src/renderers/dom/client/wrappers/ReactDOMTextarea.js

@@ -100,10 +100,11 @@ var ReactDOMTextarea = {
 
     // The value can be a boolean or object so that's why it's
     // forced to be a string.
+    defaultValue = '' + (value != null ? value : defaultValue);
     var nativeProps = Object.assign({}, props, {
-      defaultValue: '' + (value != null ? value : defaultValue),
+      defaultValue: defaultValue,
       value: undefined,
-      children: undefined,
+      children: defaultValue,
       onChange: inst._wrapperState.onChange,
     });
 

src/renderers/dom/client/wrappers/__tests__/ReactDOMTextarea-test.js

@@ -16,6 +16,7 @@ var emptyFunction = require('emptyFunction');
 describe('ReactDOMTextarea', function() {
   var React;
   var ReactDOM;
+  var ReactDOMServer;
   var ReactLink;
   var ReactTestUtils;
 
@@ -24,6 +25,7 @@ describe('ReactDOMTextarea', function() {
   beforeEach(function() {
     React = require('React');
     ReactDOM = require('ReactDOM');
+    ReactDOMServer = require('ReactDOMServer');
     ReactLink = require('ReactLink');
     ReactTestUtils = require('ReactTestUtils');
 
@@ -113,6 +115,13 @@ describe('ReactDOMTextarea', function() {
     expect(node.value).toEqual('gorilla');
   });
 
+  it('should take `defaultValue` when changing to uncontrolled input', function() {
+    var image = ReactDOMServer.renderToString(<textarea defaultValue="1" />);
+    var div = document.createElement('div');
+    div.innerHTML = image;
+    expect(div.firstChild.innerHTML).toBe('1');
+  });
+
   it('should allow setting `value` to `true`', function() {
     var container = document.createElement('div');
     var stub = <textarea value="giraffe" onChange={emptyFunction} />;