Peace Lilies should be grown between 68F and 80F. Do not let any drafts blow on the plant. If the temperature drops to less than 45F the plant will die.
Fertilizer
A 20-20-20 fertilizer made for houseplants can help the Peace Lily bloom, but it must be administered at half strength and only during the Spring and Summer. During the rest of the year you should not fertilize.
Water
The best indicator to know when the Peace Lily is thirsty is when the leaves droop. On average, you should water your plant once per week during growing season. During Winter it requires much less water.
Mist the plant regularly and if you forget to water it, do not worry. Even if you come home one day to find its leaves collapsed over the edge of the pot, try watering it and misting it. A miracle just might happen.
Chlorine in the tap water can poison your Peace Lily. So either use bottled water without chlorine or let your tap water stand overnight. The chlorine will work its way out.
Growth
You can expect your plant to grow as much as 2 to 4 feet. There is no dormant season for your Peace Lily. Instead, it stops blooming in the Winter and requires less water.
Blooming
The Peace Lily blooms in the Spring and the Fall. Its blossoms last two months. If your plant is not flowering, give it more light and make sure you are feeding it fertilizer.
The pollen from the stamen will get on everything. It is not impossible to get out of clothing, but not so easy either.
As one blossom starts to droop, save the energy of the plant by pruning that blossom off. The energy will automatically be sent to help grow the roots and the leaves.
Re-Potting
If your Peace Lily is absorbing all of the water you pour on it, within only a couple of days, then it may be root bound and in need of re-potting. Other signs of being root bound include crowded roots showing through the bottom of the pot and the stalks crowding the pot. You should re-pot it at least every 1 to 2 years.
Propagating
The fact that Peace Lilies clean your air means that you should propagate as many of them as possible. Jam them into your dwelling space and give the extras to all of your friends and family.
Use the new crowns of your plant to start a new plant. Crowns are where new groups of leaves are growing separately from the rest of the plant. To do this you have to take the whole plant out of its pot. Then determine which parts of the root mass belong to the crown that you are going to separate. Do not worry about breaking some roots. It is inevitable. Once you pot the crown in its own pot, it might wilt. It will bounce back in 1 to 2 weeks. Do not fertilize the new plant for three months. The roots are quite sensitive to burning. The full-sized plant has delicate roots and even more so for young plants.
Problems
Yellow leaves indicate too much light, but brown spots are burned areas where direct sunlight hit the leaves.
Rumor has it that Peace Lilies are poisonous for cats and dogs. While this rumor contains some truth, the Peace Lily is not deadly for your pets. In fact, the plant contains oxalates that will upset the animal’s stomach and drive them to quit eating the plant after only one bite.
Getting the oxalate from a Peace Lily on your hand could irritate the skin. This come right off when washed well with soap and hot water.
If your blossoms are green, then you have given your Peace Lily too much fertilizer. Reduce it so next season the flowers turn out white.
Keep pests off by cleaning the leaves regularly. The two that you might get are aphids and mealy bugs. The first is evidenced by sticky slime covering the plant. Use a strong spray of water to get them to fall off, followed by insecticidal soap. For mealy bugs, apply isopropyl alcohol with a cotton ball. If this fails, use insecticidal soap as well.
