Glossary

Short definitions of terms used across the site. Where a term has its own page, the definition links to it. Where an agency or extension service defines the term formally, that source is linked too.

A–B

Action threshold. The pest level at which you actually do something. The EPA describes it as the point at which pest populations or environmental conditions indicate that control action must be taken. A few aphids usually don't meet it. See no-spray pest management.

Bare-root plant. A dormant plant sold with no soil around its roots. Most strawberries and brambles ship this way. Bare-root stock can usually go in earlier in spring than potted plants; see the berry planting calendar.

Beneficial insects. Predators, parasitoids, and pollinators that help the garden, such as lady beetles, lacewings, and parasitic wasps. See beneficial insects in the garden and do ladybugs work?

Bramble. Any plant in the genus Rubus, which includes raspberries and blackberries. Also called caneberries.

Bray-P. A soil test for plant-available phosphorus, reported in ppm. The University of Minnesota soil lab reports a Bray phosphorus result for every regular test. On alkaline soils, labs such as Minnesota's also run Olsen-P and base recommendations on that instead. See soil test results explained.

C

C:N ratio (carbon-to-nitrogen ratio). The proportion of carbon to nitrogen in an organic material. High-carbon materials like wood chips and straw decompose slowly and can tie up nitrogen where they touch the soil; low-ratio materials like grass clippings and manure release it faster. See do wood chips steal nitrogen?

Cation exchange capacity (CEC). A soil's ability to hold positively charged nutrients such as calcium, magnesium, and potassium. USDA NRCS describes it as coming from negatively charged sites on clay particles and stable organic matter. You can't add clay easily, so organic matter is the part you can change.

Certified plants. Nursery stock produced under a state certification program from tested, pathogen-free mother plants. The National Clean Plant Network for Berries maintains clean material that feeds these programs. See berry viruses and clean plants.

Chill hours. A measure of how much winter cold a dormant fruit plant has received, usually hours below 45°F or between 32°F and 45°F, depending on the source. Too little chill leads to poor, uneven bud break. See blackberry chill hour requirements.

Chill units and chill portions. Alternatives to simple chill hours. The Utah model gives partial credit to some temperatures and subtracts for warm hours; the Dynamic model counts chill portions. UC Davis explains all three approaches.

Cold frame. An unheated, bottomless box with a clear lid that traps solar heat to protect plants in spring and fall. See season extension with cold frames.

Companion planting. Growing particular plants together on the theory that they help each other, for example by repelling pests or attracting predators. Some pairings have trial support; many do not. See companion planting: what the evidence says.

Cover crop. A crop grown to protect and improve soil rather than to harvest, such as cereal rye, oats, or crimson clover. See cover crops for home gardens.

D–F

Day-neutral strawberry. A strawberry type that flowers largely regardless of day length, so it can fruit through summer rather than in one flush. Compare June-bearing. See growing strawberries organically.

Dormant stock. Plants sold while not actively growing, often bare-root. Extension guides generally allow dormant brambles to be planted in early spring, earlier than green tissue-culture plants.

Extension (Cooperative Extension). The outreach arm of land-grant universities, which turns research into advice for growers and gardeners. It is the main source type on this site. See the editorial policy.

Floricane. A bramble cane in its second year. Floricane-fruiting raspberries and blackberries bear on these canes, which then die. See growing raspberries organically and growing blackberries organically.

Frost, freeze, and hard freeze. In the freeze probability tables NC State Extension explains, these correspond to 36°F, 32°F, and 28°F. Other sources use slightly different cutoffs.

Frost date probability. The chance that the last spring frost (or first fall frost) falls on or after a given date. A 50% date is a coin flip, not a safe date. See last frost date probability.

G–L

Grow light. An electric light used to start seedlings indoors. See grow lights for seedlings.

Hardening off. Gradually exposing indoor-raised seedlings to sun, wind, and temperature swings before transplanting, so they don't stall or scorch. See hardening off transplants.

Hardiness zone. A band on the USDA Plant Hardiness Zone Map, based on the average annual extreme minimum winter temperature. Zones describe winter survival, not frost dates or chill.

Integrated pest management (IPM). A decision process for pests: set thresholds, monitor and identify, prevent, and control only when needed, starting with the most targeted option. See the EPA's IPM principles and no-spray pest management.

June-bearing strawberry. A strawberry type that produces one main crop in late spring or early summer. Usually grown in a matted row in the North.

M–N

Matted row. A perennial strawberry system in which mother plants send out runners that root and fill in a wide row over the season.

Mulch. Any material spread on the soil surface to hold moisture, moderate temperature, and suppress weeds. See best mulch for a vegetable garden.

Neem oil. An oil pressed from neem tree seeds and used as an insecticide and fungicide, including in some organic-approved products. See neem oil and bees.

Nitrogen immobilization. When soil microbes breaking down high-carbon material take up available nitrogen for themselves, temporarily leaving less for plants. With wood chip mulch, WSU Extension describes the nitrogen deficiency as occurring at the boundary between the mulch and soil. See do wood chips steal nitrogen?

Non-GMO. A claim that a product was not made with genetically engineered ingredients. It is not the same as organic. See organic vs. non-GMO labels.

NOP (National Organic Program). The USDA program that develops and enforces national organic standards and accredits certifiers. See organic gardening labels.

O

Olsen-P. A soil phosphorus test designed for alkaline soils. The University of Minnesota lab runs it when soil pH is above 7.4 and bases phosphorus recommendations on it when present. Bray and Olsen numbers are not interchangeable.

OMRI. The Organic Materials Review Institute, a nonprofit that reviews input products for use in organic production. "OMRI Listed" means a product is allowed in certified organic operations under the NOP. It does not mean the product is harmless to bees or people. See what OMRI Listed means.

Organic matter. The decomposed and decomposing plant and animal material in soil, reported as a percentage on soil tests. It contributes to CEC and water holding. See building garden soil.

P

pH. A measure of soil acidity or alkalinity. It affects which nutrients plants can take up and which phosphorus test a lab uses.

Plasticulture. Growing strawberries as an annual on raised beds covered with plastic mulch, usually from plug plants set in fall. Common in the Southeast; see the berry planting calendar.

Plug plant. A young plant grown in a small cell of growing medium, such as a strawberry plug or a tissue-culture bramble plug.

Primocane. A bramble cane in its first year. Primocane-fruiting raspberries and blackberries can bear late in the first season. See growing raspberries organically.

R–S

Row cover. Lightweight spun fabric laid over crops to exclude insects and give some frost protection. See row covers for pest control.

Small farm exemption. The NOP provision that lets very small operations sell produce as organic without certification, within limits. See the USDA organic small farm exemption.

Soil temperature. The temperature of the soil at seeding depth, which controls germination for many crops better than air temperature does. See soil temperature for seeds.

Soluble salts. A soil test measure of dissolved salts, reported as electrical conductivity; the University of Minnesota lab reports it in millimhos per centimeter. See too much compost.

Spotted wing drosophila (SWD). An invasive fruit fly whose larvae, unlike most fruit flies, feed in healthy, intact, ripening fruit. Raspberries, blackberries, blueberries, and strawberries are among its main hosts. See spotted wing drosophila.

T–Z

Tissue-culture plant. A plant propagated from tiny pieces of tissue in a lab. Tissue-culture brambles are often sold as green plugs and should go in after the last spring frost.

Trailing, semi-erect, and erect blackberries. The three growth habits of blackberry canes. Oregon State Extension calls trailing types the least winter cold hardy; erect types have stiffer canes that need less support. See growing blackberries organically.

Virus-tested stock. Plants tested and found free of specified viruses before sale. UMN Extension notes that a virus-infected fruit plant will never recover, so clean stock at planting matters. See berry viruses and clean plants.