Establishing a seed planting calendar is one of the oldest and wisest gardening maxims. The success of many vegetable and flower sowings is getting the seed started at the right time of the year for germination, growing, and harvesting.
Mark on your garden calendar when seeds should be sown and when you actually sow them. Then you can arrange the seed packets in your seed drawer according to planting time. See Vegetable Garden Seasonal Calendar.
Check your seed packets. The packet will tell you what month to sow and how long the plant will take to mature or reach harvest. (If you are new to gardening, there are plants that grow best in the warm time of the year and others that grow best in the cool time of the year.) See Planting Cool Season Crops and Know Your Warm Season Crops.
Once seeds are sown, mark the calendar again; this will tell you when the harvest is coming. You can then plan succession plantings and harvests as well. Quickly you will have your season mapped out and you can then move on to organizing your harvest recipes and planning meals. (In fact, you might want to work backward: What do you want to eat and when? Count backward from Thanksgiving the days to maturity for pumpkins and you will know when to sow pumpkin seeds for pie.)
Will These Seeds Grow?
You can test old seeds—from last year or years past—to determine if they are still viable. See Seed Viability
Count out ten seeds and place them on a double thickness of a moistened paper towel. Roll up the towel and place it in a plastic bag and seal it. Put the bag in a warm—about 70° to 80°F—and well-lit spot. In six to ten days open the bag to see how many seeds have sprouted. If 5 seeds have sprouted you have 50 percent germination. See Seed Germination Requirements.
Most new packets of seed have a 90 percent or better germination rate. You can count on almost every seed to sprout.
But if you have old seeds and the germination rate is just 50 percent, you will want to plant twice as many seeds to make up for the reduced rate of germination.
Seed Starting Schedule for Next Season