The short answer
During a drought on a large green site, protect long-lived assets first: recently planted and mature trees and valuable shrubs get the deepest water, while turf is allowed to go dormant and low-priority areas are cut. Water slowly and early, rank zones by replacement cost and function, and follow local restrictions strictly.
Key takeaways
- Trees are the slowest-recovering and most valuable asset on a site, so they rank first for water, while turfgrass ranks last because it goes dormant and recovers after rain.
- Trees and shrubs planted in the last two years are most drought-vulnerable because their root systems are not yet developed; protect them before mature plantings.
- Deep, infrequent watering that reaches 8–12 inches into the soil beats frequent shallow watering: it drives roots deeper, cuts evaporation, and reduces runoff.
- Keep turf alive in 'survival mode' with about half an inch of water every two to three weeks; it stays brown but keeps its crowns hydrated and recovers later.
- Set written priorities by replacement cost, age, function, and contractual obligations before restrictions start, not while the water is already gone.
- Cut nonessential users first — non-recirculating fountains, annual beds, and low-use turf — and redirect saved water to trees.
- Build resilience before the next drought through hydrozoning, drought-tolerant species, mulching, and converting some irrigated turf.
Know which plants can wait and which cannot
A drought forces site managers to make choices that normal seasons never require: the available water will not keep turf, flower beds, shrubs, and trees all looking perfect at once. The governing rule is simple — protect what costs the most and takes the longest to replace, not what looks the most obviously stressed. A tree lost in one dry season represents decades of growth, shade, cooling, and invested money, whereas a lawn that browns will usually recover within weeks of rain.
Extension guidance consistently repeats the same order: trees first, shrubs and perennials next, and turfgrass last, because grasses are the toughest plants on the site and simply enter dormancy. Within the tree layer, those planted in the past two years are the most vulnerable, since their root systems are not fully developed; after them come established trees and rare or expensive-to-replace specimens. Trees shading buildings, play areas, and entry plazas earn extra priority because they cool the people and turf beneath them.
- First: recently planted trees and shrubs (up to 2 years) and rare or costly specimens.
- Second: established trees and valuable shrubs, especially those providing shade.
- Third: drought-tolerant perennials and shrubs.
- Last: turfgrass, which survives dry spells by going dormant.
Build a tiered priority list before the water runs out
While restrictions are still only a risk, walk the whole site and divide it into zones by age of plantings, function, intensity of use, and cost of replacement. Municipalities facing shortages rank their parks from top to low priority based on factors such as use, rentals, location, and community function — the same logic works inside a single large property. The ranking becomes the operating document that guides every watering decision.
Programmed, high-use turf such as sports fields and event lawns may carry contractual obligations and therefore stays higher than passive lawn, but usually in survival rather than display mode. The trees shading those same fields remain higher than the grass beneath them. Decide in advance which zones you can allow to look dry without damaging reputation or legal commitments, and write that decision down so staff do not improvise under pressure.
- Criterion 1 — establishment: young trees outrank mature ones.
- Criterion 2 — replacement cost and rarity: specimens outrank common plantings.
- Criterion 3 — function and obligations: rented or programmed fields outrank passive turf.
- Criterion 4 — microclimate value: shade trees outrank comparable trees in open lawn.
- Criterion 5 — condition: water first the plants that will survive with irrigation.
Irrigate deep, early, and where the roots are
In dry periods the principle is 'deep and infrequent': a slow watering that wets the soil to 8–12 inches encourages roots to grow downward and makes the plant more drought-resilient, while frequent light watering wets only the surface and is lost to evaporation. The best time is early morning, when it is cooler and less windy, so more water reaches the roots instead of the air.
Apply water slowly enough that it soaks in rather than runs off: use drip lines, soaker hoses, or the cycle-and-soak method of splitting one long run into several short cycles with pauses. For a tree, place water across the canopy and out to the edge of the root zone, not against the trunk, and keep a 2–4 inch layer of mulch over the root area to slow evaporation and cool the soil.
- A practical rule for trees is about 10 gallons of water per inch of trunk diameter per week during dry periods, delivered slowly.
- Deep watering should reach about 8–12 inches into the soil to sustain root systems.
- Water early in the morning to cut evaporation and wind drift.
- Use drip or soaker delivery, or cycle-and-soak, to prevent runoff on slopes and hard soils.
- Mulch the root zone and water across the drip line rather than at the trunk.
Set hard limits: what to let go first
The most effective conservation lever is deliberately refusing to keep everything green. Turfgrasses enter dormancy under drought and turn brown without dying, as long as the soil does not dry out completely. To keep the dormant tissue at the crown hydrated, roughly half an inch of water every two to three weeks is enough — it will not restore color, but it sharply improves the odds of survival.
During drought, stop applying fertilizer and herbicides to lawns, limit traffic and machinery, and either stop mowing or mow at the highest recommended setting, removing as little leaf blade as possible. Avoid cycling turf between dormancy and regrowth with intermittent watering, because that weakens the sod. At the same time, switch off what is not essential: non-recirculating fountains, annual beds, medians, and low-use turf. In acute shortages, municipal crews cut irrigation of green zones to a minimum and use technical or non-potable water to protect plants.
- Switch off first: decorative fountains without recirculation, annual beds, medians, and low-use turf.
- Hold high-use turf in survival mode rather than display green.
- Skip fertilizer and herbicide on drought-stressed lawns.
- Mow higher and less often; a sharper blade also heals faster.
- Use non-potable, recycled, or rainwater where permitted and available.
Harden the site so the next drought costs less
Droughts repeat, so resilience is built in advance through planning and plant selection rather than improvised in the middle of a dry season. Hydrozoning — grouping plants with similar water needs into separate irrigation zones — lets each zone receive exactly what it needs and stops water from being wasted on drought-tolerant plants just to keep a thirsty neighbor green.
Choose drought-tolerant and native species, build soil organic matter so it absorbs and holds water longer, and gradually shrink the area of intensively irrigated turf where it serves no function. Real municipal pilots show that converting a portion of irrigated turf can save hundreds of thousands of gallons a year. On the technical side, weather-based irrigation controllers and rain sensors deliver some of the largest savings because they adjust schedules automatically instead of watering on a fixed timer.
- Divide the site into hydrozones with separate irrigation programs.
- Prefer drought-tolerant and native species suited to local soils.
- Add organic matter and maintain a mulch layer to hold soil moisture.
- Convert irrigated turf to lower-water plantings where turf has no function.
- Install weather-based controllers and rain sensors.
- Audit sprinkler heads, valves, and overspray onto paving weekly.
Run the drought like a managed operation
Decisions about limits should be made and documented before the crisis, not while the tank is empty. Write down the tiered priority list, assign named staff to young trees and valuable plantings, and define how high-priority trees will be hand-watered when sprinkler runs are restricted. When municipal rules impose stages or watering windows, check your schedule against them and do not violate the rules to favor one zone.
Tell visitors and staff that brown turf is an expected consequence of drought, not a sign of poor care. Keep records of what was watered, when, and how much, and note which zones recovered once rain returned. Those records let you refine the priority list and speed up restoration when restrictions are lifted.
- Write the priority list and assign responsibility before restrictions begin.
- Check every schedule against local rules and current restriction stages.
- Set public expectations that dry turf is intentional during drought.
- Log volumes, timing, and outcomes for later analysis.
- Reassess zones after rain and adjust next season's planting and irrigation plan.
Put it into practice
Drought Irrigation Priority Board — Tiered Watering Decision Sheet
A fill-in worksheet for a site manager: assign every area of the property to a tier, then set the watering action and the limit for each. Complete it before restrictions begin and check it whenever conditions change.
- Tier 1 — recently planted trees and shrubs (0–2 years): water deep every 5–7 days in dry spells to 8–12 inches; never skip them, they die first.
- Tier 1 — mature specimen and heritage trees: water across the drip line every 2–4 weeks in extended drought, delivered slowly by soaker or drip.
- Tier 2 — established trees and valuable shrubs: water as restrictions allow, starting with those shading buildings, sports fields, and entries.
- Tier 2 — programmed high-use turf (fields, event lawns): maintain only under contractual obligations, in survival rather than display mode.
- Tier 3 — low-use turf and medians: allow dormancy; if fully dry, apply about half an inch every 2–3 weeks to keep crowns hydrated.
- Tier 4 — annual beds, temporary plantings, and non-recirculating fountains: cut or switch off first.
- All tiers — water early in the morning, slowly, with 2–4 inches of mulch, and inspect sprinklers weekly for leaks and overspray onto paving.
Questions people ask
Which plants on a large site should be watered first during a drought?
Water trees and shrubs planted in the last two years first, because their roots are not yet developed and they die before mature plants. Next come established trees and rare or expensive-to-replace specimens that provide shade and cooling. Turfgrass ranks last: it is the toughest plant on site, enters dormancy during drought, and recovers once rain returns.
How much water does a mature tree need during an extended drought?
A widely used rule is about 10 gallons of water per inch of trunk diameter per week during dry periods, applied slowly across the drip line so it reaches 8–12 inches deep. Deep, infrequent watering encourages roots to grow downward and improves drought resilience. Adjust for soil type, species, and whether the tree is established or recently planted.
Should I stop watering the lawn entirely to save water for trees?
Yes, if local rules let you choose priorities. Turfgrass survives drought by going dormant: it turns brown but does not die as long as the soil does not dry out completely. Apply about half an inch of water every two to three weeks to keep the crowns hydrated. Avoid cycling dormancy and regrowth, do not fertilize, and mow higher to reduce stress.
What time of day and what method waste the least water on a big site?
Water early in the morning when it is cooler and less windy to cut evaporation and wind drift. Apply water slowly and deeply — with drip lines, soaker hoses, or the cycle-and-soak method — rather than in one long surface run. This lets water soak into the root zone instead of running off into gutters and paving.
What should a site cut first when there is not enough water for everything?
Cut the nonessential users first: decorative fountains without recirculation, annual flower beds, medians, and low-use turf. Then move programmed turf to survival mode rather than display green. Redirect the saved water to trees, young plantings, and areas with contractual obligations. In acute shortages, use non-potable, recycled, or rainwater where permitted.
Does a smart irrigation controller really help during a drought?
Weather-based controllers and rain sensors automatically adjust schedules so the system does not water during rainfall or overwater plants. Research shows they consistently reduce landscape water use by tens of percent compared with fixed timers, especially on sites that were previously overwatered. They are a useful tool alongside a written priority list and routine leak checks, not a replacement for good management.
Sources and further reading
Sources were checked when this page was generated. Confirm changing dates, rules and prices with the original publisher.
- Ask an Expert: How to Prioritize Home Irrigation During a Drought (Utah State University Extension)Utah State University Extension
- Essential Gardening Tips for Drought ConditionsN.C. State Extension, Durham County Center
- Keeping Landscapes Resilient During DroughtNorthern Water (Northern Colorado Water Conservancy District)
- Communities Urged to Prioritize Watering Trees Amid Ongoing Drought Conditions in NebraskaNebraska Forest Service, University of Nebraska–Lincoln
- Water Conservation in Our Parks: What to Expect This SeasonArapahoe County, Colorado
- Нормы и рекомендации по поливу зеленых насажденийЗелёный город (Нижний Новгород)
- Экономный режим полива газонов: вместе бережём воду!Администрация Волновахского муниципального округа