Fall Greenhouse Prep: What to Do Before the First Frost
Quick Answer:
Start before the frost hits. Once nighttime temperatures are consistently dropping into the single digits Celsius (upper 40s Fahrenheit), it is time to clean, check equipment, and add insulation, not wait for a frost warning to show up on the forecast.
Clear out and clean first. Remove finished summer crops, wash down any plants staying in for winter, and pencil in a deep clean for mid-November before things get too cold to tackle it comfortably.
Check your equipment, then seal in the heat. Inspect fasteners, vents, and fans while the weather still allows for it, then add insulation, thermal mass, row covers, or soil warming to hold onto heat as temperatures fall.
Ease off watering and switch crops. Cut back as growth slows down, and swap warm-season plants for cold-hardy crops like kale, spinach, and Swiss chard to keep the greenhouse productive right through winter.
