Last edited on 28 Oct 2026. View history
Borage
How to sow borage: Direct seed outdoors, thin to 45cm apart when seedlings are 4cm tall
Sun requirement for borage: Plant in Partial Sun
Borage, or Starflower, is an annual flowering herb with blue, pink, or white flowers and bristly stems and leaves. It is a popular companion plant, particularly for tomatoes, as it is thought to confuse mother moths of tomato hornworms looking for a place to lay their eggs. It also attracts many pollinators. It's edible leaves can be used as a fresh vegetable or dried herb. When fresh, it has a cucumber-like taste and is used in salads, lemonade, or as a garnish. It's flowers have a sweet honey-like taste and can be used to decorate desserts or cocktails or candied. It is also cultivated for the borage seed oil extracted from it's seeds.
- 20
- plantings
- 3
- harvests
- 2
- seed packets
Borage facts
Lifespan
Height × spread
100cm × 50cmRow Spacing
30cmWhen to sow
Grown for
flower harvested 3 timesCrop cycle
Optimal light
What are growing degree days?
A plant grows with warmth, not with days. A growing degree day is one day's worth of useful warmth: how many degrees the day's average temperature is above the lowest temperature the crop grows at. Add them up from planting and you know how far along the crop is, whatever the calendar says.
Say that lowest temperature is 10°C. A day averaging 17°C gives 7 growing degree days. A day averaging 8°C gives none, as it is too cold for the crop to grow. That is why the same lettuce takes about 50 days in a summer and 90 in an autumn: it needs the same total warmth either way.
For borage, the FAO EcoCrop database gives a lowest growing temperature of 4°C and a shortest growing cycle of 150 days at its best temperature, about 2175 growing degree days to a first harvest.
Where you've told us where your garden is, we use this and the weather there to predict when your borage will be ready to harvest. We don't use it for how long a plant lives or when it finishes: we go by what members have logged for that.
Growing borage
- Sow seeds in the ground at sowing
- Thin the seedlings 3 weeks after sowing
- Water in dry weather at sowing every 2 weeks
- Pick flowers for salads and drinks at first harvest every week
- Let some plants set seed to self-sow 4 weeks after first harvest
How members grow borage
Sunniness
Planted from
Harvested for
Plant borage with
cherry tomato
Photos
PhotosBorage crops
Borage plantings
Video
Where borage grow
Only plantings by members who have set their locations are shown.
What people are saying about borage
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Who's planted borage
- shiny Raised Bed Three · Wellington, NZ
- dunia 2021 Spring · Sydney
- lejun Besançon · Besançon
- Spadix Big path patch
- dlancellotti Garden - raised bed
shiny
Borage harvests
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shiny harvested not specified.
11 days ago
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shiny harvested not specified.
16 days ago
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shiny harvested 6.
18 days ago
shiny harvested not specified.
Find borage seeds
View all borage seeds
- Purchase seeds via Ebay
- Sign in or sign up to list your seeds to trade.
Ecological requirements
Data from the FAO EcoCrop database for Borago officinalis L.
| Family / Taxonomy | Magnoliopsida Asteridae Lamiales Boraginaceae |
|---|---|
| Killing temperature | growth: 0 °C, rest: -5 °C |
| Life form | herb |
| Life span | annual |
| Habit | erect |
| Optimal soil depth | medium (50-150 cm) |
| Optimal soil texture | heavy, organic |
| Optimal soil fertility | moderate |
| Optimal soil drainage | well (dry spells) |
| Optimal soil salinity | low (<4 dS/m) |
| Photoperiod | short day (<12 hours), neutral day (12-14 hours), long day (>14 hours) |
Learn more about borage
Resources outside Growstuff.
