Frozen Grafted Cacti: Mushy Base Means They're Gone

Three Grafted Cacti Left in Cold: Two Have Mushy Bases

A gardener brought three grafted cacti in from the cold after neglect. Two have mushy, dark-green bases (the rootstock), and one shows slight discoloration at the graft union. She asks if they can be saved.

Verdict: Replace the Two Mushy Ones

Greg delivers bad news: freezing causes rapid rot in the tropical rootstock (often Hylocereus), which won't survive below 40°F for long. The mushy base indicates systemic rot—those two are dead. The third might survive if its base is firm, but monitor closely.

Lesson

Grafted cacti (like colorful moon cacti) are cold-sensitive. Bring them indoors well before frost. Once the rootstock turns mushy, the plant is unsalvageable.