Cindy, the only one in my notes says "52 DTM". If your first frost comes 3 weeks late, you're golden.
Lots of things taste better when small, but are baby Daikon radishes big enough to find, let alone eat?
I had to spot-check 6 varieties in the Plant database before finding any information other than names.
Is it a "winter" variety or a "summer" variety?
"Mino Early" matures in 40 days
This entry lists a few related threads:
Daikon Radish (Raphanus sativus var. longipinnatu 'Miyashige White Radish')
If we knew their cold-hardiness for over-wintering, you might hope for that, and get an early start next spring or else lots of seeds.. But, gee, Zone 5? That would seem ambitious. Maybe under plastic, but is the gamble worth the work?
If you have the open space and the soil is already clean and raked, you could try it ... and then be really interested in evening low temperatures for a month or two. Dig 'em up right before a hard frost is predicted ... but just how cold hardy are they?
Here's what Territorial says, but bear in mind hey target the pacific Northwest (coastal AND inland):
Minowase Summer Cross No. 3 Daikon Radish
"Best sown from June through early August."
"The season may be extended from February through October by sowing in cold frames or a greenhouse"
(But note "summer" in the variety name.)
And October, let alone "early August", isn't late September.
This year might not be a Daikon year for you!
I often find that the best planting date is 6-8 weeks before I thought about checking the calendar.
Which reminds me ... garlic ... I guess I'm not late yet.
