diff --git a/app/models/project.rb b/app/models/project.rb
index dc1709d84..b75588609 100644
--- a/app/models/project.rb
+++ b/app/models/project.rb
@@ -83,6 +83,10 @@ class Project < ActiveRecord::Base
   after_update :update_versions_from_hierarchy_change, :if => Proc.new {|project| project.saved_change_to_parent_id?}
   before_destroy :delete_all_members
 
+  attr_accessor :cached_start_date
+  
+  attr_accessor :cached_due_date
+  
   scope :has_module, lambda {|mod|
     where("#{Project.table_name}.id IN (SELECT em.project_id FROM #{EnabledModule.table_name} em WHERE em.name=?)", mod.to_s)
   }
@@ -641,7 +645,7 @@ class Project < ActiveRecord::Base
   # The earliest start date of a project, based on it's issues and versions
   def start_date
     @start_date ||= [
-     issues.minimum('start_date'),
+     cached_start_date || issues.minimum('start_date'),
      shared_versions.minimum('effective_date'),
      Issue.fixed_version(shared_versions).minimum('start_date')
     ].compact.min
@@ -650,7 +654,7 @@ class Project < ActiveRecord::Base
   # The latest due date of an issue or version
   def due_date
     @due_date ||= [
-     issues.maximum('due_date'),
+     cached_due_date || issues.maximum('due_date'),
      shared_versions.maximum('effective_date'),
      Issue.fixed_version(shared_versions).maximum('due_date')
     ].compact.max
@@ -853,6 +857,13 @@ class Project < ActiveRecord::Base
 
   # Yields the given block for each project with its level in the tree
   def self.project_tree(projects, options={}, &block)
+    
+    start_dates = Issue.where(project_id: projects).group(:project_id).minimum(:start_date)
+    due_dates = Issue.where(project_id: projects).group(:project_id).maximum(:due_date)
+    projects.each do |project|
+        project.cached_start_date = start_dates[project.id]
+        project.cached_due_date = due_dates[project.id]
+    end
     ancestors = []
     if options[:init_level] && projects.first
       ancestors = projects.first.ancestors.to_a