Answer: Cactus don't like to sit in wet soil. They rot if there's too much moisture and they must have excellent drainage. Most indoor container cactus die from overwatering. If possible, buy a soil mix especially for cactus or have your nursery order some. Or, use a mix of 1 part potting soil to 2 parts sharp sand, and 2 parts perlite or pumice. Put tiny pebbles on top of the soil after planting to help aid drainage.
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