate a little bit of leaf litter, reducing the need for constant raking and clean-up. A thin top dressing of mulch added every two to three years keeps the landscape looking fresh and replaces the material that has broken down to sustain the soil. Organic mulches are lightweight, making them easy to transport in a wheelbarrow and spread with a rake.
Mulches are available in bags from most local garden centers (avoid the dyed ones as the colors will fade) and in bulk from several retailers in the Albuquerque area. When you buy from local bulk retailers, you are supporting the recycling of local organic materials that may otherwise end up in a landfill and contribute to greenhouse gas emissions. Buying in bulk also means less plastic! Mulch is sometimes available at no cost from local tree trimming companies. In addition, Bernalillo County offers free mulch to residents who load it themselves at the East Mountain Transfer Station. County staff can load the mulch in your vehicle with a tractor for a $5 charge. The county also will deliver 30 cubic yards of mulch for $60, plus $2 a round trip mile for delivery. Mulches are a renewable resource that will improve landscape health and conserve water.
In areas of higher wind exposure or periodic inundation with water, use a wood chip mulch that is irregularly shaped and sized as the pieces will knit together better. This type of mulch can include recycled yard waste and tree trimmings as well as commercially available, locally processed wood products.
Property Data:
Grass converted to desert friendly xeriscape: 2,150 square feet
Total gallons saved in one year since conversion: 10,000 gallons.
Total rebate received: $2,250 (extra $100 bonus for using organic mulch)
Thinking about converting your yard from high-water-use grass to xeriscape? Check out the Desert Friendly Xeriscape Rebate page to learn more about the qualifications, requirements and process to apply for this generous rebate. Additionally, xeriscape rebate participants get 25% off the cost of installing bulk organic mulch, up to $100. If you want to top dress mulch around your trees, take advantage of our Treebates. You are welcome to contact our xeriscape specialist, Carl Christensen, at cwchristensen@abcwua.org or 505-289-3026.
Authors: Amos Arber, Xeriscape Rebate Inspector with the Water Resources Conservation Department for the Water Authority, and landscape architect Jill Brown, ASLA, MyLandscapeCoach.com. Have a question about the article? AskAnExpert@abcwua.or
What is urban heat? Dark surfaces like concrete, asphalt and brick absorb and retain heat from the sun. Little spaces between buildings can create heat canyons that trap this heat, forming “islands” that are warmer than rural or suburban areas.
Urban heat can affect us in many ways, such as increasing heat stroke, heart and lung diseases, energy costs, general discomfort, hyperthermia, and poor air quality. The U.S. Environmental Protection Agency projects that by 2040 Albuquerque will see four times the current annual number of days with temperatures of over 100 degrees.
But trees can help! Trees provide shade to keep us and the ground cool, as well as cooling the air through water loss, or evapotranspiration. Increasing the urban canopy can lower city temperatures.
Let’s Plant Albuquerque is a broad community alliance dedicated to planting 100,000 new trees in the city by 2030. The alliance represents a broad range of civic, government and community organizations dedicated to this goal.
DEVELOP, a NASA Applied Sciences Program, studied Albuquerque’s urban heat. DEVELOP conducts feasibility studies that bridge the gap between Earth science information and society and works with communities and organizations to address environmental and policy concerns.
NASA DEVELOP found that a 30% increase in tree shade can help offset rising temperatures and allow neighborhoods to be cooler. Trees can also increase your body’s “thermal comfort,” how cool and comfortable you feel on hot days.
The city’s parks canopy alone provides many benefits, including energy savings, air quality improvements and increased property values. The nearly 30,000 trees in the city’s public spaces provide:
$1.7 million in carbon monetary benefit
$624,000 in stormwater monetary benefit
$3.6 million in (overall monetary benefit
The Water Authority would like to encourage you to help cool our city by planting trees. The Tree-Bate program helps offset the cost of planting and maintaining trees.
When you buy a new tree, you can receive a rebate equal to 25% of the purchase price up to $100 a year. To help customers narrow down their purchasing decisions, the Water Authority assembled a list of 20 trees that are proven to thrive in our area, are commonly available for purchase, fit a variety of situations and provide numerous environmental benefits. A broader list of more than 160 qualifying trees is in the Water Authority’s Xeriscaping Guide. They include:
As one might guess, the subtropics are a great place to grow fruit trees and a particularly good place to find plants that are heat and drought tolerant — sort of a prerequisite for plant selection in a hot, dry place like New Mexico, or at least it should be!
The term subtropical refers to a climatic region, defined by latitude, that lies between the tropical and temperate zones. This region experiences warm to hot summers and mild winters with overall annual temperature variation more significant than in tropical regions but less extreme than in temperate zones. There is also plenty of rainfall variation across the subtropics, with climates ranging from arid to humid. Subtropical regions often experience seasonal rainfall patterns such as monsoons or wet and dry seasons.
The problem with growing heat and drought tolerant subtropical plants in our high desert is that we have anything but mild winters. Much like another inhabitant of the subtropical/mediterranean climate of Greece, the hero Achilles known for his one weakness, these plants have a very specific vulnerability — cold.
I love to grow plants, fruit in particular. But as irrigation access has become harder to come by and the summer heat seems to last longer than it used to, I have become more and more attracted to plants that thrive in the hot and dry. Navigating the puzzle of a changing climate while planting trees and shrubs is challenging. Long-lived perennials need to be appropriate for today's climate as well as the climate 20 years from now and even the climate 250 years from now if you are a real optimist.
It's tempting to just plant a zone or more higher than the current USDA Plant Hardiness Zone Map (which has itself been updated to reflect higher temperatures twice since 2012), but our weakening jet stream means more chance of Arctic air slipping in and spoiling the fun as we experienced to the extreme in the winter of 2011. The way things are headed has, in many cases, led us to exchange one set of growing problems — namely, heat and drought stress — with another — cold damage.
Two fruiting shrubs from the subtropics, pomegranates and figs, have proven to have the right combination of fruiting characteristics and cold tolerance to work in our moving-target-Goldilocks-growing-zone of Central New Mexico.
The fig is extremely adaptable. I imagine this has something to do with why they have evolved and been grown by humans for thousands of years. They perform well in Albuquerque, particularly because of all the heat that gets banked into concrete, asphalt and structures during the day. This heat radiates back out at night, keeping figs at much warmer temperatures than they would otherwise experience during winter in a more exposed area. Figs are tolerant of abuse and relatively content with our intense sunlight, extended droughts and alkaline soils. They can take temperatures down to the low teens, but need to be protected, buried or even brought inside if temperatures fall below that.
There are plenty of examples around town of figs without protection that rarely, if ever, freeze to the ground. Even so, freezing to the ground does not mean death for a fig — a winter-killed fig of an early ripening variety can easily end up fruiting by the end of the summer. That's because figs often come up from the roots and fruit their main crop on the current season's growth. Given an early enough ripening variety, that once-frozen fig can still yield fruit in the same year!
Pomegranates, I have found to be a bit more cold-hardy than figs — although they, too, benefit from a protected, south-facing location to improve winter survival. Optimal conditions for the wild pomegranate exist in high sunlight, hot climates with minimum temperatures not lower than 10 degrees. Although, with the protective care of a thoughtful gardener, lower temperatures are negotiable. There is also significant variation in cold-hardiness among pomegranate varieties, with dwarf varieties experiencing damage at 19 degrees, many soft-seeded varieties at 10-12 degrees and hard-seeded varieties at 0-3 degrees.
For both pomegranates and figs, young plants are more frost sensitive to cold than mature plants. So if you have trouble the first year or two with losing branches to cold, remember that these plants get more frost resistant with time. These are both wonderful subtropical fruiting shrubs that are worth the extra trouble during our high desert winter to experience their summertime beauty and bounty.
Learn more about specific types of gardening here:
Author: Graeme Davis is an ISA certified arborist and the owner of Flora Fauna Farm, a nursery that focuses on plants that grow well in the high desert. Flora Fauna Farm grows a diversity of edible trees and shrubs, useful native plants and unique landscape plants curiously underrepresented in the urban canopy of Albuquerque. You can see its offerings at www.florafauna.farm. Have a question about the article? AskAnExpert@abcwua.org
Passive rainwater harvesting allows you to collect rainwater runoff from roofs, patios and driveways as well as the overflow from rain barrels and cisterns (active rainwater harvesting sources) and direct it into the landscape. The water then gets stored in the soil where plants can take advantage of the moisture.
Several rainwater harvesting techniques can turn potential problems (i.e. erosion, flooding or excess moisture near foundations) into water for your plants. Rainwater contains extra nutrients not always found in potable water, so the plants receive additional benefits. Passive rainwater harvesting also helps filter out pollutants, increase infiltration to the aquifer and provide healthier ecosystem habitat.
Start by calculating the amount of water that flows from your potential runoff sources. For every 1,000 square feet of hard surface, 1 inch of rain will generate approximately 600 gallons of water. It’s easy to see why rain barrels or cisterns can quickly fill during medium to larger rain events, so a passive collection system for overflow is always a good idea. You want to make sure whatever system you create will be able to handle a
good-sized rain event (refer to the link above). It’s very important to create a directed overflow so that when there is a large rainstorm, the excess water will flow into a basin or other feature onsite or into the street (if your capacity is limited) without creating erosion.
There are many different techniques, and some can be used together to enhance the benefits. These techniques include rain gardens, swales, basins, soil sponges, curb cuts, French drains and pumice wicks, check dams and gabions. Study your site and these techniques to determine the best option for your garden. Watch your site during a rain to see where the runoff comes from and where it goes. You may want to take advantage of existing patterns.
Rain gardens are depressions to catch surface runoff from slopes and are best planted with native plants that can take occasional flooding.
Swales are sloped depressions that convey water into basins or rain gardens from canales, downspouts or other drains. Make sure the slopes consistently move the water downhill and are large enough to not get overwhelmed. Swales are usually lined with large gravel or cobble to prevent erosion. If you have extra material onsite, this is a great recycling solution. Make sure that swales are designed to catch the slow drip of a light rain as well as the powerful flow of a heavy downpour.
Basins are catchment ponds designed to handle large rain events and provide a great place to plant trees and larger shrubs or heavy water use plants that can benefit from the extra water. Calculating the size to match your runoff is vital here. The area where the runoff from your swale(s) enters the basin will need gravel to dissipate the erosive forces. Shredded wood mulch works best in the bottom of the basin. The capacity of the basin and the health of the plants can be further enhanced by installing soil sponges (see below) in the low points. In larger yards, you may want to create a series of basins to increase capacity and opportunities for plantings.
Soil sponges are post holes dug and filled with a soil mix containing compost to increase infiltration and introduce organic matter and beneficial microbes to the soil sponge and surrounding soil. These also provide an avenue for plant roots to quickly grow deeper, improving health and drought tolerance.
Curb cuts are made with a concrete saw to channel runoff into a basin. This can be done on your own property, but permission is needed to cut into a public curb to direct excess water into the street.
French drains and pumice wicks are progressively deeper trenches lined with geotextile fabric (to prevent silting up) and filled with gravel or pumice. These are best used when you have existing trees or large shrubs and the base of those plants is on the same level or higher than where your runoff originates. Aim them directly at the tree or shrub to minimize root damage while still providing additional water to the plants’ root zone. The open space in pumice provides additional water capacity.
Check dams and gabions are small dams used in areas where existing runoff has started to erode and cut deeply into the soil. These small dams slow down the water so it infiltrates and lessens erosion. Gabions are a type of check dam constructed of riprap (oversize gravel/cobble) held together with a wire basket. Generally, both have an area of cobble below to prevent erosion.
Passive rainwater harvesting is a great way to lessen your use of potable water, reduce erosion and provide a supplemental water source for your garden. Remember, you still will need to water your plants (through irrigation or hand watering) to establish them and, in most cases, to maintain their health.
The jujube is just one of those trees that is extra! Extra fruitful, extra nutritious, extra hardy, extra beautiful. This medium sized tree comes in 400 varieties, many of which are being cultivated and taking root in Albuquerque.
The jujube tree, often called Chinese date, has been cultivated for thousands of years around the world, in Albuquerque for nearly 60 years and in the panhandle of Texas since 1875. Its small abundant fruits are high in fiber, vitamin C, potassium, antioxidants and phenolic compounds and have been used to support nervous system, cardiac and digestive health. Medicinally, it is used as a tonic sweetener in many supportive Chinese herbal remedies.
The fruit can be eaten raw, dried or cooked. Fresh from the tree, when they’re mature and a luscious mahogany brown, they have a crunchy refreshing taste, like a cross between an apple and a date. As they dry, they become sweeter and chewy. Dried, they are delicious in oatmeal, cookies, trail mix or anywhere you would use dried fruit. They make an excellent chai — just boil dried pieces with other ingredients, letting the earthy sweet flavor complement ginger, cinnamon, cardamom, pepper and other traditional chai ingredients. You also can find recipes from Korea, China, Vietnam, India, Italy and many Persian cultures that incorporate the jujube for both sweet and savory dishes.
The fruit is very easy to dry and, in fact, many that you miss harvesting will dry right on the tree. However, we do recommend bringing them inside to dry and cutting the pits out before drying so they are easier to eat and enjoy down the road. If you have a dehydrator, that will speed the process, but they will also dry if you place them on cookie sheets in a spare room, on top of a shed in the sun or even in a car and let our New Mexico dry air work its magic. Jujubes don’t bruise and spoil quickly like other stone fruits, so windfalls and bird-pecked fruits don’t make a mess and are still usable.
We love edible landscapes, so we’re naturally drawn to these fabulous trees. But even if you aren’t looking for food, the jujube is a wonderfully hardy tree for Albuquerque. This tough specimen hails from the buckthorn family, Rhamnaceae, and will grow in USDA hardiness zones 6-11, which is an extraordinary range for any tree! At the moment, Albuquerque is generally zone 7, but as we face climate disruption, landscapers and planners are encouraging planting with an eye to zone 8 or 9 so our shade and habitat trees can withstand increasing heat. Jujubes are deeply rooted and can tolerate drought and saline and alkaline soils. Once established they can survive with small amounts of water, though a strategic watering schedule will increase your yield. Because they’re so drought tolerant, we don’t recommend planting a veggie garden under them or they’ll drink up all the water intended for your zucchini. They do well in full sun or light shade. They can handle sustained days and weeks of 100 degree plus heat, 23 below zero in winter and anything in between. They must have a frost to produce fruit, which isn’t a problem here. Jujubes do sucker quite a bit from their roots, and this rootstock, if allowed to sprout, produces very small, almost inedible fruits that are mostly pit. So, we do suggest being vigilant in cutting down the root sprouts as they appear.
Jujubes make a beautiful addition to any landscape. They have an elegant zig zag branch growth pattern and bright green, shiny oval leaves that can even withstand severe hail. They can be trained to a traditional tree structure or allowed to be a little wild and shrubby. They provide cool shade and habitat for birds, pollinators and other wildlife. Speaking of wildlife, one of us has a friend whose small dog Kipper grabs himself a couple from the ground during ripening season, carrying them happily to his bed to snack on … he’s not wildlife, but that little dog seems to love a jujube even above his biscuit treats. These trees benefit from cross pollination so plant yourself two of these beauties!
Planting trees not only gives you the riches of your tree, but it is also a love letter to the future. As gardeners who are tending land and each other in the midst of climate chaos, we have the opportunity to cultivate healing, repair and hope. With every tree we plant, we can try to leave our small patch of earth a little better than how we found it — cooled with shade, brightened with birdsong and providing nutritious food via a resilient, prized and giving tree. The next time you’re sitting in your garden, allow yourself to dream of a future where someone is harvesting jujubes and appreciating the ancestors who cultivated and left these sweet trees for them.
Learn more about specific types of gardening here:
Author: Corva Rose is an arborist and founder of Tree School, and can be reached through treeschoolNM.com, Jennifer Gardner has been gardening in Albuquerque for 30 years, with an emphasis on residential scale food planting. Have a question about the article? AskAnExpert@abcwua.org
Trees are especially important in arid, urban environments like Albuquerque and Bernalillo County. They provide shade, mitigate urban heat, reduce greenhouse gasses and air pollution, and create wildlife habitat, among many other benefits. All trees, even climate-resilient and drought tolerant species, need to be watered adequately.
It’s worth the investment to keep our mature trees healthy. The mature trees on your property are worth much more than the cost of your treasured appliances and, yes, even more than your roof. Keeping our trees healthy and happy over their lifetime is a minimal investment and a valuable contribution to our community urban forest.
In Albuquerque, we tend to overwater our lawns and underwater our trees. It’s important to understand the basics of how best to water trees. For instance, a tree has two different main types of roots. The feeder roots lie within the first 6-24”of the ground, and the stabilizer roots can be at least 3’ deep You may think your trees’ roots can reach the water table, but you should think again — most of Albuquerque has a water table between 20 and 150 feet’ deep. Your roots are never getting that deep.
Due to the importance of our urban forest and how many people are seeking guidance on how to water their trees, the Bernalillo County Water Conservation Program, and Let’s Plant Albuquerque, partners collaborated to create this How to Build an Efficient Tree Watering System guide and the associated workshops.
The tree irrigation system is inexpensive, flexible, easy to install and long-lasting. It uses drip irrigation attached to your hose bib and can be easily expanded as your tree matures.
When assembling your system there are a few key parts to consider:
Teflon tape is needed to seal the threads at every connection to prevent water coming through.
Take note of the two different types of threads: hose threads and pipe threads. Hose threads are straight and require a washer to seal. Pipe and coupling threads are tapered for water use and will seal with just the application of Teflon thread seal tape.
Timers should be uninstalled and stored with the batteries removed over the winter. Some people like to install fresh batteries every spring to ensure there is no interruption during the growing season.
A pressure regulator is important for all drip systems due to the high pressure in our Albuquerque water lines. The regulator reduces the water pressure coming in from the main water supply. Then, it creates a constant low water pressure through the system, allowing the drip tubing to put out the correct volume of water per minute.
Distribution (lateral line) drip tubing comes in two general sizes, and each has advantages and limitations:
1/2” tubing is more common, and parts are available at big box stores. The run of distribution tubing must be less than 200 feet.
¾” tubing is available from irrigation supply stores. It holds pressure better, and tubing runs can be up to 600 feet.
Inline drip line (emitter line) drip tubing comes in two sizes and includes drip emitters pre-installed in the line every 6”, 12” or 18”.
½” Netafim inline dripline tubing for use around medium and large trees. Use 12” emitter spacing.
¼” Netafim inline dripline tubing for use around small trees. Use 6” emitter spacing.
A flush type of end cap is handy for flushing out the system at season start-up or if a break occurs. It is recommended to remove and store flush caps over the winter.
The watering guidance for the system was developed to not under or over water most trees in Albuquerque. However, irrigation is highly dependent on site conditions such as soil type and microclimate as well as the species of tree. This guidance is meant to be a rule of thumb or starting point, and adjustments should be made based on the local conditions and tree species.
Below are some of the factors that should be considered in generating a watering schedule for your yard:
Soils affect how often and how long you need to water — see the Water Authority’s Irrigation Guide for more details. In general, sandy soils require shorter but more frequent run times while clay soils need longer but less frequent run times.
Always check your plants to evaluate irrigation scheduling. Most plants will look a little bedraggled at 3 p.m. during the summer so check in the morning. Do they seem wilted or pale or have cupped leaves? These can be signs your tree needs more water.
Be aware that symptoms of overwatering and underwatering may look similar.
Occasionally, feel the soil the day after irrigating or use a soil probe such as a screwdriver or coat hanger to evaluate the level of moisture in the soil. If the probe is easy to push in and there is a swampy smell, the soil has too much water. If you can’t get the soil probe more than 4” into the soil, it’s too dry. Ideally, the soil probe can be pushed 12”-18” into the soil 24-48 hours after irrigating.
Consider what size tree you are trying to water. Check out the diagrams above and below to determine how much tube length you will need to meet the required water needs of your tree.
