In most cases, use of organic mulch increases the nutrient fertility of the underlying soil and decreases the need for fertilizer application to mulched plants. However, the use of fresh wood or bark as mulch may lead to temporary nitrogen deficiency because microorganisms that decompose these high carbon content materials use up nitrogen that otherwise would have been available to the plant.
This is mainly a problem if the mulch is incorporated into the soil. Nitrogen loss can be avoided by using composted mulch or by adding nitrogen at a rate of 1-2 lbs actual N per 1000 ft2.
Over time, organic mulches break down and will need to be replenished. Replenishment can be accomplished simply by adding more mulch over the top of the decomposed mulch material. Before adding new mulch, roughen up the old mulch layer to prevent formation of a water-impervious surface between old and new mulch.
Decomposition of organic mulches sometimes can lead to nitrogen deficiency. Watch plants for telltale signs of nitrogen deficiency. If you notice yellowing that starts in older leaves, as well as decreased vigor, replace lost nitrogen using the fertilizer rate listed above.
Inorganic mulches consist of non-plant materials and may include a variety of different kinds of rock or gravel. Different sizes and colors of inorganic mulches are available. The decision about which to use will depend upon the kind of landscape, the reason for its use, and its availability.
Examples include gravel or crushed stone, lava rock, recycled tumbled glass, and cobblestones of different sizes, shapes, and colors. The size of inorganic mulch particles should complement the scale of the landscape. For example, cobblestones work great in an expansive formal or naturalized setting or in a rock garden, but would be overwhelming in a small flower bed.
Inorganic mulches provide the same benefits as organic mulches, including moisture retention, temperature moderation, and prevention of compaction. In addition, inorganic mulches provide excellent drainage that is often required of drought-adapted plants. Inorganic mulches do not decompose and need to be replaced infrequently.
The disadvantage of inorganic mulch is that it does not add to soil fertility or organic matter, and plants will need to be monitored for signs of nutrient deficiency and fertilized accordingly.
Apply organic mulch to a depth of 3 to 4 inches, and inorganic mulch to a depth of 2 to 3 inches. A 2-inch thick layer of mulch requires about 6 cubic yards of material per 1000 square feet of area.
A weed barrier may be placed on the soil surface before using either organic or inorganic mulch material. The best choices are landscape fabrics of various types that allow air exchange and water infiltration.
Plastic sheeting should be avoided because it tears easily, may generate excessively high root-zone temperatures in direct sun, and interferes with water and air exchange with the soil.
Apply landscape fabric in strips over the soil, overlapping strips about 4 inches. Place mulch material over the weed barrier. Decomposed organic mulch will favor the growth of weeds on top of the weed barrier and should be replaced rather than replenished as needed.
In Utah, urban landscape irrigation accounts for 50-65% of the annual municipal water use, and much of it is applied in excess of the plant's needs. Scheduling irrigation according to landscape plant water needs can reduce excess water use. In addition to conserving water, proper irrigation can encourage deeper root growth and healthier, more drought tolerant landscapes.
An important component of water-efficient landscaping is creating hydrozones for your irrigation needs. To provide adequate water to all plants without over or under-watering some, group plants with similar irrigation needs in one zone.
Once your plants are grouped into zero, low, medium and high water groups, you should plan your irrigation schedule to apply the appropriate amount of water to each zone. You can learn a great deal about plant-water requirements simply by observation.
Signs, such as wilting, will let you know when many landscape plants require watering, but be careful not to overdo it. Plant roots need just as much air as water and you don’t want to drown them. If you are using an automatic irrigation timer, be sure to adjust it seasonally as the weather changes.
A great deal of water is wasted when automatic irrigation systems are continually programmed for the hottest part of the summer without adjusting for times when temperatures are cooler and more natural precipitation is occurring.
Another important aspect of irrigation planning includes routine maintenance of the system. Monthly examination of the irrigation system, while in use, will help you to find and repair any broken, misaligned, or clogged sprinkler heads and keep your system running efficiently.
Drip Irrigation systems consists of plastic pipes with emitters that deliver water directly to plants. These types of systems are great for water-efficient landscapes as water goes directly to the plants roots and is not wasted on areas that do not need to be watered.
AerationTurfgrass has shallower roots than other landscape plants and therefore should be irrigated more frequently, but not as deeply as other landscape plants. Consider using turfgrasses with lower water requirements to reduce water use even further.
Plan and design irrigation systems so that turfgrass areas are irrigated separately from other landscape plants. There are several resources available to determine the appropriate watering schedule for turf areas in Utah.
Trees and shrubs have much deeper and more extensive root systems than turfgrass so they should be watered less frequently but for longer periods of time. The optimum time to water is just before you can observe any water stress. Therefore, it is important to determine sub-surface soil moisture. Soil moisture can be determined using a soil moisture probe.
Sandy soils absorb water the fastest (about 2" per hour), followed by loam soils (3/4" per hour). Clay soils have the slowest absorption rate (1/2"per hour). By allowing water to penetrate deeper into the soil profile, you are encouraging deeper rooting and a more drought tolerant plant.
Frequent, light irrigation will lead to plants that have a shallow root system and that are more prone to water stress. When using sprinkler systems about 1/2 -1 inch of water may be required weekly for shrubs and smaller trees (<4" trunk diameter). For drip irrigation about 5-50 gallons of water may be required.
These amounts would be higher in southern Utah and lower in northern Utah and would also depend on plant size. Large trees (>4" trunk diameter), depending on the size of the tree, may require hundreds of gallons of water per week. Water newly planted trees and shrubs more frequently until the root system is established.
Irrigation system maintenance is necessary to ensure the most efficient use of water that is being applied. Irrigation controllers should be checked at the beginning of each growing season before running sprinklers for the first time.
Programming: Set-up an irrigation schedule. The following basic irrigation schedule is recommended for use in Utah. Consult USU county extension offices for irrigation schedules that are directly applicable to your county
Inspect Sprinkler System: Once the irrigation schedule is programmed, inspect the sprinkler system by checking the valves,sprinkler heads, and emitters. Before running the system, remove the last sprinkler head in each line and let the water run for a few minutes to flush out any dirt and debris. Replace the sprinkler head and turn the system on, running one valve at a time.
Inspect Drip System: As with sprinkler systems, flush the drip system before running it by removing the emitters and letting water run through the tubing for a few minutes to flush out any dirt and debris. Replace emitters and run the system, one valve at a time, to check for problems.
Winterization: Basic winterization of a sprinkler system is quite simple. The water supply should be turned off at the main valve and the irrigation controller should be set to the “rain” or “off” setting. Each valve should be turned on to release pressure in the pipes and water should be drained from the system to protect any components that could freeze. Your system may have drain valves that can be opened for drainage, or you may have to blow out the system using air. You may wish to have your irrigation system blown out by an irrigation professional.
Check Your System: Check your water system at the start of the season to adjust any heads and make sure there was no damage over the winter. The Water Check program offers free irrigation checks in many Utah counties. To find out more, or to find out how to check your system yourself, go to the CWEL Water Check page.
A benefit of established water-wise landscapes is they require less time and money to maintain than a traditional landscape. This assumes you have limited turfgrass to areas where it is practical, you have selected plants adapted to your climate, and you have grouped landscape plants according to their water, soil, and sun exposure requirements. Spend less time trying to manipulate plants to fit your conditions, and more time enjoying their beauty.
A benefit of established water-wise landscapes is they require less time and money to maintain than a traditional landscape. This assumes you have limited turfgrass to areas where it is practical, you have selected plants adapted to your climate, and you have grouped landscape plants according to their water, soil, and sun exposure requirements. In such a landscape, you will spend less time trying to manipulate plants to fit your conditions, and more time enjoying their beauty.
Although the activities required to maintain a water-wise landscape are not different from those of a conventional landscape, the way you think about them will change as you reconsider your plant selections. The main activities of water-wise landscape maintenance are irrigation and irrigation system maintenance, weed control, fertilization, pruning, and pest and disease control.
Keep in mind that newly planted landscapes will require much more “upfront” maintenance, especially regarding weed control, and that all landscapes require some maintenance, whether they are water-wise or not.