Notes for folks who missed our Tomato Workshop. Happy Gardening!
Index:
History of Tomatoes
What is a Tomato?
Hybrids VS Heirlooms
Determinate VS Indeterminate
Tomato Care and Feeding
Disease and pests of Tomatoes
Tomato Old Wives Tales
History of Tomatoes
Werewolves and Tomatoes (Or How You Might Induce Your Child to Eat Tomatoes)
The scientific name for Tomato is ‘Lycopersicon esculentum’ which means ‘edible wolf peach’. The German naturalists who gave the tomato it’s ‘scientific name’ were suspicious of tomatoes as it closely resembled hallucinogenic/poisonous native berries in the nightshade family and suspected it might attract werewolves to the community,.. Thus the name ‘wolf peach’. Furthermore the ethnocentric perspective on the tomato, originating as it did from the perception of the indigenous North American people as ‘savages who engaged in human sacrifice’ delayed its acceptance in the European diet. The ethno botanical value would eventually overcome the ethnocentric prejudice as the benefit of this delicious berry, rich in anti-oxidants soon became apparent.
“Aztecs and other people of South America were cultivating and using tomatoes as early as 500 B.C. Spanish invaders of the America’s brought the fruit back to Europe sometime between 1493 and 1591 and made it popular in Italy, the Caribbean and the Philippines (from where it eventually reached Asia in the 1700s). At first considered an herbal curiosity more often mentioned in the texts of Natural Philosophers than on the pages of cook books until the Italians figured out which varieties were good for eating and which were poisonous; an understandable barrier to public acceptance at the time. So a big thank you to the Italians or spaghetti dinners just wouldn’t be the same today”.
(http://en.wikipedia.org/wiki/Tomato#Mesoamerica)
What Is A Tomato?
Lycospersicon esculentum is a member of the nightshade group of plants or ‘Solanaceae’, many of which are deadly poisonous and some of which are hallucinogenic. Nightshades include potatoes, tomatoes, eggplant, peppers and tobacco.
Tomatoes are naturally vining plants though bush types of shorter stature have been developed by horticulturalists. Leaves have a fine hair which protects the plant from pest insects. Stems and leaves contain a toxic substance, dogs are particularly susceptible to this toxin and can even succumb to poisoning if they eat the fruit itself. Yellow flowers give way to red, yellow, striped or white fruit which might come on gradually or all at once depending on the cultivar.
Nutritional Value of Tomatoes:
http://en.wikipedia.org/wiki/Tomato#Nutrition
“…. contain the carotene lycopene, one of the most powerful natural antioxidants. In some studies, lycopene, especially in cooked tomatoes, has been found to help prevent prostate cancer, but other research contradicts this claim. Lycopene has also been shown to improve the skin’s ability to protect against harmful UV rays. A study done by researchers at Manchester and Newcastle universities revealed that tomato can protect against sunburn and help keeping the skin looking youthful. Natural genetic variation in tomatoes and their wild relatives has given a genetic plethora of genes that produce lycopene, carotene, anthocyanin, and other antioxidants. Tomato varieties are available with double the normal vitamin C , 40 times normal vitamin A , high levels of anthocyanin (resulting in blue tomatoes), and two to four times the normal amount of lycopene (numerous available cultivars with the high crimson gene).”
When we consider the influence of this nutritious fruit on human health we might also consider how good nutrition in general influences our longevity and behavior and ultimately our history and the course of our societies.
Cultivars, Hybrids and Heirlooms
When we do bother to read the labels on a tomato seed package or tomato start we see information which might be meaningless to us. What do words like ‘cultivar’, ‘hybrid’, ‘heirloom’, ‘determinate’ or ‘indeterminate’ mean?
A hybrid is a type of tomato which has desirable characteristics like disease resistance, even-coloring or size which are recessive traits in the parent plants. If you collect seeds from a hybrid you will most likely be disappointed at your results the next season as the dominate traits reassert themselves and you may end up with a tomato entirely dissimilar from its parent. Hybridization has been widely adopted by commercial agriculture because of the ease by which traits like long shelf-life and perfect appearance can be reproduced and because disease resistance is very important in large mono-culture facilities where cost is the bottom line. The lack of flavor of hybrid tomatoes that some folk notice is a result of hybrid breeding. Long shelf life comes with a price and that price is less sugar in the tomato itself. It is the sugar which gives a tomato flavor and which hastens its decomposition.
A tomato label might indicate codes like F1 or F2. F1 signifies first generation hybridization and F2 signifies cross breeding of two hybrid parents. If you see this information on a label and nothing else at least you know that the tomato was produced by hybridization and is likely disease resistant if relatively flavorless compared to an heirloom variety.
The heirloom varieties of tomato reflect an older history of farming and gardening where propagation was done by collecting seeds of plants and planting those seeds again to produce the next crop. Typically heirloom tomatoes have more flavor, take longer to mature, are more interesting in appearance and are less disease resistant than hybrids. Heirlooms were often uniquely adapted to the micro-climate they were developed in. Heirloom types represent a valuable storehouse of genetic information which might prove useful to our children should agri-business create a Franken-food disaster by relying on mono-culture, genetic engineering and limited genetic stock to supply our tables. Whether you find this kind of speculation alarmist or not, there are several academic and private institutions devoted to preserving heirlooms against just those possibilities. So why not choose heirlooms and do your part to help the future? If the subject of heirloom varieties interests you, you might consider attending the International Heirloom Expo in Sonoma this September. You will find vendors with amazing heirloom seeds, starters and products for seed saving. There will be speakers from all over the world talking not just about the importance of heirloom plant varieties but heirloom livestock as well. But I warn you, if you like Monsanto now you will despise them by the end of the Expo!
Determinate VS Indeterminate
Indeterminate and determinate are terms which inform us about the growing habit of Tomatoes. The Indeterminate varieties tend to be vine-like and produce blooms and fruit more or less continuously during the growing season, often with a heavy concentration towards the later part of the year. These varieties are typically slower to reach maturity and are more often Heirloom types. But not always! Determinate varieties tend to be bush like, smaller and produce all of their fruit at once at the end of the season. These varieties are favored by folks who can tomatoes and by agri-business for their predictability in a production line.
Container gardeners might appreciate the determinate varieties for their short stature which rarely reaches 3ft. These smaller growing bush-like Tomatoes need no support. Indeterminate varieties reaching 6ft. or more will need support from a cage or stakes. Cages require less maintenance and can be re-used next season. Always secure Tomatoes loosely to stakes or cages with soft plastic plant ties rather than wire as wire will constrict and kill the growing vine.
Care and feeding of Tomatoes
Tomatoes thrive on dry heat. Make sure to plant your tomatoes in the warmest part of your garden. A reflective wall can help maximize temperature.
When your tomatoes are young water regularly and water so that moisture goes below the level of the current root system, then wait for the surface soil to dry at least finger depth before watering again. Your tomatoes will tell you when they are drought stressed by dipping their leaves. This sign in most plants would be very bad but in tomatoes is not so dangerous; think of it as a communication from your plant that water is needed but not a communication that it is going to die very shortly. NEVER water the foliage of tomato plants. DON’T DO IT.
As your tomato reaches a foot to two feet in height and has thoroughly rooted out you may water less. These are actually very drought tolerant plants and some will grow wild in your garden without any supplemental water at all.
While composting is the method we recommend for feeding your garden plants it is important to give tomatoes a complete and balanced soil to avoid nutritional deficiencies like ‘blossom end rot’. If you choose to use an organic fertilizer I recommend fertilizing two or three times early in the life of your tomato and then holding back further application. When fruit is developing you should avoid fertilizer of any significant strength. Alternately weekly applications of a diluted fish emulsion to foliage and soil will stimulate healthy growth.
Disease and Pests of Tomatoes
Tomatoes are very tough plants but there are certain diseases and pest insects to which they may succumb.
Anthracnose and bacterial spotting are diseases which are fatal to your tomato crop (see images below). If you determine you have one of these diseases on your tomato you will have to throw away your plant and soil if it was containerized. Tomatoes planted in the ground or a large bed will likewise have to be disposed of and all the soil should be destroyed. If removing the soil is not an option then you will have to abandon tomato growing in that area for a number of years. Tobacco mosaic virus is problematic every few years and smokers are advised to wash their hands before handling tomato plants. There are no treatments for these diseases and once detected you should cut your losses and destroy the plants; do not compost diseased tomatoes, throw them away with the non-recyclable garbage.
Common pest insects of tomatoes are aphids, moth larva (tiny caterpillars) and tomato horn-worm (see images below). The key to keeping these pests from destroying your tomato is early interception. Inspect the undersides of young leaves regularly and rub off any aphids you discover. Shake your tomato plant gently and look for damaged foliage, tomato hornworms are large and obvious pest larva which if not detected quickly can decimate your tomato. Folded leaves are signs of caterpillar infestation. Unfold leaves and crush the larva. You might consider spraying proactively with Spinosad and B.T.
Old Wives Tales
The secret everyone knows is that California’s climate is so friendly to tomatoes that you can plant them, water a little and just let them do their thing; they will produce lots of tomatoes. But if you want to improve the quality and flavor of your fruit you might try some of these old garden tricks.
1) When your indeterminate tomato reaches two feet (usually about 14 days) you may prune off foliage which is not receiving sunlight to improve fruit development. This will divert energy from maintaining non-productive leaves towards tips which will bear fruit. Just pinch off stems near the central stalk with your fingers. Your tomato will appear more ‘vine-like’.
2) Pinch off suckers as they appear late in the season. These are tiny stems and leaves which originate where a lateral meets the central stem of the tomato. This also diverts energy to fruit producing ends.
3) You may plant your tomato start at any depth along the length of the plant. Tomatoes can root from any point on the central stem and developing a good root system is your tomatoes first order of business when you transplant it. Do pull of any small leaves before burying the stem as they will rot off anyways when buried and might encourage disease.
4) Most tomatoes are ready to be harvested in 60 days. When fruit is just starting to develop color begin withdrawing water to drought stress the plant. Wait for leaves to droop before watering. This will improve the flavor of the fruit dramatically. It might also shorten the life of your tomato so wait till the last part of the season to do this.