To create a seed calendar, find the average frost date for the last spring, make a list of seeds, determine indoor seed sowing and transplanting dates, evaluate outdoor direct seeding dates, and create a chart for all of the data found. Seed calendars are easy-to-use visual guides for when to start growing seeds inside, when to transplant those seedlings outside and when to plant seeds directly in the ground.
To find the previous spring's frost date, consult local gardeners, the local Extension Service or Master Gardener Program, or the National Climatic Data Center's frost information. Next, create the list of seeds planned for the garden, and divide them into two categories: seeds to be started early indoors and later transplanted to the garden and seeds grown directly in the outdoor garden. KidsGardening.org provides a table that shows the categories for each type of seed.
For seeds beginning indoors, determine the number of weeks prior to the frost date to start the seeds. KidsGardening.org offers this information for commonly grown vegetables and herbs. For other plants, check the seed packet, seed catalog or gardening references for when to begin planting the seeds. Next, use the table on KisGardening.org to determine when to transplant the seeds to the outdoor garden. Other seeds grow best when planted directly outdoors, such as beans, beets, carrots and peas. A table on KidsGardening.org provides information on when to plant outdoor seeds relative to the frost date.
On a large poster, draw a table containing dates and number of weeks before and after the last frost. On the left-hand side, create a column listing the vegetables and herbs planned for the garden. Then, draw in the appropriate times for planting each kind of seed using the information gathered.