diff --git a/packages/react-reconciler/src/ReactFiberCommitWork.new.js b/packages/react-reconciler/src/ReactFiberCommitWork.new.js
index 7985366d3f67c..cc15aa0f2e996 100644
--- a/packages/react-reconciler/src/ReactFiberCommitWork.new.js
+++ b/packages/react-reconciler/src/ReactFiberCommitWork.new.js
@@ -35,6 +35,7 @@ import {
   enableSuspenseCallback,
   enableScopeAPI,
   enableStrictEffects,
+  enableStrongMemoryCleanup,
 } from 'shared/ReactFeatureFlags';
 import {
   FunctionComponent,
@@ -1212,9 +1213,28 @@ function detachFiberMutation(fiber: Fiber) {
   fiber.return = null;
 }
 
-export function detachFiberAfterEffects(fiber: Fiber): void {
+export function detachFiberAfterEffects(
+  fiber: Fiber,
+  recurseIntoSibbling: ?boolean,
+): void {
   // Null out fields to improve GC for references that may be lingering (e.g. DevTools).
   // Note that we already cleared the return pointer in detachFiberMutation().
+  if (enableStrongMemoryCleanup) {
+    if (fiber.child) {
+      detachFiberAfterEffects(fiber.child, true);
+    }
+    if (fiber.sibling && recurseIntoSibbling === true) {
+      detachFiberAfterEffects(fiber.sibling, true);
+    }
+    if (fiber.stateNode) {
+      Object.keys(fiber.stateNode).forEach(key => {
+        if (key.indexOf('__react') === 0) {
+          delete fiber.stateNode[key];
+        }
+      });
+    }
+    fiber.return = null;
+  }
   fiber.alternate = null;
   fiber.child = null;
   fiber.deletions = null;
diff --git a/packages/react-reconciler/src/ReactFiberCommitWork.old.js b/packages/react-reconciler/src/ReactFiberCommitWork.old.js
index d50095b3bebb1..78dee1e928a50 100644
--- a/packages/react-reconciler/src/ReactFiberCommitWork.old.js
+++ b/packages/react-reconciler/src/ReactFiberCommitWork.old.js
@@ -35,6 +35,7 @@ import {
   enableSuspenseCallback,
   enableScopeAPI,
   enableStrictEffects,
+  enableStrongMemoryCleanup,
 } from 'shared/ReactFeatureFlags';
 import {
   FunctionComponent,
@@ -1212,9 +1213,28 @@ function detachFiberMutation(fiber: Fiber) {
   fiber.return = null;
 }
 
-export function detachFiberAfterEffects(fiber: Fiber): void {
+export function detachFiberAfterEffects(
+  fiber: Fiber,
+  recurseIntoSibbling: ?boolean,
+): void {
   // Null out fields to improve GC for references that may be lingering (e.g. DevTools).
   // Note that we already cleared the return pointer in detachFiberMutation().
+  if (enableStrongMemoryCleanup) {
+    if (fiber.child) {
+      detachFiberAfterEffects(fiber.child, true);
+    }
+    if (fiber.sibling && recurseIntoSibbling === true) {
+      detachFiberAfterEffects(fiber.sibling, true);
+    }
+    if (fiber.stateNode) {
+      Object.keys(fiber.stateNode).forEach(key => {
+        if (key.indexOf('__react') === 0) {
+          delete fiber.stateNode[key];
+        }
+      });
+    }
+    fiber.return = null;
+  }
   fiber.alternate = null;
   fiber.child = null;
   fiber.deletions = null;
diff --git a/packages/shared/ReactFeatureFlags.js b/packages/shared/ReactFeatureFlags.js
index 75ab4b6842d90..c697dbccb2050 100644
--- a/packages/shared/ReactFeatureFlags.js
+++ b/packages/shared/ReactFeatureFlags.js
@@ -112,6 +112,8 @@ export const disableNativeComponentFrames = false;
 // If there are no still-mounted boundaries, the errors should be rethrown.
 export const skipUnmountedBoundaries = false;
 
+export const enableStrongMemoryCleanup = true;
+
 // --------------------------
 // Future APIs to be deprecated
 // --------------------------
diff --git a/packages/shared/forks/ReactFeatureFlags.native-fb.js b/packages/shared/forks/ReactFeatureFlags.native-fb.js
index b6a8016ec8b77..05eff8ba505f3 100644
--- a/packages/shared/forks/ReactFeatureFlags.native-fb.js
+++ b/packages/shared/forks/ReactFeatureFlags.native-fb.js
@@ -46,6 +46,7 @@ export const enableLegacyFBSupport = false;
 export const enableFilterEmptyStringAttributesDOM = false;
 export const disableNativeComponentFrames = false;
 export const skipUnmountedBoundaries = false;
+export const enableStrongMemoryCleanup = true;
 
 export const enableNewReconciler = false;
 export const deferRenderPhaseUpdateToNextBatch = true;
diff --git a/packages/shared/forks/ReactFeatureFlags.native-oss.js b/packages/shared/forks/ReactFeatureFlags.native-oss.js
index cb8721af25fe9..6b3f25798bd58 100644
--- a/packages/shared/forks/ReactFeatureFlags.native-oss.js
+++ b/packages/shared/forks/ReactFeatureFlags.native-oss.js
@@ -45,6 +45,7 @@ export const enableLegacyFBSupport = false;
 export const enableFilterEmptyStringAttributesDOM = false;
 export const disableNativeComponentFrames = false;
 export const skipUnmountedBoundaries = false;
+export const enableStrongMemoryCleanup = true;
 
 export const enableNewReconciler = false;
 export const deferRenderPhaseUpdateToNextBatch = true;
diff --git a/packages/shared/forks/ReactFeatureFlags.test-renderer.js b/packages/shared/forks/ReactFeatureFlags.test-renderer.js
index b504491d98de2..97199b982ddd8 100644
--- a/packages/shared/forks/ReactFeatureFlags.test-renderer.js
+++ b/packages/shared/forks/ReactFeatureFlags.test-renderer.js
@@ -45,6 +45,7 @@ export const enableLegacyFBSupport = false;
 export const enableFilterEmptyStringAttributesDOM = false;
 export const disableNativeComponentFrames = false;
 export const skipUnmountedBoundaries = false;
+export const enableStrongMemoryCleanup = true;
 
 export const enableNewReconciler = false;
 export const deferRenderPhaseUpdateToNextBatch = true;
diff --git a/packages/shared/forks/ReactFeatureFlags.test-renderer.www.js b/packages/shared/forks/ReactFeatureFlags.test-renderer.www.js
index 7098bfed2aa5b..d5234f84109ac 100644
--- a/packages/shared/forks/ReactFeatureFlags.test-renderer.www.js
+++ b/packages/shared/forks/ReactFeatureFlags.test-renderer.www.js
@@ -45,6 +45,7 @@ export const enableLegacyFBSupport = false;
 export const enableFilterEmptyStringAttributesDOM = false;
 export const disableNativeComponentFrames = false;
 export const skipUnmountedBoundaries = false;
+export const enableStrongMemoryCleanup = true;
 
 export const enableNewReconciler = false;
 export const deferRenderPhaseUpdateToNextBatch = true;
diff --git a/packages/shared/forks/ReactFeatureFlags.testing.js b/packages/shared/forks/ReactFeatureFlags.testing.js
index a321f5ea12f92..0ad3c240c971b 100644
--- a/packages/shared/forks/ReactFeatureFlags.testing.js
+++ b/packages/shared/forks/ReactFeatureFlags.testing.js
@@ -45,6 +45,7 @@ export const enableLegacyFBSupport = false;
 export const enableFilterEmptyStringAttributesDOM = false;
 export const disableNativeComponentFrames = false;
 export const skipUnmountedBoundaries = false;
+export const enableStrongMemoryCleanup = true;
 
 export const enableNewReconciler = false;
 export const deferRenderPhaseUpdateToNextBatch = true;
diff --git a/packages/shared/forks/ReactFeatureFlags.testing.www.js b/packages/shared/forks/ReactFeatureFlags.testing.www.js
index bb6a952355657..2da6498824a56 100644
--- a/packages/shared/forks/ReactFeatureFlags.testing.www.js
+++ b/packages/shared/forks/ReactFeatureFlags.testing.www.js
@@ -45,6 +45,7 @@ export const enableLegacyFBSupport = !__EXPERIMENTAL__;
 export const enableFilterEmptyStringAttributesDOM = false;
 export const disableNativeComponentFrames = false;
 export const skipUnmountedBoundaries = true;
+export const enableStrongMemoryCleanup = true;
 
 export const enableNewReconciler = false;
 export const deferRenderPhaseUpdateToNextBatch = true;
diff --git a/packages/shared/forks/ReactFeatureFlags.www.js b/packages/shared/forks/ReactFeatureFlags.www.js
index 893c2699b0d07..12a00a17fcf62 100644
--- a/packages/shared/forks/ReactFeatureFlags.www.js
+++ b/packages/shared/forks/ReactFeatureFlags.www.js
@@ -92,6 +92,8 @@ export const enableNewReconciler = __VARIANT__;
 
 export const enableRecursiveCommitTraversal = false;
 
+export const enableStrongMemoryCleanup = __VARIANT__;
+
 // Flow magic to verify the exports of this file match the original version.
 // eslint-disable-next-line no-unused-vars
 type Check<_X, Y: _X, X: Y = _X> = null;