This location is phenomenal! Absolutely stunning setting. Our wedding was on the smaller side (75 people total) and I was a little concerned due to the size of the venue, that it wouldn't feel as intimate as I wanted. Do not worry! This is the ...perfect outdoor venue for 75 or 200 guests.
The garden itself is so beautiful we didn't have to do much in the way of decor. Just some bud vases on the tables and lots of yummy candle light. Very romantic feel at night. If possible, ask the director if there are any events (open to the public of course) occuring at night so that you can see the venue in the dark. Since the garden closes before sunset, we didn't get to see what the lighting looked like until the day of our wedding.
There are only two reasons why I didn't give Umlauf 5 stars and they are really miniscule/nit picky issues. First, ask the director if they will be changing over the art exhibit inside the museum itself. The day before our wedding they were in the process of changing over to a new exhibit. Therefore, on our wedding day itself, the museum was empty. This meant that the indoor area with many large windows allowing you to look in and view the sculptures, was bare. Kind of a bummer considering that's part of why we wanted this space. When I asked the director (who is super nice by the way) he apologized and said there was no way for them to schedule exhibit change overs around events being held. So... if this means a lot to you, I would double check before. Second and minimal reason for only giving them 4 stars... My day of coordinator had to climb the metal archway over the wedding ceremony space to remove lots of string that had been used for previous events. We chose to leave the archway as it was and not decorate it. Therefore, you could visibly see all the string/fishing line/etc. that others had used before.
Overall, I LOVED having my wedding here and wouldn't have changed it for the world.
Hope this helps others in their planning process.