diff --git a/docs/interface/dashboards.md b/docs/interface/dashboards.md
index da58efe..775a847 100644
--- a/docs/interface/dashboards.md
+++ b/docs/interface/dashboards.md
@@ -16,6 +16,10 @@ Edits stay in a draft; paired screens show the published version. On phones,
 tiles stack in one column and dragging is disabled, but settings remain editable.
 In edit mode, ⌘Z / Ctrl-Z undoes an edit and ⌘⇧Z / Ctrl-Shift-Z redoes it.
 
+A widget can end up below the canvas, for example after the canvas was made
+smaller. In edit mode the canvas then grows to reach it, under a dashed line
+where the panel ends. Scroll down and drag it back, or use **Reflow**.
+
 Controls can publish real values while you edit, so choose their targets with
 care. Your new Switch may already be flipping something!
 
diff --git a/frontend/src/components/Dashboard/DashboardEditor.tsx b/frontend/src/components/Dashboard/DashboardEditor.tsx
index ed4edae..8a3acb4 100644
--- a/frontend/src/components/Dashboard/DashboardEditor.tsx
+++ b/frontend/src/components/Dashboard/DashboardEditor.tsx
@@ -561,6 +561,11 @@ export function DashboardEditor({
   // now falls past its bottom edge drawn under the clip. A round face has no
   // grid to fall off.
   const clipped = round ? [] : layout.filter((item) => item.y + item.h > rows)
+  // Editing, the canvas grows to reach them, so they can be dragged back.
+  const reach =
+    edit && clipped.length
+      ? Math.max(...clipped.map((item) => item.y + item.h))
+      : undefined
   const shown = Math.max(
     0,
     widgets.findIndex((widget) => widget.id === (selected ?? face)),
@@ -669,7 +674,7 @@ export function DashboardEditor({
         ) : null}
       </div>
     ) : (
-      <CanvasSurface dashboard={draft} dots={edit} rail={rail}>
+      <CanvasSurface dashboard={draft} dots={edit} rail={rail} reach={reach}>
         {(scale) =>
           !edit ? (
             <DashboardView dashboard={draft} rail={hasRail} />
diff --git a/frontend/src/components/Dashboard/DashboardView.tsx b/frontend/src/components/Dashboard/DashboardView.tsx
index 3c15089..4495289 100644
--- a/frontend/src/components/Dashboard/DashboardView.tsx
+++ b/frontend/src/components/Dashboard/DashboardView.tsx
@@ -176,6 +176,7 @@ export function CanvasSurface({
   dots,
   rail,
   touch,
+  reach,
   children,
 }: {
   dashboard: Dashboard
@@ -185,6 +186,13 @@ export function CanvasSurface({
   rail?: React.ReactNode
   /** Whether the panel this canvas hangs on is touched rather than pointed at. */
   touch?: boolean
+  /**
+   * How many grid rows the arrangement reaches down to, while it is being
+   * arranged. A canvas they fall off grows to reach them, with its own edge
+   * still drawn, so they can be scrolled to and moved back. The scale stays
+   * the panel's.
+   */
+  reach?: number
   children: (scale: number) => React.ReactNode
 }) {
   const ref = useRef<HTMLDivElement>(null)
@@ -208,6 +216,17 @@ export function CanvasSurface({
   const root = useCanvasRoot(dashboard, touch)
   const round = isRound(dashboard)
   const area = areaOf(dashboard, Boolean(rail))
+  // How far past the bottom edge the rows reached go, margin included.
+  const beyond = reach
+    ? Math.max(
+        0,
+        area.top +
+          reach * rowPitchOf(dashboard, Boolean(rail)) -
+          GRID_GAP +
+          GRID_INSET -
+          height,
+      )
+    : 0
   // The arrangement, held across the renders that are not about it. This
   // component reads the dashboard's own settings, so a bound one wakes it on
   // every message the flow sends — and calling a render prop again rebuilds
@@ -219,7 +238,17 @@ export function CanvasSurface({
   )
 
   return (
-    <div ref={ref} className="relative size-full overflow-hidden">
+    <div
+      ref={ref}
+      className={cn(
+        "relative size-full",
+        // The gutter is kept, so a scrollbar coming and going cannot change
+        // the width the scale is measured from.
+        beyond
+          ? "overflow-x-hidden overflow-y-auto [scrollbar-gutter:stable]"
+          : "overflow-hidden",
+      )}
+    >
       {/* Measured first: a guessed scale would place the whole panel once and
           then move it. */}
       {scale > 0 ? (
@@ -238,7 +267,7 @@ export function CanvasSurface({
               {
                 ...root.style,
                 width,
-                height,
+                height: height + beyond,
                 // Round, nothing outside the circle is drawn.
                 clipPath: round ? "circle(50%)" : undefined,
                 left: (box.width - width * scale) / 2,
@@ -255,14 +284,30 @@ export function CanvasSurface({
             {/* Full bleed, and under everything: a background covers the
                 panel, margin included. */}
             <CanvasGround dashboard={dashboard} />
-            {rail}
+            {beyond ? (
+              <div
+                aria-hidden
+                data-testid="canvas-beyond"
+                className="canvas-beyond pointer-events-none absolute inset-x-0"
+                style={{ top: height, height: beyond }}
+              />
+            ) : null}
+            {/* Centred on the panel, not on a canvas grown past it. */}
+            {rail ? (
+              <div
+                className="pointer-events-none absolute inset-x-0 top-0"
+                style={{ height }}
+              >
+                {rail}
+              </div>
+            ) : null}
             <div
               className="absolute"
               style={{
                 left: area.left,
                 top: area.top,
                 width: area.width,
-                height: area.height,
+                height: area.height + beyond,
               }}
             >
               {/* Over the ground rather than under it: the dots are what is
diff --git a/frontend/src/components/Dashboard/dashboard.css b/frontend/src/components/Dashboard/dashboard.css
index e4496d0..2676c90 100644
--- a/frontend/src/components/Dashboard/dashboard.css
+++ b/frontend/src/components/Dashboard/dashboard.css
@@ -19,6 +19,21 @@
   background-position: -1px -1px;
 }
 
+/*
+ * Below the panel's bottom edge, while the editor has grown the canvas to
+ * reach widgets that fell off it: hatched, under a dashed line where the panel
+ * ends, so what it will not show reads as outside it.
+ */
+.canvas-beyond {
+  border-top: 3px dashed
+    color-mix(in srgb, var(--muted-foreground) 70%, transparent);
+  background: repeating-linear-gradient(
+    -45deg,
+    color-mix(in srgb, var(--muted-foreground) 14%, transparent) 0 3px,
+    transparent 3px 16px
+  );
+}
+
 /*
  * View mode's grid. Column count is per dashboard (`--widget-cols`), so a wall
  * panel can be matched to its own width. It does not reflow: the grid lives on