Watering Plants In A Drought – Being Waterwise

By Richard Flowers, ACCNP-Green Thumb Nursery-Ventura

With todays water resources drastically shrinking, we can do our part in the home landscape to help conserve this precious commodity and make irrigating your garden more effective. I will provide you with many tips and first hand experience on how you could water your plants wisely in our critical drought we are in.

Many people have lawns and believe it or not the most popular grass (Marathon), a tall fescue will take surprisingly less water than you would imagine. Most people overwater their lawn in the first place. A fescue lawn can have roots that go down 1 or 2 or more feet into the soil. Most people water their lawn the wrong way, they water for 15 minutes everyday. This causes the roots of the grass to become accustomed to shallow more frequent water thus becoming dried out faster. Instead, try watering for longer periods with a sprinkler that delivers slower water for 3 or 4 hours once a week essentially mimicking a slow and steady rain fall . That way, over time, the roots will go deeper, and not depend on as much water, as often. Furthermore, you could also let your grass grow a little longer to help conserve moisture and reduce shock. It is recommended to mow your lawn on a higher setting, between 3”- 6” tall. It stands to reason that taller grass casts longer shadows and the added shading from leaving your grass taller than usual will benefit the soil by helping to retain moisture. The more you mow your lawn at a low level, the more the soil heats up and the more likely it will want to grow faster and demand more water. Additionally, you can implement grass-cycling or a mulching mower. What these processes do is when you leave the grass clippings on the grass the mulching mower cuts the grass more fine and then it deposits it on the grass. If you do not have a mulching mower, I recommend to take the bag off the mower, the grass clippings are then deposited on the grass, after when you are done with the mowing, take a rake and smooth out the clippings, mow the grass again, cutting up the grass clippings making them finer, then finally, water the grass clippings into the lawn. In a few days the grass clippings are absorbed and decomposed in the lawn especially during the summer when decomposition is faster. The result, grass-cycling or mulching is that you fertilize your lawn and the grass requires less water over time, if done routinely. Or if you prefer you can put the grass clippings in your compost bins. The practice of dethatching and aeration of your lawn is also beneficial so that water can seep into the soil more easily thus prompting healthy, deeper roots, healthier, stronger lawn, and will also make watering more efficient. Also did you know that a warm season grass like St. Augustine or Bermuda uses less water than cool season grasses like fescues i.e. Marathon grass. Warm season grass can actually survive 40% water restrictions. To help conserve even more water you may want to consider reducing the size of your lawn.

Water your garden including your lawn in the evening or very early morning hours year round especially during the critical times of summer, spring and fall or when the weather is hot. The benefit for doing this is that the plants have the rest of the evening and early morning to recover from the hot days because less evaporation occurs during these times, making watering more effective for your plants. If you must water during the day and there is no other option then water in the shaded areas. Shaded areas are cooler, have higher humidity, less evaporation, and many times plants in shaded areas don’t require as much water than plants planted in the hot sun.

One of the keys to plant growth lies with the roots. Plant roots always grow where there is water. If you want a plant to be stronger, have better anchorage in the soil and better able to take drought conditions then it is wise to water longer and deeper and less frequently. Conversely if you water more frequently, the plant will demand more water, more often because the roots are shallower and dry out quicker. Shallow roots can’t anchor a tree in the soil and is more prone to falling. By watering longer and less frequently the water reservoir in the soil will be deeper hence the plant will not dry out as fast. Most times, watering deeply involves having a slow spray or low volume of water over a longer period of time. When you water slow like that of a steady sprinkle or light rain the water has a chance to seep and absorb down into the soil and not run off becoming wasteful. In other words, don’t water like a heavy rainstorm, instead mimic a slow and steady shower over several hours of time, this is why a proper functioning drip or other low flow irrigation system has its advantages.

Below are a variety of ways to accomplish this:

  1. Wrap the end of a hose with an old cotton sock. Use a rubber band to hold it in place. Turn on the water to a slow trickle and place the sock end of the hose near the drip line. Allow the water to run for several hours, and then move the hose 1/4 revolution around the drip line. Continue until the entire perimeter of the tree has been watered. The sock breaks the force flow of the water so that it doesn’t wash the soil away.
  2. Use a soaker hose around the drip line of existing landscape trees. Turn on the water to a very slow flow and allow it to run as long as overnight.  If you are forgetful about leaving on the water, you may want to consider using a battery operated timer and set it to the desired time the water will be on for. This simple device could save you money and water at the same time.  Essentially to obtain uniform water distribution on any plant the water should be applied in all areas of the root zone. Imagine the soil around the plant is the face of a clock. The moisture should be applied at 12, 3, 6, 9 o’clock. In other words do not water in one spot because water in the soil moves down not outwards. With regard to the drip line of a plant, this means the farthest extent of all the leaves and branches i.e. under the canopy, is where the important feeder roots that bring up water and nutrients to the rest of the plant. It is not wise to water right next to the trunk or main stem.
  3. With traditional automated sprinkler systems be sure to set the timer(s) accordingly. You may need to adjust the timer(s) as needed if there is a power outage, batteries run dead, malfunction or the weather changes. When using any type of sprinkler system, routinely check to see if all the sprinklers and emitters are functioning correctly, working to maximum efficiency, and delivering water equally. Check your sprinklers and make sure nothing is broken, broken sprinklers, pipes, and leaky valves, and faucets which causes wasteful water. When the sprinklers are on make sure water is not applied to sidewalks, streets, walls, walkways or other non-planted areas. Replacing the sprinkler heads with the appropriate pattern or adjusting the flow will go long way to help conserve water. Check your water meter at the street for leaks and repair unnecessary leaks as soon as possible. To determine if you have leaks simply turn off all the water on your property then, write down the numbers from the meter, and come back an hour later and check the numbers on the meter to the number your wrote down, if they are different then corrective action needs to be made.

Anytime you water, make sure wasteful runoff or erosion is non-existent or at a minimum. Relatively new on the market are smart irrigation systems that have sensors like tensiometers (soil moisture sensor) and can take the guess work out of watering by using technology, this is something that you may need to explore. A simple and effective method used to determine the soil moisture is to use a bamboo stake. Probe the bamboo stake halfway down the root ball on all sides, if when you pull it out of the soil and you see soil moisture on the stake it is not ready to be watered at that time. This method is also useful to indicate how far water has traveled into the soil after you water. It is not wise to look at the top of the soil to determine if you need to water.

When watering new plantings and until several months old, water close to the trunk or main stem but not at the trunk. Be sure to have a watering basin or a well and apply the water to that area. Simply water slowly, filling up the well, let it drain, then repeat, this is usually sufficient until the next watering. Established plants (plants that have been growing in the landscape after several months to over a year old or more) water where drip line or canopy of the tree is. In most cases, established trees usually need watering 1 or 2 times per month or more often in extreme heat or if rains are not sufficient. When watering new trees, weekly irrigation would suffice. But remember to also check the soil before to determine if it needs water.

Watering is done when plants need it, depending on conditions, and not by the clock and calendar. When you water pay attention to various conditions. Conditions such as temperature, location, time of day, humidity, wind, time of year, soil, stage of growth, terrain, microclimates, and exposure all play a vital role in influencing when you need to water. I will break these down for you and provide you some examples. When it is hot, low humidity, and windy plants demand more water, therefore it is necessary to apply water and oftentimes more frequently. Read or listen to the weather forecasts a few days in advance. If a heat wave is expected water the landscape well before a heat wave arrives. When conditions are cool, not windy, cloudy, and higher humidity your plants demand less water, less often. During the summer, plants always demand more water, while usually during the winter many trees don’t require as much water. If you have a tree species that loses all its leaves during the wintertime (goes dormant), that is a resting period and the tree does not need additional water in most cases. Anytime when the weather changes your watering habits need to change. Where you live greatly determines when you need to water. If you live in a cooler coastal area, these areas need far less water than locales that are in hot inland climates. The same watering practices does not apply to all areas of your landscape. Be sure to take note of micro climates. Examine your own landscape and determine if there are areas where hot air settles or on the southwest side of the property, next to a hot wall or driveway, on the top of a slope, and extreme sun exposure because these areas dry out quicker and need water more frequently.

Additionally, your own garden may have areas where cooler air settles, in the shade, on the north or east side or on the bottom of a slope these areas stay moister longer and do not need as much water. It is also important to examine your yard each season as the sun and season change. The type of soil you have has a bearing on when you water. Sandy soils tend to drain quickly and therefore these soils need more frequent irrigations at shorter periods of time. If your soil happens to have clay, then these soils typically dry out more slowly, are harder to wet, and require longer watering cycles. With clay soils you water less frequently.

It is also critical to improve soil conditions by incorporating soil amendments and organic fertilizers to make the soil become more healthy, increase bioactivity, improve drainage because a healthy soil drains well, supports healthy plant roots, increase drought tolerance of plants, reduces compaction, and increase aeration, so your plants will grow stronger, and use water more effectively. Another tip is to not use high nitrogen fertilizers as often on lawns and landscape plants because that will increase its growth hence demand more water. Instead use a fertilizer that is lower in nitrogen or use an organic slow release fertilizer. In fact using higher nitrogen fertilizers on almost all plants causes them to have weak, succulent growth that is more prone to insect attacks like aphids or leaf miners especially on citrus. Instead use organic fertilizers that enhances the soil by adding beneficial microbes which in turn benefits the plants over all health and be more resilient during a drought.

Mulch is essential in so many ways. Applying a minimum of 3-5 inch layer of organic mulch reduces evaporation (wasteful water loss) up to 50 – 60 %. Mulching also improves the soil health and helps increase the bioactivity in the soil with in turn increases the beneficial soil fungus called mycorrhizae which helps plants become more drought tolerant and makes water uptake from the roots of the plant more efficient.

Implementing mulching along with the use of organic fertilizers that also contain mycorrhizae and soil conditioners works wonders on your soil and plants which equates to watering less. Mulching also helps keep weeds that compete for water at bay. Homemade compost makes an excellent mulch and fertilizes as it breaks down in the soil. I prefer a mulch that has a homogenized mix of course, fine and medium pieces. I always make sure when applying mulch to keep it away from the main stem of the plant.

Usually mulch is re-applied annually for the greatest benefit. Mulch is an organic material you use to top dress the soil and it all depends on what you like, Green Thumb supplies a wide variety of mulches. When water is applied to mulched areas it is critical to water long and slow enough to have the water penetrate both the mulch layer and
the soil.

To help decrease waterings, I suggest implementing a product called Soil Moist. Soil Moist is a polymer which are tiny granules that hold (store) over 200 times their own weight in water. When added to the soil, it releases water at a steady supply as your plants need it. This product reduces plant waterings by 50%, decreases soil compaction, increases soil aeration, lessens plant stress due to lack of available water, and is effective in the soil for up to 3-4 years. Read and follow all label directions for proper use.

Another product worth considering is the use of Grow More E-Z Wet Soil Penetrant 26. E-Z Wet is biodegradable and can be used on any soil. Regular use will promote a deeper root system, leach excess salts away from the root zone, alleviate run-off, erosion, dry spots and soil compaction problems. Read and follow all label directions for proper use. When watering be mindful that not all plants need the same amount of water. Tall trees and large shrubs require different watering than lawns. When watering trees in an existing lawn area be sure to water the tree separately from the lawn, this means you need to supplement additional deep waterings for the tree. Ideally is is best to avoid planting low water use trees and shrubs in a lawn area. Flowers and vegetables require different watering than fruit trees. Cactus, succulents, Mediterranean, Australian, South African, and California natives don’t have the same watering needs as ferns and tropical plants. To water wisely means watering your plants intelligently and not wasting water by over- watering some plants and under-watering others. Being water wise also means to choose plants that are well adapted to the climate you are planting in. Group like plants that need the same amount of water together. By doing so you will have dedicated zones to water: High water zone, medium water zone, and low water zone.

The idea behind this is to not over water drought tolerant plants or under water, high water use plants. Being water wise also means to save as much water as possible. I use a bucket that captures my shower water as I am bathing instead of having the water go down the drain, this shower water is then used to water my landscape plants. Some
people have a grey water system, check local codes and regulations before installing. When it does rain you can collect rain water and store it in a water tight large container and use it in the future. If conditions become more sever about water usage, you may need to prioritize which plants you need to part ways with. Typically, older trees and shrubs need less water than shallower rooted plants. Instead of removing the entire landscape and installing drought tolerant plants, you may want to consider removing plants that are crowded or overgrown that are competing with other plants for water and nutrients. Also make sure to remove weeds because they all compete for water. When installing brand new drought tolerant plants be mindful that they always need more consistent and regular water than older more established plants. These new plants usually need this type of water for the first couple of months then watering can be eased off. Until the plants grow a larger and deeper root system into the surrounding soil which usually takes about a year, during this time these plants need regular water. Older plants always take less water than their newer counterparts. When planting new plants it is best to plant during the rainy season to take advantage of natures water. If that is not an option then perform this procedure in the evening or during the cooler season or when there is no
heatwave because it is less stressful for the plants because you are taking advantage of the times when evaporation is at its lowest and humidity is at its highest to reduce water usage. When watering older, more established plants it is best to wait until you start to see symptoms of water stress i.e. wilting then water so you can save as much water as
you can making the soil sustainably moist and still keep the plant alive.

The more plants you have the less water you will need to apply. A denser plant canopy over an area increases the humidity, makes the area cooler, reduces evaporation, and shades the soil creating a microclimate where the ground stays moist longer therefore plants use less water. This same principle can also be applied to potted plants. Grouping potted plants closer together where the branches, leaves, and stems will create more shade, humidity, and reduce water evaporation therefore reduce intervals of water. You can also cover the sides of pots with shade cloth, to help shade the roots making them cooler and thus reducing water. Most Plants in containers are not as drought tolerant as the ones in the ground are because the confined area inside the container dries out faster therefore require more water. You may want to consider nesting a smaller pot inside a larger pot and filling the space between the pots with
potting soil. The extra space around the inner pot keeps the roots cool and reduces moisture loss. Plants will grow better and need less water than if the small pot were exposed directly to the sun and wind. When rain arrives you can move your potted plants where they can receive natures water.

Another way tp help reduce waterings is to put shade cloth over prized, special or vulnerable plants to reduce the intensity of the sun, make the plant cooler, and reduce water evaporation. By providing shade, less evaporation occurs though the stems and leaves therefore helping too mitigate and or prevent the stressful effects of heat. Another benefit of shady areas is that they have a higher relative humidity than exposed areas, which makes your plants happier. During this critical drought we are in, plants want to survive, they may look tired and not their best but give them the benefit of the doubt that they will come back.

Please be advised the above information is only a guide, different species of trees have varying water needs depending on where they are growing. It is always advisable to physically check soil moisture with a probe instead of using set watering intervals or relying upon automatic timers. With all these helpful tips you can grow beautiful plants with less water. Green Thumb carries a wide selection of plants that don’t require a lot of water once established like
cactus, succulents, trees, shrubs, rosemary, many types of salvias, many California natives, South African, Australian, Mediterranean, xerophytic, desert pants, and so much more. Please ask any of our helpful nursery staff, we will be glad to help you.

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