Summer travel means you can glean gardening tips from all over the world. This summer we led a tour that included a river cruise on the Danube.

If you are lucky enough to sail the Danube River and visit gardens along the way, well then you are lucky enough. First adjust to the fact that the Danube is not really blue, but we think of it that way because of the still famous melody named the Blue Danube Waltz. The green river water flows past some beautiful countryside and the climate in Germany, Austria and Bulgaria along the Danube River is similar to our own, so these take home ideas are practical as well as pretty:

Ivy Geraniums are practical flowers to use in a window box.

There is a reason that ivy geraniums spill from the window boxes of Bavaria. First, they repel flies so you can leave your windows open without inviting flying insects inside. Second, ivy geraniums bloom better when their roots are crowded into a shallow container like a window box. Just remember to fertilize, water and deadhead all summer for months of bright Bavarian style blooms.

Tilia trees will perfume your garden:

We may call this the Linden tree in America, but all over Europe the little-leaf Linden or Tilia cordata is successfully used as a fragrant street tree blooming in late spring and early summer. Very tolerant of city pollution with well-behaved roots, the Tilia tree would be a good choice as a patio tree and can even be sheared into a hedge. Different varieties of Tilia are available in dwarf or columnar forms but all have a silver color on the undersides of the leaves, butter yellow fall foliage color and a symmetrical branching pattern. There is even a Tilia tree that is native to North America. This tree deserves more use in American gardens.

Cleome is the hottest new plant for beds and planters

This annual flower is also called the spider flower because the fluffy pink, purple or white blooms explode with spider-like petals. The new more compact cleome varieties make this summer bloomer a low maintenance “thriller” plant that does not need staking, yet blooms taller than your more traditional geraniums and petunias. We saw cleome grouped in the center of island beds, used as focal point flower in container gardens and even as tall edging flowers to create a hedge along walkways and sidewalks. In dry soil and warm areas this annual can reseed to a fault but the newest varieties are hybrids from  Proven Winners and are not only more compact but also better-behaved. Look for cleome “Senorita Rosalita” and the “Spirit Series” of cleome at local nurseries that sell the Proven Winners brand of annual plants.

Mirabel Gardens in Salzburg will make you break out into song

Blame the gardens and not Julie Andrews for inspiring our garden tour group to line up on the same steps of this castle garden where Maria and the children sang “Doe a Deer” in the Sound of Music movie. Suddenly we were belting out the Do-Re- Me tune while posing for a group photo, surrounded by the beautiful Baroque style Mirabel Gardens. Our unrehearsed performance must have sounded pretty good as we did get a few hand claps from a confused Japanese tourist – proving once again that music and gardens are the universal language of friendship.