Tag: irrigation

Welcome to Summer

It looks like the summer heat came a little early this year. We are already experiencing some of the warmest and driest conditions that the are has seen in a few years this early in the summer season. Over the holiday weekend, while you are spending time with family and friends, take heed of the temperatures and make sure that you keep yourself and your lawn hydrated.

Your turf likely has not been able to put down deep healthy roots since the wet winter (yes, too wet is a bad thing for turf). Please keep an eye on your turf and if you haven’t already turn on your irrigation system. We haven’t really needed them until this week, but if you have one use it. If you are unsure how to operate your system, let us know and we can assist you.

Watering during periods of drought can help prevent many serious turf problems like dormancy, yellowing, bare spots, and some diseases. Here are some tips on how and when to water your lawn:

When to water

Using irrigation water to fill the gaps between precipitation events is critical to a healthy lawn, and efficient, responsible use of this natural resource will keep water bills lower. You should always pay attention to any local ordinances regarding water usage. Drought tolerant turf species, while they may go dormant during drought, will revive once precipitation occurs or watering restrictions are lifted

To be the most efficient when watering your lawn, you should always irrigate when:
 Winds are calm
 In the early morning hours, this minimizes evaporation loss and results in a more efficient irrigation event.
 Only when lawns show signs of drought stress.

Do not irrigate in the evening (increases disease pressure)

How to Water

There are two basic kinds of sprinkler systems available to homeowners:

  1.  In-Ground, automatic irrigation: This is the most efficient way to irrigate your lawn. A professionally designed and installed system will provide complete and even distribution of water across the lawn surface, should have a battery back-up for any timing devices, and a rain sensor to disable the system when precipitation occurs.
  2.  Above Ground, movable hose based sprinklers: These methods are less expensive than in-ground systems, however not as efficient or convenient. These sprinklers may either be a portable surface type, which needs to be moved from time to time in order to cover the whole lawn or a traveling sprinkler, which follows the path of the hose or a cable around the lawn.

Both methods require observation and effort on the part of the homeowner in order to avoid over watering and ensuring uniform coverage through out the lawn.

Knowing how to irrigate is one thing, but how much should you be watering your lawn?

  • A general rule for most turf species requires 1 inch of water per week in order to maintain a healthy status, this includes any precipitation.
  • Irrigation should be a supplement to natural precipitation, not the main source of water for your lawn.
  • Water once every 2-3 days in periods of drought (about a half an inch per application).
  • If one or more inches of precipitation falls in any given week, then supplemental irrigation is not necessary.
  • Soils that are primarily clay based (most around here) will require less water overall and fewer applications than more sandy soils. Clay has a very high water holding capacity.

Irrigation cycles should be run so that you are watering as deeply as possible into the soil profile, with causing runoff on the surface. Irrigation should only be applied to supplement precipitation deficits. Avoid hard and fast irrigation timer settings, be flexible with your times and days. Avoid standing water in your lawn.

To determine if you are applying the correct amount of water, place a rain gauge between a series of irrigation heads or midway between the sprinkler and the end of its coverage and check the depth of water in the gauge after a predetermined length of time. Use this information to calculate the amount of time that irrigation must be applied to reach ½ inch.

Things to keep in mind
When watering
• Water deeply and infrequently.
• Proper use of sprinkler water will result in a healthier and attractive lawn and lower water bills.
• Consider spot watering localized dry spots instead of the entire lawn.
• Water areas on mounds and berms and near buildings more often, where reflected heat dries the turf.
• Avoid irrigating until water runs off the lawn surface and on to walks and roads.
• Areas shaded from trees may require more water to support both trees and turf grasses.
• Avoid standing water for any period of time.

When Maintaining
• Make sure that you are mowing at the proper height for your turf species (not all grasses should be mown at the same height of cut).
• A sharp mower blade is essential if you want to maintain a healthy lawn through periods of stress. Dull blades tear the grass, resulting in a more stressful and jagged cut, making the turf more susceptible to fungal diseases.
• Avoid fertilization until fall for cool-season turf (fescues, ryes, bluegrasses).
• Spot spray only for weed control in cool-season turf.

Understanding Mulch

Many folks take mulching for granted. They are not sure why they need to mulch, how much or when to apply it, or why type to use. However, proper mulching is one of the most beneficial things that a homeowner can do for their landscape.

Mulches are defined as materials placed over the soil surface to maintain moisture and improve soil conditions. They are intended to help reduce moisture loss from the soil, minimize weed competition, and improve soil structure (the aggregation of soil particles).

When properly applied, mulch can really complete a landscape. However, it must be selected and applied properly in order for the homeowner to receive the full benefits. If applied too deep or the wrong material is used, it can cause significant harm to trees and other landscape plants.

Benefits of Mulch
Proper mulching has many benefits:
– Helps maintain soil moisture
o Reduces evaporation and need for supplemental irrigation/watering
– 2-4” layer reduces the germination and growth of weeds
– Improves temperature regulation
o Keeps soil temperatures cooler in the summer and warmer in the winter
– Can improve soil aeration, structure (aggregation of soil particles), and drainage over time
– Can improve soil fertility
– Mulch around trees can help facilitate maintenance and reduces the likelihood of injury or damage from lawn equipment and tools
– Gives planting beds a “finished”/ polished look

Mulch mimics the natural environment. Forests create their own mulch via leaf litter and decomposing organics on the soil surface. This is critical to the overall health of the ecosystem as it improves nutrient uptake and root growth of forest plants. Mother nature, when left to her own devices, usually gets it just right.

Urban area on the other hand, often have a more hostile growing environment. Generally speaking, land development and construction in urban areas leads to poorer soil quality, less organic material in the soil profile, and increased soil temperature and moisture fluctuations. These combine to create an environment that is hostile to the establishment and health of landscape plants. Applying a 2-4” layer of the proper organic mulch in these areas can create a more natural environment for trees, shrubs, and plants.

When considering trees, it is important to remember that tree roots are not a mirror image of the top of the tree. Roots can in fact extend out a great distance from the trunk. General tree maintenance guidelines reference the “drip line” (the outermost extension of the tree canopy), however roots can extend much further than the “drip line”.

Most nutrient absorbing roots grow in shallower soil though. These shallow, fine roots are essential for the absorption of water, nutrients, and oxygen for all plants. A think layer of mulch inside the “drip line” can improve soil structure, moisture, oxygen, and temperature in this crucial layer of the soil profile.

Mulch Types
Mulches are available commercially in many forms. The two major types of available mulches are organic and inorganic.

Inorganic mulches are generally comprised of material like:
 lava rocks
 stones
 crushed rubber
 certain geotextile material
 various other materials

These materials do not decompose and do not need to be replenished over time. They also do not provide any nutritional, structural, or organic value to the soil profile.

Organics mulches are composed of material like:
 wood chips
 pine needles
 hardwood and softwood barks
 cocoa hulls
 leaves
 other organic materials

These materials decompose in the landscape at different rates depending on the material and climate. The decomposition process improves soil quality and fertility, however they must be replenished over time.

How Much Mulch to Apply
The amount of mulch applied is just as important, if not more than the type being applied. Too much mulch can be harmful. The accepted depth for most mulch application is between 2-4”, however many landscapes fall victim to over-mulching, with large mounds around the bases of trees being quite common.

Although organic mulches must be replaced over time as the parent material decays, the rate of decomposition varies depending on material and local climate. Some mulches, like Cypress, can take years to decompose.
Many homeowners will top-dress with new mulch annually (to refresh the color). This can create a buildup to depths that become unhealthy for most plants. If top-dressing old mulch, remove the ole material every so often, keeping application rates in line with decomposition rates to avoid creating a anaerobic growing environment.

Improper mulching can lead to a host of problems:
– Excess root zone moisture
o Added stress for the plant and causes root rot
– Piling against tree trunks or plant stems can cause stem tissue stress and lead to insect and disease issues
– Certain mulches can affect soil pH (proper pH is essential for any life form to grow and develop)
o Continued use over extended periods can lead to micronutrient deficiencies in the soil or nutrient toxicities (yes, there can be toxic effects from too many nutrients in the soil)
– Mulch piled high against tree trunks may encourage rodent infestations
– Thick application of fine mulches may prevent the penetration of air and water (anaerobic and hydrophobic conditions)
o This is the opposite of why we mulch in the first place
– Anaerobic soil may give off foul odors (rotten egg smells)
– Build up of alcohols and organic acids may be toxic to young plants

 

 

Proper mulch selection and application method are very important to the overall health and sustainability of landscape plants.

Guidelines for proper mulching:
– Inspect plants and soil in the area to be mulched
o Adequate drainage?
o What type of mulch is best? (when in doubt, ask a professional)
– Check depth of any mulch already present
o Do not add if there is enough in place
o Rake old mulch to refresh the appearance and break up any matted layers
– Pull back from stems of plants and trunks of trees so that the crowns are exposed
– Organics are usually preferred over inorganics b/c of their beneficial soil contributions
o Organics should be well aerated and preferably composted
 Avoid foul smelling mulch
– Composted wood chips make a great mulch
o Especially when old leaves and bark is included
o Fresh wood chips may be used around established trees and shrubs
o Avoid non-composted chips that have been piled deep without exposure to oxygen
– For well drained sites use a 2-4” layer of mulch
o If there are drainage problems, a thinner layer should be used
o Avoid placing against tree trunks
o Do apply out to the drip line of the tree and beyond if possible

Keep in mind when selecting mulch for your landscape that there are many factors that must be considered in order to get the full benefits of mulch applications. For more information about mulch varieties, benefits, and application timings, contact a landscape professional.

Irritation or Irrigation?

Grass plants are made up mostly of water and to little or too much can be cause for concern. Water is the primary mechanism for transport of nutrients, organic compounds, and gases into turf roots and throughout the plant. While most people think a lack of water will damage their lawn, overwatering may in fact cause more damage to existing turf.  To maintain a healthy, dense, and actively growing lawn, it is essential to irrigate the lawn during dry periods. It is easy to overwater a lawn.

The consequences of overwatering a lawn include: increased weed pressure (especially crabgrass), increased disease pressure, shallow rooted turf (think weak), wasted natural resources, and for most, higher water bills. When you irrigate your lawn, it is best to err on the dry side rather than be guilty of overwatering. You can always add more water if the lawn is still dry, but you cannot take excess out of a lawn.
Frequency will vary based on the appearance of your lawn. The first signs of drought stress are a blueish-green color (caused by leaf blades beginning to curl up to conserve energy) and footprints that remain in the turf after walking across it.

 

Ideally this is the point at which you should irrigate your lawn. There is no benefit whatsoever to irrigating a lawn before this point.

As drought stress increases, your lawn will wilt and have a greyish-green color. At this point, you should irrigate the affected area immediately. Turf in this stage of drought stress can recovery quickly with prompt attention on your part.

Severe drought stress causes the plant to cease all metabolic processes and stop growing. The shoots (leaf blades will turn brown and could die.

green grass and dry grass

 

Irrigating at this point helps the plant to survive, however it can take up to two weeks to see noticeable improvement and possibly longer to make a full recovery. Patience is your friend at this stage of the game.

Another common irrigation misconception is that lawns should be irrigated on a set schedule. This is not the case, as a set schedule does not take into consideration the needs of the plant, evapotranspiration rates, or other environmental conditions, however it does increase the likelihood of over watering. Also, for those with automatic irrigation systems, you should not run the same programs for the entire season. Irrigation rates and timing should accommodate the needs of the plant at any given time.

Turfgrass species vary widely in their water requirements, with most cool-season grasses using approximately 20% more on average than warm-season grasses. Most turfgrass species will require between 1-1.5” of water per week to maintain a healthy status. Factors that influence water use rates of grasses (and all plants for that matter) are: weather, soil type, slope, etc. It is best to apply this amount of water in a single cycle or two equal applications spaced three to four days apart, rather than through light irrigations daily (if you have newly seeded or sodded turf, then you will need more frequent irrigation at first). During an irrigation event, soil should be wetted to the depth of the deepest root. Shallow, frequent irrigation encourages the plant to produce shallow root systems. A shallow root system weakens the plant when drought sets in or temperatures increase and encourages the proliferation of weeds, notably crabgrass.

Hose-end sprinklers usually apply a small volume of water to a given area and must be left to run for extended periods (2-3 hours) to provide adequate moisture. See the example below:

 

Automatic systems can deliver larger volumes (depending on system and nozzle configurations) in less time.

Irrigation of the green grass with sprinkler system.

 

If you have an automated system, then you should do an irrigation audit yearly to gauge the efficacy of the system and make any needed repairs. This will keep the system operating at peak efficiency and lower your overall water usage (your lawn and water bill will thank you).

The best time of day to irrigate turf is between 4-8am. There is little wind disruption currently of day, you do not lose water to evaporation, and temperatures are generally at their coolest. Yes, 4-8 am is early and could pose some logistical challenges for most people. The next best time to irrigate your lawn is between 8pm-12am. However, irrigating at this time of day can increase the possibility of soil borne disease that affect turf if humidity levels are high (we live in the South, when aren’t they high in the summer). Irrigation that is preformed during the middle of the daylight hours is ineffective and should only be undertaken as a last resort.
Proper irrigation practices are just as vital to a healthy lawn as fertilizer, weed prevention, or mowing and should not be intimidating. When in doubt about your irrigation practices, remember, you can always add more water, but you can’t take any out.