Because tomatoes need a long growth season, it is advisable to start them indoors at least six weeks before the day that you intend to transplant them (after the final frost of the spring). If you want the greatest results, plant the seeds half an inch deep in a starting mix that has good drainage but no soil. Plants can only grow in soil that is between 65- and 90-degrees Fahrenheit. Germination will take place more quickly in soil that is warmer. Keep soil moist, but not waterlogged while awaiting germination. Once the seedlings have broken through the dirt, you should water them moderately yet slightly. 
SOIL & GROWING NEEDS
Tomato plants thrive in soil that is rich in organic content, has good drainage, and is fertile. Although heavier, more fertile soils like clays and loams offer the best yields, lighter soils that drain and warm up more rapidly might produce crops early. It thrives on soils with a pH range of 6.0 to 6.8 and can survive in conditions that are only mildly acidic. Because tomatoes require a lot of nutrients, they should be fertilized with an organic mixture that is high in phosphorus and potassium and has a modest amount of nitrogen. Tomatoes require at least eight hours of direct sunlight every day, and their growth will be accelerated if they are exposed to more sunlight. If at all feasible, choose a location that has a gentle slope with exposure to the south or southeast. Tomatoes, which are indigenous to tropical areas, have the highest light requirements of any common garden vegetable. In seasons favorable to their growth, plants that have been staked and clipped can reach heights of well over 6 feet and can be trained to restrict their spreads. Use more compact cultivars of the determinate type if space is at a premium. If you stake them, trim them, or use plastic mulch and row coverings, tomatoes are an extremely labor-intensive crop to grow. 
TRANSPLANTING YOUR STARTS OUTSIDE
When the final frost has passed and the temperatures do not dip below around 50 degrees Fahrenheit at night, you can start to think about transplanting once you get a chance. Don't be in a hurry to have the transplant. Plants can suffer from stress brought on by cold soil and air temperatures. You should hold off for at least a week or two after the last frost has passed. When selecting plants for transplanting, aim for ones that are hardy, relatively short, and have a dark green color. Steer clear of plants that are very tall, lanky, or yellowish, or that have already begun flowering. Too-matured transplants frequently fail to thrive after being moved, while more immature ones are outcompeted by younger, smaller plants that bear fruit sooner and in greater quantities. Instead of exposing plants to freezing temperatures to "harden them off" before transplanting them, which can stress the plants and limit their growth, reduce the amount of water and fertilizer they receive. Catfacing is more likely to occur in transplants that are kept at temperatures between 50 and 60 degrees Fahrenheit at night and 60 to 65 degrees Fahrenheit during the day. This (misshaped, deformed fruit) is the result of insufficient pollination, which is typically brought on by the presence of cold weather. Take your time and wait till the weather has settled down and the earth has warmed up before transplanting. Tomatoes, unlike the majority of other plants, do better when planted deeper than they were when they were cultivated in containers. Place them in the ground at an angle such that the top of the soil is just little lower than the lowest leaves. The buried stem will eventually get covered in roots, which will result in a more robust root system. Do not plant on soils that have recently been used for growing tomatoes, potatoes, peppers, or eggplant for at least two years, since this will increase the danger of root diseases. Utilize row covers, hot caps, or other forms of protection to keep plants warm at the beginning of the season. Black plastic mulch can be used to warm the soil. When temperatures reach 85 degrees Fahrenheit or above, remove any coverings. 
SPACING & COMPANION PLANTING CONSIDERATIONS
The recommendations for spacing can be slightly different depending on the kind of starts you use, as follows:12 to 24 inches apart for types with a determinate growth habit. 14 to 20 inches for staked indeterminate types' spacing between plants. 24 to 36 inches apart for varieties of indeterminate plants that are not staked. Tomatoes and other plants such as carrots, onions, chives, garlic, asparagus, roses, and nettle can be grown in close proximity to one another in a garden. Tomatoes may, in certain circumstances, be useful in warding off parasites and other potentially damaging problems that affect the plants listed above. Tomatoes should not be planted in close proximity to other members of the Brassicaceae family, such as cabbage, kale, horseradish, broccoli, turnip, rutabega, arugula, cress, radish, mustard, kohlrabi, cauliflower, or any other of these vegetables. Additionally, keep maize, potatoes, and fennel herb separate from tomato plants. 
MULCHING, STAKING & PRUNING TOMATO PLANTS
After the earth has warmed up, apply mulch to the plants in order to preserve soil moisture and prevent weed growth. If the light circumstances are not optimum, using a reflective mulch, such as red plastic that will reflect light, can be helpful in promoting more complete development in the plant. Tomatoes require a steady supply of moisture throughout their growing process. If it doesn't rain at least an inch per week, you should water your plants to make up the deficit. The total production, the timing of the first harvest, and the quality of the fruit are all affected by a multitude of factors in addition to your choice of type. Raised beds, black plastic mulch, and watering or drip irrigation that provides a regular amount of moisture are all beneficial approaches to boost all three. The manner in which you care for plants might also have an effect on their overall performance. Determinate varieties do not need staking. However, staking and trimming indeterminate kinds can accelerate the first harvest by at least a week, improve fruit quality, maintain fruit cleanliness, and make harvesting easier. Stabling and pruning typically result in a lower overall yield, but the fruits that are produced are more likely to be of a larger size. In addition, blossom end rot and sunscald are more likely to affect plants that have been staked and clipped. It requires less work to maintain indeterminate types, but the plants take up more room and are more susceptible to disease if you let them sprawl. Tomato stakes made of wood are normally about six feet long and one and a half inches square, but you may use other materials instead. To avoid damaging the roots, drive the stakes into the ground at a depth of at least 8 to 10 inches and as soon after the transplanting as possible. Tomatoes should only have one or two vigorous stems, therefore prune them to achieve this by snipping off "suckers" (stems growing from where leaf stems meet the main stem) when they are between 2 and 4 inches in length. Stems should be secured to the stake using pliable string, twine, or cloth. This should be done by constructing a figure-8 with the stem in one of the loops and the stake in the other. This allows the stem to grow without being hampered by being confined in any way. Beginning between 8 and 12 inches above the ground, continue tying at similar intervals as the plant becomes larger. Grow multiple plants in a row between heavy-duty stakes or posts spaced approximately 4 feet apart as an alternative to using individual stakes. Use twine to weave in and out around the posts and plants. Tomatoes require a lot of work to stake, so growing them in cages is a decent compromise between that and letting them sprawl all over the place. Tomato cages can be purchased at your neighborhood garden center, or you can make your own by simply bending a piece of wire mesh measuring between 4 and 6 inches wide and 6 feet long into the shape of a cylinder with a diameter of about 22 inches. (Some effective options for this include concrete reinforcing wire mesh or cattle fencing.) As soon as the plants have been transplanted, place a cage around them and secure it with stakes. 
FERTILIZING & WATERING TOMATOES
Avoid applying too much nitrogen, since this might lead to an abnormally large amount of foliage and poor fruit set. Also, steer clear of utilizing fresh manure or fertilizers with a high nitrogen content (those with three or more times nitrogen than phosphorus or potassium). Heavy rainfall or temperatures that are either too warm (over 90 degrees Fahrenheit) or too low might also contribute to an unsatisfactory fruit set (below 55 F). When the fruits are about 1 inch in diameter and again when harvesting begins, you can sidedress each plant with approximately half a cup of 5-10-5 fertilizer and work it shallowly into the top inch of soil. This can be done on most soils. Keep soil equally moist to prevent blossom end rot. This can also help avoid breaking in the fruit that occurs when it absorbs water too quickly when heavy rain follows circumstances of dryness. 
CROSS POLLINATION
When several types of tomatoes are grown in close proximity to one another, it is possible for the pollen from one variety to land on the stigma of a blossom belonging to a different variety. This will result in the formation of hybrid seeds within the tomato fruit. This phenomenon is more colloquially referred to as "cross-pollination" or just "cross" for short. The fruit that results from cross-pollination will have a completely normal appearance during the season in which it is produced; however, the seeds that come from this process will carry DNA from both of its parents and will therefore create offspring that are unique from one another. 
If you do not want to save seeds from your plants, there is no need to worry about whether or not they will be cross-pollinated. Tomato varieties are guaranteed to produce fruit that is genetically identical to the variety that was planted. Again, any crossover that occurs during the current season only impacts the seeds that are already present within the fruit, not the flavor or the structure of the fruit.