Please help my cactus!

My cactus is shrink from middle! The shrinking part is turning white. But the top is still blooming. I repotted twice this spring and didn't water too much. It's always outdoors and has enough sunlight. Bottom part is yellow and seems smashed together..

I got it as gift. When I repotted I noticed the soil was too tight (soil was yellow due to the sand mix)..so what should I do now? Repot Again?? Or cut the babies off and transplant? THANK you!! I don't want it to die on me..

Hello Sophie,

The white is probably a sunburn. Maybe it's why it shrink.

The pot is to big and the potting compost seems too organic.

How are the roots ?

If you don't like this form, you can cut, dry the wound, put it in good compost (big sand, little stones...) and wait until the cactus makes roots.

Sorry for my rock'n'roll english

Aurore - Nord de l'Essonne - Serre hors gel depuis septembre 2017 - rocaille succulente non protégée depuis avril 2018

Hi Sophie,
To add to what Aurore is saying : for aesthetics purposes (or life-saving purposes if the roots are dead ; check them), you can indeed make cuttings of your Mammillaria ; I would cut it in four parts : the three offsprings and the main body cut above the shrunken part ; let them dry (you can wait until Spring, really) and plant them in a sandy, well-drained, low-organic soil

I would agree that it is sunburn. What type of exposure is it getting?