Cincinnati seems to have its own little pocket of 6b within the 6a zone. 6b (same as mine) has a LFD of Apr. 20th.

Of course those are just general guidelines - one of the main reasons for keeping your own annual records but for also exchanging info with other local growers. Any nurseries or greenhouses or commercial growers in your vicinity? Ask what date they use.

And of course the current charts don't take into consideration the current weather trends for the country as a whole. They indicate much warmer (earlier LFD's) for the up coming year. Many growers in my area are anticipating planting as much as 2 weeks earlier than what has been considered normal in the past.

So I'd use April 20th but monitor the forecasts closely and make provisions for April 12-15th planting with come cover if necessary.

Hope this helps but check with locals for the most accurate info.

Dave

Part of it is the difference between an official "frost" (low temp of 32 at a reporting station) and ground frost.

Here where I am now, the numbers match rather well, being that I am on highish ground not far from the airport where our temps are recorded. Typically, as long as the official temp is over 32, I rarely lose any plants.

However, when I lived in Akron, OH - I ROUTINELY had killing ground frost that would wipe out bean plants, etc in mid to late May when the "official" low was 37 or 38 degrees. It's not that Akron is different per se in that regard (other than colder overall), just that there, I lived in a valley where cold air collected, so I got later spring and earlier fall frosts.

Which is why the "Memorial Day" adage existed there - most old timers never planted annuals until Memorial Day - although the average LFD at Akron-Canton airport is Apr. 29, ground frosts into mid-May are typical.

Great info! Thank you so much. Now I get it.