Water is needed to keep grass alive. Without it, you won't need a lawn mower.
Watering your lawn is just like us drinking water. That's how it makes use of the nutrients in the soil, and to process its bodily functions. And think of healthy soil, as food. You can go a long while without food, but not water. All life needs water!
Watering FAQ's
How much do I need to water my lawn per week?
This depends on the grass type, but it is commonly advised (by various institutions) that your lawn needs to receive around 25mm per week. This is the combined total of rainfall and you irrigating. I believe that figure is heavy, especially when you're talking about grasses like Kikuyu and Bermuda. I prefer to look at my lawn, I always say "read your lawn" and if it looks thirsty, give it a drink. Monitor soil moisture. If the surface looks dry, and you haven't watered in a while, it's probably time. If the surface is still damp or even moist looking from the previous watering, leave it alone.
Do I need a rain gauge in my yard?
Yes! Without a doubt! You have to know how much rainfall you have had, so that you can determine how much water your grass needs to see that week. You cannot guess how much rain we had. It is simply not possible.
If I had 100mm in the first week of the month, do I need to water again for week 2, 3 & 4?
Yes! This would be similar to you drinking lot's of water for the first week of the month and not again for the rest. Naturally, if you have highly saturated soils, then you don't have to. Again, "read your lawn" If the surface is dry, and it hasn't rained that week, you need to water it.
Does humidity play a role in how much I need to water?
Yes, areas with high humidity do not need water as often as low humidity zones. You need to be careful in areas with high humidity as disease pressure will be higher than dry regions. These zones will benefit from deep and infrequent watering. Grass does not like to be damp continuously. In the same breath, stagnant water is also terrible for turf health. So, use penetrative wetting agents to assist water mobility in the soil. In less humid regions, you may benefit from more regular watering but again, "read your lawn". If you water too little with each session, the water may not penetrate deep enough which results in a shallow root system and barren soil. So, you will still need to do a deep watering session at least once a week to ensure that water is getting deep enough. Again, use a penetrative wetting agent to assist with water penetration.
Does wind influence how much I need to water?
Absolutely! Have you ever stood outside on a windy day and felt that your skin eventually becomes irritated. Some refer to that as wind-burn. That is because the moisture from the surface of your skin has dried up. A similar effect can happen to your lawn. Besides using penetrative wetting agents, you may want to consider using polymers in windy or inherently dry regions.
Does the HOC influence how much I need to water?
Yes. It would seem that small plants need less water than large plants. This is true for the most part. However, large plants have the advantage of storage space for carbohydrates and water. So, they have the advantage when dry conditions prevail. Additionally, short turf exposes the surface of the soil to the elements more than tall turf does, so this has to be taken into account as well. READ YOUR LAWN!!!
Does my soil type influence how much I need to water?
Yes. Clay tends to hold onto water, but when it dries out it can be extremely difficult to re-wet. Loamy soils also hold onto a good deal of moisture and can also create drainage issues but to a lesser extent than clay soils. Sandy soils usually drain well, so you will need to water more regularly. Ideally, a sandy loam foundation is great for most turf care scenarios. Keep in mind that the pore size of the sandy matters! Larger particles create Macro-pores and finer particles create Micro-pores. Macro-pores mean better drainage, and Micro-pores mean less than ideal drainage. Sandy soils can also become hydrophobic!
Do I have to install and irrigation system?
Yes and no. If you are perfectly diligent, then no. If you keep missing days or you drink whilst manually watering your yard, you may want to consider installing an irrigation system. Well-designed irrigation systems allow and even coverage of water over every square meter of your lawn. Even water distribution makes a difference! If you have the ability to install a system that can measure weather conditions, rainfall etc and automatically account for the inputs, then that is even better. Having a basic system installed is still better than not having one at all.
Stick to the basics.
1. Standing water and heavy run-off are both bad.
2. The surface should not be continuously damp.
3. Your specific circumstances dictate your watering schedule. There is no "one size fits all" scenario.
4. Evaporation and Transpiration effects your watering requirements(evapotranspiriation).
5. Read your lawn!
