Seeds

• Seeds that germinate easily and transplant readily are good candidates for egg carton cultivation. Because an egg carton contains multiple compartments, you can fill it with different seed types--for example, fill a carton with a mixture of tomato seeds such as early, cherry, heritage and other varieties. These seedlings, transplanted at the same time, will mature at different rates, offering a steady tomato harvest throughout the season. Planting an assortment of marigold seeds in an egg carton yields companion flowers for the tomatoes and other veggies.
  
  

Cartons

• Eggshells make good temporary planters.Martin Poole/Digital Vision/Getty Images
  
  Punch a drainage hole in the bottom of each egg carton compartment and remove the carton lid. Paper egg cartons wick water from the seedlings, requiring more-frequent watering, but can be planted directly in the ground much like peat pots because they disintegrate over time and with exposure to moisture. Styrofoam or other plastic-type egg cartons hold moisture for the seedlings but cannot be planted in the ground, since they don't decompose. Both egg carton types will hold eggshell planters: carefully remove a hard-boiled egg's outer shell and place it in the carton, where it can hold soil and seeds, then be crushed and added to the soil.
  
  

Growing

• Add a small quantity of seed soil to each egg compartment--use seed starter, germination mixes or potting soils. Commercial mixes are balanced formulas that are easy to use and more disease- and pest-free than garden soil. Add soil until each compartment is 3/4 full, then drop in 1 to 2 large seeds or 3 to 4 small seeds. Top with soil to the recommended depth per the seed packet. Water well and keep in a well-lighted and -ventilated space. Put the egg cartons on cookie sheets or other pans to catch excess water. Hydrate as needed using a mixture of a gallon of water containing 1 tablespoon of soluble fertilizer. As seedlings sprout, pinch or thin to 1 in each compartment.
  
  

Transplanting

• At planting time, cut and peel each egg compartment from the seedling and its soil. Cut apart paper cartons, if desired, and plant just below the level of the garden ground, making sure the paper carton is below the surface, because exposed paper will dry out the young plants. Some seedlings don't transplant well--sow seeds such as dill, carrots, cucumber and squash directly in the garden.