Cris and I used to get quite a laugh out of his dear father, a salt of the earth man who loved to garden, fish and provide high humor for his grandchildren. He was a man of strong beliefs, especially about his garden. Potatoes must be planted on Good Friday; trees must be pruned on Presidents Day; and never plant anything during the full moon.
Before starting our small farming adventure in Minnesota, I went to a number of classes, seminars and basically anything I could find on organic farming. I learned a great deal about soil, cover crops, organic disease control, etc. One of the seminars that was especially intriguing however, was a scientific lecture on Phenology. I had never heard of it before, and I couldn’t believe it when I heard some of Willis Stainbrook’s folklore being espoused as a truth based on science and history. Not the holiday planting lore, but some of the little things he used to do. I’m sure if he was still with us and someone told him his knowledge was scientifically sound, he would respond “Pwiffwah, everybody knows that.”
The National Gardening Association has this to say about Phenology:
“Phenology has been used for ages in gardening and agriculture to determine when to plant, when pest insects will become a problem, and when plants will bloom. It turns out there is scientific basis for these observations. Modern plant scientists have found that phenology corresponds to a measurement called growing degree days. Growing degree days are calculated by adding the average daily temperature to, or subtracting it from, 50°F. This information provides a way to estimate the timing of certain events, such as when controls for pest insects need to be used to maximize their benefit.”
With respect to tomatoes (especially heirloom tomatoes) a fairly specific rule of thumb in central Minnesota is to wait until memorial day to plant. I do follow this rule to great success, but understand that my heirloom tomato seedlings have been potted up into 4″ pots and have been fully hardened off, not little wispy things and not big honking plants that have already spent their energy coming to bloom.
Every time I have been fooled into planting early by a warm spring, a cold spell has followed and the plants are either stunted or they just sit there in the ground waiting patiently, but not growing. The tomatoes planted on memorial day always catch up with any progress the early plants have made.
Here’s some other phenological pieces of planting wisdom that I picked up from that class or along the way: Continue reading “When to plant heirloom tomatoes:Phenology and planting time of fruits & vegetables in a Northern Garden”