Here are some reasons your seed may have not germinated:
Impatience
Each type of plant has its own timeline for emerging from its seed. Lettuce, for instance, begins to show in as little as two or three days. Carrots can take up to 21 days before you see them. Check seed packets and other resources to find out what is the expected time of germination for the plants you’re growing. Allow a few extra days before confirming that none of the other causes are a factor.
Poor Soil Quality
Seeds have the nutrients they need to sprout, so you can plant them indoors in a soil-less mix such as Burpee’s Organic Coconut Coir Concentrate. Never use garden soil when starting seeds inside. When the seedlings have their second true leaves, (four to six leaves )you can begin feeding them with a dilute liquid organic fertilizer like Neptune’s Harvest Fish and Seaweed Fertilizer. These nutrients will keep the seedlings growing strong after sprout.
When sowing seeds directly in the garden or containers, be sure the soil is loose and well-drained. When growing in containers only use a good quality potting mix such as Burpee's Premium Organic Potting Mix In the garden, heavy clay soil can be too dense for sprouts to extend their roots outward and may hold onto so much moisture that seedlings drown before they emerge. Mix in compost before planting to help loosen the soil and help it drain better. Sandy soil, on the other hand, doesn’t hold enough water or nutrients to get seeds off to a healthy start. Add organic matter such as compost to help the soil increase its water holding capacity.
Planting at the wrong depth
Each type of seed has its own ideal planting depth, ranging from being pressed lightly onto the soil surface to being buried an inch deep. Always follow the planting depth instructions on the seed packet. Some seeds require light to germinate, while others need complete darkness.
Inconsistent moisture
Seeds need consistently moist soil to germinate. As they absorb water, their outer coat breaks, allowing seedlings to emerge. If the soil dries out, seedlings may fail to sprout or wilt after emerging. Avoid soaking the soil—keep it lightly damp until seedlings have sprouted and grown leaves. Overly wet soil can lead to damping off, a fungal disease that kills young seedlings.
Soil Temperature
Check seed packets for ideal sowing temperatures. Peas can sprout at nighttime lows of 40°F, while other cool-season crops need nights above 50°F. Warm-season crops like tomatoes and cucumbers won’t germinate until nights are over 55°F, so many gardeners start them indoors. Using a heat mat and thermostat helps maintain the ideal soil temperature for each seed type. Cooler soil can delay or prevent germination.
Seeds not making good contact with the soil
Seeds need to absorb moisture from the soil to break dormancy and start growing. If the seed are just sitting loosely on the soil or there are air gaps, th seeds may dry out and fail to germinate After sowing light the press the soil over the seeds to ensure good contact. Water gently or mist to avoid moving the seeds buy thoroughly enough to settle the soil around them. A spray bottle works well.
Old Seed
When you buy Burpee seeds, you're getting high-quality, fresh seeds that are tested to exceed USDA germination standards. However, seeds lose viability over time. If you plant seeds from a previous season, you may notice a significant drop in germination rates. Some seeds, like corn and onions, naturally have shorter lifespans.
To keep seeds viable longer, store them in a cool, dark, and dry place. A consistent temperature is key—avoid places that are too warm or humid. Proper storage helps ensure better germination when you're ready to plant.
Pesky Wildlife
Rabbits, voles, groundhogs, deer, squirrels, and birds can snatch up your seedlings before they even break the surface. To protect your plants, cover the bed with a floating row cover right after planting. This lightweight, woven fabric lets in water, air, and sunlight while keeping hungry pests out. It's an easy way to give your seedlings a safe start.