Kai Gardens Trial
Does planting cabbage over winter shorten the time to harvest?
Experiment:
- Research has shown that most plants stop active growth when day length is below 10 hours. In Auckland, this occurs from end of May to the end of July.
- Even though temperatures on Waiheke are mild in winter, plant growth is also affected by day length - this experiment will check whether planting in winter speeds up the harvest time.
Materials and Methods:
- Vegetable - Cabbage Globe
- Soil - Sheet layering compost with various organic materials
- Blood and bone fertiliser
Plantings
- End of May (10 hrs light)
- End of June (9.5 hrs light)
- End of July (10 hrs light)
Parameters to measure:
- Observe visual growth by counting leaves and measuring diameter
- This was interrupted by COVID-19
- Observe growth and judge when the cabbage is ready to harvest using cabbage head firmness and size.
Results
- End of May planting: harvested after 12 weeks (mid-August)
- End of June planting: harvested after 16 weeks (early Oct)
- End of July planting: harvested after 14 weeks (early Oct)
Trial Conclusion
- Planting the cabbages over winter did not shorten the time till harvest.
- It is better to plant cabbages either before the end of May, or after the end July, when there are over 10 daylight hours per day.
- From this experiment, we can tentatively conclude that the results would be the same for other crops planted over the winter period.
First planting
Photos taken 17th June
First Planting Measurements
Visual observations (7 weeks after planting)
Plant 1: | Plant 4: |
Diameter - 39cm
Leaf count - 14 |
Diameter - 49cm
Leaf count - 12 |
Plant 2: | Plant 5: |
Diameter - 42cm
Leaf count - 14 |
Diameter - 42cm
Leaf count - 12 |
Plant 3: | Plant 6: |
Diameter - 46cm
Leaf count - 14 |
Diameter - 42cm
Leaf count - 12 |
Second Planting
Photos taken 25 June
Second Planting Measurements
Visual observations (2 weeks after planting)
Plant 1: | Plant 4: |
Diameter - 17cm
Leaf count - 5 |
Diameter - 15cm
Leaf count - 6 |
Plant 2: | Plant 5: |
Diameter - 16cm
Leaf count - 6 |
Diameter - 12cm
Leaf count - 4 |
Plant 3: | Plant 6: |
Diameter - 17cm
Leaf count - 5 |
Diameter - 11cm
Leaf count - 4 |