Irrigation Basics

The soil type on your property is an important factor in determining how fast and how often water can be applied to the plant material.

Soil type
Soil absorbs and holds water in much the same way as a sponge. A given texture and volume of soil will hold a given amount of moisture. The intake rate of the soil will influence the precipitation rate and type of sprinkler that can be used. The ability of soil to hold moisture, and the amount of moisture it can hold, will greatly affect the irrigation schedule.

Soil is made up of sand, silt and clay particles. The percentage of each of these three particles is what determines the actual soil texture. Because the percentage of any one of these three particles can differ, there is virtually an unlimited number of soil types possible.

The simplest way to determine the soil type is to place a moistened soil sample in your hand and squeeze. Take the sample from a representative part of the site, and from approximately the same depth to which you will be watering. In other words, if you want to water to a depth of 6 in (15 cm), dig down 6 in (15 cm) to take your soil sample.

The Jar Test

A more accurate way to determine the amount of sand, silt and clay in your soil is to conduct the jar test.

1. Remove 1 to 2 cups of soil from the zone to be irrigated.

2. Place into a glass jar, like a mason jar.

3. Fill the jar half way with water. Shake and let sit for 2 hours so the particles can settle. The heavier sand particles will settle to the bottom, then silt, then clay on top.

4. Measure the height of all 3 layers of the soil then the height of each layer; divide the height of each layer by the total height to figure out the percentage of each soil in the jar.

5. Apply these figures to the “Soil Classification” chart. In the example, now you know the landscape soil is silt loam.

One of the most significant differences between different soil types is the way in which they absorb and hold water. Capillary action is the primary force in spreading water horizontally through the soil. Both gravity and capillary action influence vertical movement of water. In coarser soils, water is more likely to be absorbed vertically, but will not spread very far horizontally. The opposite is true for finer soils.

The table below lists the general characteristics of the three main soil types.

click to enlarge

Look particularly at the information in the last three columns. The soil’s intake rate, or how fast it absorbs water, dictates how quickly water can be applied by the irrigation system. Coarse, sandy soil absorbs water very quickly while silts and clays have a very low intake rate. The fine textured soils, once wet, retain moisture longer than do the coarse grained soils. The main problem we wish to avoid is applying water faster than the soil can receive it. This causes runoff, erosion or soil puddling, all of which waste water and can cause damage.

Rolling terrain further complicates the problem of matching the application rate from the sprinklers with the intake rate of the soil. As the angle of slope increases, the intake rate decreases because of the higher potential for runoff.

(thanks to Rainbird for the information in this article http://www.rainbird.com/homeowner/education/soiltype.htm)

(RENO, Nev.) – Truckee Meadows Water Authority (TMWA) reminds residents that trees, shrubs, lawns and other plants need supplemental water to stay healthy during extended winter dry spells like the one we are in now. TMWA’s Conservation Department offers these tips to help your yard get through a dry winter, while still protecting your home:

• Water in the late morning, when the water has plenty of time to reach the root zones without freezing.
• For trees and shrubs, a soaker hose is a great way to gradually water the roots. It slowly seeps water out, so you can leave it on for an hour or two at a time.
• For smaller plants or small turf areas, a hose with a nozzle is recommended.
• For larger turf areas, you may want to turn on your irrigation system. Leave the sprinklers on during the day for only 10 minutes at a time to prevent runoff.

Whatever the tool, be sure your hose or irrigation system is disconnected and properly drained the same day to prevent leaks and broken pipes due to freezing overnight temperatures. Visit http://www.tmwa.com/winterize for more information.

http://tmwa.com/news/press-releases/01-05-2012/-proper-winter-watering-during-dry-spells.

Winter Watering

All this warm, dry weather is abnormal for this time of year, so even if you’re used to just letting your plants sit dormant over the winter, right now you might want to think about pulling your hose or sprinkler out of storage.

• Get out the hoses or run the sprinklers.
• Lawns on south-facing, southwest facing areas and slopes should get special attention since they receive more sun.

Winter drought can lead to root injury or death.  These drought-injured plants may not show symptoms of the problem until the next season or even the next year.  In fact they may leaf out and flower just fine in the spring, relying on stored food reserves.  Once that energy supply runs out plants weaken and start dying back.  Even if a plant isn’t killed outright, it is made more susceptible to insect and disease attack.

Northern Nevadans, if we want to save our lawns, we’re going to need to do some unseasonable gardening.

So here’s what you need to do:

Go outside and take a look at your lawn. This time of year it’s normal to see some brown in the grass, but since the weather has been so warm, a healthy lawn should also be partially green. The next thing you want to do is check the root zone. If the soil is dry about four inches down, you need to water it.

Water only when the air temperature is above freezing and the soil isn’t frozen…  Water early in the day to allow water time to drain away from the bases of plants.  (Frozen water next to the bark can physically damage trees and shrubs.)  Soaker hoses work well for applying the water slowly and where needed.

Apply the water where it counts the most… in the root zone.  Consider that established trees have roots that go out at least as far as the tree is tall and usually further.  It is in the “dripline” and just beyond where most of the water should be applied.  The “dripline” is an imaginary vertical line that is perpendicular to the longest side branches of the tree and perpendicular to the ground.  Water applied at the tree trunk base is wasted because there are no water absorbing roots there.

Watering recently planted trees and shrubs is a different story.  Their roots don’t go out that far yet.  In this case you will want to water the root ball zone and just beyond.  The aim is to water where the roots are.  This makes sense doesn’t it?

And since our weather can be unpredictable, it’s good to remember to drain your hose and store it somewhere where it won’t freeze, and make sure your hose bibs are insulated.

If you need help with this, we are here for you.  Give us a call today at: 329-1531. All Seasons Lawn & Landscaping, serving the reno & sparks community for over 20 years.

Now that night temperatures are dipping below freezing, it’s time to think about turning off your irrigation system.

Shorter days, cooler temperatures and plant dormancy all signal decreased needs for water. To avoid damage from freezing, shut off your system before cold temperatures arrive. Watch the weather and the long-term forecasts to know when the time is right to shut down your irrigation system. Most years, you’ll want to turn it off by Halloween.

Before you do, soak your trees and shrubs to a depth of 18 inches to make sure the soil is moist. Irrigate to the drip line of the plants — the outer tips of the branches — using soaker hoses or sprinklers. Most drip systems, unless they are sprayers, don’t provide sufficiently uniform water coverage to do the job.

To determine if you’ve watered enough, stick a piece of rebar, a long screwdriver, or another indicator into the soil. If it pushes in readily to the 18-inch depth, you’ve watered enough. You can also dig a hole to the 18-inch depth to check soil moisture, but be sure to avoid damaging the roots. Note about how long you watered, and you’ll be ahead of the game next year.

To avoid damage to irrigation systems, take a few steps to prepare them for winter. If you don’t, you can expect to spend time next spring digging up your water lines to repair winter freeze damage. You can hire a professional lawn service to do the job, or do it yourself.

To winterize your irrigation system, start by turning off the controller, if you have one. Check the owner’s manual to figure out how to do this. Then, shut off the water to the irrigation system at the main valve.

Next, drain any above ground irrigation components that hold water. Blow out the pipes in your sprinkler system, keeping the pressure under 50 pounds per square inch (psi). Experts advise blowing out each valve in the system, and then repeating the process a second time. Be careful and wear safety goggles. If this sounds too complicated, or you don’t have an air compressor, consider hiring a contractor to do this part.
Don’t forget to drain your drip system. Since drip lines are usually on the ground surface or under mulch, they’re susceptible to freezing.

With the water turned off, undo the end caps and let the system drain. If you want to use a compressor, keep the pressure under 30 psi to avoid damaging system components. Don’t forget to put the end caps back on to keep water and debris from clogging up the system. You don’t need to move the tubing or emitters once emptied, but timers should be stored at above-freezing temperatures.

Even with your system shut down for winter, some plants still need water. Trees should also be watered if it’s been three to four weeks without significant precipitation such as an inch or so of water. Be sure to water the root ball of newly planted trees regularly through the winter and early spring.

Roses also appreciate water during the winter. Use a watering can to apply a few cups of water at least once a month, but don’t prune them now. Wait until spring.

Most lawns will do just fine without winter irrigation. The exceptions are newly seeded or sodded lawns that have not yet developed robust root systems. They’ll also need water if it’s been dry for three to four weeks, as long as the soil is not frozen.

If you don’t want to fire up your irrigation system, use a hose and sprinkler. A little winter care will yield healthy plants in the spring.

Susan Donaldson is water quality and weed specialist for the western area of University of Nevada Cooperative Extension.

http://www.rgj.com/article/20111029/LIV04/110290302/Master-Gardener-Time-shut-off-sprinklers?odyssey=mod|newswell|text|Local%20Life|s

How to Aerate a Lawn

Highlights:

• • Step 1: Determine the Need for Lawn Aeration
  • Step 2: Prepare the Lawn for Aeration
  • Step 3: Aerate the Lawn
  • Step 4: Apply Compost or Sand Over the Aerated Lawn

Click here to see full article  http://www.diynetwork.com/how-to/how-to-aerate-a-lawn/index.html

Step 3: Aerate the Lawn

Run the core aerator over the lawn in a pattern that covers the area only once.

Note: A mechanical core aerator is the best equipment to use for aeration. The tines on this type of machine are hollow on the inside so that they pull soil cores out of the earth. Other aerators such as those with spikes don’t work as well and may actually further compact soils. You can rent core aerators from most garden centers for about $30 to $75 for a few hours. Enlist the help of a couple of friends and a truck when picking up the equipment as it can be heavy and awkward. Read the operator’s manual carefully prior to use.

Step 4: Apply Compost or Sand Over the Aerated Lawn

The soil cores can be left on the ground after aeration and allowed to decompose. Or, rake them into piles and throw in the compost bin. However, this isn’t necessary as it should take about two to four weeks for the soil cores to break down naturally. Sprinkle compost (sand or peat moss can be used instead of compost) over the lawn to fill in the holes.

Note: After aeration, apply grass seed and fertilizer to lawns as this is an ideal time to do so.

January 29, 2011

Are there ways to improve your landscaping that will not cost you a fortune? How can you get great results without falling into a financial black hole?

Truth is most landscaping does take money, but there are some low-cost and no-cost options that you can put into action that will help you to get the best results. Landscaping in northern Nevada’s Great Basin is challenging to say the least. The average annual rainfall is 4 inches to 8 inches and the growing season is less than 160 days. Temperatures in the spring, summer and fall can fluctuate 40 degrees to 50 degrees in a single day which plays havoc on our trees, shrubs and perennials, not to mention the vegetable gardens. Our summers are characterized by 90 degree to 100 degree temperatures coupled with hot dry winds, making it difficult to keep plants from turning brown and shriveling. While these ideas will not cost you a lot of money they will cost you time, so prepare for that.

These are fantastic ideas for getting started. They also work! All too often I see plants planted in the wrong place or sprinklers heads added to a zone to water a dry spot in the lawn which only makes, matters worse.  Many landscape problems are easy to solve and diagnose and here are simple problems and solutions that occur in the field.

1. Find the cause of Dry Spots. Without getting too technical, turn the system on, then try pushing the sprinkler head riser (the pop-up part), down. If it goes down easily, this should raise red flags telling you that there is not enough water pressure to irrigate efficiently (head to head coverage), hence dry spots or “green doughnuts”.  If this is the case, visually audit the entire station while it’s running.  Examine each head to make certain the loss of pressure is not caused by worn or leaky wiper seals, mix heads (two different sprinklers with two different operating pressures and flows), a leaky valve or two stations coming on at the same time.  If your findings take you back to a water pressure problem then try retro-fitting the existing sprinkler system with low pressure and low volume heads or nozzles, i.e., MP Rotors.  Investigate every possible solution you can to fix the problem for the long term and don’t take the “band-aide” approach.

2. Don’t “baby” your trees! Other problems seen in the landscape are trees damaged by stakes and tie wires left on the tree too long.  As a general rule, and the accepted arboriculture practice, stakes can be taken off after the first season. Given, certain areas require additional time but for the most part they need to be taken off after one year.  I have seen five year to 10 year old landscapes with staked trees. This will slowly kill a tree and weaken it.  What happens over time, the wire that wrapped around the tree to anchor it in place when it was

Fig. 1.0 Tree stake and ties left on a 5 year old tree.

young, becomes imbedded into the trunk as the tree trunk expands (Figure 1.0.).

A weak spot is then formed and its’ at this point where the tree will snap off in a strong wind if left unchecked and corrected. If the wire is left on over time, the wire will girdle the tree and kill it. If a tree cannot stand by itself after 2 years, there is something wrong with the tree.

3. Prune at the right time. One common issue includes pruning flowering perennials at the wrong time of year. This is particularly true with roses.  I mark April 15^th on my calendar to prune roses in our area, give or take a few days.  The reason for this date, roses are stimulated to grow right after you prune them. If you prune say in February or March, young tender shoots will be killed by our historical late frost weakening or in some cases killing the rose.  April 15^th is far enough along in the season for young tender growth to escape a frost.  Another plant that I see pruned at the wrong time of year are lilacs.  These are to be pruned after they flower in the summer and not in the fall.  When you prune spring flowering plants in fall, you remove next spring flowering buds.

4. Know your soil… Probably the most important landscape issue we face are the diverse soil types in the Truckee Meadows.  Our area has clay, sand, sodium affected and rocky soils. Planting in any one of these soil presents problems.  One simple way to avoid problems is to check the soil texture.  The soil texture will tell you of you sand, silt or clay soils. Knowing the soil texture will help with irrigation and fertilization. For example if you have a sandy soil without to much research, you have to know this soil drains fast taking with it precious nutrients.  Having this information can help with your irrigation and fertilization scheduling. Here is a simple way of determining the soil texture type. Grab a shovel or soil probe and scoop out a ½ fist full of soil 6 inches to 8 inches deep and place it in the palm of your hand.   Slightly wet the soil while kneading it to the consistency of putty. Then try to make a ribbon by pressing the ball between your thumb and forefingers.  If the soil makes a long ribbon, an inch or more you can conclude you have clay.  If the soil doesn’t make a ribbon and falls apart, you have sand or mixture of sand silt and some clay.  If you can make a ribbon about ¾ inches long you have a sandy clay loam.  Drainage is another issue we have in our areas and if you don’t want perform a soil texture by feel test then another quick way to see if the soil drains is by digging a hole 8 inches to 12 inches deep. Fill it with water and let it stand for a few hours then fill it again and let it stand for a day.  If the hole has water in it after a 24 hour period you have a drainage problem.  If it’s dry or moist you can safely assume the soil will drains adequately and over watering won’t be an issue.  Knowing the soil texture type will help you manage your watering frequency and length of time.

5. Check for overwatering. This seems crazy in the desert right? The first sign of over watering is wilting. The second clue, the leaves turn a light green color. This happens because the root ball is sitting in saturated soil and can’t take up oxygen which plants need to grow.  To correct the problem, cut back on the amount of time the plant is getting watered and allow the soil to dry out but, not completely.  To check for over or under watering use a soil probe or shovel to check the soil moisture and the distribution of water.  While you are probing the soil near a wilting plant and can’t penetrate the soil with a shove or probe, obviously the plant is not getting enough water. If you shove the probe or shovel in the soil and it slips in and goes out easily, and is water dripping at the end of the probe, the plant is being over watered.

These are just a few challenges in northern Nevada.  We can’t control Mother Nature but we can take care of problems in field by getting the proper training and taking the time to train to your employees.  And as I always say to my crew, “if you don’t know what the problem is, don’t be afraid to ask.” There is no such thing as a dumb question. You can get the word out there without spending hundreds of dollars.