diff --git a/app/models/planting.rb b/app/models/planting.rb
index 3f88a666c..05c2a7024 100644
--- a/app/models/planting.rb
+++ b/app/models/planting.rb
@@ -23,7 +23,9 @@ class Planting < ActiveRecord::Base
 
   default_scope order("created_at desc")
 
-  validates :quantity, :numericality => { :only_integer => true }
+  validates :quantity,
+    :numericality => { :only_integer => true },
+    :allow_nil => true
 
   SUNNINESS_VALUES = %w(sun semi-shade shade)
   validates :sunniness, :inclusion => { :in => SUNNINESS_VALUES,
diff --git a/app/models/seed.rb b/app/models/seed.rb
index bb39bf15b..1f6eef887 100644
--- a/app/models/seed.rb
+++ b/app/models/seed.rb
@@ -8,7 +8,9 @@ class Seed < ActiveRecord::Base
   belongs_to :crop
   belongs_to :owner, :class_name => 'Member', :foreign_key => 'owner_id'
 
-  validates :quantity, :numericality => { :only_integer => true }
+  validates :quantity,
+    :numericality => { :only_integer => true },
+    :allow_nil => true
 
   TRADABLE_TO_VALUES = %w(nowhere locally nationally internationally)
   validates :tradable_to, :inclusion => { :in => TRADABLE_TO_VALUES,
diff --git a/spec/models/planting_spec.rb b/spec/models/planting_spec.rb
index 607a2b920..bb5d87e0a 100644
--- a/spec/models/planting_spec.rb
+++ b/spec/models/planting_spec.rb
@@ -67,9 +67,9 @@ describe Planting do
 
     it "allows blank quantities" do
       @planting = FactoryGirl.build(:planting, :quantity => nil)
-      @planting.should_not be_valid
+      @planting.should be_valid
       @planting = FactoryGirl.build(:planting, :quantity => '')
-      @planting.should_not be_valid
+      @planting.should be_valid
     end
   end
 
diff --git a/spec/models/seed_spec.rb b/spec/models/seed_spec.rb
index ce3088aa2..896416441 100644
--- a/spec/models/seed_spec.rb
+++ b/spec/models/seed_spec.rb
@@ -33,9 +33,9 @@ describe Seed do
 
     it "allows blank quantities" do
       @seed = FactoryGirl.build(:seed, :quantity => nil)
-      @seed.should_not be_valid
+      @seed.should be_valid
       @seed = FactoryGirl.build(:seed, :quantity => '')
-      @seed.should_not be_valid
+      @seed.should be_valid
     end
   end