Answer:
The key term Vern and his sister Ella should look for on the seed packets are either "Sowing Indoors"; "Start Indoors"; "Direct Sow"; or "Sowing Outdoors".
These terms help to understand the best time to begin growing the seeds and whether they are outdoor or indoor plants.
If a seed packet has the term "direct sow after danger of frost" it means the seed should be planted outside only (if there is no starting date given).