diff --git a/server/src/app-config/README.md b/server/src/app-config/README.md
index 3147d4eb0..4a3d6eea8 100644
--- a/server/src/app-config/README.md
+++ b/server/src/app-config/README.md
@@ -8,10 +8,10 @@ the pre-init Express middleware.
 ```
 env.schema.ts    Zod catalog of the whole env surface; fail-fast at boot
 derive.ts        pure (raw env) → typed namespace functions, exact per-site coercions
-env.ts           readEnv() live accessor + validateEnvAtBoot()
+env.ts           readEnv() live accessor + normalizeEnvAtBoot() + validateEnvAtBoot()
 app-url.ts       getAppUrl()/getMcpSafeUrl() instance base-URL resolution
 data-paths.ts    resolveDataPaths(): data/, uploads/, backups, tmp, logs, key files, DB file
-boot-validate.ts side-effect import used by index.ts (validates before other modules load)
+boot-validate.ts side-effect import used by index.ts (trims, then validates before other modules load)
 parsers.ts       shared coercion helpers (boolTrueLoose, numberOr, csvList, …)
 ```
 
@@ -200,3 +200,5 @@ The exemption list is enforced by the `no-restricted-syntax` ban on
 - NODE_ENV comparisons are case-sensitive at some sites (HSTS activation,
   platform statics, spa-fallback, authService dev_mode, oidcService
   frontendUrl) and case-insensitive at others.
+  Surrounding whitespace is stripped once at boot (`normalizeEnvAtBoot`,
+  together with LOG_LEVEL and DEFAULT_LANGUAGE), the casing is not.
diff --git a/server/src/app-config/boot-validate.ts b/server/src/app-config/boot-validate.ts
index a9edc1593..bd780aa51 100644
--- a/server/src/app-config/boot-validate.ts
+++ b/server/src/app-config/boot-validate.ts
@@ -1,12 +1,16 @@
 /**
- * Side-effect module: validates the environment the moment it is imported.
+ * Side-effect module: normalizes and validates the environment the moment it
+ * is imported.
  *
  * index.ts imports this immediately after `import 'dotenv/config'` — as a
  * side-effect import (not a function call) so validation runs BEFORE the rest
  * of the import graph executes its module-load side effects (config.ts key
  * resolution, ...). A plain call in index.ts's body
- * would run after all of those, because imports hoist.
+ * would run after all of those, because imports hoist. The trim runs first,
+ * so everything after it, Express and the plugin children included, reads the
+ * cleaned value.
  */
-import { validateEnvAtBoot } from './env';
+import { normalizeEnvAtBoot, validateEnvAtBoot } from './env';
 
+normalizeEnvAtBoot();
 validateEnvAtBoot();
diff --git a/server/src/app-config/env.schema.ts b/server/src/app-config/env.schema.ts
index f49250feb..d69c82231 100644
--- a/server/src/app-config/env.schema.ts
+++ b/server/src/app-config/env.schema.ts
@@ -60,6 +60,7 @@ export const envSchema = z.object({
   HOST: anyString,
   // NODE_ENV and TZ are deliberately unvalidated: non-standard values (e.g.
   // NODE_ENV=staging) behave as "not production" today and must keep booting.
+  // Surrounding whitespace on NODE_ENV is trimmed before this runs (env.ts).
   NODE_ENV: anyString,
   TZ: anyString,
   LOG_LEVEL: oneOf(['error', 'warn', 'info', 'debug']),
diff --git a/server/src/app-config/env.ts b/server/src/app-config/env.ts
index 34ee6fbed..8b2dbf433 100644
--- a/server/src/app-config/env.ts
+++ b/server/src/app-config/env.ts
@@ -39,6 +39,45 @@ function reportedValue(key: string, value: string | undefined): string {
   return SECRET_ENV_KEYS.has(key) ? '***' : JSON.stringify(value);
 }
 
+/**
+ * Variables whose surrounding whitespace is stripped once at boot. The schema
+ * already validates them trimmed, but every reader compares the raw string:
+ * NODE_ENV="production " served no web UI at all (#2565), LOG_LEVEL="debug "
+ * fell back to info, DEFAULT_LANGUAGE="de " to English. Deliberately a short
+ * list, not every variable: a secret may carry its spaces on purpose.
+ */
+const TRIMMED_AT_BOOT = ['NODE_ENV', 'LOG_LEVEL', 'DEFAULT_LANGUAGE'] as const;
+
+/**
+ * Strips the whitespace a .env line or a compose file left around the values in
+ * TRIMMED_AT_BOOT and writes the result back, so Express (`app.get('env')`),
+ * the plugin child processes and any library reading NODE_ENV itself see the
+ * same value as readEnv(). Casing is left alone. Each change is reported, since
+ * the banner cannot show a trailing space.
+ *
+ * NODE_ENV="test " is the one exception: trimmed it would switch a running
+ * instance onto an in-memory database without crons, so it is only reported.
+ */
+export function normalizeEnvAtBoot(raw: RawEnv = process.env as RawEnv): void {
+  for (const key of TRIMMED_AT_BOOT) {
+    const value = raw[key];
+    if (value === undefined) continue;
+    const trimmed = value.trim();
+    if (trimmed === value) continue;
+    if (key === 'NODE_ENV' && trimmed === 'test') {
+      bootWarning(`${key}=${JSON.stringify(value)} has surrounding whitespace and is not treated as "test".`);
+      continue;
+    }
+    raw[key] = trimmed;
+    bootWarning(`${key}=${JSON.stringify(value)} has surrounding whitespace, using ${JSON.stringify(trimmed)}.`);
+  }
+}
+
+/** Runs before the file logger exists, so it goes to stderr as a process warning. */
+function bootWarning(message: string): void {
+  process.emitWarning(message, { code: 'TREK_ENV_WHITESPACE' });
+}
+
 /**
  * Fail-fast startup validation: a variable that is PRESENT but malformed aborts
  * boot with an aggregated report; unset/blank variables always pass (their
diff --git a/server/src/index.ts b/server/src/index.ts
index ebad020c5..930de1f7b 100644
--- a/server/src/index.ts
+++ b/server/src/index.ts
@@ -53,7 +53,7 @@ const onListen = () => {
     ...(HOST ? [`  Host:           ${HOST}`] : []),
     `  Container Port: ${PORT}`,
     `  App URL:        ${appUrl}`,
-    `  Environment:    ${env.app.nodeEnv?.toLowerCase() || 'development'}`,
+    `  Environment:    ${env.app.nodeEnv || 'development'}`,
     `  Timezone:       ${tz}`,
     `  Origins:        ${origins}`,
     `  Log level:      ${LOG_LVL}`,
diff --git a/server/tests/unit/app-config/boot-normalize.test.ts b/server/tests/unit/app-config/boot-normalize.test.ts
new file mode 100644
index 000000000..ff1b49b5b
--- /dev/null
+++ b/server/tests/unit/app-config/boot-normalize.test.ts
@@ -0,0 +1,70 @@
+import { normalizeEnvAtBoot, readEnv } from '../../../src/app-config/env';
+
+import { describe, it, expect, vi, afterEach } from 'vitest';
+
+/** Everything one normalisation printed as a warning. */
+function warnings(raw: Record<string, string | undefined>): string {
+  const warn = vi.spyOn(process, 'emitWarning').mockImplementation(() => {});
+  normalizeEnvAtBoot(raw);
+  const printed = warn.mock.calls.map((c) => String(c[0])).join('\n');
+  warn.mockRestore();
+  return printed;
+}
+
+describe('normalizeEnvAtBoot (#2565)', () => {
+  afterEach(() => {
+    vi.restoreAllMocks();
+    vi.unstubAllEnvs();
+    vi.resetModules();
+  });
+
+  it('trims a padded NODE_ENV in place and says so', () => {
+    for (const padded of ['production ', ' production', 'production\r', '\tproduction\n']) {
+      const raw: Record<string, string | undefined> = { NODE_ENV: padded };
+      const printed = warnings(raw);
+      expect(raw.NODE_ENV, JSON.stringify(padded)).toBe('production');
+      expect(printed).toContain(`NODE_ENV=${JSON.stringify(padded)}`);
+      expect(printed).toContain('"production"');
+    }
+  });
+
+  it('trims LOG_LEVEL and DEFAULT_LANGUAGE the same way', () => {
+    const raw: Record<string, string | undefined> = { LOG_LEVEL: 'debug ', DEFAULT_LANGUAGE: ' de' };
+    const printed = warnings(raw);
+    expect(raw.LOG_LEVEL).toBe('debug');
+    expect(raw.DEFAULT_LANGUAGE).toBe('de');
+    expect(printed).toContain('LOG_LEVEL="debug "');
+    expect(printed).toContain('DEFAULT_LANGUAGE=" de"');
+  });
+
+  it('leaves clean, unset and differently cased values alone and stays quiet', () => {
+    const raw: Record<string, string | undefined> = { NODE_ENV: 'Production', LOG_LEVEL: 'info' };
+    expect(warnings(raw)).toBe('');
+    expect(raw).toEqual({ NODE_ENV: 'Production', LOG_LEVEL: 'info' });
+  });
+
+  it('does not turn a padded "test" into the test runtime', () => {
+    // NODE_ENV=test means an in-memory database and no crons. An instance that
+    // has been running on "test " with its file database must not wake up on
+    // an empty one after an update, so this one is only reported.
+    const raw: Record<string, string | undefined> = { NODE_ENV: 'test ' };
+    const printed = warnings(raw);
+    expect(raw.NODE_ENV).toBe('test ');
+    expect(printed).toContain('NODE_ENV="test "');
+  });
+
+  it('never touches other variables, secrets keep their surrounding spaces', () => {
+    const raw: Record<string, string | undefined> = { SMTP_PASS: ' pass ', TZ: 'UTC ' };
+    expect(warnings(raw)).toBe('');
+    expect(raw).toEqual({ SMTP_PASS: ' pass ', TZ: 'UTC ' });
+  });
+
+  it('runs from the boot import, so everything reading process.env sees the trimmed value', async () => {
+    vi.stubEnv('NODE_ENV', 'production ');
+    vi.spyOn(process, 'emitWarning').mockImplementation(() => {});
+    await import('../../../src/app-config/boot-validate');
+    expect(process.env.NODE_ENV).toBe('production');
+    expect(readEnv().app.nodeEnv).toBe('production');
+    expect(readEnv().app.isProduction).toBe(true);
+  });
+});
diff --git a/wiki/Environment-Variables.md b/wiki/Environment-Variables.md
index 88f07a870..2fbb89904 100644
--- a/wiki/Environment-Variables.md
+++ b/wiki/Environment-Variables.md
@@ -38,7 +38,8 @@ aborting, because `reset-admin.js` — the way back into a locked-out instance 
 to keep working. The three plugin caps `TREK_PLUGIN_AI_PER_DAY`, `TREK_PLUGIN_NOTIFY_PER_DAY` and
 `TREK_PLUGIN_AUDIT_MAX_ROWS` are read by the plugin host rather than by the boot schema, so a malformed value there
 falls back to the default without a warning. `NODE_ENV` and `TZ` are not validated at all, so a non-standard value
-like `NODE_ENV=staging` still boots.
+like `NODE_ENV=staging` still boots. Spaces around `NODE_ENV`, `LOG_LEVEL` and `DEFAULT_LANGUAGE` are trimmed at startup with a
+warning in the log; the web UI is only served with `NODE_ENV=production` in lowercase.
 
 ---