How to Plant Mustard Seeds. Today, we know that there are seeds even smaller than the mustard seed. If growing outdoors, plant the mustard seed about three weeks before your last frost date, or anytime indoors. However, there is great debate as to what the "mustard" plant of Jesus' parable really was. Facts about Mustard Plants The mustard plant family includes a variety of plant species, spread all over the world. That is, He wasn't making a statement of absolute fact but using a proverbial style of communication. Flavorful mustard for your sandwich or hamburger comes from the tiny mustard seed. Mustard seeds are very, very small seeds, usually measuring 1 to 2 millimeters in diameter. The mustard plant has often been mentioned in the Bible, and most of us are familiar with Jesus' parable of the mustard seed. The mustard plant is quite common in the Near East and is often considered to be a weed because it can spread so widely and quickly with its tiny seeds. The mustard tree is an evergreen that can grow to twenty feet. Many people don’t realize that a mustard seed plant is the same plant as a mustard greens plant (Brassica juncea).This versatile plant can be grown as a vegetable and eaten like other greens or, if allowed to flower and go to seed, mustard seeds can be harvested and used as a spice in cooking or ground into a popular condiment. Mustard seed plants are normally grown from seed, but can be grown from seedlings as well. Mustard seeds come in various varieties - black, brown, white and Indian. For instance, the orchid seed is so small and fine that it’s almost dust-like. Use a good quality, well draining organic soil mix. While it is in the Brassicaceae family, it is not as closely related to the other two types of mustard as they are to each other. Mustard plants and seeds are rich in calcium, potassium, vitamin C, and vitamin A! (Phase two is the Millennium) Though a mustard seed should grow into a garden plant, this one grew into a tree so big that “the birds of the air” were comfortable nesting there. Any mustard plant grown for greens can also be grown for mustard seed. Jesus was speaking proverbially. Once sprouted, thin the seedlings to … ― Mathew 13:31-32, English Standard Version. Also, he used the mustard seed to illustrate how a small seed can create a large plant… The mustard plant has often been mentioned in the Bible, and most of us are familiar with Jesus' parable of the mustard seed. Grinding and mixing the seeds with water, vinegar, or other liquids creates the yellow condiment known as prepared mustard.The seeds can also be pressed to make mustard oil, and the edible leaves can be eaten as mustard greens