Contents

1.1 Description of the Plant

Asimina triloba, North America’s largest native tree fruit, is a pyramidal understory tree 4–7 m tall. Drooping, tropical-looking leaves (up to 30 cm) turn golden in autumn, while maroon six-petalled flowers open before leaf-out in late April–May (Ontario). Oblong green fruit ripens September–October, softening to reveal custard-like, banana–mango-flavoured flesh.

1.2 Historical and Cultural Context

Cherished by Indigenous nations and recorded by early explorers, pawpaw was a frontier staple. Industrial orchard trends sidelined it until 21áµ—Ê°-century interest in regional, climate-smart crops sparked a renaissance among permaculturists and small orchards.

1.3 Edible, Medicinal, and Ecological Value

Edible: Flesh contains 7 % protein, vitamins C and B, potassium, and carotenoids. Eat fresh or freeze purée for smoothies, custards, or quick breads.

Medicinal/Utility: Bark and twigs contain natural insecticidal acetogenins; leaves host zebra swallowtail butterfly larvae, enhancing local biodiversity.

1.4 Your Seedling: What to Do on Arrival

You are receiving a Pawpaw seedling in a 250 mL or 500 mL deep pot. Handle delicately—the tap-root must remain undisturbed.

1. Unpack & Hydrate

   • Stand pot upright immediately; water until drainage appears.

2. Up-Pot Within 7 Days

   • Slide root plug intact into a 2 L tall tree pot (≈7 cm wide × 25 cm deep).
   • Medium: 60 % aged pine bark fines + 40 % peat/coir (pH 5.5–6.5).
   • Water-in with 5 mL diluted fish emulsion (5-1-1).

3. Light

   • Maintain 30–50 % shade first summer; avoid hot black pots in direct sun.

4. Watering

   • Keep medium evenly moist (1–2 L per watering, 2–3× weekly in heat). Do not allow to dry out.

5. Fertiliser

   • Mid-summer: top-dress 100 mL finished compost. No high-N synthetics.

6. Next Spring (Year 3)

   • Shift to a 7 L tall pot or plant in ground once stem ≥ 8 mm diameter and ≥ 40 cm tall.

2 Seedling Pot-Up Strategy (Years 1-3)

1. Year 0–1: Germination Tube (0.7 L) — 40–50 % shade; keep 22–25 °C.
2. Year 2: 2 L Tall Pot — Light fish-emulsion feed; partial shade.
3. Year 3: 7 L Tall Pot or Ground — Harden to full sun; install deer guard.

3 Planting Outdoors (Year 3 or 4)

1. Site — Full sun for fruiting; moist, well-drained loam, pH 5.5–7.0.
2. Spacing — 4–5 m between trees in rows 5–6 m apart.
3. Hole Prep — 50 cm × 40 cm; mix back-fill with 5 L compost + 250 mL rock phosphate.
4. Planting — Set root flare at soil level; water 10 L. Provide 50 % shade screen first summer.
5. Pollination — Pawpaws are self-incompatible; plant at least two unrelated trees within 15 m. Hand-pollinate if yields are low.
6. Mulch — 8 cm wood chips in 1 m ring, keep 10 cm clear of trunk.

4 Winterizing Potted Pawpaws

Pawpaws (Asimina triloba) are hardy to Zone 5 and can survive outdoor winters when planted in the ground. However, young trees grown in pots are much more vulnerable to cold damage due to exposed roots and limited insulation.

Why Winterize?

Pawpaw roots are sensitive to freezing, especially in small containers. Protecting potted trees through winter is essential for survival and healthy spring regrowth.

Overwintering Options

• Unheated Garage or Shed: Move pots to an unheated, sheltered space (e.g., garage, shed, root cellar) where temperatures stay between and . Avoid spaces that get too warm or too dry.
• Bury the Pot: Sink the entire pot into the ground in a protected area (e.g., next to a building or under mulch). Cover the soil surface with straw or leaves to insulate against deep freezes.
• Insulate Above Ground: Wrap the pot with layers of insulating material such as bubble wrap, foam, or straw bales. Group several pots together for shared warmth and wind protection.
• Keep Dormant: Pawpaws lose their leaves and go dormant in late autumn. During dormancy, they require no light and only minimal watering—just enough to keep the soil from drying out completely.
• Avoid Basement Heat: Do not overwinter in a heated basement or living space. Warm indoor temperatures can confuse the plant’s dormancy cycle and reduce vigor.

Watering During Dormancy

Check soil every few weeks. If the top 2–3 cm is bone dry, give a small amount of water. Do not allow the pot to become soggy or freeze while wet.

When to Bring Out

Move potted pawpaws back outdoors in early spring, once the risk of deep frost has passed (typically mid-April to early May in Grey-Bruce). Resume regular watering as buds swell.

5 Ongoing Care

1. Watering — 15 L week during dry spells first two years.
2. Fertilisation — From year 3, apply 100 g balanced organic fertiliser per trunk-cm each March.
3. Pruning — Minimal; remove crossing branches in late winter.
4. Shade Transition — Reduce shade gradually; full sun by year 3 for best fruit.
5. Protection — Use 1.5 m tree guards against deer browse.

7 Harvesting and Storage

• Ripening — Late Aug–Oct; fruit soft, fragrant, and detaches easily.
• Shelf Life — 3–4 days room temp; 7–10 days at 1 °C. Purée freezes 12 + months.

8 Propagation Notes

• Seed — Stratify 90 days at 4 °C; sow 2 cm deep. Germination 70–90 %.
• Grafting — Whip-and-tongue onto 1-year seedlings in May for named cultivars.

9 Summary

Follow the simple up-pot schedule, keep roots cool and moist, and plant at least two genetically distinct pawpaws for cross-pollination. With patient care, your nursery seedling will reward you with lush foliage and custard-sweet fruit in 5–7 years—bringing a taste of the tropics to your Ontario garden.