Mammillaria - thimble cactus - succulent

Mammillaria gracilis - thimble cactus

APPEARANCE : Small, cluster-growing cactus comprising dark green balls covered in overlapping rosettes of white spines. Happy plants produce cream flowers.
USE FOR : Waterwise garden landscaping, indoors, pots and containers.
CLIMATE : Frost tender, drought hardy
PLANTING : Grow in any free-draining loam or sandy soil, or cacti-specific potting mix. Site in bright filtered light out of direct noon sun. Water in summer growing period, allow to dry out a little between watering; keep almost dry in winter.
CARE : Needs very little aftercare. Remove dead flowers. Repot when it gets too large for the pot.
MATURE HEIGHT & WIDTH :   10-15cm H x 15-20cm + W.
YOUR PLANTS : These are tubestock plants, healthy young plants with new roots that will establish quickly in your garden. The pot size is 80mm high and 42 mm wide.
You can see an example in the image gallery.
What is tubestock?