â–¶What is seed stratification and when do I use it?
Stratification is a pretreatment that breaks dormancy in seeds by simulating the winter conditions they naturally experience before germinating in spring. Methods: (1) Cold stratification—moisten seeds, seal in a plastic bag, place in refrigerator (33-40°F) for 2-12 weeks depending on species; (2) Warm stratification—moisten seeds, keep at 70-80°F for 2-4 weeks; (3) Scarification—mechanically scratch the seed coat (sand paper) or briefly soak in hot water to allow water uptake. Common plants needing cold stratification: most perennials, shrubs, trees. Vegetables like tomatoes and lettuce do not need it. Check seed catalogs or extension seed guides for specific species. Skipping stratification results in poor or zero germination.
â–¶How do I determine if seeds are viable and ready to germinate?
Seed testing: (1) Germination test—place 10-50 seeds on moist filter paper in a sealed container at the species' ideal temperature (usually 65-75°F) for 7-14 days; count how many germinate; viability % = germinated seeds ÷ total × 100 (target >80% for field planting). (2) Tetrazolium (TZ) test—stain seeds with a chemical (TZ chloride) that turns living tissue red/pink; examine under a microscope or hand lens. (3) Floatation test—place seeds in water; viable seeds sink, dead ones float (crude but quick). Old seeds (>2-3 years) or improperly stored (hot, humid) seeds have low viability; test before planting to avoid sowing a field of dead seeds.
â–¶What are the differences between hardwood and softwood cuttings?
Softwood cuttings are taken from actively growing green tissue in spring/early summer, usually 3-4 inches long. They root quickly (2-4 weeks) due to high auxin (rooting hormone) levels and active growth, but are fragile and require high humidity and bottom heat. Hardwood cuttings are taken from dormant woody tissue in fall/winter (after leaves drop), stored in cool moist sand, and planted in spring. They root slowly (2-3 months) but are less fussy about humidity and more robust. Easy propagation by softwood: herbs (basil, mint), ornamentals (begonias, impatiens). Hardwood: woody shrubs (forsythia, elder, willow). Choose based on species and available infrastructure.
â–¶What causes seedling leggy growth and how do I prevent it?
Leggy seedlings (tall, thin, weak stems) result from insufficient light or excessive height stimuli (stretching to find light). Causes: (1) Inadequate light (natural window light is usually 5-10% of full sun), (2) Light too far from seedlings (light intensity drops with distance), (3) Overly warm growing area (promotes stretch), (4) High nitrogen (promotes soft vegetative growth). Prevention: (1) Use grow lights placed 2-4 inches above seedlings, adjusting height as they grow, (2) Keep growing temperature cool (55-65°F, especially at night), (3) Ensure good air circulation (oscillating fan at low speed), (4) Gradually increase light intensity (acclimatize seedlings). Proper seedlings are short, stocky, and dark green.
â–¶What is pinching and pruning and when should I do it?
Pinching: removing the top ½ inch of growing stem (between thumb and forefinger) to promote branching. Use on: seedlings (when 3-4 inches tall), basil and other herbs (encourages bushiness), and ornamental plants (fuller shape). Do pinching while plants are actively growing (spring/summer). Pruning: removing larger branches to shape the plant, remove dead/diseased wood, improve air circulation, or control size. Timing depends on species: (1) Spring-flowering shrubs: prune immediately after flowering, (2) Summer-flowering: prune in early spring, (3) Evergreens: prune in late winter or spring, (4) Fall-fruiting trees: minimal pruning in growing season. Pruning cuts should be clean (sharp shears), at 45° angle above a bud pointing outward, and no stubby stubs left.
â–¶How do I know when to harvest fruits and vegetables for peak quality?
Harvest timing varies by crop: tomatoes—pick when fully colored but still slightly firm (ripen on counter if needed); peppers—green when immature, fully colored (red, yellow, orange) when sweet, can pick either stage; lettuce/greens—harvest young and tender (bolt-resistant varieties are mature when young); cucumbers—thin-skinned immature (6-8 inches) versus seedy mature (full size); berries—ripe when fully colored and slightly soft (for fresh), firmer if shipping; stone fruits (peach, plum)—slightly soft to touch, fragrant; root crops (carrots, beets)—pull when 1-3 inches diameter, or full-size. Taste a sample when in doubt. Harvest in morning after dew dries; plants are hydrated and produce keeps longer.
â–¶How do I manage diseases and pests in a propagation or nursery setting?
Disease prevention (fungal is most common): (1) Use sterile media and tools (sanitize with 10% bleach between plantings), (2) Ensure good air circulation (fan, spacing), (3) Avoid overhead watering (wet foliage promotes fungal spores), (4) Remove infected plants immediately (isolate to prevent spread), (5) Apply preventive fungicide (sulfur, copper) if disease is endemic to your operation. Pest prevention: (1) Isolate new stock (check for pests before bringing into greenhouse), (2) Scout weekly (inspect leaf undersides, soil surface), (3) Remove affected plants, (4) Spray with insecticidal soap or neem oil if needed (follow label), (5) Maintain hygiene (remove fallen debris, disinfect benches). Beneficial insects (parasitoid wasps, ladybugs) reduce pest pressure; introduce if pests are persistent.
