Arisaema--also known as cobra lily and Jack-in-the-pulpit---is a carnivorous plant with a sweet smell designed to lure insects into its leaf opening. Arisaema prefer temperatures that average between 70 to 80 degrees during the day and about 20 degrees cooler at night. Some varieties, however, can tolerate near freezing or extremely hot temperatures. Arisaemas can grow to 4 feet tall.
Choose a location to plant or place your Arisaema. Most Arisaema species need full sun to partial shade, however, there are a few, like Arisaema serratum (Mt. Fuji Form), that prefer light shade and shady areas only. Check the label that came with your Arisaema for its sun needs. Most species also need wet soil conditions, so if planting outdoors, a site near a water source, such as a pond or lake, would be ideal.
Prepare the soil. Almost all species of Arisaema need consistently wet soil conditions. On the other hand, the Asian Arisaema varieties do not. They can tolerate some dryness. Regardless, your soil should be well draining for all ArisaemasIf you are growing your Arisaema in a pot, use one with drainage holes and fill it first with an inch of gravel or rocks and then with high quality potting soil. Outdoors, add several inches of compost or peat most to your soil, if necessary. If you are planting in marshy or wet areas, you should not need to do this.
Dig a hole that is twice as wide and just as deep as the container the Arisaema is in when you buy it. Place it in the center of the hole and back-fill the soil, pressing to remove air pockets. Water well. For potted plants, you can set the container in a tray of standing water for constant moisture. Remember to read the label carefully for your Arisamea's water needs.