Culture NotesTomato plants can be grown from seed or seedlings. Growing tomatoes from seed will take longer to reach cropping stage and seeds tend to do poorly unless raised to seedling stage in protected conditions and then planted out. This is much more cost efficient than seedlings when done well but requires a bit more skill and equipment. In temperate and cooler climates, seedlings need to be planted out as early in spring as possible, to maximise the growing season. Tomato plants are susceptible to frosts, so protection from frost may be needed in cooler climates until the risk has passed. One guide to timing planting is to feel when the soil begins to warm and when it feels comfortable to the (extended) touch, it is warm enough to start planting, under cloches if neccessary.
Some quick and easy covers for young plants are re-used water-cooler bottles with the bottom cut out and the lid off, or a small tunnel cloche made from flexible cane bent into arcs and some clear plastic sheeting. These can be removed (or rolled back) on sunny days and replaced for frosty nights. Traditional cloches were made from glass in frames of metal or wood, with handles. The heavier build is more wind resistant but harder to store in the off-season.
Whatever media is chosen, it should be friable, enriched and have good moisture-holding properties before planting. Soil pH needs to be neutral to slightly alkaline (pH 7 - 8) for best results, but the pH range is wider for acceptable results, ranging from moderately acid to alkaline (pH 5.5 - 9.0). Better root development can be achieved by planting the seedlings deep. Tomatoes have the ability to develop roots on the stem of the plant when planted deep and kept moist. (Not many plants share this ability so avoid this practice with other seedlings.) Male plants, or 'sports' are totally unproductive and should be discarded. Sports can be recognised by the broad leaves with only minor segmentation. Water the plants in well, to achieve good soil:root contact at planting time. Bush varieties should be allowed room for each plant to spread, staked varieties need strong stakes that are solid in the ground orcontainer. Pinch out unwanted lateral growth from time to time to encourage more flowering. Feed and water the plants well once fruit starts to swell and show signs of ripening. The best tasting fruit is ripenened on the vine but tomatoes can be harvested with partial colour and will still ripen in storage.
Water requirement for tomato plants is quite high, so soils/media should be kept moist, most of the time. Wilting due to dry conditions and heat should be avoided. Plant in spaces where plenty of sunlight is available, morning to early afternoon sun is best but full sun conditions are also suitable in all but the hottest climates. Trellised varieties need protection from strong winds (hot and cold). Bush varieties may need their fruit protected from contact with soil surfaces as this can cause rot. It is also best to avoid spraying water onto tomato plants as they are susceptible to attack from a number of fungal species that prosper in humid conditions. It's preferable to water the soil or use systems that deliver water to the roots directly. Young seedlings may need protection from chewing animals such as cut-worms, in early stages but the tomato plant will develop better natural defences as it matures.
Nutrient RequirementsNutrient requirement in tomato plants is quite high but avoid over-use of nutrient-rich fertilizers as this can create problems in the soil and the plants. Focus on supplying the 13 essential (mineral) nutrients and the three other essential elements (hydrogen, oxygen and carbon) in sufficient quantities to achieve the best outcomes in terms of productivity and soil health. Maintaining a good nutrient balance for the plants may also (no scientific proof available) have a positive outcome in regard to the nutrient content of the fruit. Nitrogen (N), phosphorous (P) and pottasium (K) are the major (macro) nutrients and these are the nutrients most required by the plant for healthy growth.The secondary nutrients are calcium (Ca), magnesium (Mg), and sulfur (S). There are usually enough of these nutrients in the soil so fertilization is not always needed. Also, large amounts of Calcium and Magnesium are added when lime is applied to acidic soils to adjust pH. Sulfur is usually found in sufficient amounts from the slow decomposition of soil organic matter. (Personally, I was taught that these are micro-nutrients as well and if you buy a trace element soil additive, it will contain all of these and the seven micro-nutrients below.)
The micro nutrients, or trace elements are only required in trace amounts. Most soils contain traces of all mineral elements but availability may vary. Trace element applications in water-soluble form will address any defficiencies but go lightly, more is not neccessarilly better. The micronutrients are boron (B), copper (Cu), iron (Fe), chloride (Cl), manganese (Mn), molybdenum (Mo) and zinc (Zn). The ten micro-nutrients are required in minute amounts. Over-dosing the soil with micro-nutrients will not improve production and could have negative consequences in regard to soil and plant health.Most commercial plant foods have a three number nutrient ratio that is the N:P:K ratio. If you use commercial brands look for a ratio higher in phosphorous than normal and with a strong pottasium number as well. Nitrogen is important but too much nitrogen will encourage green leafy growth, rather than fruit production. In organic systems with minimal commercial input, a good understanding of the properties of the applied organic fertilizers needs to be understood to avoid problems but it's not as difficult as it might sound. Your plants will tell you what they need and experience will teach you how to meet those needs. *Fish emulsions and kelp emulsions are very good for tomato production as they are rich in phosphorous and pottassium and can be applied as a foliar feed/soil conditioner.
Pests and Diseases
Young tomato plants are susceptible to attack from stem-chewing insects. This can be dealt with by using a physical barrier such as a collar to protect the plant. There are a number of fungal organisms that may also cause problems. Avoid spraying water onto the foliage and allow enough room for air movement. Remove any fruit, foliage of plant material affected by fungal attack and treat with a very light application of sulphur. (Sulphur is poison. Follow all safety instructions and be sparing with applications. Avoid using sulphur at all when fruit is being harvested.)
The major insect pests in tomato production are leaf/fruit mining grubs. These can be dettered by applying Derris powder. Derris powder is made from the roots of the Derris plant. It is organic but has a (slight) level of toxicity, so wash fruit well and wash hands well after handling the fruit or working on dusted plants. Another 'organic' control is a product usually known as Dipel which contains Bacillus thuringiensis, a bacteria which infects the gut of catterpillars. It is non-toxic to humans and most animals but I have heard it said that it may kill earthworms, so if you use this product it would be a good idea to avoid spraying the ground too much. (Earthworms are our friends)
There are a number of other pests and diseases that may infest tomato plants but good healthy plants don't normally have many problems. In warmer climates there is a slight risk of fruit fly infestation but that is normally only a concern in the hottest months of the year or in tropical climates. Setting fruit fly traps and monitoring those traps regularly will show when further action may be required to deal with an issue. Even with organic sprays, it's best to minimise the use of sprays until it is absolutely needed. This type of management system is known as IPM or Intergrated Pest Management. This is further enhanced by planting some host plants for beneficial species (mainly, insects that eat other insects or small insect-eating birds).
Companion PlantingTomatoes love Basil is an expression that holds true in the garden as well as the kitchen. Another aromatic herb that is beneficial in the productive garden is Rosemary. The early flowers draw bees into the garden and this aids the pollination of early-set tomato flowers and any other flowering plants. Basil, Rosemary and garlic chives combined is a powerful combination of aromatic herbs to keep most chewing and sucking insect pests away (as well as being usefull kitchen herbs). Avoid over-crowding, but allow plants to come close and allow some contact. (With some companion planting combinations, such as corn and cucumbers, the contact is quite intimate and entwined.) There are many other beneficial plants that may be less use in a cullinary sense but do help bring a natural pest:predator balance in the garden as a whole. There are also sources for beneficial insects that can be released into the garden at times, to deal with specific problems and a diverse planting with host plants and prey species will provide a good environment for those species to remain in the system. I will write more about companion planting, when I pull together some more detailed good companion/bad companion examples.
I don't have all the answers but I hope these tips help. Feel free to ask questions or add sugestions via the comment section and maybe we can help each other?