Moisture and warmth encourage seeds to germinate. There are seeds that require special needs in order to germinate. It is important to follow the specific recommendations for a high success rate.
Open flats are fine for seed starting though individual containers are preferable so as not to disrupt root growth. Peat pots are the perfect container since you can plant them right into the ground eliminating the risk of root injury.
Seeds contain enough nutrients to nourish themselves through sprouting. Fertilizers are not necessary at this time.
Vermiculite, peat moss, perlite, and compost are good soil-free materials for seed starting. They can be used alone or you can mix 2 or more together. Let your seedlings grow in this mixture until they develop their first true leaves and then transplant into a nutrient-rich potting mix. If you prefer to use potting mix to eliminate transplanting, mix equal parts compost and vermiculite. Moisten the planting mix with warm water before you fill your containers.
Space large seeds at 1" apart, planting 2-3 seeds in each pot-later snip off the the weaker seedlings. Plant medium size seeds 1/2" - 1" apart and tiny seeds 1/2" apart. Cover the seeds to a depth of 3x their thickness with your seed starting mix. It is important not to cover seeds that need light to germinate.
Label your pots right away to avoid confusion.
Either set your containers in shallow trays of water and let them soak until the surface of the soil looks moist or gently but thoroughly mist the mix. Always water with a gentle stream.
Cover your containers with clear plastic - dark plastic is ok for seeds that do not require light to germinate. Finally, place your containers in a warm place where you can check them daily.
LIGHT---Seedlings need strong light or they will become spindly-16 hours is ideal. Occasionally rotate your pots to help the plants to grow straight.
WATER---It is best to use tepid water and let the plants soak the water up from the trays.
TEMPERATURE---Try to keep an even temperature of about 60-70 degreesF-a 10 degree drop at night is ok and actually promotes hardiness. Remember cool-weather plants will prefer cooler temperatures.
AIR CIRCULATION---As soon as the seeds sprout, remove the coverings. The plants need air.
FERTILIZING---The first few weeks, it is really not necessary to feed your seedlings. With soilless mixes, a weak solution may be needed. A natural fertilizer such as fish emulsion is ideal. Natural products are less likely to burn than chemical ones. Use weak solutions to start and gradually build up to a full-strength solution at around three weeks.
PROVIDING SPACE---Thin out your seedlings as they begin to develope leaves. You will have a much hardier plant if you thin out the weaker plants. The healthy remaining ones will benefit from plenty of space and good soil. Use scissors to clip the weaker plants so as not to disrupt the roots. If your plants seem to need more room, transplant them to a bigger pot.
HARDENING OFF---As the days get warmer, take your plants outside each day. They will need to be taken in at night. Each day, you can gradually extend their time outside.
PLANTING OUTSIDE---Keep an eye on the last expected frost date-here in Danbury, CT we always get a 30 degree night in early-mid May. The seedlings really should not be planted outside before this time. It is best to plant on an overcast day-late in the afternoon. Planting your seedlings in the middle of a hot, sunny day is stressful to the plants. Keep the plants evenly moist-always be sure the water is reaching the roots. Protect the plants at night, as needed, from wind or frost. An over-turned container that fits over the plant without touching it, works well. Just remember to remove it early in the morning so the plant doesn't fry underneath. Enjoy your plants! Remember to water, as needed, throughout the season and be sure the water reaches the roots.