sudo tee /opt/plantsbyj/data/pages/watering_irrigation.md > /dev/null <<'EOF'

Watering & Irrigation — Precision from Backyard to Micro-Orchard

If germination is step one, consistent water is step two—and it’s where most gardens rise or fall. This chapter gives you a practical framework for when and how to water, plus simple ways to design drip systems that match your plants, beds, and budget. You’ll learn how to size emitters, set schedules that track the seasons, and diagnose uneven wetting, salt issues, and clogged lines.

Plant–water basics (why “1 inch per week” is only a starting place)

Plants lose water via transpiration (through leaves) and evaporation (from soil). Together, that’s ET (evapotranspiration). ET accelerates in sun, wind, heat, and low humidity; it slows in cool, still, humid conditions. The “1 inch/week” rule is a rough average—your true need depends on crop, stage, canopy size, mulch, and weather.

Translate ET to minutes:

If your drip line applies 0.6 inches per hour, and your target is 1 inch this week, you need ~1 hr 40 min of runtime, spread across several days to keep soil moisture even.

Soil, roots, and how water actually moves

  • Sandy soil drains fast, holds little water → shorter, more frequent sets.
  • Loam holds moderate water → fewer, deeper sets.
  • Clay holds lots of water but can be slow to absorb → longer sets, lower flow, avoid ponding.

Roots chase oxygen and moisture. Deep, infrequent watering encourages deeper roots; shallow, frequent watering keeps roots near the surface—fine for annual beds if consistent, risky in heat waves if you skip days.

Mulch (2–3") cuts evaporation dramatically and stabilizes surface moisture so microbial life thrives, roots are cooler, and irrigation is more forgiving.

Drip beats overhead (and why you’ll still use overhead sometimes)

Drip puts water where it’s used—at the root zone—keeping foliage dry and reducing disease. It’s efficient in wind and sun and plays nicely with mulch. Overhead has uses (seedling establishment, cover crops, frost protection), but for fruiting perennials—brambles, mulberries, passionfruit, pomegranates—drip is king.

Starter kit for one bed/row

  • Backflow preventer (protects your potable system)
  • Filter: 150–200 mesh for clean water; add pressure regulator (15–25 psi)
  • 1/2" poly header line + 1/4" tubing + barbed fittings
  • Emitters (1 gph typical) or dripline with built-in emitters (0.5–0.9 gph @ 12–18" spacing)
  • End caps or figure-8s
  • Hose timer (single or dual-zone battery timer)

Designing simple, reliable systems

Step 1 — Decide emitter type

  • Button emitters (inserted): flexible placement around shrubs/trees; easy to add more for bigger plants.
  • Inline dripline: fast to install for vegetable beds and long rows; even spacing.

Typical flows: 0.5 gph or 1.0 gph per emitter at 15–25 psi. Lower flows infiltrate heavy soils more gently and improve uniformity over long runs.

Step 2 — Estimate water need

Start with plant category and seasonal ET:

  • New transplants: keep the root zone constantly moist (smaller, more frequent sets).
  • Brambles (actively fruiting): ~1–1.5" water equivalent/week; in heat waves up to ~2".
  • Young trees/vines: 1–2 emitters initially (1 gph each), expand to 3–4 as canopies grow.
  • Containers: depend on pot volume, medium, and weather—see container section below.

Step 3 — Convert inches to runtime

1" water equals 0.623 gallons per square foot. If a 50 ft blackberry row wets a 2 ft band, that’s 100 sq ft. One inch ≈ 62.3 gal. If you have 10 emitters @ 1 gph total 10 gph, you need about 6.2 hours of irrigation spread over the week (e.g., 4 x 95 minutes). Mulch allows longer intervals between sets.

Step 4 — Layout for uniformity

  • Keep runs under manufacturer’s max length for your emitter/dripline at your pressure.
  • Use pressure regulation and filtration upstream of your manifold.
  • Avoid too many tees off a single regulator—keep each zone’s hydraulics simple.

Schedules that track the season (without babysitting)

Rule of thumb: Water deeper, not just more often as weather warms, then taper late season.

  • Spring (cool): 2–3 sets/week, shorter runtimes.
  • Summer (hot): 4–7 sets/week, longer runtimes.
  • Fall: reduce frequency and runtime.
  • Rain events: skip cycles—use a rain sensor or “skip” button on your timer.

Automating the logic:

A budget two-dial timer handles most needs; nicer Wi-Fi controllers let you adjust from your phone and apply “weather intelligence” (ET/rain). For high-value rows, a soil moisture sensor or tensiometer can automate irrigation when the root zone dries to a threshold.

Container irrigation (where most failures happen)

Containers warm and dry faster than ground. Keys:

  • Media: high-porosity mixes (peat/coir + perlite/pumice).
  • Pot color & exposure: dark pots in sun dry very fast.
  • Emitters: 1–2 per pot; for 10–15 gal pots use 2 x 1 gph; for 25–30 gal use 3–4.
  • Top-dress with mulch (bark/compost) even in pots.
  • Schedule: little-and-often works best—daily in hot spells; sometimes twice daily for small pots.

Test by weight: lift a pot right after watering (feel “full”) and again when it’s time to water—learn the contrast. If pots tip over easily, stake or cluster them; wind accelerates drying.

Water quality, pH, and salts

  • High alkalinity (bicarbonates) drifts media pH up over time—use acidifying fertilizers or occasional citric/phosphoric acid injections (advanced) and repot periodically.
  • Salts build up with frequent fertigation or hard water; leach pots monthly with clear water until 10–20% runoff.
  • Iron chlorosis: high pH reduces Fe availability; chelated iron drenches/foliar sprays can help in the short term; fix pH long term.

Fertigation (feeding through irrigation)

For steady growth, especially in containers or intensive beds, fertigation is efficient:

  • Use a proportioner or a simple siphon mixer; start low (e.g., 50–75 ppm N) and observe.
  • Flush with clear water occasionally to prevent salt accumulation.
  • Never inject products without a backflow preventer and follow label rates.

Frost and heat tactics with water

  • Overhead irrigation for frost can protect blooms by releasing latent heat as water freezes—this is specialized and risky without adequate water volume and correct timing.
  • Heat waves: irrigate pre-dawn so the root zone starts the day topped up; a mid-afternoon syringe can help containers but avoid creating a steamy disease-prone canopy.

Diagnosing problems

  • Dry spots in the bed: emitter clogged, kinked 1/4" tube, or pressure drop at row end—check flow and consider lower-flow emitters for long runs.
  • Plants wilting despite watering: hydrophobic media (especially peat) needs a wetting cycle—apply a drop of non-ionic surfactant or submerge pots briefly to re-wet.
  • Yellow edges, salt crust: overfertilization or poor leaching—flush and reduce feed.
  • Mildew on brambles: switch to drip (if overhead), thin canopy, water early so leaves dry quickly.
  • Surface crusting: heavy top watering; start bottom watering or reduce flow and use a gentler rose.

Simple, scalable build examples

A. One 50 ft blackberry row, new planting

  • 1/2" poly header, pressure regulator to 20 psi, 150-mesh filter
  • 10 x 1 gph button emitters, two per plant
  • Start with 4 x 45 min/week in spring → 4 x 75–95 min in peak summer (adjust to plant response and mulch depth).

B. Two 16 ft raised beds (vegetables)

  • Inline dripline 0.5–0.6 gph, 12" spacing, one run per bed
  • Spring: 3 x 20–30 min/week; summer: 5–6 x 30–45 min/week depending on mulch and wind.

C. Container orchard corner (ten 15–25 gal pots)

  • Manifold with 1/4" lines; 2–3 x 1 gph emitters per large pot
  • Daily watering in summer: start at 30–45 min; add an afternoon 15–20 min cycle during heat waves.

Maintenance that keeps systems running

  • Filter flush monthly (more often with well/surface water).
  • Line flush at season start and after any repair—open the ends and run until clear.
  • Inspect emitters while running—look for weak drips or sprays (a sign of partial clogs).
  • Winterize in freezing climates—drain lines, bring controllers indoors, store filters and pressure regulators dry.

Putting it all together

Great irrigation is boring: same time, same dose, predictable plant response. Aim for repeatability:

  • Standardize emitter types and flow rates.
  • Document starting schedules for each crop/zone and month; tweak based on weather.
  • Keep spare fittings, caps, and a punch on hand.
  • Watch leaves and soil—plants are honest communicators when you’re looking.

Do that, and your garden will move from scrambling to steady—the growth every week will feel nearly inevitable.

EOF