Guerrilla gardeners, we salute you—and so do plenty of holidays, believe it or not. Celebrate this summer by getting down and dirty on whatever land you can find. If anyone asks you to justify your planting, throw up a green thumb and refer them to one of these national or international days meant just for folks like you.
APRIL: Happy National Garden Month in the U.S.! Celebrate by playing in the dirt a little. If you don't have your own compost pile, start one—and in the meantime, many cities turn municipal green waste (from food and yards) into compost and sell it to neighbors.
Plant: Any trees and shrubs. Schedule your veggies and herbs around the date of your city's last frost: Just before it, you can plant small ones like lettuce, kale and broccoli, and afterward, move on to tomatoes, peppers and beans. Make sure everything will get enough sunlight even after the plants start growing.
MAY: Celebrate International Sunflower Guerrilla Gardening Day by—you guessed it—planting a guerilla sunflower on May 1. In seven years, the Brussels-based holiday has grown to about 6,000 participants. And they don't want any excuses: If you lack seeds, send a self-addressed, stamped envelope to the group's London address. They'll send you everything you need.
Plant: Any vegetables you have left. Also, since you're probably well beyond the last frost, start planting flowers like crazy before it gets too hot.
JUNE-JULY: There isn't much planting to do in the middle of the summer, but luckily, June 13 is National Weed Your Garden Day. Spend a weekend clearing summer sprouts away from your precious flowers. If your garden looks like it might become a permanent installation (congratulations!), bring some mulch and lay a walking path—even a bench, if you're feeling ambitious. Put a fresh tomato on your sandwich. You deserve it.
AUGUST: Start clearing your spring flowers to make room for fall's crop. Revitalize your soil with a summer's worth of compost (remember that pile you started?) You'll have to wait for the end of the month for your last summer celebration, but August 29 is National More Herbs, Less Salt day. What's the lowest-sodium recipe in your file?
Plant: Fall vegetables—green onions, kale, broccoli, spinach—and fall mums.
SEPTEMBER: America's original guerrilla gardener, Johnny Appleseed, was born this month in 1774. He singlehandedly planted thousands of apple trees and became one of the country's great folk heroes for it. Pat yourself on the back for the work you did this summer, and before the leaves fall, set up a long-term infrastructure for what you've created.