Spring Sprinkler Startup Guide for Treasure Valley Homeowners

Published: November 25, 2025 | By: Lawn Care Kuna Team | Category: Irrigation

Tags: sprinkler startup, irrigation activation, spring lawn care, sprinkler maintenance, Idaho irrigation

Why Proper Spring Startup Matters

After a long Idaho winter, your sprinkler system has been dormant for five to six months. Proper spring startup isn't just about turning the water back on—it's about systematically activating your irrigation system to identify any problems, prevent damage, and ensure efficient operation throughout the dry summer months ahead.

Rushing through startup or skipping important steps can cause water hammer damage, miss freeze damage from winter, waste water through undetected leaks, and leave your lawn under-watered during critical spring growth periods. Taking time for proper activation protects your irrigation investment and sets your lawn up for summer success.

For homeowners in Kuna, Boise, Meridian, Eagle, Star, and Middleton, spring startup marks the beginning of irrigation season that will sustain your landscape through our characteristically dry summers when we receive less than one inch of rainfall monthly.

When to Start Your Sprinkler System in Idaho

Timing Guidelines for Treasure Valley

The ideal sprinkler startup window for most Treasure Valley properties falls between late March and mid-April. Several factors determine the right timing for your specific situation:

• Frost risk: Wait until consistent overnight temperatures stay above 32°F
• Ground temperature: Soil should be thawed at least 4-6 inches deep
• Grass growth: When lawn begins active growth, irrigation becomes necessary
• Weather patterns: Extended warm, dry forecasts indicate startup time
• Last frost date: Average last frost in Treasure Valley is early to mid-May

City-Specific Recommendations

Microclimates across the valley affect optimal startup timing:

Boise: Urban heat island effect allows earlier startup, typically late March to early April for most neighborhoods. The Boise Bench and North End warm fastest, while river corridor properties should wait slightly longer due to cold air drainage.

Meridian: Central location means average timing applies. Most Meridian homeowners can safely start systems in early to mid-April. Watch for late cold snaps that occasionally hit in April.

Kuna: Agricultural surroundings and slightly higher elevation mean colder spring nights. Wait until mid-April for safest startup, monitoring forecasts for late frost warnings.

Eagle: Foothill properties experience later last frosts. Higher elevation areas should wait until late April, while valley floor properties can start mid-April.

Star and Middleton: Western valley locations often have later frosts than Boise. Plan for mid to late April startup, especially in low-lying agricultural areas where cold air pools.

Pre-Startup Preparation Checklist

Before Turning On the Water

Complete these steps before activating your system:

1. Inspect the backflow preventer: Check for visible cracks, damage, or freeze damage from winter. Ensure test cocks are closed and the device appears intact.
2. Check the controller: Verify power, replace backup battery if needed, and ensure programming wasn't lost during winter. Reset date and time.
3. Walk the property: Look for obvious damage—sunken areas that might indicate broken lines, disturbed sprinkler heads, or visible leaks at valve boxes.
4. Clear sprinkler heads: Remove debris, leaves, or soil that accumulated over winter from around visible heads.
5. Locate the main shutoff: Identify your irrigation shutoff valve and ensure it's accessible and operable.

Gather Necessary Supplies

Have these items ready for startup:

• Replacement sprinkler heads (keep a few common sizes on hand)
• Teflon tape for threaded connections
• Screwdriver for head adjustments
• Controller manual or programming guide
• Notepad to record any issues found

Step-by-Step Spring Startup Process

Step 1: Open the Main Water Supply Slowly

This is the most critical step for preventing water hammer damage:

• Locate the main irrigation shutoff valve (usually near the water meter or where water enters the house)
• Open the valve very slowly—take at least 30-60 seconds to fully open
• Listen for any unusual sounds indicating leaks or water hammer
• If you hear hammering or banging, close the valve and open even more slowly
• Allow system to pressurize gradually before moving to next step

Rushing this step causes water hammer, which creates pressure spikes that can crack pipes, damage valves, and break fittings throughout your system.

Step 2: Open Backflow Preventer Valves

Your backflow prevention device needs proper activation:

• Close any test cocks that may have been left open for winter
• Open the two shutoff valves on the backflow preventer slowly
• The downstream valve should be opened first, then the upstream valve
• Check for any leaks around the device
• Verify no water is spraying from relief ports (indicates internal damage)

Step 3: Test Each Zone Individually

Run through every irrigation zone systematically:

• Start with zone 1 and run for 3-5 minutes
• Walk the zone and observe every sprinkler head
• Note any heads that don't pop up, spray incorrectly, or leak
• Watch for water bubbling up from ground (indicates line break)
• Check valve box for leaks at zone valve
• Repeat for each zone in your system

Document all issues found—this list guides your sprinkler repair priorities.

Step 4: Check Sprinkler Head Performance

While zones are running, evaluate individual heads:

• Pop-up height: Heads should rise fully above grass level
• Spray pattern: Water should reach intended coverage area without gaps
• Arc adjustment: Rotors should rotate through correct arc
• Nozzle condition: Look for clogged or damaged nozzles creating poor patterns
• Alignment: Heads should be vertical, not tilted
• Precipitation: Similar heads should output similar water volumes

Step 5: Program Your Controller

Set up proper watering schedules for spring conditions:

• Verify date, time, and day of week are correct
• Program appropriate start times (early morning 4-7 AM is best)
• Set run times for each zone based on head types and coverage
• Establish watering days (typically 2-3 days per week in spring)
• Consider seasonal adjustment feature if available
• Enable rain sensor if your system has one

Spring watering needs are typically 30-50% less than summer requirements. Start conservative and increase as temperatures rise. Our irrigation maintenance service includes controller programming optimization.

Common Spring Startup Problems

Freeze Damage From Winter

Even with proper fall winterization, freeze damage can occur:

• Cracked pipes: Water bubbling from ground, wet spots in lawn
• Broken heads: Heads that won't pop up or spray erratically
• Damaged valves: Zones that won't turn on or won't shut off
• Backflow preventer damage: Leaking or failed device

If winterization was skipped or incomplete, spring startup often reveals extensive damage requiring professional sprinkler system repair.

Clogged Heads and Nozzles

Debris accumulation during winter is common:

• Dirt and sand in nozzles creating poor spray patterns
• Grass and debris blocking pop-up mechanisms
• Mineral deposits from hard water (common in Treasure Valley)
• Insect nests in unused heads

Most clogs can be cleared by removing the nozzle and flushing, or replacing inexpensive nozzle components.

Pressure Problems

Incorrect water pressure causes system inefficiency:

• Low pressure: Heads don't pop up fully, reduced coverage, dry spots
• High pressure: Misting instead of droplets, excessive wear, water waste
• Pressure variation: Some zones work well while others struggle

Pressure issues may indicate main line problems, stuck valves, or municipal water pressure changes over winter.

Controller and Electrical Issues

Electrical problems are common after winter:

• Dead backup battery causing lost programming
• Tripped breaker or blown fuse
• Corroded wire connections at controller or valves
• Lightning damage to controller (more common than you'd think)
• Solenoid failures preventing zones from activating

Spring Irrigation Scheduling for Idaho

Early Spring (March-April)

Lawns need minimal irrigation during cool spring weather:

• Water 1-2 times per week if no rain
• Run zones for 50-60% of summer duration
• Water only when lawn shows signs of needing moisture
• Skip watering during rainy periods

Late Spring (May-June)

Increase watering as temperatures rise:

• Transition to 2-3 times per week
• Gradually increase run times toward summer levels
• Begin early morning watering schedule (4-7 AM)
• Monitor for dry spots needing head adjustment

The goal is applying 1-1.5 inches of water per week including rainfall. Our heavy clay soil holds moisture well but needs deep, infrequent watering rather than frequent shallow irrigation.

When to Call a Professional

DIY vs. Professional Startup

Many homeowners can handle basic spring startup, but professional service makes sense when:

• You're unsure about proper procedures
• Winterization was incomplete or skipped
• System is complex with many zones
• You notice multiple problems during startup
• Backflow preventer needs testing (required annually in some areas)
• Controller programming is confusing
• You want comprehensive system evaluation

Professional Startup Services

Our professional irrigation startup includes:

• Slow, proper system pressurization
• Backflow preventer inspection and testing
• Zone-by-zone operation and inspection
• Head adjustment and minor repairs
• Controller programming and optimization
• Written report of any issues found
• Recommendations for repairs or upgrades

Professional startup typically costs $75-$150 depending on system size and complexity, providing peace of mind and catching problems before they cause lawn damage or water waste.

Maintaining Your System Through the Season

Monthly Inspection Tasks

Keep your irrigation system performing optimally:

• Run each zone manually and observe head performance
• Check for new leaks, especially around valve boxes
• Adjust heads that have been knocked out of alignment
• Clear any debris from around heads
• Verify controller is maintaining correct programming
• Adjust seasonal watering percentages as temperatures change

Summer Watering Best Practices

Maximize efficiency during peak irrigation season:

• Water early morning (4-7 AM) to minimize evaporation
• Apply water in cycles to prevent runoff on clay soil
• Increase run times rather than frequency for deeper watering
• Adjust for rainfall—skip cycles when significant rain occurs
• Watch for dry spots indicating coverage problems

Proper summer irrigation keeps your lawn healthy while conserving water. Combined with regular professional mowing and fertilization, your lawn will thrive through Idaho's challenging summers.

Schedule Your Spring Startup

Don't wait until your lawn is stressed to activate your irrigation system. Our team provides professional spring startup services throughout Kuna, Boise, Meridian, Eagle, Star, and Middleton.

Request a quote for spring irrigation startup, or contact us to schedule service. We'll ensure your system is ready for the dry months ahead, catching any winter damage before it affects your lawn's health.