Trachycarpus palm — Quadro-K soil drench (monthly maintenance, K supply + slow pH acidification)

Zone: Trachycarpus palm — windmill palm (in ground) · Stage: any

Sustained K supply to root zone + slow soil pH acidification via S oxidation. Companion to monthly foliar; addresses root cause of K deficiency.

Products (1)

#	Product	mL/L	Role
1	Quadro-K (Doktor Tarsa, DRT)	None	K + S — main delivery; ~4.6 g K + ~3.7 g S per 10 L drench

Intentionally excluded

Bacto-Line in same drench — OK to add but better to alternate weeks (Bacto needs pH ~6.5, drench is more concentrated)

topraq-ca — Soil already Ca-rich; thiosulfate precipitation risk in concentrated drench

Apply 10 L solution slowly across drip-line of palm, every month May-Sep, every 2 months Oct-Apr. Same drench applies to roses (lattice + tall bush jasmines too — same K-deficient Alt Bahçe). Annual Quadro-K usage at this rate: ~500-1500 mL per palm/year.