Starting limes from seed indoors is a project that rewards a little patience, and this guide walks you through it from the first seed to a plant that is ready for the garden. Lime seeds are best sown fresh — scoop them from a ripe fruit, rinse off the pulp, and sow the same day, because citrus seed loses viability quickly once it dries out. Sow two seeds per pot in case one fails, about half an inch deep, and keep the pots warm. Seedlings are variable: a seed-grown lime will not be identical to the parent fruit, and it may carry thorns and take years to fruit, which is why most growers buy a grafted tree. Starting from seed is still a rewarding project, especially if you are happy to grow a handsome evergreen pot plant while you wait.
Limes belong to the Rutaceae family, need full sun, and grow best in soil with a pH of 5.5–6.5. Seeds take 14–28 days to germinate, plants take 1095–1825 days to reach maturity, they are tender — frost will damage or kill it, and they are usually spaced 120–180 inches apart.
Limes at a glance
| Growing factor | What limes need |
|---|---|
| Days to germination | 14–28 |
| Sowing method | both |
| Days to maturity | 1095–1825 |
| Soil pH | 5.5–6.5 |
| Spacing | 120–180 inches apart |
| Sun | full sun |
| Cold tolerance | tender |
When to start limes seeds indoors
The short answer: start limes seeds indoors 8–10 weeks before your last frost, or at any time of year if you plan to grow the tree in a pot indoors.
Because limes are tender and frost kills them, indoor starting is about warmth and protection rather than beating a frost date. In Zones 3–8, start seeds indoors in late winter so seedlings are strong by the time warm weather arrives — but remember a seed-grown lime will live in a pot that comes indoors for winter in these zones. In Zones 9–10, start indoors in late winter or sow in pots outdoors once nights are reliably warm. In frost-free Zones 11–13, you can start lime seeds in pots at almost any time of year; check your local extension service for the best local window. Use the frost date calculator to find your last frost date, and the hardiness zone finder to confirm your zone.
Frost dates vary by microclimate, so confirm your dates with your local extension service, and use the last first frost lookup to check your own frost dates before you sow.
What you need
- Fresh limes seed — check the packet date; test old seed with the seed viability checker.
- Seed starting mix — fine, sterile and free-draining. Do not use garden soil.
- Containers — cell trays, small pots or soil blocks, cleaned before use.
- A tray and a clear lid — to hold humidity until germination.
- Labels and a marker — you will not remember what you sowed in three weeks.
- A spray bottle — for gentle watering that does not wash small seeds away.
- A grow light — a sunny windowsill is rarely enough. Our grow light calculator helps you set it up.
- Potting mix for potting on — seedlings outgrow seed mix once they have true leaves.
Step by step: starting limes seeds indoors
- Fill containers with damp seed mix. Moisten the mix first — it should feel like a wrung-out sponge. Fill to just below the rim.
- Sow the seed. Sow two seeds per pot, about half an inch deep, and cover with mix. Limes germinate in the dark, so cover them — but sow fresh seed the same day you open the fruit, since citrus seed dies quickly once it dries out.
- Label everything. Write the crop and the sowing date on the label now, not later.
- Cover to hold humidity. Put a clear lid or cling film over the tray so the surface stays moist.
- Keep warm and wait. Limes seeds take 14–28 days to germinate — do not throw the tray away after a week. The germination time calculator gives you a realistic window.
- Remove the cover as soon as seedlings appear. A closed, humid tray is where damping off starts.
- Give light immediately. Move the tray under a grow light or to your brightest window, with the light 2–3 inches above the leaves.
- Water from below. Stand the tray in a shallow dish of water, let the mix soak it up, then drain.
- Thin to one seedling per cell. Snip the weaker seedling off at soil level — do not pull it out, or you will disturb the roots of the one you keep.
- Pot on when the roots fill the cell. Once seedlings have two sets of true leaves, move each one into a larger pot of potting mix. Handle seedlings by their leaves, never by the stem.
Light for seedlings
Light is the single biggest difference between sturdy seedlings and leggy ones. A windowsill that looks bright is often far too dim for a seedling, because glass cuts light and late-winter days are short. Give limes seedlings 14–16 hours of light a day from a grow light hung 2–3 inches above the leaves, raising it as the plants grow. Our grow light calculator helps you set it up. Seedlings that stretch tall, pale and thin need more light — move the light closer at once.
Watering seedlings
Limes have moderate water needs. Keep the mix evenly moist, never soggy and never bone dry: check daily by touching the surface, and water if it feels dry. Water from below when you can, by standing the tray in a shallow dish for ten minutes and then draining it, so the surface stays dry and the roots grow down. Our watering calculator gives a starting point for amounts. Use room-temperature water and water in the morning. The two mistakes that cause most seedling losses are overwatering, which rots roots and invites damping off, and letting trays dry out completely, which kills fine roots in hours.
Hardening off
Hardening off is the week of gradual exposure that turns a soft indoor seedling into a plant that can survive outdoors. Start 7–10 days before planting out: put seedlings outside in a sheltered, shady spot for an hour or two on day one, then leave them out a little longer each day, with more sun and wind, until they spend full days outside. Do not leave them out overnight until the last couple of days, and bring them in if frost is forecast — limes are tender, so a frosty night can undo weeks of work.
Transplanting outdoors
A seed-grown lime is a long-term pot plant first and a garden tree second. Move seedlings into their own pots once they have two sets of true leaves, and pot on into a larger container as the roots fill each one. In Zones 9–13 you can plant out in the ground once the seedling is sturdy and all frost danger has passed, in full sun with 120–180 inches of space around it — that is the mature spacing, so give a young tree room to grow into. In colder zones, keep it in a pot that spends summer outdoors and winter in a bright, cool room. Our plant spacing calculator works out container and bed spacing, and the companion planting finder suggests neighbours — borage, marigolds, clover and chives all grow well around citrus.
Transplant on a cloudy day or in the evening, water each plant in well, and mulch lightly around the base. Check daily for the first week — a seedling's roots are still shallow.
Common problems and fixes
| Problem | Likely cause | Fix |
|---|---|---|
| Seeds never sprout | Seed dried out before sowing, or old seed | Sow fresh seed the same day you open the fruit; keep pots warm and moist for the full 14–28 day germination window |
| Seedling wilts after watering | Cold water or cold draughts on a tender tropical seedling | Water with room-temperature water and keep seedlings away from cold windows and draughts |
| Leaves turn yellow | Overwatering in a pot without drainage, or cold roots | Use pots with drainage holes, let the top of the mix dry between waterings, and keep pots warm |
| Leggy, pale seedling | Not enough light indoors | Move to the brightest window or under a grow light 2–3 inches above the leaves |
Watch for pests once plants are outdoors: the common pests of limes are aphids, slugs, cutworms. Check plants weekly, looking under leaves as well as on top, and act early. Our pest identifier helper can help identify what you are seeing, and the plant disease checker helps narrow down leaf and stem problems.
Seeds that never germinate
Lime seed is the classic case of fresh-is-everything.
Yellowing leaves on a young lime
Yellow leaves on a potted lime seedling almost always mean wet, cold roots.
A seedling that never becomes a fruiting tree
This is not a failure, it is the nature of seed-grown citrus.
Frequently asked questions
Can I grow a lime tree from a seed in a supermarket lime?
Yes, you can, and it will usually germinate if the seed is sown fresh. But the tree will not necessarily produce fruit like the parent lime, and it may take many years to fruit at all. Grow it as a fun project and a houseplant; buy a grafted tree if you want reliable fruit.
How long do lime seeds take to germinate?
Lime seeds take 14–28 days to germinate. Keep the pots warm and the mix evenly moist for the whole period, and do not throw the pots away after two weeks — citrus is slow to wake up.
Do lime seeds need light to germinate?
No. Sow lime seeds about half an inch deep in seed mix and cover them; they germinate in the dark. Light matters once the seedling appears — then give it as much bright light as you can.
Can I grow limes indoors all year?
Yes, in a large pot in a bright spot, and many gardeners in cold zones do exactly that. Move the pot outdoors for summer and bring it in before the first frost. Limes are tender and frost will damage or kill them.