Physalis philadelphica 'Purple' (Purple Tomatillo)
Physalis philadelphica 'Purple' (Purple Tomatillo)
Contents
- Introduction & History
- Botanical Description
- Varieties & Selection
- Planting & Sowing
- Climate & Hardiness
- Growing & Training
- Watering & Feeding
- Propagation & Seed Saving
- Diseases & Pests
- Companion Planting & Crop Rotation
- Container Growing
- Harvesting & Storage
- Culinary Uses & Nutrition
- Preserving & Fun Facts
- Seasonal Care Calendar
- Frequently Asked Questions
Introduction & History
Purple Tomatillo (Physalis philadelphica 'Purple') is a annual solanaceae other vegetable in the Solanaceae family, growing to 100 cm tall with a 60 cm spread. It produces purple round in husk fruit ready for harvest in approximately 75 days from transplant. Hardy in USDA zones 3-11, it thrives in full sun with moderate watering and prefers soil pH 5.5-6.8.
Harvested part: fruit • USDA zones: 3-11 • Sowing: indoor
Chromosome count: 2n=24 • Pollination: self-pollinating with occasional cross-pollination by insects • Key secondary metabolites: alkaloids (solanine, capsaicin, nicotine)
Contains both food crops and poisonous species; leaves and stems of most edible species are toxic
History & Origin
The Solanaceae family from the Americas and Asia gave us eggplants (domesticated in India/Southeast Asia), tomatillos (Mexico), and ground cherries (Americas). Many were initially mistrusted in Europe due to their nightshade kinship. Purple Tomatillo has been cultivated as a valued garden variety, selected for its purple fruits and reliable performance across a range of growing conditions.
Botanical Description
Physalis philadelphica 'Purple' is a annual member of Solanaceae, forming a bushy/compact plant reaching 100 cm tall. Flowers are yellow, giving way to purple round in husk fruit. The root system is moderately spreading with fibrous roots.
| Height | 100 cm |
| Spread | 60 cm |
| Growth habit | Annual |
| Foliage | green |
| Flowers | yellow |
| Fruit colour | purple |
| Fruit shape | round in husk |
| Harvested part | fruit |
Varieties & Selection
Within the Physalis genus, numerous varieties have been developed for different climates, uses, and growing conditions. Select varieties suited to your growing conditions, space, and culinary preferences. Disease-resistant varieties reduce the need for chemical intervention.
Planting & Sowing
Grow in full sun (6-8+ hours direct) in well-drained, fertile soil with pH 5.5-6.8. Start seeds indoors 6 weeks before last frost at 22-28°C. Transplant when soil reaches 18°C minimum. Space plants 60 cm apart in rows 75 cm apart.
| Sun requirement | Full Sun |
| Soil pH | 5.5-6.8 |
| Sowing method | Indoor |
| Sowing depth | 0.5 cm |
| In-row spacing | 60 cm |
| Row spacing | 75 cm |
| Germination temp | 22-28°C (optimum) |
| Days to germination | 10 days |
| Min soil temperature | 18°C |
| Water needs | Moderate |
Climate & Hardiness
Purple Tomatillo grows in USDA zones 3-11 and tolerates temperatures down to 0°C. Protect from hard frosts with fleece or cloches. In mild climates, autumn sowings can overwinter for early spring harvests.
🌍 Origin Map
Origin: South America/Asia
Growing & Training
Purple Tomatillo grows as a self-supporting bush and requires no special training or staking.
Group-Specific Growing Guide
Beyond tomatoes and peppers, the Solanaceae family includes eggplants, tomatillos, ground cherries, and cape gooseberries. All share susceptibility to the same soil-borne pathogens (Verticillium, Fusarium, Phytophthora) — never plant any Solanaceae where another has grown in the past 3–4 years. Eggplants are particularly heat-demanding, requiring sustained soil temperatures above 21°C for healthy growth. Tomatillos are self-incompatible and require at least two plants for cross-pollination. Ground cherries (Physalis) develop their characteristic papery husk (calyx) as a protection mechanism — fruit is ripe when it drops and the husk turns papery and straw-coloured.
Watering & Feeding
Watering
Water deeply once or twice per week, allowing the top 2-3 cm of soil to dry between waterings. Increase frequency during heatwaves and fruiting. Consistent moisture prevents cracking and blossom end rot.
Feeding
Heavy feeder. Prepare beds with well-rotted compost/manure. Side-dress with balanced fertilizer at transplanting, switch to high-potash (tomato feed) once flowering begins. Feed every 10-14 days during fruiting.
Propagation & Seed Saving
Seed saving difficulty: moderate. Solanaceae are mostly self-pollinating, making seed saving relatively straightforward. Allow fruit to fully ripen on the plant, extract seeds, ferment 2-3 days to remove gel coating, rinse and dry.
Diseases & Pests
Common Diseases
Verticillium Wilt: Asymmetric wilting, yellowing from base. No cure — rotate 4+ years, use resistant varieties where available. Flea Beetles: Small round holes in leaves (shotgun pattern). Use fleece early season, neem spray, diatomaceous earth. Fruit Rot (various): Soft, watery rot on fruit. Avoid fruit contact with soil, improve airflow, harvest promptly. Spider Mites: Fine stippling on leaves, tiny webs underneath. Mist regularly, introduce predatory mites, insecticidal soap. Whitefly: Tiny white flying insects on leaf undersides. Yellow sticky traps, introduce Encarsia parasitic wasps, neem.1. Cultural controls — crop rotation, resistant varieties, proper spacing, good hygiene (remove debris, sterilise tools)
2. Physical controls — insect mesh, fleece barriers, slug traps, hand-picking, companion planting
3. Biological controls — encourage natural predators (ladybirds, lacewings, hoverflies, ground beetles); use parasitic wasps, nematodes, or Bt spray
4. Chemical controls — last resort only; organic options (neem oil, pyrethrum, copper fungicide, insecticidal soap) before synthetic products
Companion Planting & Crop Rotation
Companion planting works through multiple mechanisms: aromatic plants repel pests (basil deters whitefly on tomatoes), deep-rooted plants break compaction for shallow-rooted neighbours, and nitrogen-fixing legumes enrich soil for heavy-feeding brassicas.
Antagonistic relationships include allelopathy (chemical growth inhibition), shared pest/disease vulnerability, and direct competition for the same soil nutrients or root zone space.
Crop Rotation
Purple Tomatillo belongs to no specific rotation group. It can be fitted into most rotation schemes flexibly. Avoid planting in the same spot annually to prevent soil-borne disease buildup.
Container Growing
Purple Tomatillo is not ideally suited for containers due to its deep root system. If attempted, use the largest container possible (60+ cm diameter) with support.
• Drainage: Ensure generous drainage holes; use crocks or mesh at the base to prevent compost washout
• Feeding: Container compost nutrients deplete in 6–8 weeks; begin liquid feeding fortnightly from this point
• Watering: Check moisture daily; the 'finger test' (dry to 2 cm depth = water needed) prevents both over- and under-watering
• Position: Most vegetables need 6+ hours of direct sunlight; rotate containers weekly for even growth
• Insulation: In hot weather, double-pot (pot inside a larger pot with insulating gap) to prevent root overheating
Harvesting & Storage
Harvest Purple Tomatillo when fruits reach full size but before over-maturity. For most varieties, this is approximately 75 days after transplanting. Pick regularly to encourage continued production. Morning harvest after dew dries gives best quality and shelf life.
Storage
Store Purple Tomatillo in fresh conditions. Expected storage life: 2 weeks under optimal conditions. Most fruiting vegetables are best used fresh within 1-2 weeks. Can or freeze surplus.
Preservation Methods
Freezing: Blanch briefly, cool, and freeze on trays before bagging. Canning: Process in pressure canner (low-acid) or water bath (tomatoes with added acid). Drying: Slice thinly, dehydrate at 57°C for 8-12 hours. Fermenting: Lacto-ferment for probiotic-rich pickles.
Culinary Uses & Nutrition
Eggplant's spongy flesh absorbs oil readily — salt and press for 30 minutes first to collapse air pockets. Tomatillos are tart raw but mellow when roasted, forming the base of Mexican salsa verde. Purple Tomatillo is a versatile ingredient used across multiple cuisines.
Preserving, Succession & Planning
Freezing: Blanch briefly, cool, and freeze on trays before bagging. Canning: Process in pressure canner (low-acid) or water bath (tomatoes with added acid). Drying: Slice thinly, dehydrate at 57°C for 8-12 hours. Fermenting: Lacto-ferment for probiotic-rich pickles.
Year-Round Growing Calendar
Maximise your productivity with Physalis philadelphica 'Purple' by planning across the full year:
- Late winter (Feb–Mar): Order seeds, clean and repair equipment, plan crop rotations, start indoor sowings for warm-season crops
- Spring (Apr–May): Direct sow hardy crops, transplant indoor-started seedlings after hardening off, apply compost and mulch
- Summer (Jun–Aug): Main growing and harvesting season; succession sow for autumn; water consistently; monitor for pests
- Autumn (Sep–Nov): Harvest storage crops, sow overwintering varieties, clear spent plants, incorporate green manures
- Winter (Dec–Jan): Process and store harvests, plan next season, maintain tools, order seed catalogues
Frequently Asked Questions
How long does it take to grow Purple Tomatillo?
Purple Tomatillo typically takes approximately 75 days from planting to harvest, depending on variety, climate, and growing conditions.
What are the best growing zones for Purple Tomatillo?
Purple Tomatillo grows well in USDA hardiness zones 3-11. In colder zones, start seeds indoors and transplant after the last frost.
Can I grow Purple Tomatillo in containers?
Purple Tomatillo is better suited to open ground due to its size, but can be grown in large containers (60+ cm diameter).
When should I plant Purple Tomatillo?
Start seeds indoors 6-8 weeks before the last frost date, then transplant outdoors when soil reaches 18°C.
What pests affect Purple Tomatillo?
flea beetles, Colorado potato beetle, aphids, whitefly, spider mites, thrips, fruit worms, slugs
Seasonal Care Calendar
🌱 Spring (Mar–May)
Water: Moderate as growth begins
Feeding: Apply balanced fertiliser at transplanting
Start seeds indoors; harden off before transplanting after last frost.
☀️ Summer (Jun–Aug)
Water: Regular deep watering, especially during fruit set
Feeding: High-potash feed every 2 weeks
Peak growing season. Monitor for pests, maintain mulch, train and support as needed.
🍂 Autumn (Sep–Nov)
Water: Reduce as growth slows
Feeding: Stop feeding
Harvest remaining crops. Save seed from best plants. Clear and compost spent plants. Green manure empty beds.
❄️ Winter (Dec–Feb)
Water: None (dormant)
Feeding: None
Plan next season. Order seeds. Prepare beds with compost. Check stored produce for rot.