Dear people of the forum,

please help me with my lily plant. All bottom leaves are turning yellow. The only reason I found for this issue was too much light/heat, but, as it is winter time here, I do not think this is the case. Is it possible that the plant is too close to the heater? I bougt it a few days ago.

These normally bloom outside in the summer months and after done blooming, the leaves gradually turn yellow and die off until the stems totally dry and the bulbs are dormant until the following year.
They were obviously forced to bloom outside of the normal cycle and sold this way. Once you brought it home to an entirely different environment, it now reacts to the lower light.

Too much water can cause the leaves to yellow and drop from the bottom up. If you can transplant outdoors when they are done blooming they should reset their cycle and bloom next year. Lilies are not indoor plants and will do better in a garden.

Too much water, or just as likely, the plant is reacting to its new environment. It was growing in the greenhouse with perfect watering, lots of sun, high humidity, perfect fertilizing and temperature. Now it has none of these, and it has to cope. It already is experiencing lower humidity, and if it is close to a heater, that will make it worse. In addition, Lilies (and all plants) prioritize the health of the flowers over the health of leaves. If a plant cannot support both, it will allow leaves to die so it can support the flower.

Too much water can be part of this overall stress, since when there is too much water, roots do not function properly. However, not enough water does the same thing. More often, when I see lilies grown in pots for sale, they suffer from this overall stress, rather than only too much water.

Even if the stem and flowers die, the underground bulb should be alive. You can plant the dormant bulb outside in the garden to come up in the spring. I don't think the ground freezes in Ljubljana. (I have relatives in Novo Mesto and Metlika.) When the top dies down, stop watering and put the pot in an unheated place like a garage for one week. Then plant outside in the garden.

Srečno novo leto!

Thank you for all the valuable replies! I went by the store recently and all of the lilies that are still in the shop have also turned yellow at the bottom... I will try to give mine a decent life in the garden. Thank you again for all the info.

Srečno tudi vam!