Tomatoes are in the same botanical family as peppers and eggplants, Solanaceae. Like them, they originated in considerably warmer climates than our own. Thanks to this, their tolerance of cold soil and air temperatures are low. And this spring has been a cold and wet one.
Extended text: Despite blandishments from garden centres, local grocery stores, supermarkets and big box retailers rare is the spring when such temperatures are at their optimum for these crops before the first week of June in southern Ontario.
Planted out earlier, tomatoes, peppers and eggplants run the risk of being cut down by late frosts – remember Victoria Day weekend just weeks ago?
Soil temperature should have reached 12ºC to 15ºC, air temperature the same at night. Such can vary widely over quite limited areas, so rely on your own garden thermometer. Of course, keen gardener that you are, you have one, right? As an alternative, when the neighbour starts sunning herself wearing a bikini can be used as a somewhat less reliable guide.
Below about 15ºC, pollination will be poor, even if the first truss, or stems of blooms, were already formed on the tomato plants you purchased.
Tomato plants are voracious feeders but do not commence feeding until after the first truss has little green fruit the size of a dried pea. Old-time gardeners did, however, make a slurry of dried eggshells with water in an electric blender. This was applied soon after planting to supply the additional calcium required for healthy fruit development later.
Following the first fruit set apply a liquid commercial plant fertilizer ever other week. On the alternate weeks, a teaspoon of magnesium sulphate (Epsom salts) to each plant. Carefully water in, avoiding splashing the foliage.
Bush tomatoes are fine on the farm but in the home garden space is liable to be more limited. Grow them up stakes as a single stem – technically they are vines – with a tie below each truss. Used pantyhose is excellent for this purpose. Eight-foot stakes of two-by-two pounded up to two feet into the ground will allow room for six or seven trusses and perhaps nine or ten pounds of fruit per plant.
Tomatoes are thirsty subjects. Each plant can require as much as two gallons of water a day at the height of the season. If possible water before noon without splashing the foliage, which can spread disease.
The principal insect pest is probably white fly, whose name is descriptive. It hides on the underside of the leaves, sucking the sap and leaving sticky excrement on lower foliage. This later turns black from a fungal growth. A simple solution is to suck the little beggars up with a hand vacuum.
Botanically, the tomato is a fruit, a berry to be precise. But not according the U.S. Supreme Court who deem it a vegetable. Over a century ago, in 1886, a botanically savvy New York businessman imported a shipment of tomatoes from the Caribbean. The customs authorities demanded 10 per cent duty on the load as laid down by law for vegetables coming into the country. No way, argued the importer: Tomatoes are a fruit, not a vegetable. It took seven years wrangling to reach the rarified heights of Washington’s legal eagles where the judgment was rendered in favour of a vegetable interpretation, and botany be damned. It is perhaps worth noting that more recently the U.S. Supreme Court has also judged carbon dioxide, vital to all plant life, a pollutant.
