Top 10 Tomato Growing Tips

When growing tomatoes from seed, give the seedlings plenty of room to branch out.1 Yes, this means thinning out the seedlings to one strong plant per cell or small pot. Cut down the weaker, smaller seedlings in favor of the best growth. Crowded conditions stunt their growth, which stresses them and leads to disease later. Transplant tomato seedlings into their own 4-inch pots shortly after they get their first true leaves.

Tomato seedlings need strong, direct light. Days are short in winter, so even a spot near a sunny window won't provide them with enough natural light. Unless you are growing them in a greenhouse, it is best to use some type of artificial plant lighting for 14 to 18 hours per day.
To make sure the tomato plants grow stout and not spindly, keep the young plants just a few inches away from the fluorescent lights.1 As the seedlings grow, you'll need to raise the lights (or lower the plants). When you are ready to move the plants outdoors, choose the sunniest part of your vegetable garden as the location.

Tomato plants need to move and sway in the wind to develop strong stems. This happens outdoors, of course, but if you're planting your seedlings indoors, you'll need to provide some sort of air circulation. Create a breeze by pointing a fan at them twice a day for five to 10 minutes. This small amount of time will make a big difference.
Another option is to curl your tomato plants by running your hand back and forth over their tops for a few minutes several times a day. It's a little more effort, but the wonderful tomato scent will rub off on you as a bonus.

Tomatoes love warmth. They don't really start growing until both the soil and air temperatures are warm. You can speed things up in the soil by covering the planting area with black or red plastic wrap a few weeks before planting. Those extra degrees of soil warmth will translate into earlier tomatoes.
You can remove the film before planting, but some studies claim that red plastic mulch has the added benefit of increasing tomato yield.

Plant your tomato plants deeper than they will go in the pot, down to the topmost leaves. This allows the tomatoes to grow roots all along the stem. And more roots make for a stronger plant.
You can either dig a deep hole or simply dig a shallow trench and lay the plant on its side. It will quickly straighten up and grow towards the sun. Just make sure you don't drive your tomato stake or cage into the buried stem.

If you don't want to leave a film on the soil, wait until the soil warms up before mulching. Although mulching saves water and prevents soil and soil-borne diseases from splashing onto plants, it will also shade and cool the soil if you apply it too soon. Since tomatoes love warmth, let the sun warm the soil in the spring. If temperatures stay warm both day and night, you can apply a layer of mulch to retain moisture.

After your tomato plants have grown to about three feet tall, remove the leaves at the bottom of the stem. These are the oldest leaves, and they are usually the first leaves to develop fungal problems. As the plants spread, the lower leaves get the least amount of sun and airflow. Because these leaves sit close to the ground, pathogens from the soil can easily splash up on them. Removing these leaves helps prevent fungal diseases. Weekly spraying with compost tea also seems to be effective in warding off fungal diseases.

Pinch and remove suckers that develop where two branches meet. They will not bear fruit and take energy away from the rest of the plant.
However, don't cut back the rest of the plant too much. You can thin out a few leaves to allow the sun to reach the ripening fruit, but it is the leaves that photosynthesize and produce the sugars that make your tomatoes taste good. Less leaves means less sweet tomatoes.

Water deeply and regularly as the fruit develops. Irregular watering - skipping a week and trying to catch up - will cause blossom end rot (a calcium deficiency) and cracking and splitting. As a rule of thumb, your plants should receive at least an inch of water per week, but during hot, dry periods they may need more. If your plants start to look wilted most of the day, give them something to drink.
After the fruit begins to ripen, you can reduce watering. When you reduce the watering, it will cause the plant to concentrate its sugars for better flavor. Use your judgment. Don't withhold water so long that the plants are constantly wilted and stressed, or they will drop their flowers and possibly their fruit.

Tomato ripening is pretty much at the mercy of the weather, but sometimes we can speed things up. Cutting off the tips of the main shoots in early summer encourages indeterminate tomatoes (those that fruit all the time) to put their energy into flowering.
Indeterminate tomatoes like to grow tall before they fruit, so don't be alarmed if your tomato plants don't bloom in the first month or two. Pinching is also a handy trick towards the end of summer if you want the last of your tomatoes to ripen quickly.
There should be no problem getting determinate tomatoes (which ripen all at once) to set fruit, unless weather conditions are unfavorable and cause a condition aptly called "bloom drop."