diff --git a/app/models/planting.rb b/app/models/planting.rb
index 270a827d2..e5955f04f 100644
--- a/app/models/planting.rb
+++ b/app/models/planting.rb
@@ -56,6 +56,14 @@ class Planting < ActiveRecord::Base
         :allow_nil => true,
         :allow_blank => true
 
+  validate :finished_must_be_after_planted
+
+  # check that any finished_at date occurs after planted_at
+  def finished_must_be_after_planted
+    return unless planted_at and finished_at # only check if we have both
+    errors.add(:finished_at, "must be after the planting date") unless planted_at < finished_at
+  end
+
   def planting_slug
     "#{owner.login_name}-#{garden}-#{crop}".downcase.gsub(' ', '-')
   end
diff --git a/app/views/gardens/_form.html.haml b/app/views/gardens/_form.html.haml
index dc0c2c6a1..f5cd7c429 100644
--- a/app/views/gardens/_form.html.haml
+++ b/app/views/gardens/_form.html.haml
@@ -39,7 +39,8 @@
     = f.label :active, 'Active? ', :class => 'control-label col-md-2'
     .col-md-8
       = f.check_box :active
-      You can mark a garden as inactive if you no longer use it.
+      You can mark a garden as inactive if you no longer use it.  Note:
+      this will mark all plantings in the garden as "finished".
 
   .form-group
     .form-actions.col-md-offset-2.col-md-8
diff --git a/spec/factories/planting.rb b/spec/factories/planting.rb
index 5d229d545..60b4842e8 100644
--- a/spec/factories/planting.rb
+++ b/spec/factories/planting.rb
@@ -33,6 +33,7 @@ FactoryGirl.define do
 
     factory :finished_planting do
       finished true
+      planted_at '2014-07-30'
       finished_at '2014-08-30'
     end
   end
diff --git a/spec/features/plantings/planting_a_crop_spec.rb b/spec/features/plantings/planting_a_crop_spec.rb
index 46d293dec..faa4438e8 100644
--- a/spec/features/plantings/planting_a_crop_spec.rb
+++ b/spec/features/plantings/planting_a_crop_spec.rb
@@ -42,6 +42,7 @@ feature "Planting a crop", :js => true do
     fill_autocomplete "crop", :with => "m"
     select_from_autocomplete "maize"
     within "form#new_planting" do
+      fill_in "When?", :with => '2014-07-01'
       check 'Mark as finished'
       fill_in "Finished date", :with => '2014-08-30'
       click_button "Save"
diff --git a/spec/models/planting_spec.rb b/spec/models/planting_spec.rb
index 13b910d22..5248e0b0a 100644
--- a/spec/models/planting_spec.rb
+++ b/spec/models/planting_spec.rb
@@ -229,6 +229,24 @@ describe Planting do
       Planting.current.should_not include @f
     end
 
+    context "finished date validation" do
+      it 'requires finished date after planting date' do
+        @f = FactoryGirl.build(:finished_planting, :planted_at =>
+            '2014-01-01', :finished_at => '2013-01-01')
+        @f.should_not be_valid
+      end
+
+      it 'allows just the planted date' do
+        @f = FactoryGirl.build(:planting, :planted_at => '2013-01-01', :finished_at => nil)
+        @f.should be_valid
+      end
+      it 'allows just the finished date' do
+        @f = FactoryGirl.build(:planting, :finished_at => '2013-01-01', :planted_at => nil)
+        @f.should be_valid
+      end
+
+    end
+
   end
 
 end