Being neither Lois Hole nor Brian Minter, when my two tomato plants grew as differently as Schwarzenegger and DeVito in “Twins”, I pondered Why?
A height of 24 inches satisfied the cherry tomato plant. It quickly branched out around the base, and within days replaced blossom clusters with clumps of tomatoes.
Beside it, a Mr. Stripey tomato plant shot up like Jack’s beanstalk, growing ever higher, blossomed energetically here and there, but soon the blooms withered. Nary a tomato appeared.
Why the exceptional height? And why no sign of a tomato?
Gardeners suggested hanging a sun catcher or importing a flowering annual irresistible to bees.
I browsed an end-of-season potting plant display and bought a purple petunia. Bees ignored it.
I returned to Google. A cursory check identified my Stripey as a beefsteak heirloom tomato known to attain a height of 10 feet! Already it was either wield a hatchet and decapitate the plant or raise the greenhouse roof.
One Google website led to another until I found “How to prune a tomato plant” by pinching off suckers. Poised to pinch, I advanced on my unsuspecting beanstalk.
In another Youtube, tantalizingly titled “Spank Your Tomatoes for Bigger Harvests”, Reaganite71 posed in front of his tomato hedge bragging about his 66 tomatoes on eight plants early into the season. He advises rolling up a newspaper and lightly spanking the stems of tomato plants, their wire cages, or stakes to distribute the pollen of strains that trust their pollination to wind. Use only the flat part of the newspaper roll or you can bruise the stems. He also advises spraying blossoms with apple juice; methane from the juice helps set the blossoms and hasten maturity.
Serendipitously, a day or two after my Google search the New York Times published Carl Zimmer’s review article, “Unravelling the Pollinating Secrets of a Bee’s Buzz”. This article explains why tapping stems with a newspaper or using an electric toothbrush might stimulate tomato production.
Studies are being done by scientists in Scotland, Nevada, and Arizona to determine exactly how bees pollinate plants. It turns out, there’s more to bees’ tactics than inadvertently rubbing their furry bodies on one flower after another while searching for nectar.
Plants like tomatoes, potatoes and cranberries that offer insects pollen rather than nectar as food, hide their pollen in tubes too deep to be accessible by just any insect. Bumblebees clamp their jaws on the tube like an angry pit bull and rev their buzzing like a lawnmower attacking too thick grass shaking the tube hundreds of times a second. If they didn’t hang on tight, they could fling themselves off the blossom. The pollen grains loosened by the bee’s vibrations bounce up and down in the tube until they gain so much energy they blast out of the tube in a cloud.
Pollen grains from the cloud stick in the bee’s fur where they tuck most of the grains in damp clumps on their legs to carry back to the hive as larvae food. But bees lose some pollen grains. These are rubbed off on the next flowers they visit.
Plants that deliberately grow tubes too long for the average insect such as spiders to steal their pollen thus assure wider propagation of their species. Only bumblebees can achieve this 330 Hz vibration level; even honey bees cannot.
Yesterday I ate the first fruit of my labour – three cherry tomatoes. Several more will ripen in a day or so. As for Mr. Stripey, I may have been overzealous, pruning stems that might have produced more blossoms. But if the plant produces a dozen beefsteak-sized tomatoes, it will be acceptable return for an $8 investment.