Dracaena Warneckii Plant Care :
"Warneckii" dracaena is highly sensitive to fluoride in the water. Too much fluoride will cause brown tips on the leaves and brown streaks along the white-striped edges. Water often contains fluoride naturally but it is also added to public water supplies to help prevent tooth decay. The amount of naturally occurring fluoride in water ranges from 0.1 to 10 parts per million. When fluoride levels are high, water processing plants use an ion-exchange process to bring it down closer to 1 part per million, which is considered acceptable for human health. Where water contains more fluoride, which is toxic to "Warneckii," use bottled, fluoride-free water. If brown tips have developed, you can trim them off with sharp scissors.
Watering and Humidity
Overwatering, underwatering and dry conditions can cause brown tips on "Warneckii" leaves. It should generally be watered once per week but this varies, depending on the season and humidity levels. In dry homes or dry outdoor conditions in spring, summer and fall, "Warneckii" dracaena may need to be watered more often. Give it a thorough drenching with water that is the same temperature as the air when the soil is dry at a depth of 1/2 inch. Water the plant in the morning. A "Warneckii" dracaena grown in a container should be watered until the water drains from the bottom. Empty the water from the catch basin below the container. "Warneckii" does not require high humidity but, if the humidity level is less than 40 percent, the leaf tips may turn brown and brittle. Misting the plant in the morning can help raise the humidity. A humidity tray or shallow dish with 2 to 3 inches of gravel in the bottom can be filled with water and set below the "Warneckii" to increase humidity.
Perlite is a common ingredient in potting soil. It is added to improve drainage. Unfortunately, perlite contains fluoride, which can leach into the potting soil. Read the ingredients listed on the potting mix bag or look closely at the potting soil. Perlite looks like tiny white balls. If perlite is present in the potting soil, repot the "Warneckii" in potting soil that contains course builder’s sand and pine bark for improved drainage. A good ratio is one-third sand, one-third pine bark and one-third peat moss. The soil pH should be 6 to 6.5.
Superphosphate fertilizer contains fluoride and should not be given to "Warneckii" dracaena. Instead of superphosphate, mix 1 1/2 tablespoons of 6-6-6 or 5-10-5 fertilizer or 1 ounce of slow-release fertilizer into each 2 gallons of potting soil. Water-soluble fertilizer may also be used rather than mixing the fertilizer into the soil. Dilute it at a rate of 1 teaspoon per 1 gallon of water, or at the rate recommended by the manufacturer, and water the "Warneckii" with the solution once each month during spring and summer.