Growing a cactus indoors or out can create visual interest and a feel reminiscent of a dry, rugged landscape. While many cacti grow well when planted in the ground in a preferred climate, container grown cacti can sometimes begin to wilt as a sign they are either receiving too much water or not enough. Luckily, you can fix a wilting cactus by improving your soil and making changes to your watering schedule.
Feel the soil around the base of your cactus for wetness. If the soil is powdery and dry, then water quantity or frequency is the issue. Proceed to Step 2.
If the soil is overly wet, then an excess of water is the cause of the wilting and you'll need to follow steps 3 to 5.
Water dry soil using 1/2 cup of water for every 4 inches in diameter of your cactus' pot. For example, an 8-inch pot would require a cup of water. Supply this quantity of water weekly from spring to fall, but provide this amount of water every two to three weeks during the winter.
Ease the cactus out of the soggy soil container and knock off any excess soil to expose the roots. Inspect the roots of the plant to see if they appear firm and white or if they have turned brown and mushy. Cut off any bad, mushy roots using a clean knife.
Rinse out and wash the old pot your plant was in or use a new pot no more than 1 to 2 inches larger in size. Fill the pot with succulent soil or an equal mix of potting soil and builder's sand.
Plant the wilting cactus into the center of the prepared pot at an equal depth to how it was previously planted. Leave the plant unwatered for one week. Resume watering according to Step 2 for quantity and frequency during the year.