I did add fertilizer for 40 days, mid May to end of June. Cascade burrs had already appeared.
The ingredients were these:
20%N,
5%P2O5
10% K2O
3%MgO
5% S
0.3% B
0.3% Fe
0.1% Zn
Friarsmith, since 1st of July I didn't add anything else, just water. At that time, I recall that there were 2-3...