Winter Growing & Season Extension


Calculate Planting Dates for a Seamless Winter Harvest

Use our Winter Harvest Planting Chart as a guide, staggering your plantings for a seamless winter harvest.

How to Use This Chart

  • Each crop's planting window is indicated by a range of weeks before the beginning of the Persephone Period, ie, the last 10-hour day before the winter solstice.
  • To find your planting dates, count back from the last 10-hour day at your latitude the number of weeks indicated. (To quickly identify the date when day length is 10 hours at your location, you can use an almanac or app such as Sundial • Solar & Lunar Times or SunriseSunset.)
  • The crops are ranked in tiers, as outlined in the  key KEY , by their reliability for winter-production success — from relatively easy to more challenging — using input from experienced, high-latitude four-season growers.
  • Click on the crop names to browse varieties trialed and selected by our research team for winter-harvest success.
  Planting Dates for Winter-Harvest Crops
  CROP Start Transplant Direct Seed Week 16 Week 15 Week 14 Week 13 Week 12 Week 11 Week 10 Week 9 Week 8 Week 7 Week 6 Week 5 Week 4 Week 3 Week 2 Week 1 10 hour day
TIER 1 Kale (Full)     15 14 13                          
Tatsoi (Full)                 9 8                
Spinach (Full)                 8 7              
Claytonia (Full)                   8 7              
Kale (Baby)                     7 6            
Spinach (Baby)                       6 5          
Baby Leaf Brassicas                       6 5          
TIER 2 Chicory (Cichorium intybus) 16 15 14 13                          
Pac Choi (Full)               10 9 8                
Cilantro (Full)               10 9 8                
Cilantro (Baby)                     7 6            
Broccoli Raab*               9 8   6 5          
Choi Sum*               9 8   6 5          
Wild Arugula (Diplotaxis tenuifolia)                 9 8                
Salad Arugula (Eruca sativa)                       6 5          
Mizuna (Baby)                         5 4        
TIER 3 Carrots         13 12                        
Bunching Onions (Scallions)         13 12                        
Lettuce (Full)             11 10                    
Swiss Chard (Full)             10 9                  
Turnips               10 9                  
Lettuce (Baby)                     7 6            
Swiss Chard (Baby)                     7 6            
Radishes                     7 6 5          
OTHER CROPS Mâche                 9 8                
Use our chart as a scheduling guide, staggering your plantings for a seamless winter harvest.  Keep in mind that the planting dates are back-scheduled from the last 10-hour day at your latitude.  The number of weeks before the Persephone Period is calculated for each listed crop.  The crops are grouped, as outlined here in the Key, to reflect their reliability for winter production.  Click on the crop names to view varieties selected for winter harvest success.
TIER 1 Most Reliably Successful: Kale, Tatsoi, Spinach, Claytonia, Baby Leaf Brassicas
TIER 2 Second Most Dependable: Chicory, Pac Choi, Cilantro, Broccoli Raab, Choi Sum, Arugular, Mizuna
TIER 3 More Challenging: Carrots, Bunching Onions, Lettuce, Chard, Turnips, Radishes
PLANTING TIME 4–16 = Number of weeks to seed prior to last 10-hour day
* For winter harvest, broccoli raab and choi sum can be sown at 8–9 weeks prior to the last 10-hour day for transplanting, or direct-seeded at 5–6 weeks prior to the last 10-hour day.