Seed starting is a great way to get a jumpstart on the spring growing season. It’s an enjoyable activity and an inexpensive way to grow a wider selection of plants. Just one pack of seeds will produce a lot more plants per penny, compared to buying them as full-grown plants.
Another reason for starting your own seeds is that more varieties of plants are available as seeds. Seed starting gives you the flexibility to decide which variety to grow for each vegetable and flower. You can grow that rare heirloom tomato that you can’t find at a garden center.
Seed Starting Basics
Before you begin, follow the directions on the seed packets so that you know when to start your plants indoors. They’ll need to be at the correct stage of development when it’s time to move them outside after the last frost. Many vegetables typically need to be started indoors in early spring, usually six weeks before the last frost date.
Next, gather your supplies for seed starting which typically include: seeds, potting mix, containers, labels/markers, plastic bags, water, bottom heat, light source. You can use biodegradable pots, plastic pots, or flat trays for the container. Also, make sure that your container has adequate drainage at the bottom.
Steps to Success
Seed starting is relatively easy if you follow some simple steps:
- Dampen the potting mix after placing it in a container (always water from the bottom) and sow the seeds. Depth placement is usually the depth of the seed. Smaller seeds can be placed on top of the potting mix.
- Place granite grit/chicken grit on top of the potting mix and seeds (optional step). This is an excellent way to gauge when the seeds/seedlings need water and the grit may discourage airborne viruses.
- Label each container or group of containers, using Popsicle sticks or other markers.
- Place containers in plastic bags, cover with plastic wrap, or place a clear plastic cover over the container. This creates humidity.
- Place the containers with their plastic covering over some type of bottom heat (top of the refrigerator is a good spot). You can also use a heated seed starting mat.
- Remove the plastic covering once the seedlings emerge. The bottom heat is no longer needed.
- Place the seedlings in a light source. They will need 12 to 18 hours of light each day. Fluorescent lights are best but natural sunlight also works well.
- Water the seedlings when the soil appears dry. You can also give them an optional “feeding” with any plant fertilizer at the recommended dosage for houseplants. As your plants start to grow, repot the seedlings if necessary by using a larger container. Wait until the seedlings develop their first “true” leaves for this.
- Harden off your plants. Gradually introduce your seedlings to the garden after threat of frost. Ten days to two weeks prior to setting them out in the garden, bring the plants outside into a shady area. Gradually expose them to outdoor conditions and bring them inside if the temperature falls below 40 degrees.
- When your plants are large enough for easy handling and hardening-off is complete, plant them in the garden Select a cloudy day for the task and dig a hole twice as wide as the plant. Carefully remove the plant (retain as much soil as possible) and set it in the hole at the same level it was growing in the container.
For more information on seed starting, supplies and seed packets, contact Floral & Hardy of Skippack.
“Tips for Successful Seed Starting” presentation by Susan Doblmaier, Penn State Master Gardener.
Penn State Extension article: http://extension.psu.edu/plants/gardening/news/2015/seed_starting_demystified