Slow-release fertilizer works fine, too. Unless your soil is poor, there is no need to feed your plants. If there is too much nitrogen, the plants will have lush leaves but with weak stems. (In hot, wet areas, nitrogen can cause rotting of bulbs.) Water After they flower, lilies don t need much water like they used to. Plant food Leave the mulch in spring until the danger of hard frost is over. Fertilize the soil with a phosphorus formula like the 5-10-10. Follow the instructions to the letter in fertilizer application. Slow-release fertilizers work very well with lilies. Pests Lilies have few enemies, but aphids and botrytis blight (a fungal disease) can cause problems on the buds and leaves, respectively. You can use the 10-10-10 complete formulation at the start of spring when the shoots are beginning to be seen. You have to be careful that the bulbs won t get in direct contact with the fertilizer. By handling everything properly, you are also ensuring that your lilies are going to be prevented from acquiring diseases. When transporting lilies that you bought during summer, make sure to avoid placing it in a car with its windows shut because the temperatures may change, this sudden change in temperature can destroy the plant in no time. Also, make sure that you shade the lily plant from direct sun while it is inside the car. This is very important if you want to keep your indoor lilies alive since the soil will serve as the lifeline of the plant. It is a must that you know the most suitable soil that you can use so your potted lilies can get all the nutrients it need. Among all the types of soil available for indoor lilies, experts say that clay would be the best option. First time gardeners should be aware that growing indoor lilies need repotting every now and then because its roots already filled up the space of the original pot. Crucial to repotting is the type of containers to be used. Since repotting is inevitable, you should know what kind of pot to use and how to take care of that pot.