A packet showing a high germination percentage can still produce a disappointing row of seedlings. The label and the garden are measuring different stages under different conditions. Germination in a specified test does not guarantee that the same proportion will emerge and establish in your particular soil.
The University of Minnesota Extension’s discussion of seed quality and field stands makes that distinction in a crop context. Its guidance on seeding depth also explains how a seedling can struggle to reach the surface. Specific planting recommendations vary by crop; do not transfer a small-grain depth directly to a vegetable seed.
Follow the seed through separate stages
First identify the seed lot, test information and storage history available to you. Then record the sowing date, depth and conditions in the bed or container. Finally, count emergence at an appropriate time for the crop and conditions. A count made too early can mistake delayed emergence for complete failure.
For an invented example, sowing 100 seeds from a lot labelled 90% germination does not promise 90 established plants. Soil moisture, temperature, placement and subsequent losses can affect the result. The label is useful evidence about the lot, but it is not a field forecast.
If a row is patchy, inspect the pattern before changing everything. Are missing plants concentrated where the soil crusted, where water collected or where seed placement differed? Keep observations separate from explanations: “fewer seedlings in the low corner” is a finding; “the seed was defective” requires more evidence.
Consult crop-specific local guidance before deciding to reseed or change the sowing rate. Increasing seed quantity indiscriminately may create crowding where establishment is already good.
A useful growing record links the packet or lot number with the actual site conditions and emergence count. Over several sowings, that record helps distinguish a recurring bed problem from a particular seed-lot concern and gives a supplier or adviser something concrete to assess.