1. Don’t Crowd Seedlings.
If you are starting tomatoes from seed, be sure to give the seedlings plenty of room to branch out. Crowded conditions inhibit their growth, so transplant them into their own individual 4 in. pot, shortly after they get their first true leaves.
2. Provide Lots of Light.
Tomato seedlings need strong, direct light. Days are short during winter, so even placing them near a very sunny window may not provide them with sufficient natural light. Unless you are growing them in a greenhouse, your best option is to use some type of artificial plant lighting, for 14-18 hours every day.
To ensure the plants grow stocky, not spindly, keep the young plants only a couple of inches from florescent grow lights. You will need to raise the lights (or lower the plants) as the seedlings grow. When you’re ready to plant them outside, choose the sunniest part of your vegetable garden.
3. Put a Fan on Your Seedlings.
It seems tomato plants need to move and sway in the breeze, to develop strong stems. That happens naturally outdoors, but if you are growing your seedlings inside, provide a breeze by turning a fan on them for 5-10 minutes, twice a day. Another option is to ruffle them by gently rubbing your hand back and forth across their tops for a few minute
4. Preheat the Soil in Your Garden.
Tomatoes love heat. Cover the planting area with black or red plastic a couple of weeks before you intend to plant. Those extra degrees of soil warmth will translate into earlier tomatoes.
A reader, David, wrote to say he thinks clear plastic works best. It “…lets the sun’s energy through and then traps that heat energy.” Plus it causes weed seeds to germinate and then fries them, so they won’t come back.
5. Bury Them
Plant your tomato plants deeper than they come in the pot, all the way up to the top few leaves. When planted this way, tomatoes are able to develop roots all along their stems. And more roots will make for a stronger plant.
You can either dig a deep hole or simply dig a shallow trench and lay the plant sideways. It will quickly straighten itself up and grow toward the sun. Just be careful not to drive your stake or cage into the buried stem.
6. Mulch Later
Hold off on mulching until after the ground has had a chance to warm up. While mulching does conserve water and prevents the soil and soil born diseases from splashing up on the plants, if you put it down too early it will also shade and therefore cool the soil. Try using plastic mulch for heat lovers like tomatoes and peppers.
7. Remove the Bottom Leaves.
Once your tomato plants reach about 3 ft. tall, remove the leaves from the bottom 1 ft. of stem. These are the oldest leaves and they are usually the first leaves to develop fungus problems. As the plants fill out, the bottom leaves get the least amount of sun and air circulation. And being close to the ground, soil born pathogens can easily splash up onto them. Spraying weekly with compost teaalso seems to be effective at warding off fungus diseases.
8. Pinch & Prune for More Tomatoes
Pinch and remove suckers that develop in the crotch joint of two branches. They won’t bear fruit and will take energy away from the rest of the plant. But go easy on pruning the rest of the plant. You can thin out a few leaves to allow the sun to reach the ripening fruit, but it’s the leaves that are photosynthesizing and creating the sugars that give flavor to your tomatoes.
9. Water the Tomato Plants Regularly.
Water deeply and regularly while the plants are developing. Irregular watering, (missing a week and trying to make up for it), leads to blossom end rot and cracking. The rule of thumb is to ensure your plants get at least 1 in. of water per week, but during hot, dry spells, they may need more. If your plants start to look wilted for most of the day, give them a drink.
Once the fruit begins to ripen, you can ease up on watering. Lessening the water will coax the plant into concentrating its sugars, for better flavor. You your judgement. Don’t withhold water so much that the plants continually wilt and become stressed or they will drop their blossoms and possibly their fruit.
10. Getting Them to Set Tomatoes
A lot of vegetable gardening is at the mercy of the weather, but sometimes we can help things along. There are two types of tomato plants. Determinatetomatoes reach a certain height and then set and ripen their fruit all at one time, making a large quantity available when you’re ready to make sauce. These tend to start flowering fairly early in the season and shouldn’t be a problem getting them to set fruit, unless weather conditions are unfavorable and cause a condition aptly named “blossom drop”.
Those big, juicy beefsteak tomatoes we all crave grow on indeterminate plants. By indeterminate, they mean the plants just keep growing. Tomatoes are vines, after all, and indeterminate tomatoes reach for the sun. They like to grow tall before they start setting fruits. If you’re impatient, pinching off the tips of the main stems in early summer will encourage them to start putting their energy into flowering. This is also a handy trick toward the end of the summer, when you want the last tomatoes to hurry up and ripen.