When I bought this plant at the store, it did not show any of these marks and it was also in a smaller pot, so I repotted it. I have had it less than a week. After i planted it, I just watered it enough to where the built in tray wouldn’t overflow, I did some research and learned the importance of leaching and bought a bigger tray and leached it. I ran it under the sink for about 5 minutes and let the water pour out. What else can I do? Are you able to identity the problem?
You have been much too kind to your plant which is called a Dracaena Lemon Lime. You should never re-pot a new plant until you have had it at least 6 weeks. Dracaenas like to be in small pots and their roots should totally fill the pot before you move it to a larger container. Leaching is only done after you have had a plant for a LONG time and the salts from plant food or the chlorine and fluoride in the water have built up in the soil. Dracaena Plants should never be allowed to sit in a tray of water. The black leaves are a sign that you have over- watered the plant with all of your tender loving care. STOP watering, leaching, & repotting! Place you dracaena in bright indirect lightVery few houseplants should be placed in direct sun. High light refers only to bright indirect light since direct sun often burns the leaves of indoor houseplants. An area that is too hot and dry encourages Spider Mites and causes blooms to quickly fade. A northern exposure really doesn't provide enough light for high light plants. These plants need to be placed directly in front of an east-facing window, within 1-3 feet of a west-facing window, and within 5 ft. of a south facing window. A high light area has over 300 ft. candles of light. and do not water again until the soil is just about totally dry. You can read more about Dracaena Lemon Lime Plants in the popular HousePlant section of the website.