I love being a sidewalk gardener in Manhattan. Whenever I’m tending the large planter box outside my West Village building, people smile, stop to chat, and thank me for making the block look beautiful. Like dogs or babies, colorful flowers inspire people to drop their guard and be friendly.

To the tourists, I’m a source of information, an ambassador of good will. To the locals, I’m that obsessive gardener always clipping and weeding and watering. Neighbors compliment my green thumb and ask me to identify the plants: begonia, dianthus, verbena, hydrangea, lobelia, sweet potato vine, and so on. I’ve done this for 10 years and know what works on my street.

After many trips to the green market, my showy garden features wild splashes of purple, pink and red and various vines that drape over the side. During the warm weather, I’m outside every evening playing with my plants. I put lots of energy into my urban garden.

So I take it personally when my box gets trashed.

This year, I’m ranting early in the season. My garden box is not an ashtray, a garbage can, a park bench, a picnic table or a urinal. I don’t want to fish out cigarette butts, gum, soda cans, juice cartons, candy wrappers or the occasional used condom. (For that icky chore, I wear disposable gloves.)

What with garbage cans at both corners of my block, there is no excuse for tossing that coffee cup into my box of flowers. Cigarette butts belong in the curb, where sanitation trucks sweep, or on the sidewalk, where maintenance guys hose them away.

Sitting on the edge of my garden to eat your lunch crushes the plants and can kill them. Do people think they are fertilizing when they leave behind banana peels and peanut shells? My soil is rich enough to host earthworms, and compost dumping encourages littering.

I realize I feel territorial about my plot of greenery, but the sidewalk gardens of New York City are very vulnerable. So on behalf of the brave plants that brighten the concrete, this caretaker begs everyone — locals and tourists alike — to show respect.