" in containers in potting soil {Miracle grow}"

I sure hope it was MG Potting Mix and not MG Garden Soil.

Doesn't it say on the pack? Pro-Mix always clearly states 3 or 9 months.

Yes but experienced container growers have learned that what they say on the pack isn't accurate in most cases. The nutrients run out and need to be replaced far sooner then the manufacturer claims - which is why most manufacturers have now somewhat lowered their initial advertised claims.

Dave

Ya well it's not like .3.3.3 will really do anything anyway. I always fert bomb.

"Ya well it's not like .3.3.3 will really do anything anyway. I always fert bomb."

We are talking about very young seedlings here and 3-3-3 can be more than sufficient for young seedlings and even detrimental if used too often. So while you may choose to "fert bomb" (whatever that means) it is your choice. But it is hardly a common practice as excess fertilizer is a good way to kill plants, burn roots, interfere with photosynthesis, stunt and deform internode lengths and affect later production.

Like Dan said, when one doesn't know what they are doing, fertilizer use on young seedlings has to be done with care.

Dave

Promix. Decimals.

Also. Peat leeches fast.

We use MG potting mix and fertilize every week or two after 1st true leaves using half strength liquid fert (10-10-10). This year's seedlings were the best we've ever grown under lights. When we got closer to hardening them off, we shifted to the "high bloom" stuff, half strength 9-58-8 or thereabouts.