Is Charger safe on newly germinated grass?
I sowed a new lawn about three weeks ago and got a really good strike. The seedlings are about a week post germination and the lawn is looking surprisingly good so far.
I was planning to apply Charger as a foliar application this weekend. Is it safe to use at this stage of establishment, or should I wait a bit longer before applying it?
Yes, Charger's fine on newly germinated grass. That said, your seedlings are only about a week old, so they're still on the young side. Wait until they've put out their 2nd tillers
At this time of year I'd steer you toward Liquid Starter instead. Charger is a foliar growth promoter, mostly nitrogen and potassium with some iron. Pushes leaf growth and colour. No phosphorus. Liquid Starter has phosphorus, and that's the bit that matters for what you need right now.
Cool-season grass needs soil temps above 10°C for roots to really get going, and root activity drops off fast below that. Below 5°C it basically stops. So there's a window now to push as much root development as possible before winter.
Soil temps right now are surprisingly warm for this time of year compared to previous winters. That's why the window is still open.
Best time to apply Liquid Starter is at the 2nd tiller stage (about 2 weeks post-germination). That's so the seedlings have built up enough leaf area to take a foliar feed properly.
I'd hold the Charger for now, try and get a couple of applications of Liquid Starter in before those soil temperatures drop even more.