Plant a blooming Lilac Tree outside your bedroom window and let mother nature be your air freshener. The smell of the lilac is to die for and you should enjoy and revel in it. They are simple to grow perennials that bloom in summer. They will offer a lovely fragrant air to your space like no other. They are small trees that can be started indoors and then planted in the earth. Temperate climates for outdoor. 100 seeds.