The next time you chop green onions, prepare celery or trim a bunch of basil, look at what is left on the cutting board before tossing it in the compost. Some of those scraps still have the growing points they need to produce fresh leaves, new stems or even a whole new crop.

A small windowsill garden will not replace a vegetable patch or your weekly grocery trip. But it can cut down on waste, provide fresh garnishes, and make a wonderful hands-on project for children and beginner gardeners. You don’t need much to get started: a few clean jars, some water, a sunny window and, for longer-term growing, a container of potting mix.

A useful distinction: Regrowing celery, lettuce or bok choy generally gives you a modest second harvest of leaves—not another full supermarket-sized head. Potatoes, sweet potatoes, garlic, ginger and turmeric are different: given the right season, soil and growing conditions, they can develop a genuinely new edible crop.

What you’ll need

• Clean jars or shallow bowls; use only food-safe containers.
• Fresh, healthy vegetable bases, garlic cloves, rhizomes or herb cuttings.
• Clean water, replaced regularly.
• Small pots with drainage holes and fresh, well-draining potting mix.
• A bright window, or an LED grow light during dark Canadian winter months.
• Clean scissors, a knife and plant labels.

Water versus soil: Water is an easy way to observe roots and start new growth. Soil is usually better for keeping a plant productive because its roots can access nutrients and space. Never submerge a whole lettuce or celery stump, and discard scraps that become slimy, mouldy or foul-smelling.

1. Green onions: the quickest place to start

Green onions (scallions) are an excellent first project because the white rooted end often starts sending up new green growth within days. They are also handy in soups, omelettes, salads and baked potatoes.

Water method

1. Save the base: Leave about 5–8 cm (2–3 in.) of white and pale-green stem with the roots attached.
2. Add water: Stand the bases upright in a narrow jar. Add enough water to cover the roots and very bottom of the white section, not the entire bulb.
3. Give light: Put the jar in bright light, ideally with several hours of indirect sun.
4. Refresh: Empty and replace the water every one or two days; rinse the jar if it develops a film.
5. Harvest: When green shoots are long enough to use, snip some tops with clean scissors while leaving the white growing base intact.

Soil method

1. Fill a pot with drainage holes with damp potting mix.
2. Plant the rooted ends upright, covering the roots while leaving the cut tops above the soil.
3. Keep them in bright light and water when the top of the mix begins to dry.
4. Harvest the green tops selectively; allow the plants to recover between cuts.

What to expect: Green shoots may become visible in roughly 3–7 days under good conditions. Water-grown onions can make several small harvests, but growth often weakens without nutrients. Soil is better if you want to keep them going.

2. Celery: new leaves from the centre

The bottom of a celery bunch can form a small crown of fresh growth. It is a satisfying experiment, although the result is usually leafy, slender celery—not a replacement for a full grocery-store bunch.

Water method

1. Cut the stalks away, preserving a firm base about 5 cm (2 in.) tall.
2. Set the base cut-side up in a shallow dish with around 1 cm (½ in.) of water touching the bottom.
3. Put the dish in bright indirect light.
4. Replace the water every one or two days; remove deteriorating outer tissue.
5. Once new central leaves and roots develop, move the base to potting mix for continued growth.

Soil method

1. Choose a healthy celery base showing a growing centre; roots are helpful.
2. Nestle the base into moist potting mix, covering its bottom and any roots while leaving the crown exposed.
3. Place it in bright light and keep the soil evenly moist, not soaked.
4. Harvest only the outer, developed leaves or small stalks once the plant is established.

What to expect: New central leaves can appear within about a week, but substantial stalk regrowth takes longer and may be limited.

3. Romaine lettuce and bok choy: regrow the leafy centre

Both plants have a central growing point capable of sending up another flush of leaves. The trick is preserving the base and keeping it from rotting.

Romaine lettuce: water start

1. Save the bottom 5 cm (2 in.) of a romaine heart, keeping its centre intact.
2. Stand the base upright in a shallow bowl with roughly 1 cm (½ in.) of water around its bottom.
3. Place it near a bright window, out of intense midday heat.
4. Change the water daily or whenever cloudy; watch for fresh leaves in the centre.
5. Harvest small tender leaves, or plant the base in potting mix once healthy roots appear.

Romaine lettuce: direct-to-soil option

1. Set the trimmed base into damp, well-draining potting mix with its crown above the surface.
2. Keep it in bright light and keep the mix lightly moist.
3. Pick young centre leaves while the plant remains healthy.

Realistic result: A handful of young leaves is more likely than a second full head. Older leaves may turn bitter, particularly in heat.

Bok choy: water start

1. Save 4–5 cm (about 1½–2 in.) of the firm white or pale-green base.
2. Put it cut-side up in a shallow dish with only the bottom touching water.
3. Keep it in bright indirect light.
4. Change the water daily and check the base for soft spots.
5. Once centre leaves and roots have developed, move it into soil; harvest outer leaves as they grow.

Bok choy: direct-to-soil option

1. Place the firm base into a pot of damp mix, leaving the central growing point exposed.
2. Provide bright light, moderate temperatures and regular but not excessive watering.
3. Harvest small leaves after they have developed.

Canadian growing tip: Lettuce and bok choy generally prefer cooler conditions. A hot summer windowsill can make growth tough or bitter.

4. Potatoes and sweet potatoes: growing an actual new crop

Unlike lettuce and celery, these are not really windowsill snip-and-regrow projects. The goal is to raise new plants and eventually harvest new underground potatoes or sweet potato storage roots. They also require more space and time.

Regular potatoes: soil method

1. Choose planting stock: For a real garden crop, buy certified disease-free seed potatoes. Sprouted grocery potatoes demonstrate the principle but may carry plant diseases and should not be introduced into productive garden soil.
2. Prepare pieces: Small seed potatoes can be planted whole. Cut larger ones into sturdy pieces with at least one or two healthy eyes per piece.
3. Allow healing: Let cut surfaces cure according to the seed supplier’s directions, generally for several days in suitable conditions, rather than putting wet cuts straight into soil.
4. Plant: Place the pieces eyes-up and cover with roughly 10 cm (4 in.) of loose soil. Give each plant adequate spacing.
5. Hill and water: As leafy stems grow, mound additional soil around them so developing tubers are kept out of sunlight. Water deeply as needed without leaving soil waterlogged.
6. Harvest: Dig new potatoes when the variety has developed tubers, or wait until the plants mature for a main crop.

Important: Never eat potato leaves, shoots or green tubers. Tubers exposed to light can accumulate harmful glycoalkaloids. Plant potatoes for their underground tubers, not their foliage.

Sweet potatoes: water-start method for slips

1. Choose a firm, healthy sweet potato, preferably disease-free planting stock for a garden crop.
2. Support it over a jar using toothpicks, leaving its lower portion in water; alternatively, lay it partly buried in moist potting mix.
3. Keep it warm and bright, replacing water whenever cloudy and at least about weekly.
4. When vine-like shoots called slips are approximately 15–30 cm (6–12 in.) long, gently twist them off.
5. Put the lower parts of the slips in fresh water, keeping leaves out of the water, until roots develop.
6. Plant rooted slips in loose, warm, well-drained soil after frost danger has passed, spacing them roughly 30–45 cm (12–18 in.) apart.

Sweet potatoes: soil-start option

1. Lay the parent sweet potato partly buried in a tray of moist, clean growing medium in a consistently warm spot.
2. Keep the medium moist but not saturated until shoots develop.
3. Separate and root the slips, then transplant them outdoors when the soil has warmed.

Ontario note: Sweet potatoes can grow successfully in Ontario, especially with sufficient warmth and a long frost-free season. They are frost-sensitive. Short-season varieties and warm raised beds are particularly useful for home gardeners.

5. Garlic: grow greens quickly, bulbs slowly

A garlic clove contains everything needed to form a new plant. For a quick indoor project you can grow garlic greens; for a full bulb, plant cloves in soil and give them a proper growing season.

Water method: short-term garlic greens

1. Select a firm, sound garlic clove and leave its basal plate intact.
2. Stand it root-end down in a tiny amount of water; only the base should touch the water.
3. Keep in bright light and replenish clean water as needed.
4. When a green shoot develops, harvest a little of the young green growth, or transplant the clove to soil before it deteriorates.

Soil method: greens or a new bulb

1. Separate a garlic bulb into individual cloves, leaving the papery skins on.
2. Plant pointy-end up, typically a few centimetres deep in well-drained soil. Follow regional guidance for fall depth and winter protection.
3. Give the plants a sunny position and avoid soggy soil.
4. Snip green shoots for a modest early harvest or leave the foliage to feed a developing bulb; frequent clipping will reduce bulb development.
5. For mature bulbs, harvest when the appropriate portion of the foliage has yellowed, then cure before storage.

Ontario note: Garlic is normally planted in autumn and harvested the following summer. Many garlic varieties need a period of cold to form bulbs properly.

6. Ginger and turmeric: warm-weather rhizomes

These are slower projects, but they are excellent choices for containers if you can provide consistent warmth. Both grow from underground stems called rhizomes, rather than ordinary roots.

Ginger: soil method

1. Select a firm, plump ginger rhizome with visible buds or eyes.
2. Cut into pieces about 2.5–5 cm (1–2 in.) long if needed, keeping at least one good bud on each piece.
3. Let cut faces dry and begin healing for a day or several days, depending on conditions.
4. Place pieces horizontally, buds facing up, about 2.5–5 cm (1–2 in.) deep in a wide pot of moist, well-draining mix.
5. Keep warm (roughly room temperature or warmer), with bright filtered light and lightly moist soil until shoots appear.
6. Grow on for many months, eventually harvesting tender baby ginger or allowing larger rhizomes to develop.

Water option: A brief warm-water soak can help rehydrate a slightly dry rhizome before planting, but do not grow ginger submerged in a jar as if it were a green onion. Soil is the recommended home method.

Turmeric: soil method

1. Choose a firm turmeric rhizome with at least one clearly visible bud.
2. Divide into sections if necessary, ideally keeping one or two buds per piece.
3. Allow fresh cut surfaces to dry briefly to reduce rot risk.
4. Set the pieces buds-up in a broad pot and cover with roughly 5–10 cm (2–4 in.) of potting mix, following the variety and growing guidance. Keep the medium moist but well-drained.
5. Give the plant consistent warmth, good light and space for the large tropical leaves.
6. Harvest mature rhizomes after a long growing season, commonly when the foliage begins to die back.

Water option: Use water only to rinse or briefly rehydrate planting pieces; soil is the practical propagation medium. Prolonged submersion can encourage rot.

Canadian growing tip: Start both indoors. Move containers outside only once nights are reliably warm and bring them back before chilly autumn weather. Neither is suitable for an unheated Ontario winter windowsill.

7. Basil: root a cutting and keep harvesting

Basil is one of the more rewarding herbs to propagate because a healthy cutting can produce its own root system. With enough light and warmth, one plant can become several.

Water method

1. Take a healthy, non-flowering basil tip about 10–15 cm (4–6 in.) long, cutting just below a leaf node.
2. Remove the leaves on the bottom half while preserving healthy upper leaves.
3. Put the stem into a clean glass of water with at least one lower node underwater; no leaves should be submerged.
4. Keep in bright, indirect light and replace the water every one or two days.
5. When a healthy group of roots is roughly 2.5–5 cm (1–2 in.) long, transfer the cutting into potting mix.

Soil method

1. Plant the rooted cutting in a small pot of moist, well-drained mix, covering the roots while keeping the leaves above the surface.
2. Keep warm and in bright light; avoid a cold window in winter.
3. Water when the surface starts to dry, without letting the root ball become bone dry.
4. Once growth is vigorous, pinch the tip just above a leaf pair to encourage branching.
5. Harvest stems regularly, always leaving healthy leaves so the plant can regrow.

Best use: Pizza, pasta, pesto and fresh salads.

8. Mint: an easy cutting that needs its own pot

Mint roots readily and often grows vigorously once established. That is useful for kitchen harvests but a warning for gardeners: mint can spread aggressively in open ground.

Water method

1. Snip a healthy 10–15 cm (4–6 in.) mint tip just below a node.
2. Remove leaves from the section that will be underwater.
3. Put the stem in clean water, submerging one or more lower nodes.
4. Place in bright indirect light and refresh the water every one or two days.
5. When several roots have formed, move the cutting to potting mix.

Soil method

1. Plant the rooted cutting in a separate pot with drainage holes.
2. Give it bright light or partial sun, depending on heat and exposure.
3. Keep the mix moderately moist, not saturated.
4. Pinch growing tips to encourage more branching.
5. Cut stems as needed, leaving enough leafy growth for recovery.

Best use: Tea, iced drinks, fruit salads, sauces and desserts.

9. Cilantro: possible from cuttings, more reliable from seed

Cilantro deserves a place in the experiment, with one important qualification. A cutting may root if it is fresh and has viable nodes, but supermarket bunches often wilt or rot instead. Direct sowing seeds is a more reliable way to get repeat harvests.

Water method: optional cutting experiment

1. Choose a very fresh, living cilantro stem with healthy leaves and identifiable lower nodes. A trimmed supermarket stalk without growing nodes is unlikely to work.
2. Take a 10–15 cm (4–6 in.) section, if available, and remove leaves from its lower portion.
3. Put a lower node into a glass of water while keeping the leaves dry.
4. Refresh the water every one or two days and provide bright, indirect light.
5. If genuine roots form, pot the cutting carefully. If the stem softens or yellows instead, compost it and switch to seed.

Soil method: the recommended approach

1. Fill a pot at least 15–20 cm (6–8 in.) deep with potting mix.
2. Sow cilantro/coriander seed about 0.5–1 cm (¼–½ in.) deep, following the seed packet for spacing.
3. Keep soil evenly moist through germination and provide plenty of light.
4. Grow in relatively cool conditions; hot weather can trigger early flowering (bolting).
5. Harvest outer leafy stems while the centre grows. Sow another small batch every two to four weeks for a steadier supply.

Best use: Salsa, curries, soups, tacos and fresh garnishes.

What works best? A realistic comparison

Scrap or cutting	Best starting method	Likely result	Difficulty
Green onions	Water or soil	Repeated green tops	Very easy
Celery	Shallow water, then soil	Small new leaves and stalks	Easy
Romaine lettuce	Shallow water or soil	Small leaves, not a whole new head	Easy
Bok choy	Shallow water, then soil	Young leaves	Easy
Regular potatoes	Soil; certified seed tubers	New potatoes over a season	Moderate
Sweet potatoes	Warm water or soil for slips, then soil	New plants and storage roots	Moderate
Garlic	Soil	Garlic greens or a mature bulb	Easy to moderate
Ginger	Warm potting mix	New ginger rhizomes over months	Moderate
Turmeric	Warm potting mix	New turmeric rhizomes over months	Moderate
Basil	Water-rooted cuttings, then soil	A new herb plant	Easy
Mint	Water-rooted cuttings, then soil	A vigorous new herb plant	Very easy
Cilantro	Seed; cuttings only as an experiment	Fresh leaves from seed-grown plants	Easy from seed

Five mistakes that spoil regrowing projects

1. Too much water. A shallow base should only touch the water; completely submerging it can cause rot.

2. Forgetting to change the water. Cloudy water, slime or an unpleasant smell are warning signs. Change it promptly and discard anything mouldy or rotten.

3. Expecting soil-grown harvests from a jar alone. Water helps many scraps start growing, but it is not a complete long-term growing system without nutrients and management.

4. Providing too little light in winter. In much of Canada, short winter days mean weak, stretched growth. A suitable grow light may be more effective than a dim windowsill.

5. Expecting a full crop from every scrap. Treat celery, lettuce and bok choy as a way to enjoy a small second harvest. Treat potatoes, sweet potatoes, garlic, ginger and turmeric as proper gardening projects.

A small Canadian windowsill garden is a good place to begin

If you’re trying this for the first time, start with green onions, basil and mint. They’re inexpensive, show visible progress and don’t demand much space. Next, try a celery base or a bok choy stump. When spring arrives, make room for a potato grow bag, sweet potato slips or containers of ginger.

The most satisfying part isn’t getting something for nothing. It’s learning which foods still have the potential to grow, making better use of what you buy, and finding small opportunities to produce fresh food—even when you don’t have a large garden.

What have you successfully regrown from kitchen scraps? Share your experience in the comments at Canadian Country Life, especially if you have tips for growing indoors through an Ontario winter.

Verified sources and further reading

• University of British Columbia Okanagan — Regrow Plants From Kitchen Scraps
• Royal Botanical Gardens, Ontario — Re-Growing Table Scraps in Your Garden
• Iowa State University Extension — How to Grow Vegetables from Kitchen Scraps
• Ontario Ministry of Agriculture — Garlic Production
• University of Minnesota Extension — Growing Potatoes
• University of Illinois Extension — Sweet Potato Growing Guide
• Foodland Ontario — Sweet Potatoes
• Penn State Extension — Growing Ginger
• Penn State Extension — 2026 Herb of the Year: Turmeric
• Penn State Extension — Cilantro, a Unique Culinary Herb

Editorial note: All illustrations are original AI-generated educational images. The article’s written measurements and safety qualifications take precedence where a simplified illustration differs from horticultural recommendations.