Lemons from seed are a fun indoor project with a catch: the seed germinates in 14–28 days, the seedling grows into an attractive evergreen, but the tree takes 3–5 years to mature — and the fruit will not match the parent lemon, since citrus is normally grafted. Many seed-grown lemons never fruit well at all, but as a houseplant with fragrant leaves, the seedling is a delight.
Be honest about the goal before you sow: if you want lemons to eat, buy a grafted nursery tree. If you want a fragrant evergreen to grow in a pot — and the small thrill of a fruit one day — seed is perfect. Lemons are tender, so indoor sowing is not just a head start, it is the only option in most of the United States. Lemons can be started indoors or direct-sown — its sowing method is listed as "both" — and indoor sowing is the better choice if you want an earlier start, more even germination, or plants ready for the first warm weeks of the season. This crop is in the Rutaceae family, needs full sun, and takes 1095–1825 days to reach maturity, so the timing below is built around those facts, not guesswork.
Lemons at a glance
| Growing factor | What lemons need |
|---|---|
| Days to germination | 14–28 |
| Sowing method | both |
| Days to maturity | 1095–1825 |
| Soil pH | 5.5–6.5 |
| Spacing | 120–180 inches |
| Sun | full sun |
| Cold tolerance | tender |
When to start lemons seeds indoors
In Zones 3–8, start indoors 10–12 weeks before your last frost and grow the seedling on in a pot — it will live indoors for winter. In Zones 9–10, start indoors in late winter and move the pot outside once nights are warm. In frost-free Zones 11–13, sow any time; lemons are perennial trees there. 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: sow indoors 10–12 weeks before it if you are starting indoors at all, and check the seed packet against the germination time of 14–28 days. Our seed-starting calculator does the backwards maths for you, and the germination-time calculator helps you plan around that 14–28-day window. If you are unsure of your zone, the hardiness-zone finder will confirm it.
What you need
fresh lemons, a seed tray or small pots, seed-starting mix, a clear lid, a spray bottle, a heat mat (helpful), a grow light or the brightest windowsill you have, labels, and larger pots for potting on. Citrus seedlings grow a taproot early, so deep pots are better than shallow trays.
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 14–28 days, and it is easy to forget when you sowed.
Step by step: starting lemons 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. Take fresh seed from a lemon — seed from a shop lemon works, though it may be a hybrid — rinse off the pulp, and sow promptly while it is still moist, about half an inch deep in damp seed-starting mix. Do not let the seed dry out; dried citrus seed germinates poorly. Keep the tray warm (70–80°F) and bright. Germination takes 14–28 days and is usually good with fresh seed.
- 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 14–28 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
Lemon seedlings need 14–16 hours of bright light a day. A grow light a few inches above the leaves is the reliable option; a sunny windowsill works in spring. Without enough light the seedlings go pale and leggy, and a leggy citrus seedling rarely recovers into a sturdy tree.
Watering seedlings
Lemons have moderate water needs. Keep the mix evenly moist while seeds germinate, then water from below and let the surface dry slightly between waterings. Young citrus dislikes both drought and waterlogging — damp, not wet, is the rule. Our watering calculator can help you work out how much water your seedlings need as they grow.
Hardening off
Lemons are tender and hate cold wind as much as frost. Harden off over 10–14 days in warm, sheltered shade, building to a few hours of sun. Do not put a young lemon out at all until nights are reliably warm, and in Zones 9 and colder plan to grow it in a pot you bring indoors for winter.
Transplanting outdoors
Grow seedlings on in pots, moving them up as they grow, and plant out only in frost-free areas — in Zones 10–11, in full sun and soil pH 5.5–6.5. Space trees 120–180 inches apart. Our plant-spacing calculator works out the layout. In colder zones, keep the lemon in a large pot outdoors for summer and indoors by a bright window for winter. For the full picture — soil, feeding, pests and harvest — see our complete growing lemons guide.
Common problems and fixes
| Problem | Fix |
|---|---|
| Seeds do not germinate | The seed dried out before sowing, or the tray was too cool. Sow fresh, moist seed promptly and keep the tray warm — germination takes 14–28 days. |
| Leggy, pale seedlings | Not enough light. Move the grow light closer and give 14–16 hours a day. |
| Leaves yellow and drop | Usually overwatering, cold, or both. Keep young lemons warm, let the surface dry between waterings, and make sure pots drain freely. |
| Aphids on young growth | Wipe them off by hand or blast with water. Avoid sprays on a plant you may eat from. |
Seeds do not germinate
The seed dried out before sowing, or the tray was too cool. Sow fresh, moist seed promptly and keep the tray warm — germination takes 14–28 days.
Leggy, pale seedlings
Not enough light. Move the grow light closer and give 14–16 hours a day.
Leaves yellow and drop
Usually overwatering, cold, or both. Keep young lemons warm, let the surface dry between waterings, and make sure pots drain freely.
Good companions for lemons include borage, marigolds, clover, chives. 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
How long do lemon seeds take to germinate?
14–28 days in warm, damp conditions. Sow fresh seed promptly — dried seed germinates poorly.
Will a seed-grown lemon taste like the parent?
Probably not — citrus does not come true from seed, and many seed-grown lemons fruit poorly or not at all. Buy a grafted tree for eating lemons.
Can I grow a lemon tree indoors?
Yes — in a large pot by your brightest window or under a grow light. It makes a fragrant evergreen houseplant, and may fruit after several years.
How far apart should lemon trees be?
120–180 inches apart in full sun, in soil pH 5.5–6.5 — or one tree per large pot in cold zones.
When will a seed-grown lemon tree fruit?
Lemons take 1095–1825 days to mature, so expect fruit in 3–5 years at the earliest, if at all.