Tomato

Solanum lycopersicum

Solanaceae · nightshade family

Matures: 50–90 days
Harvest: Continuous · Annual
Sun: 6–8+ hrs
Spacing: 18–36 in

Planting window

When to sow, by microclimate — foggier blocks run a different calendar than sunnier ones.

	Jan	Feb	Mar	Apr	May	Jun
Foggy				◐	◐	◐
Sunny				●	●	◐

	Jul	Aug	Sep	Oct	Nov	Dec
Foggy	◐	◐
Sunny	◐

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Foggy				◐	◐	◐	◐	◐
Sunny				●	●	◐	◐

Well-suitedMarginalNot suited

Sunlight

How well it does at each level of direct sun per day.

<2 hrs

2–4 hrs

4–6 hrs

6–8 hrs

8+ hrs

Well-suitedMarginalNot suited

Soil depth

Root room it needs — useful for sizing raised beds and containers.

6–10"

10–15"

15–18"

18–24"

Well-suitedMarginalNot suited

Spacing

Room each plant needs — along the row and between rows — for sizing beds.

In-row: 18–36 in
Between rows: 36–60 in

Growth habit

The shape it makes in the bed and how tall it gets — what tells you whether to give it a trellis, a stake, or just room.

Habit: Climbing
Mature height: 3–6 ft

Climbs — give it a trellis, netting, or poles to run up.

How to start it

Sow it where it grows, or raise it under cover and set it out — and how far ahead to start the seedlings if it's the latter.

Usually: Transplant
Start indoors: 6 weeks ahead

Direct-sow

Transplant

Started under cover, then set out as a seedling.

Well-suitedMarginalNot suited

Getting started

How it goes in the ground — how deep to sow or set it, and the soil temperature it needs to wake up. The cold-soil floor is the real limiter for direct-sowing in a foggy SF spring.

Started from: From seed
Ideal soil temp: 65–85°F
Sow depth: 0.25 in
Time to emerge: 6–14 days

Germinates between 50–95°F; happiest around 65–85°F.

30°F110°F

IdealWorkable

Pests & diseases

What tends to trouble this crop — what it is, what you'll see, and what to do about it, least-toxic first.

Pests14

Aphids

What it is: Aphids have soft pear-shaped bodies with long legs and antennae and may be green, yellow, brown, red, or black depending on the species and the plants they feed on. A few species appear waxy or woolly due to the secretion of a waxy white or gray substance over their body surface.
What you'll see: Low to moderate numbers of leaf-feeding aphids aren't usually damaging in gardens or on trees. However, large populations can turn leaves yellow and stunt shoots; aphids can also produce large quantities of a sticky exudate known as honeydew, which often turns black with the growth of a sooty mold fungus.
What to do: Before planting vegetables, check surrounding areas for sources of aphids and remove these sources. On the other hand, these aphid-infested weeds can sometimes provide an early source of aphid natural enemies.

Armyworms

What it is: Armyworm larvae feed in groups, which distinguishes them from other vegetable pests such as corn earworms and loopers. Markings on newly hatched armyworms are usually hard to distinguish from those of other caterpillars; older larvae have distinct lengthwise stripes.
What you'll see: Armyworms may feed on the crowns of seedlings. On larger plants, armyworm caterpillars skeletonize leaves.
What to do: Handpick. Virus diseases, parasites (Hyposoter and Trichogramma), and general predators may be effective on caterpillars.

Corn Earworm or Tomato Fruitworm

What it is: The corn earworm or tomato fruitworm is a common caterpillar pest of many vegetables and flowers. Newly hatched larvae have several rows of dark bristles on their backs.
What you'll see: Earworms feed on leaves, buds, and flowers of many vegetable crops. They destroy seedlings, bore into lettuce heads and bean pods, make deep watery cavities in fruit, and leave frass.
What to do: Handpick, and avoid spraying with insecticides. Bacillus thuringiensis may kill 40 to 60% of the population but must be applied just after eggs hatch and before caterpillars enter fruit.

Cutworms

What it is: Cutworms are dull brown caterpillars ranging in length from 1 to 2 inches when fully grown. They curl into a C-shape when disturbed.
What you'll see: Cutworms feed on blossoms and leaves of many ornamental plants and attack most garden crops. They clip off seedling stems near or just below the soil level.
What to do: Cutworms are pests mainly in the spring. Destroy crop residues; keep garden weed-free in winter.

Flea Beetles

What it is: Their small size, enlarged back legs, characteristic shot-hole damage, and habit of jumping when disturbed make flea beetles easy to identify. There are numerous flea beetle species.
What you'll see: Adults feed mostly on leaves, leaving tiny pits or small holes at their feeding sites. Flea beetles feeding together can cover leaves with bleached, pitted areas or ragged holes.
What to do: Remove debris in the fall to remove any overwintering beetles. Reflective mulches applied very soon after planting and before plants become infected can be helpful.

Hornworms

What it is: Tomato hornworms are likely to be the largest caterpillars you see in the vegetable garden. Their striping pattern makes them hard to spot despite their size.
What you'll see: Entire leaves and small stems may be consumed. Large pieces from green fruit may also be chewed.
What to do: Handpick or snip hornworms with shears. Natural enemies normally keep populations under control.

Loopers

What it is: Loopers are green caterpillars with several white stripes down their backs. They arch their backs as they crawl, this looping movement giving them their name.
What you'll see: Loopers eat irregular holes in leaves, most often older leaves. They may also bore holes in lettuce and cabbage heads or damage fruit.
What to do: Handpick. Apply Bacillus thuringiensis or spinosad; they are effective against loopers, especially when caterpillars are small.

Snails and Slugs

What you'll see: Snails and slugs feed on a variety of living plants and on decaying plant matter. They create irregular holes with smooth edges on leaves and flowers by scraping with their rasp-like tongues.
What to do: It will not be possible to eliminate some shelters, such as low ledges on fences, the undersides of wooden decks, and water meter boxes, so make a regular practice of trapping and removing snails and slugs from these areas. The survivors congregate in the remaining shelters, where you can more easily locate and remove them.

Stink Bugs

What it is: Adult stink bugs are distinguished from other insects by the large triangle shape with a rounded rear end (scutellum) that occurs on top of the back, covering the rear of the thorax and front portion of the abdomen. In comparison with most insects, adults are wider relative to their length.
What you'll see: Adults suck and feed on plants with their strawlike mouthparts. Stink bugs attack a variety of fruits, nuts, and vegetables from beans to tomatoes and apples to stone fruits.
What to do: Handpick the bugs and their eggs from small plants. Parasites and general predators can contribute to the control of some stink bug species if natural enemies are not destroyed, such as by the application of persistent, broad-spectrum insecticides.

Thrips

What it is: Most adult thrips are elongate, slender, minute (less than 1/20 inch long), and have long fringes on the margins of both pairs of their long, narrow wings. Immatures (called larvae or nymphs) are oblong or slender and elongate and lack wings.
What you'll see: Thrips feeding on plants can damage fruit, leaves, and shoots and very noticeably affect plants’ cosmetic appearance. However, thrips rarely kill or threaten the survival of trees and shrubs.
What to do: Thrips species that feed on many different plant species often move into gardens and landscapes when plants in weedy areas or grasslands begin to dry in spring or summer. Avoid planting susceptible plants next to these areas, and control nearby weeds that are alternate hosts of pest thrips.

Tomato Pinworm

What it is: Tomato pinworm caterpillars are tiny and have a mottled pattern. Caterpillars may sometimes be quite dark.
What you'll see: Pinworms cause leaf mines and folded shelters on leaves. They bore into fruit at the stem ends, creating narrow, blackened tunnels.
What to do: Tomato pinworms are difficult to control with insecticides, and natural enemies are not effective. Disc all plants immediately after harvest.

Tomato Russet Mite

What it is: Tomato russet mites are very small — only about 1/5 mm long, so you need at least a 14X lens to see them. Damage would first be present mid- to late summer when plants are half-grown or longer.
What you'll see: Leaves and stems damaged by mites develop a greasy appearance, then dry out and turn bronze. Damage starts at the base of the plant and moves upward.
What to do: Both sulfur dust and wettable sulfur are effective for russet mite control. Do not grow tomatoes near petunias or any solanaceous plants, such as potato, as they are other hosts of the russet mite.

Vegetable Leafminers

What it is: Adult leafminers are small, active, black flies often with a prominent yellow triangle between the bases of the wings. The head behind the eyes is mostly black.
What you'll see: Leafminers attack many different vegetable and flower hosts, including cole crops, cucurbits, tomatoes, peas, beans, aster, begonia, dahlia, impatiens, lily, marigold, petunia, and verbena. Adult female leafminers puncture leaves and sometimes petals to feed on exuding sap.
What to do: Leafminers rarely require treatment in gardens. Clip off and remove older infested leaves.

Whiteflies

What you'll see: Whiteflies use their piercing, needlelike mouthparts to suck sap from phloem, the food-conducting tissues in plant stems and leaves. Large populations can cause leaves to turn yellow, appear dry, or fall off plants.
What to do: Whiteflies have many natural enemies, and outbreaks frequently occur when these natural enemies have been disturbed or destroyed by pesticides, dust buildup, or other factors. General predators include lacewings, bigeyed bugs, and minute pirate bugs.

Diseases7

Black Mold on Tomato

What you'll see: Black mold is characterized by obvious lesions that appear on the surface of ripe fruit. Lesions are light to dark brown and vary from small flecks affecting only epidermal tissue to large, more or less circular, sunken lesions.
What to do: Black mold is favored by wet conditions and high humidity. Avoid overhead sprinklers late in the season and keep beds dry.

Early Blight on Tomatoes

What you'll see: Symptoms of early blight include black or brown spots, usually about 1 cm in diameter, that appear on leaves, stems, and fruit. Leaf spots are leathery and often have a pattern of concentric rings.
What to do: Spores of early blight are carried by wind and require moisture for germination and infection. Avoid overhead irrigation.

Fusarium Wilt on Tomatoes

What it is: Both Fusarium and Verticillium wilt cause leaf yellowing and discoloration of the water-conducting tissues of the plant. Cut affected plants at the base of stems and examine them in cross section to see the browning of the water-conducting tissue compared to the healthy ivory of uninfected plants.
What you'll see: Fusarium oxysporum, f. sp. lycopersici Plants infected with the Fusarium fungus turn yellow starting with one side or branch and gradually spreading through the plants, eventually killing them. Disease is caused by a fungus that infects tomatoes only.
What to do: Fusarium wilt of tomatoes can be avoided in many cases by planting resistant varieties which are indicated by the letters F or FF. If you wish to grow susceptible varieties, problems can sometimes be minimized by removing all residue, including roots, which may be susceptible, and using soil solarization before you plant.

Phytophthora Root Rot on Tomato

What you'll see: Aboveground symptoms of Phytophthora root rot are typical of plants with a weak root system; infected plants are slow growing and may wilt or die in hot weather. Roots may have water-soaked injured areas that gradually dry and turn chocolate brown as the disease progresses.
What to do: Avoid prolonged saturation of the soil or standing water. Provide good soil drainage.

Powdery Mildew on Tomato

What it is: On plants infected with powdery mildew spots of dead tissue, sometimes with rings like those in early blight lesions, may appear in the blotches. However, there are no lesions on stems or fruit, and there is no vascular discoloration as with Verticillium or Fusarium wilt.
What you'll see: Leaves of plants with powdery mildew have irregular, yellow blotches. Severely affected leaves die, but seldom drop.
What to do: This disease occurs late in summer or fall and does not cause significant losses unless very severe, so no control is normally needed. If young plants are attacked, applications of sulfur will control the disease.

Tomato Spotted Wilt Virus

What you'll see: Infected plants exhibit bronzing of the upper sides of young leaves, which later develop distinct, necrotic spots. Leaves may be cupped downward.
What to do: The tomato spotted wilt virus is transmitted by thrips. Control thrips with applications of insecticidal soap.

Verticillium Wilt on Tomatoes

What it is: Both Fusarium and Verticillium wilt cause leaf yellowing and discoloration of the water-conducting tissues of the plant. Cut affected plants at the base of stems and examine them in cross section to see the browning of the water-conducting tissue compared to the healthy ivory of uninfected plants.
What you'll see: Verticillium wilt often starts as a yellowing between the major veins of the leaves. The fungus moves throughout the plant and eventually whole leaves and stems wither and die.
What to do: Verticillium wilt of tomatoes can be avoided in many cases by planting resistant varieties, which are labeled V. If you wish to grow susceptible varieties, problems can sometimes be minimized by removing all residue, including roots that may be susceptible, and using soil solarization before you plant.

Disorders1

Blossom End Rot

What you'll see: Blossom end rot affects tomatoes, peppers, and cucurbits. Plants with blossom end rot show small, light brown spots at the blossom end of immature fruit.
What to do: Blossom end rot results from a low level of calcium in the fruit and water balance in the plant. It is aggravated by high soil salt content or low soil moisture and is more common on sandier soils.

Sources

Every figure above is backed by these.

UC Master Gardeners, San Mateo–SF Countiesbacks plantingWindow, startMethod · Foggy & Sunny calendars, Tomato row: transplant Apr (foggy), Apr-May (sunny). Start method: Foggy & Sunny calendars, Tomato row: (T) transplant only.
Golden Gate Gardening (Pam Peirce)backs plantingWindow, sunlight, lifecycle, harvestStyle · Foggier/Sunnier planting-times charts, Tomato (plants): foggy May-Aug marginal, sunny Jun-Jul; GGG tomato entry: full-sun fruiting crop, 6+ hrs direct sun. Heat-lover: all foggy months marginal (maybe). Habit and harvest: annual, continuous — from this source's entry for this crop.
UC Master Gardeners, Santa Clara County (Containers)backs soilDepth · Soil-depth-by-crop, deep-rooted (18-24 in): tomatoes.
UC Master Gardeners, Sonoma County (Planting Summary)backs daysToMaturity, inRowSpacing, rowSpacing, startMethod · Vegetable Planting Summary, Tomatoes row: 50-90 days, 18-36 in in-row spacing. Between-row spacing 36-60 in (Tomatoes row). Start method: Vegetable Planting Summary, Tomatoes row: method T (usually transplanted).
UC Master Gardeners, Sacramento County (Germination)backs germination · GN 154 soil-temp table, tomatoes row: 50/65–85/95°F; germinationDays 6–14 derived from Table 2 across the optimum band.
USDA GRIN Taxonomybacks botany
Colorado State University Extension (Master Gardener)backs plantingDepth · Table 2 Warm Season, Tomato row: 1/4 in.
University of Minnesota Extensionbacks growthHabit · UMN Extension 'Growing tomatoes': indeterminate (vining) tomatoes 'need support such as cages, stakes or trellises' and 'grow to three to five feet long, sometimes more' (habit climbing; height 3-6 ft as the vining home-garden default). Determinate (bush) types 'reach 24 to 30 inches in height' and 'do not need pruning, staking or trellising' — noted here as the compact alternative.
UC Master Gardeners, Santa Clara Countybacks startMethod · Start method: Planting chart: Tomatoes carry a Transplant row only; From seed to transplant 6 weeks.