I just pick them, rinse then off, put them in the freezer in a freezer ziplock bag and use them throughout the rest of the year. Hard to tell from fresh.
I also like to make Freezer Salsa. Thawed, it's almost like fresh.
Freezer Salsa
7 lbs tomatoes
3 Cups chopped chile peppers, such as Anaheim or poblano
1/2 Cup seeded, finely chopped jalapeno or Serrano chiles
2 Cups chopped onion
5 Cloves garlic, minced
1/2 Cup chopped fresh cilantro
1/2 Cup vinegar
1 T sugar
1 t salt
1 t pepper
Peel, seed and coarsely chop tomatoes. Place tomatoes in a large colander and drain for 30 minutes. Place drained tomatoes in a large kettle and bring to a boil. Reduce heat and simmer uncovered for 45 minutes or until thickened. Add remaining ingredients and bring to a boil. Remove from heat and place kettle in a sink filled with ice water to cool quickly. When cool, spoon into freezer-proof containers, leaving 1/2 inch head space. Freeze for up to 6 months. (I have kept it longer with no adverse effects).
Makes 4 pints.