How to Start Perennial & Annual Seeds Indoors


Seeds are a great way to get the most bang for your gardening buck but sowing seeds outside once the danger of frost has passed means waiting longer for your garden to take form. Forcing seeds indoors can be as simple as good seeds, good soil, water and sunlight. By starting seeds 6-8 weeks before the last frost, you'll be planting seedlings instead of seeds in the spring.

Step 1

Choose quality seeds packaged for this growing season, for best results, or seeds saved from last growing season. Some plants' seeds are still viable for a few years, but most lose their ability to germinate after one season. Many bargain seeds are too old to grow. Check the packaging to see if it is recommended to force seeds indoors-- some plants are just too fragile to survive a transplant and most perennials need to establish their roots quickly.

Step 2

Prepare your growing space. Seed-starting kits are available in most stores that provide a base, peat pellets and a clear greenhouse top, but you can make your own with peat pots or soil/pellets in egg carton bottoms. If growing with peat pellets, follow the instructions for activating the pellet correctly. Peat is the decomposed matter of wetland plants that makes an excellent, light-weight growing medium. In pellet form, it is vacuum-packed in a netting to a manageable size. To activate, place pellets in your container and slowly add warm water. The warm water rehydrates the peat and grows the pellet to the right size. Tear the netting away from the top of the area so you have room to plant the seeds. If using peat pots, fill to the top with a quality potting soil made for seed-starting.

Step 3

Plant seeds as per the instructions for each particular plant. Some flowers will instruct you to plant only one seed per pot and others will tell you to plant more and then thin out once it begins to germinate.

Step 4

Water pots to a moist but not soggy state. If using peat pellets, you may not need to add much more water than what was added to activate the pellets. Cover with the greenhouse lid or plastic wrap tightly and place in a mostly sunny location in your home.

Step 5

Leave covered for as long as possible, watching for sprouts through the see-through top. You need to create a warm, humid environment for the seeds to sprout. Once sprouted, you can remove the lid to add water a few times a week to keep moist. Sprouts need more moisture than your mature plant would, so keep it wet until it begins to mature.

Step 6

Thin sprouts to 1-2 hardy plants in the middle of your pot.

Step 7

Move seedlings outdoors on your porch for about a week before planting in the ground to help get them acclimated to the outdoor temperatures. Be sure that the danger of frost has passed before doing so.

Step 8

Plant entire peat pot or pellet into the ground or container. Roots will grow through (if they haven't already at this point). Water and care for as normal.

Tips and Warnings

  • Never use garden soil brought indoors for seed-starting. You could be introducing your seeds to microorganisms or pests that can damage them.

Things You'll Need

  • Window seed-starting kit, peat pots, or egg cartons
  • Quality potting soil or peat moss pellets
  • Plastic wrap
  • Water


  • Growing Seeds Indoors
  • Seed Starting Basics

Who Can Help

  • Seed Starting Indoors
Keywords: window greenhouse, peat pellets, force seeds

About this Author

Bobbi Keffer attended Kent State University, studying education but soon found her true love to be in the garden. She prides herself on her frugal skills, re-using, recycling, and re-inventing her whimsical style in her home and garden.