Environmentalists often complain about the consumption frenzy associated with the holidays, the long car rides they entail, the air pollution of Lag B'Omer, the fireworks on Independence Day and the dirty streets the following day. In comparison, Tu B'Shvat is definitely the greenest of Jewish holidays. Can you have any complaints regarding this celebration of nature? Well, I happen to think that at this time of a difficult water crisis, this warrants a second thought. For me and for many others, Tu B'Shvat symbolizes our connection with nature. Many go out to plant trees in JNF forests, or plant flowers in their garden. And frankly, I wish we could go on doing so. But we must keep in mind the water crisis, which slightly spoils the party. At a time when we are called upon to stop watering lawns and gardens, and when our ultra-conscious children reproach us for every tap left running, how can we afford watering new plants? Before you call me a party pooper and complain of how "these greens are once again ruining a national Zionist holiday," try asking yourself a simple question: Doesn't being green and protecting the environment require of us to change habits? Doesn't nature, which we seek to preserve, ask us to be more accommodating to it and to our dry reality? Yes, I know, trees, unlike, lawns, do not need constant irrigation. I also know that trees provide shade and reduce the temperature, absorb carbon dioxide from the air and help battle climate changes. And yet, do we or our children understand the difference between planting a new forest and planting a new lawn at the city park? After all, both seem natural and green… So, perhaps we should pause for a moment to think about how to connect the tree - which symbolizes roots and tradition on the one hand, and caring for the next generations on the other - with the grim reality of the water economy. Maybe avoiding planting this new tree and saving the water would help save other trees that are dying of thirst? Maybe instead of planting a new tree and watering it so that it grows and blooms, we can salvage an existing tree? Take a look around you and see how many trees are standing miserable and dehydrated, not to mention others which have been uprooted to make way for another highway or mall. If you insist on planting, in the name of holiday tradition, try planting a tree that fits the Israeli climate. But you can wish nature a "happy new year" without wasting water. You can encourage the preservation of a forest, work to protect open areas and green lungs, or save energy and paper. And you can also save water – because if we save now, we might have enough left for our grandchildren's trees, and for nature – which is always last on the list. Dr. Adi Wolfson is a lecturer at the Department of Chemical Engineering, Shamoon College of Engineering