Creepy, crawly and just plain scary, spiders are generally harmless yet fill many people with fear. Even though spiders have a variety of benefits including a natural pest control, some people do not want them inside or outside their home. Fortunately, several plants and flowers will help keep spiders away. A genus of flowering trees and shrubs, the eucalyptus tree has a variety of uses including repelling various pests -- such as spiders -- from your yard. Furthermore, you can create eucalyptus essential oil with the fresh leaves to keep spiders, mosquitoes and fleas out of your home. Eucalyptus requires warmer temperatures and cannot survive in temperatures below 20 degrees Fahrenheit. In addition, eucalyptus trees can grow up to 200 feet. Featuring a pleasant aroma, lavender will keep spiders away with various methods. Drying the flowers of the lavender plant, placing them inside sachets and hanging them from closets where spiders hide will keep them out of that location. Furthermore, make essential oil with the lavender and spray it around your home. Not only will the lavender freshen your home, it will also drive spiders away. You can grow lavender either inside your home in containers with drain holes or outside in well-drained soil. To keep red spiders out of your garden, plant onions. Red spiders -- also called spider mites -- are a common problem in house and garden plants. The mites feed off the plant's nutrients, causing the leaves to wilt, turn yellow and stunt the plant's growth. Before adding onions to your garden, get rid of the spider mites by spraying them with a mixture of 1 tbsp. rubbing alcohol, 2 tbsp. dish soap, 1 tbsp. vegetable oil and 1 gallon of cool water. Make sure to coat all plants infested with the red spiders with the treatment. Commonly used as an herb, mint is a hardy perennial that you can grow indoors or outside in a garden. The strong, pleasant aroma of mint -- that many people associate with gum or candy canes -- will fill your home when kept indoors. Along with keeping spiders at bay, mint has a variety of benefits including brewing it as a tea for upset stomachs. Mint thrives in rich, well-drained soil. Mint planted outdoors requires full sun while indoor mint will grow under normal fluorescent lights.