Question
Dear Darlene, I had about a 3 foot peace lilly which I repotted in a big pot (giving it room to grow), but the leaves wilted, and I couldn't seem to revive it.  I did think at first I had over-watered and the roots rotted.  In the end I threw it out and bought a new one.  I've repotted the new one in the big pot again (using new compost) and the same thing seems to be happening, although I have been careful not to overwater and the top soil is quite dry.  I have been feeding it once a week, and now am wondering whether I've fed it too much.  They were both in a bright, sunny conservatory but I have since moved the new one into a shady spot in the living room in hopes it will revive.  Is there any more I can do?

Your help would be much appreciated.  Thanks.

Ann (in England).

Answer
Ann,

Your problem is "I repotted in a big pot (giving it room to grow)". When you repot any houseplant do not move it to a pot more than 2 inches larger diameter than the pot it was moved out of. The reason for this is that roots of all plants need alternating periods of wet then dry so roots can breath carbon dioxide through the soil. When you water plants you need to water them enough so all the soil in the pot gets moist so some roots are not left dry. When you move a plant to a "large pot" and you do that the roots do not have time to use all the moisture in the pot and have a breathing period before you water again. Even when the surface of the soil feels dry in the root zone there may still be way too much moisture. You can dig down about 6 inches with your finger and see what I am saying or you can buy a moisture meter with a soil probe that will tell you when it is dry in the root zone. In the states they cost about $10-15.00.
Now about peace lillies in particular. They like to be root bound and will produce more blooms if they are rootbound. If you want them to be healthy in your big pot then buy 2-3 plants to fill up the pot immediately. They will then use up the moisture and the roots will be able to breathe.It helps when repotting if you ad extra perlite to the soil mix so it drains well and never leave it sit with water in the drain tray. If it is too large to pour off use a turkey baster and suction it off. I never water my peace lilly more often than once a week during the summer with a fan blowing on it and during the winter when it is semi-dormant I only water every 2-3 weeks. These plants really like to dry out between waterings. Fertilize once a month according to the monthly package directions or weekly at 1/4 the monthly rate. Use a bloom building fertilizer with a higher middle #. As for sun, peace lillies love bright light but do not like the sun actually shining on their leaves, they burn easily. They are originally from the floor of the jungle in the tropics, the sun is bright and hot but little of it filters through to the peace lillies leaves. It is also humid in the jungle. A peace lilly will benefit from other plants sitting around it. If you set your plants in groups it raises the humidity in the air in that area. I hope these suggestions help.If you have more questions write again. Good luck.

Darlene