Olbrich Gardens in Madison is the best that area has to offer! It's wonderful. www.olbrich.org

Monches Farm is a little further east of Lake Mills and a breathtaking drive. Here's their website.

V.

Here is a link that might be useful: Monches Farm

Morton Arboretum is just north of Chicago. It wouldn't be too far out of your way if you took I-94. It's a large and very nice arboretum.

Morton Arboretum

Jerger

I am a native of the Detroit area and have been living in Madison for 3 years,and for a time commuting to downtown Chicago. My husband and I often drive the roads you are taking.This is what I would do...leave NW Ohio as early as possible, if you are nervous about traffic aim to hit Chicago after 10am but not later than 1pm central time.Chicago traffic is never great, but during those times on a Friday during the summer you have a chance of getting through w/out adding an extra hour or more to your drive. Follow the Eden's Expy./I-94 toward Milwaukee.You will exit Lake Cook and the gardens will be 4 miles off the expy. When leaving follow I-94 north to WI HWY. 50 toward Lake Geneva catch Hwy. 67 NW of Lake Geneva and take it up to I-94 at which point you are 3 exits east of Lake Mills and you have had a nicer drive than the interstate through Milwaukee. I strongly recommend Monches Farm also if you can do both. If you can, leave the Botanic Gardens and keep on I-94 to Milwaukee.South of Milwaukee follow I-894 to avoid downtown and pickup I-94 again east of Brookfield. Take exit 293 (Hwy. 16?) and follow directions from the Monches Farm website. If you return home on Monday and take I-90/39 be aware I-90 traffic out of Wisconsin is especially thick after holiday weekends so give yourself some extra time. Have a great time, the weather should be excellent.

How about a biggie? The Chicago Botanic Garden is in Glencoe, IL, just off I 94. It's certainly the biggest in the area. Check out their website, www.chicagobotanic.org. If you have a membership at a garden in Ohio they have a reciprocal membership admission system: the partner gardens should be on their website. (Technically, admission is free, they just charge for parking. But there is no local street parking so that option is not open.) But don't let that stop you. I go several times a year and it's always worth the parking fee.

You can use I 94 to easily get to Madison, too. It goes straight north from Chicago to Milwaukee, then makes a sharp left west and goes straight to Madison.

Thanks for all the suggestions. I ended up going to the Olbrich Gardens in Madison, WI. Well worth the drive out of the way!! Even DH was impressed, which is saying something since he's not into gardening at all!

-Stephanie