Den Speciosum with spikes beginning - How much water now??

[Spartacus]

Hello all.

I have a den speciosum x kingianum that is just starting to spike. There are little nubs swelling on ALL of the mature canes. Some canes have 4 spikes a piece.

Does that mean I should water more or less than when in growth???

I fert and water heavy in the summer growing season but I heard they need a rest period. When does the rest period start???

Thanks