---
title: "Chloride and boron tip burn—specific-ion injury on lawns and landscape plants"
description: "Late-July DIY companion for chloride and boron specific-ion tip burn beside total-salinity and sodium stories: UF/IFAS reclaimed-water / EP616 framing—chloride not a problem below about 70 ppm, increasing concern about 70–300 ppm, severe above about 300 ppm, with foliar damage often framed above about 100 mg/L (ppm) as yellow-to-tan leaf-tip firing; boron not a problem below about 0.7 ppm (EP616 desired often < about 0.5), increasing about 0.7–2.0 ppm, severe above about 2.0 ppm, with yellowing then dark necrosis on older-leaf margins; sodium foliar injury themes above about 70 ppm while sodicity/SAR is a separate soil-structure story; NC State AG-759—chloride root-absorption bands roughly <70 / 70–355 / >355 mg/L and foliar absorption caution above about 100 mg/L, boron excessive when about 1–2 ppm with some ornamentals sensitive near 0.33 ppm, turf often more boron-tolerant than woody plants but clippings-return can recycle tip boron, and boron is harder to leach than ordinary soluble salts; UC ANR 8009—chloride rarely kills turf first but trees/shrubs/groundcovers are more sensitive, boron phytotoxic to most ornamentals near 1–2 mg/L while many turfgrasses tolerate higher soil boron; heat without leach rain concentrates ions under overhead spray—affiliate TDS/EC meter, irrigation water / soil-test kits, rain gauge, soil probe, moisture meter, hand lens, soaker hose, and rain-barrel links—not a fungicide panic because tips browned after weeks of reclaimed or well water in a heat dome."
pubDate: 2026-07-23
canonical: "https://lawncarejournal.app/articles/chloride-boron-specific-ion-tip-burn-lawn-ornamentals/"
---

By late July, a **heat dome without a leach rain** often turns reclaimed, well, or coastal irrigation into a **tip-burn week**—and the cart item becomes a fungicide. Sometimes the real story is not total ECw alone or a sodium/SAR soil seal, but **specific ions**: **chloride (Cl−)** and **boron (B)** that accumulate in leaf tips and margins (and, for boron, linger in soil longer than everyday soluble salts). UF/IFAS reclaimed-water and irrigation-analysis guides, NC State AG-759, and UC ANR 8009 all separate that chapter from “the water is just salty.”

This page is the **chloride / boron companion** to [irrigation water quality—salinity, sodium, and tip burn](/articles/irrigation-water-quality-salinity-sodium-lawn-tip-burn). It is not a lab report for your ZIP code and not permission to blame every scorched hedge on boron. Confirm chronic injury with [county extension](https://www.extension.org/) and a water or tissue lab when large areas collapse or sensitive ornamentals die while turf still looks decent.

## Key takeaways

- **Specific ion ≠ ECw alone:** High total salts cause **physiological drought**; high **SAR / sodium** wrecks **infiltration**; **chloride and boron** can still injure leaves at concentrations that look “okay” on a TDS dial if you never read the ion columns (UF/IFAS; NC State; UC ANR).
- **Chloride cues:** Yellow-to-tan **leaf-tip firing**; UF/IFAS—foliar damage often framed when Cl exceeds about **100 mg/L (ppm)**; management bands roughly **<70** not a problem → **70–300** increasing → **>300** severe.
- **Boron cues:** Yellowing then **dark necrosis on margins of older leaves**; UF/IFAS—**<0.7** not a problem → **0.7–2.0** increasing → **>2.0** severe (EP616 desired often **< about 0.5**); NC State—excess often discussed near **1–2 ppm**, with some ornamentals sensitive near **0.33 ppm**.
- **Turf vs landscape:** Turf is often **more tolerant** than woody ornamentals and groundcovers; UF/IFAS notes specific-ion toxicity is frequently a **landscape-plant** concern first because turf is mowed often—still check Cl/B when hedges brown under the same overhead spray (EP616; UC ANR 8009).
- **DIY order:** Read the water report for **Cl and B** → separate [fertilizer salt burn](/articles/fertilizer-salt-burn-vs-disease-midsummer-lawn) stripes and [disease lesions](/articles/#seasonal-focus-heading) → change delivery (drip / soaker vs overhead on sensitive plants), blend or alternate sources, leach when drainage and rules allow → do **not** expect gypsum to “eat” chloride or boron.

## Side-by-side look-alike table (tip burn week)

| Clue | Chloride / boron specific ion | Total salinity (ECw) | Sodium / sodicity (SAR) | Fertilizer salt burn | Lawn disease |
| --- | --- | --- | --- | --- | --- |
| **Pattern** | Tip firing (Cl); older-leaf margin yellow → dark necrosis (B); often worse under **overhead** spray on hedges and bed edges | Fairly uniform tip/margin scorch; wilt with moist soil | Ponding, crusting, poor infiltration; sometimes foliar Na burn | Spreader **stripes**, turn blobs | Circles, lesions, mycelium, smoke rings |
| **Lab cue** | Cl and B columns high even if ECw looks “moderate” | High ECw / TDS | High SAR / sodium; soil seals | Recent bag + stripe map | Hand-lens pathogens |
| **First DIY move** | Ask provider / lab for Cl & B; reduce foliar wetting on sensitive plants; leach / blend | Leach when allowed; salt-tolerant species | Softener bypass; gypsum **only** if Na confirmed + leach | Journal the bag → leach → fix spreader | Disease guides before jugs |

A [hand lens](https://www.amazon.com/s?k=illuminated+hand+lens+30x&tag=lawnjournal0c-20) still rules bordered leaf spots in or out. A handheld [TDS / EC meter](https://www.amazon.com/s?k=tds+ec+meter+water&tag=lawnjournal0c-20) screens source changes but **does not** report chloride or boron—send a bottle when tip burn persists on reclaimed or well water. As an Amazon Associate, Lawn Care Journal LLC earns from qualifying purchases.

If brown **stripes** appeared the day after a fertilizer bag, start with [fertilizer salt burn](/articles/fertilizer-salt-burn-vs-disease-midsummer-lawn). If the whole zone wilts with moist soil and high ECw, stay on the [salinity / sodium parent guide](/articles/irrigation-water-quality-salinity-sodium-lawn-tip-burn). If you want a **low-salt stored source** for leaching or bed watering, read [rainwater harvesting](/articles/rainwater-harvesting-cistern-vs-municipal-salinity-lawn-irrigation).

## Why late-July heat makes Cl and B look like “fungus”

| Setup | What extension is telling you | DIY correction |
| --- | --- | --- |
| **Reclaimed overhead in a heat dome** | UF/IFAS—reclaimed water varies daily; Cl foliar injury often >~100 ppm; B toxic in excess at very low ppm | Ask the utility for constituent reports; reduce leaf wetting on sensitive shrubs; leach / blend when allowed |
| **No leach rain for weeks** | Salts and mobile Cl move with water—ET without excess irrigation leaves ions in the root/shoot zone | Occasional deeper soak (leaching fraction) when drainage and [watering rules](/articles/cool-season-overseed-watering-restrictions-variance-hand-water) allow; measure inches |
| **Turf OK, hedges crispy** | EP616 / UC ANR—specific-ion injury often shows first on landscape plants; turf may still look acceptable | Treat beds and lawn as different crops; drip/soaker for ornamentals when Cl/B are elevated |
| **Clippings returned on high-B water** | NC State—boron accumulates in leaf tips; returning clippings can recycle B; excess often >~1–2 ppm | Bag clippings temporarily on documented high-B sites; prefer leaching where soils drain |
| **Gypsum bag for “salt burn”** | Gypsum helps **sodic** soils (Na); it does **not** remove chloride or boron without a water-quality plan | Test SAR vs Cl/B; fix the right problem |
| **Fungicide because tips browned** | Abiotic tip firing ≠ leaf-spot lesions | Hand-lens before chemistry |

Oklahoma State / NC State themes also note **boron is harder to leach** than everyday soluble salts (often framed as needing **about 2–3×** the leach water of ordinary salts)—patience and drainage matter more than another soluble fertilizer dump.

## How to read Cl and B on a water report

Ask the lab—or your reclaimed-water provider—for at least **ECw**, **SAR**, **chloride**, **boron**, and **sodium** (plus bicarbonate/pH when offered). Compare against extension bands, not a neighbor’s guess:

| Ion | Rough “not a problem” | Increasing concern | Severe / caution themes |
| --- | --- | --- | --- |
| **Chloride** | UF/IFAS **<~70 ppm**; NC State root absorption **<~70 mg/L** | UF/IFAS **~70–300**; NC State **~70–355** | UF/IFAS **>~300**; foliar injury often **>~100 mg/L** (UF/IFAS; NC State foliar band) |
| **Boron** | UF/IFAS **<~0.7 ppm** (EP616 desired often **<~0.5**); OSU theme **<~1.0 mg/L** usually fine for many plants | UF/IFAS **~0.7–2.0**; NC State / UC ANR concern **~1–2 mg/L** | UF/IFAS **>~2.0**; OSU **>~2.0** often unsuitable; some ornamentals sensitive near **~0.33 ppm** (NC State) |
| **Sodium (foliar)** | UF/IFAS **<~70 ppm** foliar theme | **~70–200** | **>~200**; foliar injury themes **>~70**—pair with [SAR / gypsum parent page](/articles/irrigation-water-quality-salinity-sodium-lawn-tip-burn) |

Shop screening and measurement starters: [tds ec meter water](https://www.amazon.com/s?k=tds+ec+meter+water&tag=lawnjournal0c-20), [irrigation water test kit](https://www.amazon.com/s?k=irrigation+water+test+kit&tag=lawnjournal0c-20), [lawn soil test kit lab](https://www.amazon.com/s?k=lawn+soil+test+kit+lab&tag=lawnjournal0c-20), [lawn rain gauge](https://www.amazon.com/s?k=lawn+rain+gauge&tag=lawnjournal0c-20), [soil probe lawn](https://www.amazon.com/s?k=soil+probe+lawn&tag=lawnjournal0c-20), [soil moisture meter lawn](https://www.amazon.com/s?k=soil+moisture+meter+lawn&tag=lawnjournal0c-20), [illuminated hand lens 30x](https://www.amazon.com/s?k=illuminated+hand+lens+30x&tag=lawnjournal0c-20), [soaker hose](https://www.amazon.com/s?k=soaker+hose+garden&tag=lawnjournal0c-20), [rain barrel](https://www.amazon.com/s?k=rain+barrel+mosquito+screen&tag=lawnjournal0c-20). As an Amazon Associate, Lawn Care Journal LLC earns from qualifying purchases.

## DIY decision tree (specific-ion week)

1. **Map the pattern**—whole irrigation zone and bed edges vs spreader stripes vs bead-positive [localized dry spot](/articles/localized-dry-spot-hydrophobic-thatch-wetting-agent-midsummer) circles.  
2. **Hand-lens blades and leaves**—lesions / mycelium → disease guides; pure tip/margin scorch without pathogens stays abiotic.  
3. **List the water source**—municipal, well, pond, reclaimed; softener on the irrigation line?  
4. **Read Cl and B**—do not stop at a TDS pen reading; request the ion columns or a provider report.  
5. **Separate sodium**—poor infiltration and softener effluent → parent [salinity / SAR guide](/articles/irrigation-water-quality-salinity-sodium-lawn-tip-burn).  
6. **Change delivery on sensitive plants**—soaker / drip and early-morning cycles cut foliar Cl/Na wetting when overhead spray is the injury path (UF/IFAS management themes).  
7. **Leach when allowed**—measure inches with a [rain gauge](https://www.amazon.com/s?k=lawn+rain+gauge&tag=lawnjournal0c-20); expect boron to need more patience than ordinary salts on some soils (NC State / OSU leach themes).  
8. **Blend or alternate sources**—rain barrels / cisterns for beds, or a fresher hose zone for leaching soaks, when rules allow ([rainwater harvesting](/articles/rainwater-harvesting-cistern-vs-municipal-salinity-lawn-irrigation)).  
9. **Match plants**—salt- and ion-tolerant turf and ornamentals beat forcing centipede or sensitive shrubs on marginal reclaimed water ([centipede decline](/articles/centipedegrass-decline-take-all-root-rot)).

## What not to do

- Buy a **fungicide** because tips browned after a month of reclaimed overhead spray in heat.  
- Treat a **TDS pen** as a chloride or boron test.  
- Dump **gypsum** for chloride or boron—that chemistry is a **sodium / sodicity** tool when tests support it.  
- Answer tip burn with a **quick-release fertilizer** dump—more soluble salts on an already salty profile.  
- Nightly **one-minute mist**—you evaporate water and leave ions in the top inch.  
- Ignore **drainage**—you cannot leach a bathtub soil; fix grade / compaction first ([core aeration](/articles/liquid-aeration-vs-core-aeration-compaction)).

## What to journal

Log water source, utility or lab **ECw / SAR / Cl / B / Na**, which zones are overhead vs drip, tip-burn photos on turf vs ornamentals, leach dates and measured inches, rainfall, softener bypass yes/no, and any source blend (rain barrel vs reclaimed). That record turns next July’s mysterious scorch into a water-quality checklist instead of another jug. [Lawn Care Journal](/) for iPhone and iPad is built for those dated notes; download on the [App Store](https://apps.apple.com/us/app/lawn-care-journal/id1507797403). Optional in-app Assistant is educational only—not a prescription for your well or reclaimed-water utility.

Related reads: [irrigation water quality—salinity, sodium, and tip burn](/articles/irrigation-water-quality-salinity-sodium-lawn-tip-burn), [rainwater harvesting—barrels, cisterns, and low-salinity irrigation](/articles/rainwater-harvesting-cistern-vs-municipal-salinity-lawn-irrigation), [summer lawn watering](/articles/summer-lawn-watering-deep-infrequent), [rain gauge and soil probe measurement](/articles/lawn-rain-gauge-soil-probe-measure-watering), [hose-end vs in-ground irrigation](/articles/hose-end-vs-in-ground-lawn-irrigation-efficiency), [fertilizer salt burn vs disease](/articles/fertilizer-salt-burn-vs-disease-midsummer-lawn), [localized dry spot / hydrophobic thatch](/articles/localized-dry-spot-hydrophobic-thatch-wetting-agent-midsummer), [herbicide phytotoxicity vs disease](/articles/herbicide-phytotoxicity-spray-drift-vs-disease-midsummer-lawn), [dormant vs dead grass](/articles/dormant-grass-vs-dead-grass-summer), [liquid vs core aeration](/articles/liquid-aeration-vs-core-aeration-compaction), [soil test before fertilizer](/articles/spring-soil-test-before-lawn-fertilizer), [centipede decline](/articles/centipedegrass-decline-take-all-root-rot), [watering restrictions / hand-water rules](/articles/cool-season-overseed-watering-restrictions-variance-hand-water). More DIY topics: [articles index](/articles). App help: [Support](/support).