No home vegetable garden is complete without a good crop of tomatoes. The tomato (Lycopersicon esculentum) is a warm-season crop and one of the most popular, and easily grown, vegetables in the country. Once you’ve tasted a fresh picked tomato from your own garden, you’ll wonder what those bland, waxy, tasteless red orbs are that you’ve been getting from your grocery store produce section.
According to the USDA, tomatoes are low in Sodium, and very low in Saturated Fat and Cholesterol. They are also a good source of Vitamin E (Alpha Tocopherol), Thiamin, Niacin, Vitamin B6, Folate, Magnesium, Phosphorus and Copper, and a very good source of Dietary Fiber, Vitamin A, Vitamin C, Vitamin K, Potassium and Manganese.
Tomatoes can be grown either from seed started indoors, or from transplants purchased at your local garden center. There is usually a large selection of transplants available at reasonable prices this time of the year, and transplants are usually the easiest way to start your tomatoes. Select healthy plants that are 6 to 8 inches tall. Check to be sure that the transplants are not root bound. That is, that they don’t have a large amount of roots poking out of the bottom of the pot.
To start your own tomato plants from seed, plant the seeds in a light, seed starter type, soil mixture at least 4 to 7 weeks before they are to be planted outdoors in your garden. One week before they are to be planted, harden-off the tomato plants by placing the potted plants in your garden to gradually expose them to increased amounts of sunlight.
Tomatoes come in all sorts of shapes, sizes, colors, and varieties and are classified as being either determinate or indeterminate. Determinate varieties stop growing once the plant sets fruit and the entire crop is produced all at one time. Indeterminate varieties continue to grow and set fruit as long as the temperature permits.
Tomatoes do best in well-drained soil that is rich in organic matter and with a pH in the range of 6.2 to 6.8. They require at least 6 hours of sunlight per day. Although tomatoes love warm weather, once daytime temperatures rise above 95 degrees, nighttime temperatures stay above 85 degrees or fall below 55 degrees, tomato flowers will no longer set fruit.
Before planting tomatoes, remove all rocks, trash and weeds from the planting area and till the soil to a depth of 8 to 12 inches. To help prevent disease, be sure to practice proper crop rotation by NOT planting tomatoes in soil in which tomatoes, or any other member of the Nightshade family such as potatoes, peppers, or eggplant, were grown in the past two years.
Tomatoes should be planted after the danger of frost has passed. The table below lists the Spring and Fall Planting dates for each state but you can refer to our Freeze and Frost Dates Tool to find the Last Frost Date for your specific area. Remember, if a frost is expected after you have planted your tomatoes, you will need to cover them with a “planket” type material or the frost will kill them.
An excellent way to encourage a vigorous root system on your tomato plants is to lay the plant on its side when planting. Dig a hole that is as deep as the transplant root ball is wide. Next dig a shallow trench just below the surface to bury the transplant’s stem in. Leave the top 3 to 4 inches of the plant sticking out of the ground and pile a little bit of dirt under this part to angle it slightly upward. Be sure to carefully trim off any leaves that are to be buried. Within a few days the plant will be completely vertical.
Stakes & Cages
If left to their own devices, tomatoes will grow only so tall before they fall over and grow along the ground. This encourages disease, poor fruit production, and is not an efficient use of space. Use stakes or cages to help support your tomatoes and keep them growing upright. Place the stake or cage in the ground shortly after planting to minimize possible root damage. If using stakes, they should be about 6 feet tall and the tomato plant should be loosely tied to the stake at 10-inch intervals to support the plant.
Keep the garden free from weeds, as weeds will compete with the growing tomatoes for soil nutrients and water. Do not dig too deep when using a hoe, or pulling weeds to avoid damaging the plant’s roots.
Watering & Fertilizing
Tomatoes need about 1 to 2 inches of water per week. A good way to help keep them from drying out and wilting is to put a 2-inch layer of mulch around each plant. If you don’t have adequate rainfall, water them once or twice a week. Consider drip irrigation as it conserves moisture and avoids getting the plant’s foliage wet, which can cause diseases. Fertilize your plants once every week or two with an application of a balanced fertilizer.
Insects & Diseases
Tomatoes are relatively hardy but are affected by several insects and diseases. Hornworms are 3-inch long curled caterpillars that cut plants off at the soil line, chew 1/4’’ holes in pods or seeds, and occasionally chew leaves. Apply a Bacillus thuringiensis based insecticide to control them.
Whiteflies are small, whitish insects that may be found in masses on the underside of leaves. Hose off the underside of leaves to knock off aphids or apply an insecticidal soap.
Neem oil, sulfur, and other fungicides can be used to help prevent blossom-end rot.
Deer or bird net is always a good idea, once the plants have set fruit, to keep our furry and feathered friends from enjoying our tomatoes before we do.
Harvesting & Storing
Harvest tomatoes when they are fully ripe. If you harvest them while they are still green, they can be allowed to ripen over time in the house. Keep unripe tomatoes in a well-ventilated area at room temperature until they are ripe. While fully ripe tomatoes can be kept fresh in the refrigerator for several weeks, never store green tomatoes in the refrigerator.
Check out our YouTube video “How to Grow Tomatoes: 30 Master Gardener Tips” that includes the Recommended Varieties, Days to Harvest, Spring Planting Dates, and where applicable, the Fall Planting Dates for tomatoes in each state.