|I have just planted two sago palms. How often should I be watering them. I have been watering them daily for 4 minutes in the morning (on a drip feed system) for about a week. Do I need to give them more water? Less? Best method (drip feed/hose/etc.)?
|I can't tell you exactly how long to run your system because I don't know how much water it puts out, such as how many emitters there are and how much water each puts out. For example, some drip emitters put out 1 gallon per hour, others 2, 4 or more. A one-gallon drip emitter running for 15 minutes would put out only 1 quart of water! Running for just 4 minutes (assuming 1 emitter, at 1 gallon) would be just a splash that wouldn't penetrate very far. To visualize, think about pouring a coffee cup's worth of water around your plant. Does that seem like enough? Nope!
In addition to insufficient water, rief periods of drip irrigation such as you describe are not healthy for the plant in the long run. Here's why:
Desert soil and water both contain salts, which can accumulate in the root zone over time. This salt buildup forms where the water stops penetrating. Short periods of watering cause salts to build up in the top layers of soil and damage or kill your plant. Salt burn shows up as yellowing, browning along leaf edges, and leaf drop. Deep watering?or leaching?prevents this by flushing the salts past the root zone. Always water slowly, deeply and as infrequently as possible. This is true for any plant.
It's important that water always soak deeply through the entire root system.
Use the 1-2-3 Rule as an easy method to figure out how much water to apply. Small plants with shallow root systems, such as perennials, veggies, herbs, cacti, succulents have roots that reach about 1 foot deep, so water needs to penetrate that far. When the top 1 inch of soil dries out, it's usually time to water again. Shrubs have root systems that are 2 feet deep so water needs to soak 2 feet deep. When the top 2 inches of soil dries out, it's time to water. Trees are 3 feet, etc. As plants establish root systems, the time between waterings can be lengthened, but it is always essential to water to the same depth. So you are applying the same amount of water with each irrigation regardless of the time of year, but the frequency changes. As warm weather arrives, you need to water more frequently than during winter. A soil probe will help you determine how far water has soaked. It moves easily through wet soil but stops when it hits hard soil. I?d suggest you let your drip run for 30 minutes or 1 hour, then wait an hour or so (for the water to continue penetrating), then use a sharp stick or pointy thing as a soil probe to determine how far the water penetrated in your soil. For most areas, it's necessary to run irrigation much longer than people would think. The majority of the plant problems we see are because drip isn't running long enough. In improved soil garden beds, such as for veggies, it will soak more readily through the soil than it will in landscape settings.
Here are some watering guidelines for establishing desert-adapted plants from Desert Landscaping for Beginners, published by Arizona Master Gardener Press. Weeks Since Planting 1-2, water every 1-2 days; Weeks 3-4, water every 3-4 days; weeks 5-6, water every 4-6 days; weeks 7-8, water every 7 days. Gradually extend the watering as plants establish. Note these are guidelines, which will vary depending on your soil type, microclimate, etc. and they apply to desert-adapted plants.
As plants mature, emitters must be moved outward to keep pace with the expanding root system. Feeder roots that absorb water are spreading out past the dripline (canopy edge), so apply water just beyond that. Add a layer of organic mulch around the base to help maintain moisture and reduce soil temperatures. I hope this info helps!