Whether you fancy yourself a seasoned urban farmer or a novice balcony vegetable grower, you probably have a couple tomato plants under your care. Tomatoes are an urban farmer’s favorite: with enough sunlight they are fairly easy to grow, with enough pruning they can adapt to any plot size, and boy, do they ever produce. While a lot of other vegetables put all their energy into bearing one or two fruits in a season, tomatoes, like the Energizer bunny, just keep going and going. In fact, tomato abundance can be one of the gardener’s most delicious challenges, which is why the kitchens of many urban farmers are likely to turn into canning factories in weeks of July and August.
But dealing with bounty is only one of the challenges that a tomato grower is liable to face. Tomatoes are somewhat paradoxical vegetables – while easy to grow, they nevertheless need some specific attention, and while prodigious producers, they are susceptible to a number of pests and diseases.
We thought it would be useful to post some general information about tomato maintenance and care to ensure that your tomatoes will be the juiciest, healthiest, most flavourful and most numerous tomato armies that they can be.
Pruning and Staking
There are two general types of tomato plants, which require different types of care. Vine tomatoes have branches that grow off a tall, central stem. These tomatoes are referred to as “indeterminate” because they have no maximum size or height, and will continue to keep growing until the arrival of cool weather. If the conditions were right, and old man winter never woke up from his seasonal slumber, these tomatoes could theoretically continue to grow forever. Vine tomatoes need to be regularly trellised throughout the season to keep up with their high growth rate. To do this, place a large stake (such as a bamboo shoot) in the ground, and loosely tie the main stem to the stake with a piece of string.
Furthermore, it is important that indeterminate varieties are pruned throughout the season. As vine tomatoes grow, they will begin to develop “suckers” that grow out of the “V” of the stem.
These suckers are actually entirely new tomato plants, and consume a lot of the plant’s energy in order to produce more foliage. Gardeners have more success with tomatoes when suckers are removed, as the plant focuses its energy on producing flowers and fruit.
Bush tomatoes are more compact, and a good choice for container gardens. Their fruits ripen more quickly than vine tomatoes do, and so they are often preferred in cooler climates like ours. Since they stop growing once they produce flowers, bush tomatoes are considered to be “determinate” varieties. Bush tomato plants produce a set amount of fruit, which often comes all at once. Determinate tomatoes do not need pruning, trellising, or staking, and can be placed within a tomato cage for support.
Watering and Fertilizing
As is the case with most fruit-bearing plants, tomatoes need lots of sunlight, water, and nutrients to be productive.
It is a good idea to add some fertilizer to your plants every two or three weeks, which can include broken up eggshells, kelp, fish emulsion, and manure tea. However, it is best to apply fertilizer only on an as-needed basis, and to be cautious of over-application. Tomatoes plants with too much nitrogen will produce healthy foliage and little fruit. If you find your tomatoes are continually producing greenery and no flowers, do your best to prune them and withhold applying any kind of fertilizer.
While we gardeners like to think of ourselves as tender, loving nurturers, in the case of tomatoes the reality is more sordid. For tomato plants (especially bush varieties), the arrival of the fruit signifies the beginning of the end. Therefore, the tomato gardener’s task is not to keep the plant happy, but to keep it constantly fearing its death. Although this somber advice may sound like Werner Herzog‘s take on tomato maintenance, some farmers swear by the method of stressing your tomato plants. When tomato plants are under stress they focus energy away from producing foliage and towards producing fruit. While tomatoes need lots of water, some find greater success allowing their soil to dry out almost entirely before generously dousing with water. It should be noted, however, that drought stress can be a dangerous game. Never deny your plants too much water.
The Toronto urban garden guru Gayla Trail suggests tossing some Epsom salts into the watering can a few times during the growing season. She believes that the magnesium will help prevent tomato blossoms from dropping prematurely.
Pests and Diseases
While tomatoes are voracious growers that will pop up like weeds once established in your plot, they are also susceptible to numerous pests and diseases. This is part of the tomato paradox: the plants are incredible hearty, yet also quite vulnerable. Diseases can be soil-borne, bacterial, parasitic, fungal, and are often weather-related.
Since tomato diseases are so numerous, they deserve an entire post (or book, or series of books) on their own. Common blights and diseases include tomato blight, blossom end rot, tobacco mosaic virus, and damping off. Cornell University have published a Tomato Disease Identification Key with some disease identification and solution tips. As a general safeguard, Gayla Trail argues that “brushing your hands lightly across tomato foliage produces a hormone that promotes stronger, stockier growth” (You Grow Girl, pp. 140)
Tomatoes can also fall prey to numerous forms of pests, such as sap-suckers and leaf-eaters. Some common pests include tomato fruitworm, cabbage loopers, cutworms, leafhoppers, aphids, whiteflies, and red spider mites. Once pests have been identified, they can be targeted and dealt with. Some can be sprayed with water, or a mixture of water and soap. Neem oil is an extract from an Indian tree that has insecticidal properties. Cutworm collars can be made to discourage the pests from climbing up the plants.
Like all organic gardening, there is no magic bullet solution that will guarantee protection from pests and diseases. Weather and other factors beyond our control will always exert more of an influence than even the greenest of thumbs. The best practice is to monitor your tomatoes, and ensure as best you can that they are getting enough water, their nutrient requirements are being met, they are not falling victim to pests or diseases, their suckers are not getting out of control, and they have enough structural support to keep on going. With a watchful eye (and a forgiving climate) you’ll hopefully be dealing with that more delicious problem: tomato abundance.