I purchased this plant from Save-On-Foods in Victoria a couple weeks ago. I've watered it a few times using tap water %26amp; it's currently in a white room with a large west-facing window that receives plenty of light (even when the blinds are closed).
I heard it could be overwatering (cold temperature %26amp; fluoride), so I've been using rainwater or filtered water instead. I had a leaf already fall off (turned yellow, then black on the tips; however, it wasn't soggy or dry). Meanwhile, the roots look plump and yellow/creme, which I assume is healthy.
It's still in its original pot from the store (with holes on the bottom), placed in a ceramic vase on my TV table in the living room.
Leaf Spots on My Dracaena Lemon-Lime Warneckii?
You did a great job of showing the problem and describing what it is not. The root system being 'vital', means to me that you are not overwatering.
The first diagnostic indication that I get is from your pictures. Good job there too. In plants, spots can be caused by Biotic and Abiotic reasons. In this case, the darker color surrounded by a halo, in various degrees indicates that this is Biotic. This is not the splashing of chemicals, or some other Man caused problem.
You have some sort of living pest. Check the underside of the leaves for signs of bugs (use a magnifying glass). Try first, cleaning the leaves with a solution of soapy water. Be sure that you do not put the leaves in direct sun while wet. If this does the trick, then stop, problem solved.
If it does not do the trick, then get a mild organic (if possible) fungiside, and apply according to the label on the product.
This should help.
Reply:You probably don't need to water as much as you actually are. It may have very wet roots. Try this test: use a wood or bamboo skewer and push it into the soil until it reaches the bottom. Remove the skewer and check the moisture of the soil that sticks to it. It's alot like checking a cake or brownies with a toothpick. If the soil is moist after only an inch or so down, it's plenty wet. Check the moisture periodically, and if it reaches a point near the bottome one or two inches of the pot, give the plant some water.