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Growing Lavender
in Plastic Boxes

A plastic boxes growing guide for lavender — container size, soil mix, watering, and the mistakes that quietly kill your yields.

🌱Medium difficulty
🪣2 gal min
📅90-100 days
☀Full Sun
⏱Low maintenance
Published

Quick answer: Lavender grows well in plastic boxes. Use a 2-gallon, 12"-deep bag with sandy; gritty; lean; well-drained; alkaline tolerant, pH 6.5-7.5. Every 2-4 days in summer, weekly in cool weather; the large soil mass holds moisture well, so check 3 inches deep before watering. Feed weekly with 5-10-10. Expect harvest in 90-100 days, yielding Continuous flowers and oil.

Why do plastic boxes work for lavender?

Repurposed storage totes or boxes converted into deep planters offer large soil volume at low cost, but solid walls trap heat and require post-purchase drainage modification.

For lavender specifically (Lavandula angustifolia, Lamiaceae family, Perennial edible), this matters because lavender are heavy-rooted, high-water plants that need fast drainage. The controlled root environment lets you dial water and nutrients in tighter than open-ground growing allows.

"Get the plastic boxes substrate and water rhythm right and the rest is variety choice. Get either wrong and no cultivar saves you."

Picking the right size plastic boxes for lavender

Soil recipe

From the plastic boxes specialist playbook: 50% potting mix, 30% compost, 20% perlite - the large volume warrants extra drainage to prevent the closed base from staying soggy.

Lavender-specific tweak: lavender prefer pH 6.5–7.5, soil type sandy; gritty; lean; well-drained; alkaline tolerant. Most quality potting mixes land in that range out of the bag — test before adjusting.

Lavender in plastic boxes: the setup walkthrough

  1. Choose your plastic boxes. 2-gallon minimum, 12" deep. Black is fine indoors; choose tan or grey for outdoor desert/hot-summer settings.
  2. Mix the soil. 50% potting mix, 30% compost, 20% perlite - the large volume warrants extra drainage to prevent the closed base from staying soggy. Mix in a wheelbarrow or tarp before filling.
  3. Fill and transplant. Fill to 2 inches below the rim. Transplant.
  4. Water in. Soak until water drains through the fabric walls (yes, the sides will weep — that's normal).
  5. Position in sun. 6–10 hours direct Full Sun. Elevate dark-colored pots off hot concrete on a plant caddy.
  6. Mark feeding schedule. Begin weekly feeding 2 weeks after transplant with 5-10-10 fertilizer.

Which lavender varieties do best in plastic boxes?

Plastic Boxes work for any lavender type, but the fast root-zone drying favors plants that handle steady deep watering. Top picks from breeders' lists (varieties verified via All-America Selections and university extension trials):

Lavender watering, dialed in for plastic boxes

Method baseline: Every 2-4 days in summer, weekly in cool weather; the large soil mass holds moisture well, so check 3 inches deep before watering.

Lavender-specific: the baseline holds for lavender (water_category: Low, baseline 7 days), with adjustments:

The feeding schedule for lavender in plastic boxes

Method baseline: Slow-release granules at planting plus monthly liquid feed, or biweekly compost tea throughout the growing season.

Lavender-specific: lavender are a light feeder. Use 5-10-10 (low-nitrogen, high-phosphorus/potassium) once flowers appear. High-nitrogen fertilizer in plastic boxes gives you a beautiful leafy plant with zero fruit. Start feeding 2 weeks after transplant, then weekly through the harvest window.

Sun and placement for lavender in plastic boxes

Method baseline: 6+ hours direct sun; lighter-colored boxes stay cooler than dark ones in summer heat.

Lavender-specific: lavender want 6–10 hours of Full Sun. South or west exposure is ideal. If you're growing on a balcony with only morning sun, choose compact varieties (more forgiving with less light) and skip the long-season heirlooms.

Fruit set: getting lavender to produce in plastic boxes

Lavenders are self-pollinating — a single plant will set fruit on its own through wind or gentle shaking. First flowers typically appear 90 days after transplant. In plastic boxes, the air-pruned root system actually produces flowers a few days earlier than in rigid containers — a nice side bonus.

Pollination tip for indoor plastic boxes: hand-pollinate by tapping the cage gently once flowers open, or use an electric toothbrush against the stem for 1 second per cluster. Vibration shakes pollen loose like a bee would.

Lavender in plastic boxes: common mistakes to avoid

Plastic Boxes mistakes (top 3)

  1. Forgetting to drill enough drainage holes.
  2. Using boxes that held chemicals or food residue.
  3. Placing dark boxes in full afternoon sun, cooking the roots.

Lavender mistakes

  1. Overwatering causing root rot.
  2. Heavy soils retaining moisture.
  3. Planting in shade.
  4. Over-fertilizing reducing oil.
  5. Pruning into old wood (will not regrow).
  6. High humidity without airflow leading to fungal issues.

What pests and diseases hit lavender in plastic boxes?

Common pests: aphids; spittlebugs; whiteflies.

Common diseases: root rot (Phytophthora); fungal leaf spot; shab disease; botrytis.

Plastic Boxes keeps soil-borne disease pressure low when the substrate is fresh and clean. Spider mites still come for dry-summer plants; mist the underside of leaves weekly if you see stippling.

Lavender maintenance routine for plastic boxes

Method routine: Inspect for UV stress cracks each spring, drill additional drainage holes if water pools after rain, and consider painting dark boxes a light color to reduce heat absorption.

Lavender-specific: Prune by one-third after flowering; never cut into old woody growth; shape in early spring; harvest just before full bloom Growth rate: Slow.

Bringing the lavender in from plastic boxes

Expect Continuous flowers and oil in plastic boxes (roughly 70-80% of ground-grown yield). Harvest window: 30 days from first ripe fruit. Standard harvest months: Jun; Jul; Aug; year-round indoors with grow lights.

What you harvest: flowers; leaves. Culinary uses: Culinary lavender in baking; sugars; lemonade; herbes de Provence; tea; ice cream; essential oil; sachets; potpourri

Lavender safety notes for pets and wildlife

Wildlife value: bees; butterflies; hummingbirds; pollinator magnet; deer and rabbit resistant. Originally from Mediterranean region (France; Spain; Italy).

Deer resistant: Yes · Rabbit resistant: Yes. Elevated containers on a balcony or fenced patio solve deer/rabbit pressure naturally.
Pet safety: Toxic to cats: No · Toxic to dogs: No. Non-toxic per ASPCA in normal amounts; essential oil concentrated form may cause GI upset in pets; flowers safe in culinary use; per ASPCA

Pro tip from the plastic boxes playbook

Drill drainage holes through the sides 1 inch above the base instead of the bottom - keeps a small water reservoir for dry spells while preventing fully soggy roots.

Grower's tip for Lavender

Excellent drainage essential; add perlite or grit to potting mix; terracotta containers preferred for moisture wicking; full sun mandatory; do not over-fertilize; zones 3-4 overwinter indoors; SE USA humidity is challenging; harvest just before flowers fully open for best oil

Plastic Boxes lavender FAQ

Can I use plastic boxes for lavender indoors?

Yes, with a saucer. Plastic Boxes weep water through the sides for the first few days after watering — protect indoor floors with a tray or saucer that catches sideways drips, not just bottom drainage. Light requirement: 6–10 hours of Full Sun, so plan supplemental grow lights for low-light rooms.

What size plastic boxes do I need for lavender?

2 gallons absolute minimum, 12" deep. The practical sweet spot is 4 gallons for steady production. Larger is better for indeterminate or high-yield growing.

How often should I water lavender in plastic boxes?

Every 2-4 days in summer, weekly in cool weather; the large soil mass holds moisture well, so check 3 inches deep before watering.

Will lavender grow as well in plastic boxes as in the ground?

Yield is roughly 70-80% of ground-grown for the same variety, but plant health is often better — fewer soil-borne disease problems and no competition from other roots. For most home growers, plastic boxes are a net win.

How long do plastic boxes last?

2-4 years outdoors before UV degrades the fabric. Up to 6 years if stored indoors during winter and dried completely before folding.

What soil mix works best for lavender in plastic boxes?

50% potting mix, 30% compost, 20% perlite - the large volume warrants extra drainage to prevent the closed base from staying soggy. The extra perlite compensates for fabric's fast moisture loss while keeping the root zone aerated.

Do plastic boxes get too hot in summer?

Dark-colored plastic boxes can heat the soil 10-15°F above ambient in direct afternoon sun. Use tan or light grey fabric for hot climates, mulch the soil surface 3-4 inches deep with straw, and elevate pots off concrete or pavers on a plant caddy or wood block.

Can plastic boxes be reused across seasons?

Yes — rinse inside and out at season's end, dry completely before folding, store flat indoors. Expect 2-4 years of outdoor use before UV degrades the fabric. Replacements run $5-12 per pot in 3-packs.

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Sources & references

Climate, geographic, and toxicity data on this page come from public datasets. Cultivar profiles and growing recommendations draw on land-grant university extension research.