How to do a Simple Plastic Tunnel Cold Frame or Row Cover. Grow salad greens all winter long, to grow out tomatoes and other tender plants, to extend the season for an early Spring start or a late Fall harvest, or even as a screen house to keep birds off of your strawberries or vine borer moths off of your squashes.
Let the pod stay on the stem until late summer when the pod is brown and starts to split open. The seeds should be dark and shiny. At that stage, you can gather the seeds and store them dry in an envelope.
Last frost date for Oak Park Zone 6a April 20th (50% chance) The classification of freeze temperatures is usually based on their effect on plants. Light freeze: 29° to 32°—tender plants killed. Moderate freeze: 25° to 28°—widely destructive to most vegetation. Severe freeze: 24° and colder—heavy damage to most plants.