How to Grow potatotree
Solanum erianthum D. Don
The potato tree (Solanum erianthum) is a tropical to subtropical woody shrub in the Solanaceae family that produces abundant small, edible fruits resembling cherry tomatoes. As a relative of cultivated tomatoes and peppers, it yields readily to cultivation and has been used traditionally in subtropical regions for both food and ornamental purposes, making it an excellent addition to warm-climate gardens.
soil preparation
Prepare a well-draining, fertile soil mix before planting. Solanum species prefer slightly acidic to neutral soil with a pH of 6.0 to 7.0. Work 2-3 inches of compost or aged manure into the top 8-12 inches of soil to improve fertility and drainage. If planting in containers, use a high-quality potting mix with added perlite or coarse sand (30% by volume) to ensure rapid drainage. Avoid heavy clay soils; amend with 40% peat moss and 30% coarse sand if necessary. The soil should retain moisture but never become waterlogged, as root rot is a common problem in Solanaceae species.
planting steps
Start from Seed or Cuttings Indoors
Begin seeds indoors 6-8 weeks before your last frost date. Sow seeds 0.25 inches deep in seed-starting mix kept at 70-75°F with 12-14 hours daily light. Maintain consistent moisture (not soggy). Seeds typically germinate in 7-14 days. Alternatively, propagate from 4-6 inch semi-hardwood cuttings in spring, dipping the base in rooting hormone and placing in moist sand or perlite under shade cloth.
Tip: Keep seedlings under grow lights to prevent stretching. Once seedlings develop two true leaves, thin to 2-3 inches apart or transplant to individual containers.
Harden Off and Transplant Outdoors
About 2-3 weeks before planting outside, gradually expose seedlings to outdoor conditions, starting with 1-2 hours daily in shade and increasing duration over 10-14 days. Transplant into the garden after your last frost date when soil temperature reaches 60°F. Space plants 3-4 feet apart in locations receiving full sun (6-8 hours minimum). Dig a hole slightly larger than the root ball, plant at the same depth as the container, and water thoroughly to settle soil.
Tip: In cooler zones (3-6), plant in containers you can move indoors before frost, as Solanum erianthum is frost-sensitive and cannot tolerate temperatures below 50°F.
Mulch and Establish Root System
Apply 2-3 inches of organic mulch (wood chips or straw) around the base, keeping it 3-4 inches away from the stem to prevent rot. Avoid piling mulch directly against the plant. In the first 4-6 weeks, water deeply every 2-3 days to establish a strong root system. Once established, transition to less frequent but deeper watering.
watering
Water deeply when the top 1 inch of soil feels dry. During the establishment phase (first month), provide 1-1.5 inches of water weekly, divided into 2-3 waterings. Once established, reduce to 1 inch per week during growing season (spring through fall) and 0.5 inch during dormancy or winter months. During fruiting, maintain consistent moisture without waterlogging; fluctuating water availability causes fruit drop and blossom-end rot. Water at the base using soaker hoses or drip irrigation to keep foliage dry and reduce fungal disease. Signs of underwatering include wilting leaves and flower drop; overwatering causes yellowing leaves, root rot, and mushy stems. In hot climates (zones 9-10), mulching helps retain soil moisture and keep roots cooler.
feeding & fertilizer
Apply a balanced fertilizer (10-10-10 or 14-14-14) at planting time, working 2-3 tablespoons into the soil around the base of each plant. Once growth begins, feed every 2-3 weeks with a diluted liquid fertilizer (half-strength) through the growing season. When flowering begins, shift to a phosphorus-rich formula (5-20-20) to encourage fruit set. Continue feeding every 2-3 weeks through the fruiting period with the same ratio. In containers, feed every 2 weeks as nutrients leach through drainage. Cut back to no feeding during dormancy (fall-winter in zones 3-6). Solanum species respond well to foliar feeding with fish emulsion or seaweed extract applied every 3 weeks to boost fruit production.
pruning & training
Prune potato trees lightly in early spring before active growth begins. Remove any dead, diseased, or crossing branches at the base of the plant. Pinch out the growing tip when plants reach 12-15 inches tall to encourage branching and a bushier form. As the plant develops, thin crowded interior branches to improve air circulation and light penetration—this reduces fungal diseases and improves fruit quality. In the second and third seasons, consider light shaping to maintain a 4-5 foot height and width, removing any branches growing inward toward the center. Remove any flowers or fruit that appear during the first year to allow the plant to establish a strong framework. No major pruning is needed if the plant is healthy; light maintenance pruning maintains form and productivity.
harvesting
Fruits mature 60-90 days after flowering, depending on temperature and light. Pick fruits when they turn from green to yellow or orange and yield slightly to gentle pressure—they are still firm but show color change. Full ripeness is indicated by a sweet aroma at the base of the fruit and deeper color. Harvest every 3-5 days during peak season as new fruits mature continuously. Use pruning shears or scissors to cut fruit with a 0.5-inch stem attached rather than pulling, which can damage branches. In cooler zones, expect lighter harvests than in tropical climates where potato trees produce year-round. Succession harvesting continues through fall until frost threatens; any remaining fruit should be picked before temperatures drop below 50°F.
storage & preservation
Refrigerate harvested fruits in a breathable container or perforated plastic bag; they keep 7-10 days at 45-50°F, or 3-5 days at room temperature. Avoid storing in sealed containers as moisture accumulation promotes rot. Fruits can be used fresh (eaten raw or cooked), dried, or preserved as jam. For drying, slice fruits 0.25 inches thick and dry at 135-140°F in a dehydrator until leathery (6-8 hours). Dried fruits store in airtight containers for up to 3 months in a cool, dry place. No special curing is required. If frost threatens and fruit remains on the tree, harvest green fruits and ripen them indoors in a paper bag at room temperature (60-70°F) away from direct sunlight; they will yellow over 5-7 days. Frozen fruits (whole or processed into puree) keep for up to 8 months.
common mistakes to avoid
- ✗Overwatering or planting in poorly draining soil—Solanum species are prone to root rot; prioritize well-draining soil and allow the top inch to dry between waterings to prevent fungal diseases
- ✗Planting in shade—potato trees require 6-8 hours of direct sun daily for optimal flowering and fruiting; insufficient light results in sparse flowers and small fruit
- ✗Freezing in winter (zones 3-8)—bring container-grown plants indoors when temperatures approach 50°F; frost damage kills branches and reduces next year's productivity
- ✗Harvesting immature fruit—wait for color change and slight softness to develop full flavor; green fruit tastes bitter and lacks sweetness
- ✗Neglecting first-year pruning—failure to pinch out the central stem results in tall, leggy plants with weak branching; establish a strong framework in year one for better long-term productivity
explore more
ready to grow potatotree?
Get personalized planting dates for your zone, progress tracking, and community support.