Dahlia plants can be put into the ground at the same time you plant tomatoes. That is many weeks away and your plants are going to be very tall by then.

I'm in North Jersey. All of my plants go in the ground right around Mother's Day.

Give them lots of light until then.

I usually harden off my dahlias for at least 4 or 5 days. They'll definitely get stressed without it.

This weekend (Friday) I started hardening off my petunias, verbanas, and agastache (all in the shade) and leaving them out overnight because it's been mild but I'm hesitant about hardening off the dahlias until I know what conditions they're capable of tolerating. With heavy rain for tomorrow and highs only in the 50s later this week, I'm not even sure it's worth the effort to start hardening them off yet.

I wouldn't rush getting those plants outside. April is a wacky month. We can still get snow one day and 70ð three days later, or a frost. You never know...

As far as the dahlia's go, I hear they're from Mexico originally, so I would definitely keep them inside until it gets warmer.

This post was edited by digdougdig on Tue, Apr 15, 14 at 13:27