Moss rose, (Portulaca grandiflora), is a bushy, low-growing annual, favored for its succulent, greyish-green leaves, brightly colored blooms, and its ease of care, even in desert climates and poor, rocky soil. The blooms of the moss rose are show stoppers in nearly neon shades of orange, pink, red and yellow. Moss rose does well in a border, in a rock garden, or planted in a hanging container. Harvest the seeds of the moss rose and preserve them for planting the following spring.
Choose a few blooms from a healthy moss rose plant. Keep an eye on the blooms as they begin to fade in late summer. When the blooms wilt and turn brown, they are ready to be harvested. Harvest the moss rose seeds on a warm, dry day, in early afternoon when the air is dry.
Hold a paper bag under the dead moss rose bloom. Roll the bloom between your fingers and allow the moss rose seeds to fall out of the seed pod at the base of the bloom. If the seeds aren't quite ready to fall out of the seed pod, clip the entire bloom with your fingers and let the bloom drop into the paper bag. Use a separate paper bag for each color, and label the bag before you clip the bloom.
Put the paper bag in a cool, dry, well-ventilated room for 1 to 2 weeks, until the seeds are dry. Shake the bag occasionally so the seeds will dry evenly.
Pour the contents of the bag on a paper plate. Pick out any stems, leaves or petals with your fingers or a pair of tweezers. Don't worry about removing small plant matter that is mixed in with the seeds. Be sure to do this indoors, because the moss rose seeds are no larger than specks of dust, and will blow away in the slightest breeze.
Pour the moss rose seeds into a small, white paper envelope, and put the envelope in a glass jar with a lid. Put the jar in a dry, cool room until you're ready to plant the seeds in the spring.