Place a waterproof protective furniture cover over the eucalyptus wood furniture when not in use. Although eucalyptus is moisture-resistant, all wood eventually is ruined by moisture, so cover the furniture when it's not in use.
Mix a solution of 1 tbsp. bleach, 5 tbsp. dish soap and 1 gallon of bleach. Scrub the surface of the wood once or twice a year with this solution, using a soft bristle brush. Dry the wood with old towels. This removes any residue from the wood and kills any mold or mildew spores.
Spray some wood sealer protector over the wood about once per week. Rub the solution over the wood with a soft cloth to buff the wood to a shine and keep the finish in good condition. Do not use this spray if your wood is not sealed.
Paint the surface of unsealed wood with a thin coat of polyurethane sealer. Allow the sealer to dry for two hours, then apply another coat. Apply a total of three coats. This will help the wood resist water damage and protect it from scratches, stains, nicks and weathering.
Prevent further damage to the wood by keeping hot objects, such as hot plates and cooking dishes, off the surface. Wipe spills immediately with a dry towel. Do not leave the wood in a humid or extremely shady area. Cover the bottom of the furniture legs with rubber shoes to protect the bottom of the wood from rotting.