How to Manage Pests

Pests in Gardens and Landscapes

Cultural Tips for Growing Tomato

In This Guide

Site selection

Plant your garden in a convenient location, where you can check it frequently. Choose an area near an abundant supply of water so you can water as needed easily. Vegetables do best if they receive full sunlight (at least 4 to 6 hours a day). Plant them in a well-exposed area in the garden, where they are not shaded by trees, fences, or walls. Try to plant away from areas that will be watered by lawn sprinklers.

Whenever possible, select a location that is not heavily infested with weeds, especially weeds such as field bindweed, nutsedge, and Bermudagrass that can be hard to control with hand weeding. Also avoid areas that have had previous disease problems.

Try to plant on level ground. Level ground is easier to work on than sloping ground. Vegetables will do well on a wide range of soils; they do best in well-drained soils. If your soil forms a clump when squeezed, then it is too wet; if the soil crumbles easily, it is a good soil to use. Damp soil surfaces encourage snails, slugs, sowbugs, and root diseases; fruit decay and leaf spot diseases may also increase. Soil amendments can make clay and sandy soils easier to work with, and correct soil preparation can improve poor soil.

Adding organic matter (compost, peat moss, manure, sawdust, ground bark) makes clay and sandy soils easier to work with. The soil should be kept at a pH level of 6.0 to 6.5. Lime or gypsum can be added to soils low in calcium.

Soil recommendation

Medium-textured, soft, well-drained soil is recommended. Light sandy soils or heavy clay soils are hard to work with but can be made easier with amendments.

Soil improvement

Any type of soil can be improved with soil amendments. Heavy clay or sandy soils can be improved by adding organic material such as compost, manure, or leaf mold. Texture is an important consideration when choosing an amendment. An amendment that is granular and fine grained is important for container mixes. For gardens, a more coarse-grained amendment can improve drainage and aeration. Work amendments into soil by rototilling, raking, or double-digging.

Soil preparation

The preparation of your soil is just as important as adding fertilizer and soil amendments. Before working the soil, make sure it is moist but not thoroughly wet.

  1. Use a shovel, rototiller, metal bow rake, or all of them together to loosen the top 1 to 2 inches of soil. Rake the area to remove weeds and old crop debris. Be sure to dig out roots.
  2. Irrigate the plot deeply to encourage the germination of weed seeds.
  3. In a week or two, after a substantial number of weeds have germinated, work the area again to kill the weed seedlings. Be sure to break up the clods in the soil, as seeds planted in cloddy soil will germinate poorly and won't live long because the soil dries too quickly.
  4. Form soil into beds if desired, and plant while soil is still wet.

Time to plant

Tomatoes are warm-weather plants. They like sunshine and produce best when planted in a well-exposed area in the garden. If you plant earlier, provide frost protection such as plastic jugs or covers that go over small plants. However, you can help prevent seedlings from damping off and diseases such as early blight by planting when the weather is warmer.

Trapping the heat from the sun during the day and slowing the re-radiation of that heat at night by using row cover helps protect tomato plants from varying temperatures during the springtime.

Tomatoes are suitable for a small garden if compact varieties are grown. Transplants, shoots, or roots are used for field planting.

Temperature tips
  • 100°F: flowers will not set
  • 80° – 90°F: optimum growth
  • 70° – 80°F: optimum germination
  • 50° – 55°F: minimum night temperature for fruit set
  • 45°F: will grow slowly
  • 32°F: potential frost injury
Planting Dates for Tomatoes in California*
North and North Coast
Monterey County north
South Coast
San Luis Obispo County south
April – mid-July
Interior Valleys
Sacramento, San Joaquin valleys
March – May
Desert Valleys
Imperial and Coachella valleys
December – March
*Transplants may be started indoors from seed 4 to 6 weeks before planting dates. Planting dates are only approximate as the climate may vary greatly within the regions denoted. Contact your local UC Master Gardener program and experiment on your own to find more precise dates.

Planting Tomato

Tomatoes can be seeded directly or transplanted into the garden. They are best planted on raised beds made by adding large amounts of sifted compost or other soil amendments so that a bed is established above the previous level of soil.

If seeding, plant more seeds than necessary so as to make up for any losses from insects such as cutworms. Plant seeds in rows with 3 to 5 feet between rows. Push them into the soil 1 inch deep. Fill these holes by scratching the surface, firm the soil lightly, and cover with a thin mulch of grass clippings or other organic material in order to hold soil moisture. Water well and keep moist during the germination period. When the plants are about 3 inches high, thin to 2 feet apart down the row.

For transplants, use young plants, 3 weeks old with 4 to 6 true leaves, wider than tall, stocky, succulent, and slightly hardened to outdoor conditions. Make sure the planting site is level and smooth. Spread and mix organic matter and a high-phosphorus fertilizer over the area. Mark where you want each plant and make the hole deep enough to bury the stem as far as the first leaf. Tip the plant out of a plastic pot to remove it. If it's in a peat pot, tear the top edge off so it can't act as a wick. Place the plant deep into the hole. Place plants about 2 feet apart in 4- to 5-feet rows. Press the soil firmly around the plant and water thoroughly to remove any air pockets. If transplanting in the summer, shade the plants in the middle of the day for the first week or use floating row cover.


Most vegetables require fertilizer for growth. Organic materials, such as manures and compost, and inorganic materials, such as chemicals, can be used to fertilize plants. Using both types of materials usually provides the best growth. Manures and compost can be used to increase soil fertility. They are usually applied at 1 pound per 4 or 5 square feet. These materials should be worked into the soil several weeks before planting in order to allow it to decompose. Manure that contains straw, sawdust, or similar materials should be applied with a commercial nitrogen fertilizer. Generally, if the soil has been properly amended with compost or manures or other organic materials, the only nutrient needed is nitrogen, if anything. Some commercial nitrogen fertilizers available are urea, ammonium sulfate, calcium nitrate, and ammonium nitrate. Apply these fertilizers at rates of 0.5 to 1 pound of nitrogen per 100 feet of row.

If manure and other organic material has not been used, apply fertilizer that contains both nitrogen and phosphorus before planting. All commercial fertilizers are labeled by the percentages of N-P-K; nitrogen (N), phosphorus (P), and potassium (K). Some common mixed fertilizers are 5-10-5, 5-10-10, 8-16-16, and 12-12-12. Apply these fertilizers at rates of 1 - 2 pounds per 100 feet of row. After plants are 3 to 4 inches tall, sidedress nitrogen in narrow bands or furrows and water thoroughly after application, or apply through the drip system. Consider light but frequent applications of nitrogen fertilizer every 3 to 4 weeks. Avoid letting the fertilizer come into contact with the plant stems to avoid burning.

Application tips

Inorganic fertilizers can be sidedressed. Manures are more difficult to use as a side dressing and must be tilled into the soil.

Banding: Make a small groove 1 or 2 inches deep on both shoulders of the bed, 4 to 6 inches from the plant row and band in the fertilizer. Replace the soil and irrigate.

Watering Tomato

Examine your soil visually and with your hands to determine the need for additional water. Water deeply by drip or furrow irrigation to encourage deep rooting. However, avoid wetting the foliage or fruit with overhead watering. If you allow water to seep through to the top few inches of your soil only, root growth will be stunted and, in some crops, may cause blossom drop. Keep adequate moisture in the deeper soil layers even when plants are small. Deep moisture is harder to replace later in the growing season without over irrigating.

Proper irrigation will keep your plants vigorous and help protect them from thrips damage and sunburn.

Pruning tomato

Pruning is not always necessary. However, if pruning your tomatoes, remember the following:

  • Plants with two or more stems produce more tomatoes with better foliage protection from the sun than plants with one stem. Tomatoes pruned to one leader will bear earlier but with less yield overall.
  • Choose the stems you want to keep and pinch out the others as they develop. A dense leaf canopy may reduce the incidence of black mold and cracking but may increase the incidence of other fruit molds such as gray mold.
  • Severe pruning to one stem will reduce your total crop greatly and also is likely to increase the incidence of some diseases or disorders.
  • Before removing suckers or side shoots on a tomato plant, wait until two leaves develop and pinch above them.

Harvesting and Storing Tomato

Don't leave ripe fruit on the vines longer than necessary. This may increase exposure to rain, which may lead to cracking. Harvesting before it rains also helps avoid fruit molds such as gray mold.

Generally, it is best to harvest red ripe fruit and store it at room temperature. However, if it can't be eaten right away, the fruit can be held in the refrigerator a few more days.

To extend tomato season, green fruit can remain on the plant as long as temperatures are above 50° F most of the time. When the tomatoes start to color, select the best to ripen indoors.

When harvesting less ripe but full-size fruit late in the season, pick them and store at 70° F to ripen. As they become pink, move them to cooler temperatures (55° F) and then to the refrigerator when fully ripe.

Storage tips

Wrap fruit in brown paper during the ripening process to reduce bruising and decay.

Cherry tomatoes on the vine.

Cherry tomatoes on the vine.

Seed bed preparation.

Seed bed preparation.

Amending soil to prepare for planting.

Amending soil to prepare for planting.

Bag of fertilizer.

Bag of fertilizer.

Irrigation shut off valve.

Irrigation shut off valve.

Statewide IPM Program, Agriculture and Natural Resources, University of California
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