To harvest your cilantro pinch the upper stems that contain leaves and pull it off the main stem. The general rule is to cut cilantro … To harvest and save cilantro seeds, wait until there is a stretch of dry weather. Once cilantro flowers die back, they produce clusters of round, brown-colored seeds. Harvesting cilantro seeds is easy, and a great way to save money. Cilantro (Coriandrum sativum) is a cool-weather herb that’s fast-growing and easy to harvest.Cilantro is a staple ingredient in many cultures, like in Mexican food (think salsas and pico de gallo), or Southeast Asian cuisine (where it can be sprinkled over a bowl of pho or on top of pad thai).Home gardeners can plant cilantro in their vegetable garden or even just a sunny windowsill. It’s never a good idea to harvest seeds after a rain because moisture is the greatest enemy to storing viable seeds. To get the seeds, you must cut the flower clusters in their stems when the seeds are reddish, and let them dry upside down or inside a paper bag. Harvest your cilantro when it becomes 6 inches tall. Anything taller may be too late and your cilantro may bolt. How to Save Cilantro Seeds. Cilantro plants bolts quickly during the heat of summer, but by harvesting the seeds on time, you can plant a second phase crop for the fall for a continuous harvest. Once stems have dried up, you can get the seeds. Allow cilantro flowers to develop. How to Harvest Cilantro Seeds. Harvesting cilantro: When it comes to harvesting Cilantro, it is simple. Harvesting cilantro this way will promote more growth. cilantro seeds. With their long shelf life, and diverse uses, cilantro are the perfect ones to start out with if you are just getting into collecting your own seeds. You can also keep them in a paper bag until you need them.