Success at starting vegetables from seed outdoors begins with proper soil preparation. After organic material is mixed into the soil, level the surface and remove large clods for a fine bed. There should be no cracks in the surface of the soil where small vegetable seeds can be buried.
A rule of thumb is that seeds should only be covered to a depth of twice their diameter, or to the depth listed on the seed packet. Vegetable seeds that are buried too deeply will not germinate. Be sure to follow directions on seed packets to determine when to plant the seeds. Cool season vegetables are able to germinate under cool soil temperatures, but warm season ones will not.
Small vegetable seeds are perhaps the hardest to germinate in Colorado’s intense sun and drying wind. The soil surface dries quickly, killing seedlings that have started to grow but have not yet emerged from the soil. Water seedlings often for short periods of time during the germination period. The days to germination are usually listed on the seed packet.
When watering seeds, be careful not to wash them away. A water breaker or a watering can that produces a gentle stream of water is recommended. If seed-bed drying is a problem, consider mulching it with straw, dried grass clippings or floating row cover fabric.
Pests can also destroy seeds. For example, seed corn maggots will destroy large seeded vegetables such as corn and beans, particularly when they germinate slowly in cool soil temperatures. Cutworms can girdle young seedlings. Birds will eat not only seeds, but seedlings and chunks from young plants as well. To protect seedlings, make sure they are planted in the appropriate time, and cover seedlings with floating row cover fabric.
For “Organic soil amendments” refer to message number 1604.
For more information, see the following Colorado State Extension fact sheet(s).