diff --git a/lib/elements/dom-bind.html b/lib/elements/dom-bind.html
index 436791d85c..19497e0d32 100644
--- a/lib/elements/dom-bind.html
+++ b/lib/elements/dom-bind.html
@@ -103,7 +103,7 @@
           for (let n=this.root.firstChild; n; n=n.nextSibling) {
             this.__children[this.__children.length] = n;
           }
-          this._flushProperties();
+          this._enableProperties();
         }
         this.__insertChildren();
         this.dispatchEvent(new CustomEvent('dom-change', {
diff --git a/lib/mixins/element-mixin.html b/lib/mixins/element-mixin.html
index 9465d1d034..41d7551767 100644
--- a/lib/mixins/element-mixin.html
+++ b/lib/mixins/element-mixin.html
@@ -631,9 +631,7 @@
         if (window.ShadyCSS && this._template) {
           window.ShadyCSS.styleElement(this);
         }
-        if (!this.__dataInitialized) {
-          this._flushProperties();
-        }
+        this._enableProperties();
       }
 
       /**
diff --git a/lib/mixins/property-accessors.html b/lib/mixins/property-accessors.html
index a586f31a2d..7104d229f8 100644
--- a/lib/mixins/property-accessors.html
+++ b/lib/mixins/property-accessors.html
@@ -475,6 +475,18 @@
         }
       }
 
+      // TODO(kschaaf): document.
+      _enableProperties() {
+        if (!this.__dataPropertiesEnabled) {
+          this.__dataPropertiesEnabled = true;
+          if (this.__dataInstanceProps) {
+            this._initializeInstanceProperties(this.__dataInstanceProps);
+            this.__dataInstanceProps = null;
+          }
+          this.ready()
+        }
+      }
+
       /**
        * Calls the `_propertiesChanged` callback with the current set of
        * pending changes (and old values recorded when pending changes were
@@ -487,9 +499,7 @@
        * @protected
        */
       _flushProperties() {
-        if (!this.__dataInitialized) {
-          this.ready()
-        } else if (this.__dataPending) {
+        if (this.__dataPending) {
           let changedProps = this.__dataPending;
           this.__dataPending = null;
           this.__dataCounter++;
@@ -513,12 +523,6 @@
        * @public
        */
       ready() {
-        // Update instance properties that shadowed proto accessors; these take
-        // priority over any defaults set in constructor or attributeChangedCallback
-        if (this.__dataInstanceProps) {
-          this._initializeInstanceProperties(this.__dataInstanceProps);
-          this.__dataInstanceProps = null;
-        }
         this.__dataInitialized = true;
         // Run normal flush
         this._flushProperties();
diff --git a/lib/mixins/property-effects.html b/lib/mixins/property-effects.html
index b45e7453b9..4bb5ea43b4 100644
--- a/lib/mixins/property-effects.html
+++ b/lib/mixins/property-effects.html
@@ -230,9 +230,8 @@
     // And the host has already initialized clients; this prevents
     // an issue with a host observing data changes before clients are ready.
     let host;
-    if (notified && (host = inst.__dataHost) && host._flushProperties
-      && host.__dataClientsInitialized) {
-      host._flushProperties();
+    if (notified && (host = inst.__dataHost) && host._invalidateProperties) {
+      host._invalidateProperties();
     }
   }
 
@@ -1430,6 +1429,7 @@
        */
       _flushClients() {
         if (!this.__dataClientsInitialized) {
+          this.__dataClientsInitialized = true;
           this._readyClients();
         }
         // Flush all clients
@@ -1438,7 +1438,10 @@
           this.__dataPendingClients = null;
           for (let i=0; i < clients.length; i++) {
             let client = clients[i];
-            if (!client.__dataInitialized || client.__dataPending) {
+            // boot up client if necessary, otherwise flush properties
+            if (!client.__dataPropertiesEnabled) {
+              client._enableProperties();
+            } else if (client.__dataPending) {
               client._flushProperties();
             }
           }
@@ -1479,9 +1482,9 @@
        * @override
        */
       ready() {
-        super.ready();
+        this._flushProperties();
         if (!this.__dataClientsInitialized) {
-          this._readyClients();
+          this._flushClients();
         }
         // Before ready, client notifications do not trigger _flushProperties.
         // Therefore a flush is necessary here if data has been set.
@@ -1498,7 +1501,7 @@
        * @protected
        */
       _readyClients() {
-        this.__dataClientsInitialized = true;
+        this.__dataInitialized = true;
       }
 
       /**
diff --git a/lib/utils/templatize.html b/lib/utils/templatize.html
index 456c01510f..31f792ec55 100644
--- a/lib/utils/templatize.html
+++ b/lib/utils/templatize.html
@@ -63,7 +63,7 @@
         // or when there isn't instance props.
         let options = this.__templatizeOptions;
         if ((props && options.instanceProps) || !options.instanceProps) {
-          this._flushProperties();
+          this._enableProperties();
         }
       }
       /**
@@ -251,7 +251,7 @@
         template.__dataTemp = {};
         template.__dataPending = null;
         template.__dataOld = null;
-        template._flushProperties();
+        template._enableProperties();
       }
     }
 
diff --git a/test/unit/property-accessors.html b/test/unit/property-accessors.html
index 9fb9a4f61c..8af5eeb265 100644
--- a/test/unit/property-accessors.html
+++ b/test/unit/property-accessors.html
@@ -29,7 +29,7 @@
         this._propertiesChanged = sinon.spy();
       }
       connectedCallback() {
-        this._flushProperties();
+        this._enableProperties();
       }
     }
     XFoo.createPropertiesForAttributes();
diff --git a/test/unit/property-effects.html b/test/unit/property-effects.html
index c1be29da2d..b236897d5b 100644
--- a/test/unit/property-effects.html
+++ b/test/unit/property-effects.html
@@ -1514,7 +1514,7 @@
     BaseClass = class extends Polymer.PropertyEffects(HTMLElement) {
       connectedCallback() {
         this.pcSpy = sinon.spy();
-        this._flushProperties();
+        this._enableProperties();
       }
       _propertiesChanged(props, changedProps, oldProps) {
         this.pcSpy(props, changedProps, oldProps);