Generally there's no expectation of a tip so anything you do is hugely appreciated by all.

ditto what marcinde said. They will think you walk on water.

A pitcher of cold ice tea or a few cold bottles of soda are always appreciated during the install but beyond that, nothing is expected.

As the designers we always appreciate the generosity of a Thank-you card or a written referral on Houzz , and would consider it icing on the cake.

Nice to hear that you are pleased with your team.
Good clients make great projects.

I will echo what others have said here. No tip is expected, however water or soda is always greatly appreciated. That being said, if you want to tip your landscape crew that is just fine as well. I've had many people tip me after doing a beautiful job for them, that had obviously surpassed what they had envisioned. Word of mouth is an excellent "thank you" as well. It's your choice.

Yes!! I had two, and tipped each $40, after 12 hours of work. Also bring out a pitcher of iced water/glasses, or bottles of water in a cooler~I had soda and water.