Borage is the blue-flowered herb that bees adore, cooks love in salads and drinks, and gardeners love as a companion plant — it is even one of the listed companions for strawberries and many other crops. It is also one of the easiest herbs to grow, which makes the advice about starting it indoors a short story.
The honest truth: borage is usually direct-sown. It germinates fast, grows fast, and has a taproot that resents transplanting — a seedling moved at the wrong moment sulks for weeks. Indoor starting is possible in soil blocks or peat pots, but it is a limited option for gardeners who want a head start in a short season. This guide explains both, and why direct sowing wins for most people. This crop is in the Boraginaceae family, needs full sun, and takes 50–60 days to reach maturity, so the timing below is built around those facts, not guesswork.
Borage at a glance
| Growing factor | What borage need |
|---|---|
| Days to germination | 7–14 |
| Sowing method | direct sow |
| Days to maturity | 50–60 |
| Soil pH | 6.0–7.0 |
| Spacing | 12–18 inches |
| Sun | full sun |
| Cold tolerance | hardy |
When to start borage seeds indoors
Borage is hardy and fast. In Zones 3–5, direct sow after the last frost, or start indoors in soil blocks 3–4 weeks before last frost for a head start. In Zones 6–8, sow in spring and again in late summer. In Zones 9–10, sow in autumn or early spring to avoid summer heat. In frost-free Zones 11–13, sow in the cooler months. Check your local extension service for frost dates, or use our frost-date calculator and seed-starting calculator.
As a rule, work backwards from your last frost: indoor sowing, where you use it at all, is only a short head start of a few weeks before your last frost — direct sowing where the plant will grow is the default. Our seed-starting calculator does the backwards maths for you, and the germination-time calculator helps you plan around that 7–14-day window. If you are unsure of your zone, the hardiness-zone finder will confirm it.
What you need
soil blocks or peat pots if starting indoors (do not use shared trays — the roots tangle and the taproot breaks), seed-starting mix, a spray bottle, a bright windowsill or grow light, and labels. For direct sowing, you need only the seed and a patch of bare soil.
You will also want a spray bottle or a watering can with a fine rose, and a notebook to record the sowing date — germination takes 7–14 days, and it is easy to forget when you sowed.
Step by step: starting borage seeds indoors
- Fill your containers. Fill trays or pots with fresh, damp seed-starting mix — not garden soil, which is too heavy and can carry disease. Press it down lightly and level the surface.
- Sow the seed. If you start borage indoors, sow one seed per soil block or peat pot, about half an inch deep, and keep the mix damp. Germination takes 7–14 days and is usually quick and even. Transplant the whole block out as soon as seedlings have two true leaves — do not wait, because the taproot grows fast and a pot-bound borage never recovers well. Most gardeners should simply sow where the plant will grow.
- Cover and label. Cover the tray with a clear lid or cling film to hold humidity, and label it with the crop and the date. Put it somewhere warm and bright, out of direct sun until seeds sprout.
- Wait for germination. Germination takes 7–14 days. Check the tray daily, mist the surface if it dries, and be patient — uneven germination is normal, especially for slow crops. Our germination-time calculator helps you track the window.
- Remove the cover. As soon as seedlings emerge, take the lid off. Good airflow from this point on is what prevents damping off.
- Give them light. Move the tray under a grow light or to your brightest window immediately — seedlings stretch within a day or two if the light is weak.
- Thin and pot on. Thin to one seedling per cell once they have two true leaves, snipping the extras rather than pulling them. Pot on into larger pots when roots show at the drainage holes, keeping the seedlings at the same depth.
- Feed lightly. Once seedlings have two sets of true leaves, feed with a half-strength liquid feed every week or two. Do not overfeed — soft, overfed seedlings are more likely to damp off and less likely to harden well.
Light for seedlings
Borage seedlings are not fussy about light compared with most herbs, but they still want 14–16 hours of bright light a day indoors. Without it they stretch and go pale. A sunny windowsill is usually enough for the short indoor period borage needs.
Watering seedlings
Borage has moderate water needs. Keep the mix evenly moist until seeds germinate, then water when the surface dries. Once established outdoors, borage is fairly drought-tolerant, but seedlings must not dry out — a dry seedling wilts fast and may not recover. Our watering calculator can help you work out how much water your seedlings need as they grow.
Hardening off
Borage is hardy, so hardening off is easy: a few days of increasing outdoor time is enough. Start in sheltered shade, build to full sun, and plant out once the seedlings look sturdy. Handle the pots, not the plants.
Transplanting outdoors
Plant the whole soil block or peat pot at the same depth it grew in the pot, spacing plants 12–18 inches apart in full sun. Our plant-spacing calculator works out the layout. Water in well. Borage self-seeds freely, so one planting often becomes a permanent patch — site it where you are happy for it to return. For the full picture — soil, feeding, pests and harvest — see our complete growing borage guide.
Common problems and fixes
| Problem | Fix |
|---|---|
| Seedlings wilt after transplanting | The taproot was disturbed. Always transplant the whole soil block or peat pot, and move seedlings while they are small. |
| Seeds do not germinate | The mix dried out. Borage seed needs steady moisture — keep the mix damp for the full 7–14 days. |
| Slugs eat young plants | Slugs love young borage. Protect seedlings with collars or beer traps, and keep the area free of damp debris. |
| Plants grow huge and flop | Borage reaches 50–60 days to maturity and grows fast. Give it its 12–18 inch spacing and let it bush out — staking is rarely needed if it is not crowded. |
Seedlings wilt after transplanting
The taproot was disturbed. Always transplant the whole soil block or peat pot, and move seedlings while they are small.
Seeds do not germinate
The mix dried out. Borage seed needs steady moisture — keep the mix damp for the full 7–14 days.
Slugs eat young plants
Slugs love young borage. Protect seedlings with collars or beer traps, and keep the area free of damp debris.
Good companions for borage include tomatoes, peppers, marigolds, cabbage. Watch out for aphids, slugs, cutworms — check young plants regularly, and deal with pests early while plants are small. Our pest-identifier helper can help you work out what you are looking at.
Frequently asked questions
Should I start borage seeds indoors?
Usually not — borage is best direct-sown because it germinates fast and dislikes transplanting. Indoor starting in soil blocks or peat pots works if you want an earlier start, but transplant while seedlings are small.
How long do borage seeds take to germinate?
7–14 days in damp soil. Germination is usually quick and even.
Will borage come back next year?
Yes — borage self-seeds freely. Leave a few flowers to set seed and new plants will appear next spring.
How far apart should borage plants be?
12–18 inches apart in full sun.
Is borage good as a companion plant?
Yes — it is listed as a companion for strawberries and many other crops, and its blue flowers attract pollinators to the whole bed.