How to Grow Wonderberries

At a Glance

Quick Facts

Factor	Value
Soil texture	Light (sandy), medium (loamy) or heavy (clay) (PFAF)
Drainage	Fertile, well-drained preferred (PFAF)
Lifecycle	Grown as an annual outside the tropics; killed by frost (PFAF; University of Illinois Extension).
Edible parts	fruit

Soil & Growing Conditions

Water: Prefers moist soil (PFAF)

Growth Stages

Stage	BBCH	Notes
Sowing and establishment	0	Sow seed under cover/indoors in spring; transplant out only once frost danger has fully passed -- treat much like a tomato (PFAF; University of Illinois Extension).
Vegetative growth	3	Bushy, upright-branching growth; needs full sun and a fertile, well-drained, consistently moist soil (PFAF). Watch closely for tomato hornworm -- a University of Illinois Extension trial found a severe infestation (55 caterpillars hand-collected) on this crop.
Flowering	6	Small white flowers, produced in quantity once established -- one University of Illinois Extension trial plant recovered from pest damage to produce "several hundred" flowers.
Fruiting and harvest	8	Small (about 1cm) dark blue-purple fruits form in clusters (PFAF). Only pick and eat fully ripe (dark) berries -- green, unripe fruit is poisonous (University of Illinois Extension; PFAF).

Harvest & Storage

When to pick: Pick only fully ripe, dark blue-purple berries -- green, unripe fruit is poisonous and reactions to it vary by individual (University of Illinois Extension). Ripe fruit is soft and juicy with a mild, bland, slightly sweet flavour; not very appetizing eaten raw, and best used cooked into jelly, jam or pie filling (PFAF; University of Illinois Extension).

Pests

Hornworms

high

Manduca spp.

A University of Illinois Extension field trial recorded a severe infestation -- 55 hornworm caterpillars hand-collected from the planting, alongside five-spotted hawk moths (the adult form) -- before the crop recovered…

What the research guides add

An Illinois Extension educator grew wonderberries and wrote up what happened, which is rare for this crop.

• Wonderberry (also called sunberry) was created by the plant breeder Luther Burbank in the early 1900s and belongs to the nightshade family (Solanaceae). (Illinois Extension)
• The seeds were started in a small greenhouse until the threat of frost passed; the article says wonderberries are annual in growing zone 6 and will not tolerate a frost event. (Illinois Extension)
• In the high tunnel the stems were shredded by tomato hornworms, and the advice was to give plenty of water and increase pest monitoring. The plants then branched out with several hundred white flowers and clusters of berries. (Illinois Extension)

Sources for this section

• University of Illinois Extension: The quest of growing wonderberries

Section researched and checked on 25 October 2026 by the SoilCommander Editorial Team. How we check facts: editorial policy.

Sources

1. Plants For A Future (PFAF) - Solanum retroflexum (sunberry)

   Annual, spring-sown under glass, planted out after last frost. Soil: light/medium/heavy, mildly acid to mildly alkaline, prefers fertile well-drained. Full sun required, prefers moist soil. Fruit about 1cm diameter in small bunches. Edible: fruit only, raw or cooked (improved by cooking); many Solanum members have poisonous leaves and sometimes unripe fruit too. Native to Ethiopia, South Africa, Tanzania and other African countries.

These source is specific to this region. The full list of 2 sources behind this guide (Plants For A Future (PFAF), University of Illinois Extension) is in the references of our UK guide to wonderberries; they describe the plant itself, which is the same wherever it grows.