"Barb" wrote:

While watching a gardening show, they said that you should not plant your
flower garden until two weeks after the average last frost for your zone.

Does anyone know what the average date of the last frost is for Zone 6?




Last frost date and Zones are not directly related. The zones are based
on the average minimum winter temperature. Last frost date will depend
on your local climate and possibly microclimate. It is an estimate based
on historical weather data and it is possible to have frost after that
date. For example, I'm in zone 6 judging by minimum winter temperatures.
Our average last frost date is May 15, but we've had frosts after
memorial day. Average first frost is Sep 15, but it's come as early as
labor day and as late as November.

There are estimates of last frost dates for zones, but they are
extremely broad, and to my thinking, not very useful. See for example
http://home.xnet.com/~jjy/last-freeze.htm. The last frost date range
covers a month, so it's so broad as to be useless.

Your best bet is to contact your local extension agent for accurate
local information. Another possibility is to try to find long range
weather forecasts. The longest range I've come across that has any
semblance of accuracy is
http://www.cpc.ncep.noaa.gov/product...ctions/610day/ but it only
predicts in general terms for 10 days.

Also, you should know which plants can withstand cold weather best. You
can plant them around the last frost date (which you can modify based on
the 10-day outlook), but the more tender plants should wait for a couple
of weeks to be sure. Also, the tender plants may get set back at low
(but non-freezing) temperatures, while the hardy plants won't notice.