S1 seeds come from self-pollinating a single female plant. The female is induced to produce pollen (via silver thiosulfate, colloidal silver, or other reversal techniques), and that pollen is used to pollinate the same plant — or a clone of itself.

Because both 'parents' are genetically identical, the offspring is theoretically a near-copy of the original. In practice, recessive traits hidden in the heterozygous original surface in S1, so variability still exists — but much less than an F1 hybrid.

S1 is how clone-only mothers become accessible to the seed-buying public. Wedding Cake S1, GMO S1, Forum Cut S1 — all are attempts to bottle a famous cut into seed form.

Result quality depends heavily on how stable the mother was. Highly heterozygous mothers produce S1 packs with significant phenotype variation; more homozygous mothers produce tighter S1s.

Are all S1 seeds feminized?+
Yes — selfing only produces female offspring (no Y chromosome in the cross), so S1 seeds are inherently feminized.
Is S1 the same as a clone?+
Genetically very close, but not identical. Recessive traits and minor variations still appear.