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Abscission - A layer of cells that forms at the base of a fruit or leaf stalk where it is attached to the stem.

Acid soil  - Soil with a pH reading below 7.0.

Alkaline soil- Soil with a pH reading above 7.0

Angora - Leaves which are covered in fine silky gray hairs.

Annual - A plant that completes its entire life cycle in a single growing season.

Anther -The pollen bearing part of a flower’s male sexual organ. In the tomato, this is also referred to as the anther cone.

Anthocyanin - A blue, violet, or red flavonoid pigment found in plants or on the fruits themselves.

Axil -The upper, or inside, angle between a leaf stalk and the stem where new buds and new stems may arise.

Balanced fertilizer- A fertilizer containing equal percentages of (N) Nitrogen, (P) Phosphorus, and (K) Potassium.

Beneficial insects - Insects considered helpful in the garden because they prey on pest insects (i.e. - Lady beetles, ground beetles, tachinid flies).

Bicolor - A tomato fruit which either the skin or flesh is more than one color.

Bolt- To produce flowers and seed prematurely, often due to hot weather.

Blossom End Rot (BER) - A sunken, leathery black or brown spot on the bottom of the fruit near the blossom end. It is not a disease. Usually caused by a deficiency in calcium. Tomato plants that suffer from water stress or extreme fluctuations in moisture are prime candidates for blossom-end rot. Other conditions that make tomatoes susceptible are cool, humid weather, compacted soil and high levels or ammonia or potassium in the soil. Prevent BER by keeping soil evenly moist and well mulched. Add lime if you have acidic pH and low calcium; add gypsum if your soil is alkaline and calcium-deficient.

BT (Bacillus thuringiensis) -naturally occurring pathogen that's toxic to insect larvae but not harmful to other organisms or humans; various strains are sold commercially.

Calcium (Ca) - A major element necessary for healthy growth. Deficiencies contribute to spindly growth, retarded plant growth and Blossom End Rot. Unlike many other nutrients, calcium does not move around within the plant. Upon absorption, it moves into the growing tissue - leaves, stems, fruits - and there it stays. Therefore, plants need a constant supply. Water is essential to calcium absorption. Drought will therefore hasten the plants entire system. Consistent moisture is mandatory.

Calyx - The green pointed structures beneath the flower petals and at the top of the fruit; a collective name for all the sepals of a tomato blossom. These are green modified leaves which surround and protect the male and female parts of a tomato flower bud.

Catfacing -  Scarred, puckered and deep indentations found on the blossom end of the fruits caused by insect damage, poor pollination, and environmental factors. The most common cause of catfacing is exposure to temperatures below 50° F during flowering and fruit set. Low temperatures inhibit pollination and cause the blossom to stick to the developing fruit. Both of these factors prevent certain parts of the fruit from developing. The undesirable scarring and indentation occurs when unaffected parts of the fruit continue to expand. There is evidence to suggest that even when temperatures are warm, excessive soil nitrogen, exposure to the pesticides, and erratic soil moisture can cause catfacing.

Cloning / Cuttings  - Vegetative portions that are removed from a plant for the use of propagating new plants. Plants reproduced from cuttings will be genetically identical to the parent plant.

Complete fertilizer -A fertilizer that contains nitrogen, phosphorus and potassium. It may also include micronutrients.

Concentric growth cracks -  Concentric, circular cracks or splitting of the fruits skin around the top of the tomato around the stem. It is usually associated with the tomatoes growing conditions. Cracks are caused when a plant receives too much water after a dry spell, either through excessive watering or after a rainy period. In essence, the plant receives too much water too fast, causing the interior of the tomato to expand too fast for its skin to stretch enough. The skin then cracks to relieve the pressure.

Cotyledons - The first set of leaves formed immediately after germination.

Cover crop - A crop grown on garden soil to prevent erosion. It is often cut and turned into the soil, to add nutrients and organic matter. (See: Green manure)

Crop rotation - Growing annual vegetables in a different site either each season or two , primarily to prevent the buildup of pests and diseases and to maintain nutrients in the soil.

Cross-pollination - The transfer of pollen between two separate plants of the same species.

Cultivar - A variety strictly raised through horticultural processes, rather than nature.

Cutworm - The larvae of several species of moths that pupate just beneath the surface of the soil. While in the larval stage, they emerge at night and “cut down” seedlings, and then devour them, leaving no evidence beyond the severed stem. Control is attempted by putting one-inch-tall collars around the stem of newly set transplants so that the cutworms cannot get to them.

Damping off - A disease caused by any of several fungi that destroys emerging seedlings by rotting the stems at soil level. There is no good cure for affected plants, but any remaining plants can be saved by removing all the diseased material and moving the seedlings to a warm, bright, airy location. Proper thinning and avoidance of over watering, especially during cloudy/cool periods, is the best preventative.

Determinate (DET) - A plant growth habit in which stems stop growing at a certain height terminating in a flower cluster. They tend to be shorter, earlier, have a concentrated fruit set, meaning fruits tend to ripen "all at once". They make good candidates for home processing.Once the vine produces its first set of flowers on the main growing stem, it will then produce flowers on every following internode or every second internode until finally terminating the growing stem with a flower truss instead of a continuation of the growing tip. Same holds true for all the side shoots.


Days to maturity (DTM) - A very loose date of expectation from the time of transplant set into the garden to the first ripe fruit.

Dwarf - A misleading name for a classification of tomato plant, as height is NOT indicative of the eventual size of the plant. Dwarf plants are characterized foremost by shortened internode spacing, thick stems on bushy plants that usually have rugose foliage, but not always. Plants can either be determinate or indeterminate, ranging from 12 inches to 4 feet, depending on the variety.

Emasculation - The removal of the anther cone (the portion of the tomato blossom which contains the pollen) so as to prevent self-pollination.

F1 hybrid - First-generation plants or seeds that have been bred under strict conditions from specific parental lines to create a crop that is uniform and possesses distinct, desirable characteristics. Seeds gathered from F1 hybrids will not come true, so you will need to buy fresh stock each year. ( See: Hybrid )

Filament - Portion of the stamen (male part of the flower) that supports the anther.

Germination - The active growth of the embryo of a seed, beginning the life of a new plant.

God-cross - Synonym for Natural Cross Pollination

Green When Ripe (GWR) - The color of a tomato when it is fully ripe.

Green manure - A crop grown in soil for the purpose of cutting it down and turning in under, to add organic matter to the soil. (See: Cover crop)

Harden off - The process of gradually exposing a plant to outdoor conditions before transplanting into the garden.

Hardiness Zones - A geographically defined area in which a specific category of plant life is capable of growing, as defined by climatic conditions; representing the plants ability to withstand average minimum temperatures of the defined zone. First developed for the United States by the Department of Agriculture (USDA), the use of the zones has been adopted by other nations.

Heading back - A pruning cut that removes the end of a branch or stem, reducing its length.

Heat stress - Injury resulting from high temperatures. May be caused during exceptionally hot weather when transpiration rates are limited and the plant cannot cool itself adequately.

Heirloom - Seeds passed down from generation to generation with no discernible divergence; this is the true definition of a family heirloom. Seeds are saved because they are revered.

Hornworm - Likely the largest caterpillar you'll find in your garden, the tomato hornworm reaches 3-4 inches long, is light pale lime-green in color with seven diagonal white stripe along its back and a black horn projecting from the rear. The adult moth, called a sphinx or hawk moth, fly quickly and are able to hover like a hummingbird. The hornworm feeds on the leaves and new stems of the tomato plant, causing extensive damage. During July and August they also occasionally feed on the fruit. Natural control includes hand-picking, use of Bt and planting host plants to encourage the beneficial small, parasitic braconid wasp. Tip: To find the larvae hidden among plants, look for black droppings ( frass = poop ) on the leaves and ground and spray the foliage with water. The caterpillars will thrash about and give away their hiding spots.

Humus / Compost - The dark substance that represents the end result of organic matter decomposition; the organic content of the soil that helps provide plant nutrients and improves soil structure.

Hybrid -The offspring of two genetically different plants. (Also see: F1 hybrid)

Impure seed - An unacceptable percentage of plants containing excess genetic variability.

Indeterminate (IND) - A plant growth habit in which stems keep growing indefinitely until disease or environmental conditions kill the plant. Indeterminate tomatoes, for example, often continue to grow and produce fruit until they are killed by frost.

After setting out its first flower truss (usually at the fourth or fifth internode from seed emergence), an indeterminate will continue to put out flower trusses on every third internode of the main growing stem until terminated by frost, disease, etc. Same pattern on the side shoots.


Internode - The part of a stem that is in between leaves. (See Nodes)

Isolation distance - The physical distance required to limit (NCP) Natural Cross Pollination.

Late Blight - Caused by a fungal pathogen, disease development is favored by high humidity, warm days and cool nights. Late blight can go a year or two as not much of a problem only to blossom into a full-blown epidemic the following season. There are differences, from year to year, in humidity levels, the amount of rainfall, irrigation practices, varietal susceptibility, and other factors that can help foster a late blight outbreak. It is important to note that this disease requires free-standing water on the plants to take hold. KEEP PLANTS AS DRY AS POSSIBLE. Prune for air circulation. Stake plants to keep vines off the ground; prune lowest branches so there are no leaves touching the soil. All above ground parts are susceptible. Dark, dead areas appear on the leaves, stems and fruit. Vines may collapse as though hit by early frost. Infected green fruits rot before maturity. Late blight over-winters in weed hosts, tomato plant debris, and tomato volunteers. Spores can be carried by wind and rain up to 40 miles, according to some researchers.

Lateral - A stem or branch arising from a main stem or leader.

Leader (Central Leader) - A primary branch from which lateral branches are produced. Central leaders form the main stem or trunk at the center of the plant.

Leaf mold - Decomposed leaves. Excellent winter mulch, attractive to earthworms.

Locules - The chambers or cavities within the tomato fruit that holds the seeds which are surrounded by a gelatin-like substance. Smaller fruits will usually contain two locules, while larger varieties may have between 5 to 10.

Lycopene - An antioxidant which helps to protect cells and repair damaged cells. It is only found in red tomatoes.

Magnesium (Mg) - Magnesium is an essential component of chlorophyll, which gives plants their green color and allows them to turn sunlight into energy via photosynthesis. Dolomitic lime and Sul-Po-Mag are good sources of this important nutrient.

Microclimate - Local conditions of shade, exposure, wind, drainage, and other factors that affect plant growth at a given site.

Mycorrhizae- Mycorrhiza are symbiotic associations between plant roots and certain soil fungi which play a key role in nutrient cycling in the ecosystem and also protect plants against environmental and cultural stress.

Natural Cross Pollination (NCP) - Variables which affect this occurrence include location, time of year, changes in insect population and climatic factors.

Nitrogen (N) - A major plant nutrient especially important in the growth of foliage and stems.

Node - A slightly swollen spot on the stem of a plant where both leaf and axial buds develop.

Open-pollinated (OP) - Seed produced from natural random pollination. Prodigy will come true from seed.

Ovary - The part of a flower containing the ovules that will develop into seeds upon fertilization. With the style and stigma, it comprises the pistil, the female sexual organ of tomatoes.

Ovule - Within the ovary, the body which will contain the seeds upon fertilization.

Pedicel - A flower stem, as opposed to a leaf stem, or peduncle, from which individual pedicels arise. (See: Peduncle)

Peduncle - The main stem supporting a cluster of flowers, as opposed to the pedicels, which are the stems of individual flowers. (See: Pedicel)

Petal - A specialized leaf that surrounds the reproductive parts of a flower. They are yellow on tomatoes. Petals are often colored to attract pollinating insects.

pH - A scale that is used to measure acidity and alkalinity of soil. The scale ranges from zero (acid) to 14 (alkaline), with pH7 being neutral.

Phosphorus (P) – A major plant nutrient especially important in the development of flowers.

Photosynthesis – The process by which chloroplasts in the plant cells use sunlight to convert carbon dioxide from the air with water vapor to form carbohydrates that are used as the basic food stuff for the growth of the plant.

Pistil – The female sexual organ of a flowering plant, comprising the stigma, style and ovary.

Potato Leaf (PL) - Large leaves with few entire-margined primary leaflets and few or no secondary leaflets. There are many forms of a Potato Leaf tomato.

Pollen – The male sex cells which are held on the anther for transfer by insects, wind, or some other mechanism to the tip of the stigma, where they attempt fertilization of the female egg-cell, or ovule, in the ovary at the base of the style.

Pollination – The transfer of pollen from the male anther to the female stigma, enabling fruits to set and develop.

Potassium (K) – A major nutrient that is especially important to the development of roots and stems.

Powdery Mildew - Fungal disease creating a powder like, white to grayish white cover on the leaf surface.

Radial Cracking -  Splitting or cracks, in the fruits skin, which extends in a straight line down the side of the tomato from the stem. It is usually associated with the tomatoes growing conditions. Cracks are caused when a plant receives too much water after a dry spell, either through excessive watering or after a rainy period. In essence, the plant receives too much water too fast, causing the interior of the tomato to expand too fast for its skin to stretch enough. The skin then cracks to relieve the pressure.

Regular leaf (RL) - The most common type of tomato leaf. Technically, The leaves are 10–25 cm long, odd pinnate, with 5–9 leaflets on petioles, each leaflet up to 8 cm long, with a serrated margin; both the stem and leaves are densely glandular-hairy.

Rugose – Usually associated with dwarf plants, leaves are compact, dark green, crinkled and bumpy and thick.

Self-fertile - A plant that is able to pollinate its own flowers.

Sepal – In a flower, one of the outer, usually protective leaves that surround the petals. These are green in tomatoes and make up the outer layer of a blossom.

Semi-determinate - Instead of the regular pattern of a flower truss on every internode or every other internode, a semi-determinate will do something like set out a flower truss on every other internode, then every third internode, then all of a sudden send out a flower truss on a node itself directly opposite the leaf frond, but eventually terminate the shoot in a flower truss, therefore identifying itself as a determinate at heart.

Semi-indeterminate - Similar to the semi-determinate but never terminating its shoots with an efflorescence, rather growing until terminated by frost, disease, etc.

Sexual propagation – Production of new plants by seed, whereby the genetic material from the two plants is combined, producing a new plant that is distinct, even if quite similar, to its parents.

Shapes, tomato - There are six main tomato shapes: Cherry, Salad/Saladette, plum, pear, heart/oxheart and standard/beefsteak.

Side dressing - Application of fertilizer either around individual plants or along a row of plants, usually during the growing season.

Side-shoot - A stem that arises from the side of a main branch.

Species – The basic unit of plant classification. Plants within a species have several characteristics in common, but most importantly, can cross with one another, but not normally with members of another species. The classification of species is quite fluid, with periodic revision by botanists.

Stamen - The male portion of a flower consisting of the anther and the filament.

Stigma – The part of the female sex organ which receives the pollen from the anther. Supported by the style, through which it is connected to the ovary; often sticky when receptive.

Style – They part of the female sex organ that supports and connects it to the ovary.

Sucker - A new branch which grows out of the crevice (leaf crotch) of the main stem and a leaf stem. If you don't prune your suckers, they will grow roots, leaves and flowers just like the rest of the plant, which will actually increase the overall number of tomatoes you can harvest. However, it will decrease the size of each individual tomato since resources have to be spread throughout the now bigger plant. 

Sulfur (S) - Sulfur is a major component of all living organic matter. Soils which are low or depleted of organic matter are almost always low in sulfur. Nitrogen needs enough sulfur to do its job. Organic sources of sulfur include gypsum and Su-Po-Mag.

Sweat bees - The common name for a very large population of bees which are known to be attracted to human sweat. They are generally black or metallic colored, and some are brilliant green or brassy yellow. Sweat bees are among the most common bees wherever bees are found. Although their small size makes them relatively inconspicuous, hundreds may swarm over flowers in gardens. They are considered the culprits of many Natural Cross Pollinations.

Terminal bud - The bud located at the tip of a stem. The terminal bud of an indeterminate tomato plant does not set fruit, it always produces leaves and more stem from the growing tip. The vine can grow indefinitely if not killed. Terminal buds on determinate type tomatoes do not set fruit. The plant has self-stopped; stem growth is terminated.

True Leaves - The first set of leaves on a seedling, after the appearance of the seed leaves (cotyledons).

Variety – A strain of plant having distinctive features which persist over successive generations in the absence of human intervention. Generally, variety applies to these naturally occurring strains, while cultivar applies to horticulturally developed strains. Cultivars are often mistakenly referred to as varieties. (See: Cultivar)

Wispy-leaved - Regular tomato leaves which are finely dissected.

 Glossary of Common GARDEN TERMS

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