Just the other day I mentioned the phenomena of winterbottom during a conversation with an old mainland friend. She practically split her gut laughing. "Winterbottom?", she said, "You don't get winter in Hawaii!" Not true. While we don't have winters like back on the mainland, the plants are fully aware that it's wintertime.
Winterbottom on my farm occurs from late December to early February. The entire month of January is a complete wipe out when it comes to productivity. Most plants just sit there. Very little growth.
How do the plants know? Chilly nights. Cooler afternoons. And most important, shorter sunlight hours. With the chilly nights and cool afternoon temps, the plants simply can't get the heat units they require for growth. It doesn't matter that it's not freezing. Not enough warmth combined with not enough sunlight equals little or no growth.
Some plants suffer worse during winterbottom than others. So.....here's what happening on this particular farm.
...green beans. Those seeded in December are stunted and showing obvious unhappy damage. This is a variety that has preformed well for me in past Decembers, but this winter has been dreary, moist, very little sun, low afternoon temperatures. So the two December sowings are crop failures to be fed to the livestock. I've held off reseeding until last week, where I optimistically tried again. I'll sow another bed next week and hope for improved conditions.
...lettuce, radishes, Chinese greens, peas - slow growing but otherwise ok. Where I can harvest greens starting at 21 days during the rest of the year, greens need 30-45 days during winterbottom for their first picking. Radishes can be harvested 21 days during summer, but are taking 35-45 days right now.
...papayas. Nothing is ripening on the main farm, but I'm seeing ripening down on my seed farm where it is warmer, drier, and sunnier.
...pipinolas. They're at a stand still, and the older vines are yellowing.
...tomatoes. The young plants are just sitting their. Their color is dull. The slightly older plants that had set fruit are sitting there with green fruits since mid December. Nothing is ripening.
...peppers, herbs, potatoes, bananas, etc are all simply sitting in limbo awaiting sun and warmth.
...pasture grasses. Only the Guinea grass seems to be doing much growth at all. Everything else is pretty much at a standstill. As a result I'm supplementing the sheep with hay cubes.
This year seems to be the most intense winterbottom I've yet experienced in Hawaii. While the seed farm isn't effected as badly, the main farm has been seeing little sun and mostly cool afternoons. Lots of nights have been in the 50s.
I'm anticipating winterbottom to break in mid February, so February 1st is when I'll till the gardens and plant the beds. From then on I should be busy growing stuff again.