How to Decide Whether to Start Seeds Indoors or Direct Sow

Using the information on the seed packet, you can determine the best approach for planting your seeds.

Start Indoors If:

• The seed packet suggests starting indoors (e.g., tomatoes, peppers, eggplants).

• The crop has a long growing season and requires an early start to produce before frost (e.g., tomatoes, peppers, some herbs).

• The plant requires warm soil to germinate and grow (e.g., basil, tomatoes, petunias).

• You want a head start on the growing season, particularly in short-season climates.

Direct Sow If:

• The seed packet states “Direct Sow Only” (e.g., carrots, radishes, beets, corn, beans).

• The plant does not transplant well due to delicate roots (e.g., squash, cucumbers, peas).

  • The exception to this is if you have a short growing season and need extra time. In this instance, start seeds in as large a container as feasible to avoid disturbing roots when transplanting.

• The plant has a short growing cycle and can mature within your growing season (e.g., lettuce, spinach, arugula).

• You are growing a crop that needs room to establish itself without disturbance or has a deep taproot (e.g., sunflowers, poppies).

Using Seed Packet Information to Start Seeds Indoors

Once you decide to start seeds indoors, the seed packet provides critical instructions for doing it correctly.

Step 1: Timing Your Start

Use the recommended indoor start time (e.g., “Start indoors 6-8 weeks before last frost”) to determine when to begin. Count backward from your local last frost date.

Step 2: Choosing the Right Growing Medium

A high-quality seed-starting mix is ideal. Regular garden soil is too heavy and can harbor diseases.

Step 3: Planting Depth and Containers

Follow the planting depth instructions carefully. Use seed trays, small pots, or soil blocks to give seedlings room to grow.

Step 4: Providing Adequate Light

Most seedlings need 12-16 hours of light per day. If growing indoors, use grow lights to prevent leggy growth.

Step 5: Temperature Control

Check the seed packet for the optimal germination temperature. A heat mat can help maintain warmth for warm-season crops.

Step 6: Watering Properly

Seeds need consistent moisture but should not be waterlogged. Covering trays with a humidity dome can help retain moisture.

Step 7: Hardening Off

About a week before transplanting, gradually expose seedlings to outdoor conditions by placing them outside for increasing lengths of time each day.

Download my free Seed Starting Essentials eBook HERE for an in-depth guide to starting seeds indoors!

Final Thoughts

The information provided on a seed packet helps determine whether to start seeds indoors or direct sow, as well as how to properly care for seedlings. By using the details on the packet, you can give your plants the best possible start and set yourself up for a productive gardening season.

Your Friend in the Garden,