The fastest harvest you will ever grow
Outside, the garden is winding down. Nights are cooler, daylight is shrinking, and most outdoor crops have either been picked or are limping toward the compost heap. Inside, though, October is the perfect month to start the fastest harvest you will ever grow: microgreens on a windowsill.
Microgreens are young seedlings of vegetables, herbs and other edible plants, harvested when they are just a few centimetres tall, shortly after their first true leaves appear. A tray sown on a Monday can be on your plate the following weekend. Few other gardening projects reward you that quickly, and none of them ask so little in return: a shallow tray, some seeds, a little growing medium, water, and the brightest windowsill in the house.
That combination of speed and simplicity is why microgreens are having a moment this October. Kitchen-garden coverage this month has turned toward small indoor harvests, with fresh guides on starting a mini kitchen garden and growing microgreens without special equipment appearing in the last few days. The appeal is easy to understand. As outdoor beds empty out, a tray of green on the kitchen sill keeps fresh flavour coming, week after week, through autumn and winter, with no garden, no greenhouse and no experience required.
This guide covers everything a beginner needs: what microgreens are and how they differ from sprouts, why October is an ideal starting month, the small kit you need, ten reliable varieties with their own growing notes, a step-by-step method, a simple weekly sowing plan that keeps harvests continuous, and the mistakes that trip most first-timers up. By the end, you will know exactly how to turn one windowsill into a year-round supply of fresh greens.
What microgreens actually are
Microgreens, sprouts and baby greens are not the same thing
People often use these three terms interchangeably, but they describe different stages and methods, and the distinction matters for food safety as well as for growing.
Sprouts are seeds germinated in water, usually in a jar, and eaten whole, roots and all, after just a few days. They grow in the dark, in damp conditions, with no growing medium and no light. Bean sprouts and alfalfa sprouts are the familiar examples.
Microgreens grow in a shallow layer of growing medium, in the light, and are cut just above the surface once their first true leaves have opened. You eat the stem and leaves, not the roots. They typically take seven to twenty-one days from sowing, depending on variety, and they develop real flavour and colour in that time. Radish, broccoli, mustard, pea shoots and sunflower greens are all classic microgreens.
Baby greens are the next stage on: leafy crops such as spinach or lettuce picked young, usually three to four weeks after sowing, once the leaves are several centimetres across. They need more space and more time than microgreens, and they are grown much like ordinary salad crops.
For the windowsill grower, microgreens hit the sweet spot. They are faster than baby greens, sturdier and more flavourful than sprouts, and they grow in ordinary light rather than needing a jar-rinsing routine.
Why they taste like so much more than their size
A microgreen is a small plant with a big personality. Because the seedling is harvested at the stage when its stored energy and early growth are concentrated in a tiny shoot, the flavour is often more intense than the mature plant. Radish microgreens carry the same peppery bite as a full radish, mustard microgreens are sharply pungent, and pea shoots taste like sweet, fresh peas. That intensity is exactly why chefs scatter them over finished dishes: a small pinch changes the flavour of a whole plate.
Their texture matters too. Most microgreens are crisp and tender at the same time, which makes them useful in places where a mature leaf would be too bulky or too chewy. They sit lightly on soups, eggs, toast, sandwiches and grain bowls, adding colour, crunch and a fresh finish without dominating the dish.
Why October is the ideal month to start
The outdoor garden is closing, but the windowsill is not
October is the month when the outdoor growing season visibly turns. Beds are cleared, tender plants are brought under cover, and the first frosts start to threaten anything still standing. A windowsill tray ignores all of that. Indoors, the temperature stays in the range most microgreens prefer, roughly 15 to 22 degrees, and a bright window still delivers useful light well into autumn.
Starting in October also sets up a useful habit before winter. If you sow your first tray now, you will have worked out your windowsill, your watering rhythm and your favourite varieties by the time the shortest days arrive. Then, when the garden is truly dormant in December and January, the weekly tray is already routine rather than a new project competing with the festive season.
Light is the only thing to watch
The one seasonal factor that genuinely matters is light. As days shorten, a windowsill that was blazing in June may be merely bright in October and gloomy by December. For now, most varieties will do well on a bright, south- or west-facing sill, or the brightest window you have. If seedlings grow tall, pale and floppy, they are telling you they need more light. Rotating the tray a quarter-turn each day keeps growth even, and a small clip-on LED grow light, run for twelve to fourteen hours a day, solves the problem entirely if your windows are shaded. You do not need a special grow room, just enough light to keep the stems short and the leaves a healthy green.
The kit: almost nothing you do not already own
One of the best things about microgreens is how little gear they require. You do not need a special kit, a greenhouse, or a shelf of equipment. This is the complete list:
- Two shallow trays or containers, about 3 to 5 centimetres deep, with drainage holes in at least one. Clean takeaway containers with holes poked in the base work perfectly, as do ordinary seed trays. The second tray acts as a lid during germination and as a drip tray afterwards.
- A growing medium: fine seed-starting mix, coconut coir, or a soilless grow mat. Ordinary garden soil is not ideal; it can be heavy, uneven and carry weed seeds. A bag of seed-starting mix will last dozens of trays.
- Seeds labelled for microgreens or sprouting. This matters more than it sounds: seeds sold for growing to maturity may carry chemical treatments that are not meant for eating at seedling stage. Buy from a reputable seed supplier and check the packet says the seeds are untreated and suitable for microgreens.
- A spray bottle for gentle watering.
- A small board, plate or second tray to press seeds into contact with the medium.
- Clean scissors for harvesting.
That is everything. The total outlay for a first tray is small, and each subsequent tray costs little more than the seeds themselves, which is part of why a weekly tray works out far cheaper than buying small punnets of cut microgreens.
Ten easy microgreens for your first trays
The ten varieties below are chosen for reliability, speed and distinct flavour. Start with two or three, learn how they behave on your windowsill, then widen the rotation. Harvest times are approximate; warmer rooms and brighter light speed things up, cooler rooms slow them down.
1. Radish
Radish is the classic beginner microgreen and the fastest of the lot, often ready in six to ten days. The seedlings are vivid, with pink stems and green leaves, and they carry a clean peppery heat that wakes up salads, sandwiches and noodle bowls. Sow densely, keep the tray covered for the first two or three days, then give it bright light. Radish tolerates a little beginner clumsiness, which is why it is the variety most guides recommend first. If you grow only one microgreen, grow this one.
2. Broccoli
Broccoli microgreens are mild, fresh and slightly earthy, which makes them the most versatile variety on this list. They are ready in about eight to twelve days, and they suit people who like the idea of microgreens but are unsure about strong flavours. Scatter them over eggs, stir them into grain bowls, or pile them on toast. They are also one of the most forgiving varieties if your light is less than perfect, though they still grow sturdier with a bright window.
3. Mustard
Mustard microgreens deliver a sharp, almost horseradish-like kick, and they are ready in about seven to twelve days. A small amount goes a long way: a pinch on top of a curry, a sandwich or a soup adds heat without changing the dish. Sow them a little less densely than radish, because crowded mustard trays are more prone to mould. If you enjoy bold flavours, mustard earns its place in every rotation.
4. Pea shoots
Pea shoots are the sweetest microgreen on this list and the only common one that regrows after cutting. Soak dried marrowfat peas for about twelve hours before sowing, spread them over the medium, and harvest in ten to fourteen days. The shoots are crisp, sweet and substantial, excellent in stir-fries, salads, or eaten straight from the tray. After the first cut, leave the tray in the light and water lightly, and a second, smaller harvest usually follows within a week to ten days.
5. Sunflower
Sunflower microgreens are crunchy, nutty and satisfying, with thick stems and broad leaves that feel like a real ingredient rather than a garnish. They take a little longer, roughly ten to fourteen days, and the seeds benefit from an overnight soak before sowing. Use seeds sold specifically for microgreens, and check the packet: some sunflower seed is sold for bird feed and is not suitable for eating. Their size means they need slightly deeper trays and a bit more space per seed than the small brassicas.
6. Fenugreek (methi)
Fenugreek, familiar in Indian kitchens as methi, is one of the speediest and most useful microgreens for everyday cooking. It is ready in about seven to ten days and has a gentle, slightly bitter, aromatic flavour that works in salads, flatbreads, dals and raitas. The seeds are cheap, widely available, and germinate enthusiastically. Because fenugreek grows so readily, it is an excellent choice for a first tray if you already cook with methi leaves and want a fresh supply through winter.
7. Kale
Kale microgreens are mild, slightly sweet and very tolerant of cooler indoor temperatures, which makes them a strong autumn and winter choice. They take about nine to fourteen days to reach harvest. The leaves are a deep green with a pleasing texture, and they blend into any salad or smoothie without dominating it. Kale is a good bridge variety: easy enough for beginners, but with enough character to keep growing once you are experienced.
8. Cress
Cress is the microgreen many people grew as children, and it still earns its place. It germinates in days, is ready in about seven to ten days, and has a peppery flavour similar to watercress. Cress grows well on a damp mat or a shallow layer of medium, and it is a good choice if you want visible results quickly, especially when growing with children. Keep it moist but never waterlogged, and harvest as soon as the leaves look full and green.
9. Beet
Beet microgreens are the showpiece of the tray: deep red stems and green leaves flushed with crimson, with an earthy sweetness that pairs well with goats cheese, citrus and roasted vegetables. They are slower than the brassicas, usually taking twelve to eighteen days, and the seeds are actually seed clusters, so you may see two or three seedlings emerge from each one. Sow them a little more thinly than radish and give them bright light to bring out the colour. They are worth the wait.
10. Basil
Basil is the slowcoach of this list, and the one to try once you have a few trays under your belt. It needs warmth, steady light and about fourteen to twenty-one days to reach a useful size, and it dislikes cold draughts and wet leaves. The reward is unmistakable: tiny leaves with the full, sweet aroma of fresh basil, ready in the middle of winter when shop-bought basil is at its most disappointing. Keep the medium barely moist, give basil your warmest, brightest sill, and harvest by pinching the tops rather than cutting at the base.
The step-by-step method
Every variety above follows the same basic routine. Once you have done it twice, it becomes a ten-minute job.
Step 1: Prepare the tray
Fill your tray with about 2 to 4 centimetres of moist growing medium and level the surface gently. The medium should feel like a wrung-out sponge: damp all the way through, but not dripping. If you are using a grow mat, soak it first and lay it flat in the tray. If your tray has no drainage holes, be extra careful with water, since there is nowhere for excess to go.
Step 2: Sow densely and evenly
Scatter the seeds across the surface so they sit close together but in a single layer, with no piles and as few gaps as you can manage. Microgreens are sown far more densely than ordinary crops; the seedlings support each other as they grow, which keeps stems upright. As a rough guide, a standard seed tray of about 20 by 30 centimetres takes roughly one to two tablespoons of small seed such as radish or broccoli, and a good handful of large seed such as peas or sunflower. Check the seed packet for the variety you are growing, and sow a little more thinly the first time if you are unsure.
Step 3: Press the seeds into contact
Press the seeds gently down with a small board, the base of another tray, or the flat of your hand. Good contact between seed and damp medium is what gets germination started quickly. Do not bury the seeds; most microgreen seed germinates best sitting on or just barely below the surface. A very light dusting of fine medium over the top is fine for larger seeds such as peas and sunflower, but skip it for small seeds.
Step 4: Mist and cover for germination
Mist the surface lightly with the spray bottle, then cover the tray. You can use an inverted second tray, a lid, or a board. The cover does three jobs: it keeps moisture in, it keeps the seeds in the dark, and it gives the emerging seedlings something to push against, which encourages strong root growth. Keep the tray somewhere warm, at ordinary room temperature, for two to three days. Check daily and mist if the surface is drying out.
Step 5: Uncover and move into the light
Once most of the seeds have sprouted and you can see small pale shoots, remove the cover and move the tray to your brightest windowsill. The seedlings will look pale and yellowish at first; this is normal. Within a day or two of light they will green up as their leaves open. From this point on, light is the main thing they need.
Step 6: Water from below where you can
Once the seedlings are standing, switch to bottom watering when your tray setup allows it: set the growing tray into a shallow tray of water for a few minutes, let the medium draw moisture up, then drain away any excess. Bottom watering keeps the leaves dry, which is the single most effective thing you can do to prevent mould. If your tray has no drainage, keep misting gently, but aim at the medium rather than soaking the leaves, and never leave water standing in the tray.
Step 7: Harvest at the first true leaves
Most microgreens are ready when they are about 5 to 8 centimetres tall and their first true leaves have opened. The first leaves you see after germination are the seed leaves, which are smooth and simple in shape. The true leaves that follow look like miniature versions of the adult plant's leaves, and they mark the moment of peak flavour. Cut with clean scissors just above the medium, and harvest only what you need for a meal, leaving the rest standing. Harvested greens taste best eaten the same day.
Soil, coir or grow mat: which medium should you choose?
Beginners often assume the medium matters more than it does. All three common options work, and the best one is the one you will actually keep using. The comparison below sets out the trade-offs.
- Seed-starting mix: cheap, widely available, and forgiving. It holds moisture well and gives seedlings a stable base. The downside is a little mess when you empty spent trays, and you should use fresh mix for every batch rather than reusing it, since old roots and leftover moisture can carry disease.
- Coconut coir: light, clean and easy to handle. Coir holds water well while still draining freely, and it produces tidy trays with very little mess. It is usually sold as compressed bricks that expand in water, so a single brick lasts for many trays. The downside is that it contains almost no nutrients, but microgreens grow so quickly that they rarely need feeding anyway.
- Soilless grow mats: the tidiest option of all. You soak the mat, scatter the seed on top, and compost the whole mat after harvest. They are excellent for small seeds and for anyone who dislikes handling loose medium. The downside is cost: mats are more expensive per tray than mix or coir, and large seeds such as peas and sunflower root less securely into them.
If you are unsure, start with seed-starting mix or coir. Both are cheap, both work, and both let you learn the watering rhythm that matters far more than the medium itself.
Light, water and air: the three things that decide success
Light
Microgreens want bright, indirect light for most of the day. A south- or west-facing windowsill is ideal in autumn; an east-facing sill works too, though growth may be slightly slower. If the seedlings stretch tall and pale, with long gaps between the leaves, they are reaching for light they are not getting. Move the tray to a brighter window, or add a small LED grow light about 15 to 30 centimetres above the tray, running for twelve to fourteen hours a day. Rotate the tray a quarter-turn daily so the seedlings do not all lean toward the glass.
Water
The aim is consistent dampness, never sogginess. Water little and often rather than drenching the tray once. Bottom watering is best once roots are established, because wet leaves in still air are what invites mould. If you are misting, a light spray once or twice a day is usually enough in a normal room. In a warm room or on a sunny sill, check more often, since shallow trays dry out quickly.
Air
Gentle airflow is the most underrated factor in microgreen growing. A room with moving air dries leaf surfaces between waterings and keeps mould at bay. You do not need a fan aimed at the tray; simply keeping the tray in a lived-in room rather than a sealed cupboard, and leaving a small gap for air around the trays, is usually enough. If you notice persistent dampness and fuzzy growth, improve airflow before you change anything else.
The one-tray-a-week plan
A single tray gives you a burst of greens for a few days, then nothing. The fix is staggering: sow one tray every week, and you will always have a tray coming into harvest as the last one finishes.
- Week 1, day 1: sow tray one (radish).
- Week 1, day 7: harvest tray one; sow tray two (broccoli or mustard).
- Week 2, day 7: harvest tray two; sow tray three (pea shoots).
- Week 3, day 7: harvest tray three; sow tray four (sunflower or fenugreek).
Once the rhythm is running, the weekly job takes about ten minutes: empty the finished tray onto the compost, refill with fresh medium, sow, mist, cover. Keep a simple note of what you sowed and when, on a scrap of paper or in a phone note, so you know which tray is due for harvest. If you eat a lot of salads, sow two trays a week instead of one, or use a larger tray. The system scales easily in either direction.
For slower varieties such as beet and basil, sow them a few days earlier than the rest of the week's tray, or simply accept that they will overlap with the next batch. They are worth the small scheduling wrinkle.
Harvesting and storing
Harvest in the morning if you can, when the seedlings are crisp and cool. Use clean scissors and cut just above the medium, holding a small bunch gently so you do not crush the stems. Do not wash microgreens until you are about to use them: extra water on stored greens shortens their life. If they are gritty, rinse briefly and pat dry in a clean tea towel or a salad spinner.
For storage, line a small airtight container with a dry sheet of kitchen paper, lay the greens in loosely, and refrigerate. Most varieties keep for three to five days this way. Radish and mustard hold up best; delicate varieties such as basil and cress are best eaten within a day or two. Never store warm or wet greens, and check the container daily, removing any leaves that have gone soft.
One food-safety habit matters more than any other: clean the tray thoroughly between batches. Old medium, leftover roots and damp corners are where mould and bacteria build up. Wash trays with hot, soapy water, rinse well, and let them dry fully before reusing. Fresh medium for every batch, clean trays, and seeds sold for microgreens are the three habits that keep the whole enterprise safe.
Using microgreens in everyday meals
Microgreens are at their best as a finishing touch rather than a main ingredient. Think of them the way you would think of fresh herbs: a small amount, added at the last moment, lifts a dish that is already cooked.
- Salads and grain bowls: toss a generous handful through just before serving, so the greens stay crisp.
- Sandwiches, wraps and toast: layer them with the filling rather than underneath it, so they stay visible and crunchy. Radish and mustard are particularly good here.
- Eggs: scatter over scrambled eggs, omelettes or fried eggs at the table. Broccoli, cress and fenugreek all work well.
- Soups and dals: add a pinch on top of each bowl rather than cooking the greens into the pot, where they would wilt and lose their colour.
- Stir-fries and noodles: pea shoots and sunflower greens are sturdy enough to toss through at the very end, off the heat.
- Smoothies and juices: a small handful of kale or broccoli microgreens blends in without the fibrous texture of mature leaves.
A useful rule of thumb: if the dish is hot, add the microgreens after cooking, not during it. Heat collapses their texture in seconds.
Seven mistakes that spoil a tray
1. Sowing seeds that were not meant for eating
Garden seeds sold for growing to maturity may be treated with fungicides or coatings that are not safe to eat at seedling stage. Always buy seeds labelled for microgreens or sprouting, from a supplier you trust.
2. Overwatering
More trays fail from too much water than from too little. A soggy medium suffocates roots and invites mould. Aim for damp, not wet, and tip away any standing water.
3. Sowing too thickly
Dense sowing helps seedlings support each other, but a solid carpet of seed with no air between the stems traps moisture and encourages mould. If your first tray goes fuzzy, sow the next one about a third less densely and improve airflow.
4. Mistaking root hairs for mould
Fine white root hairs are a normal part of microgreen growth and are often mistaken for mould. Root hairs are short, straight and evenly distributed along the root; true mould is fuzzy, web-like, and usually grey or white in patches on the surface, often with an unpleasant smell. Learning to tell them apart saves many healthy trays from being thrown away.
5. Too little light
Leggy, pale seedlings with long stems and small leaves are almost always short of light. Move the tray to a brighter window, rotate it daily, and consider a small LED light in winter.
6. Harvesting too late
Microgreens left standing too long become tough, bitter and sometimes stringy. Harvest when the first true leaves open, not a week later. If a tray has gone past its best, compost it and sow fresh rather than eating tired greens.
7. Reusing medium and dirty trays
Old medium carries leftover roots, mould spores and depleted structure. Fresh medium and a clean tray for every batch cost almost nothing and prevent most problems.
Frequently asked questions
Do microgreens need fertiliser?
No, not for a normal harvest. The seed itself carries enough stored energy to grow a healthy seedling through the microgreen stage, and the growing medium supplies what little else is needed. Feeding is unnecessary and can encourage weak, leggy growth. If you are growing a slow variety such as basil to a larger size, a very dilute liquid feed is optional, but most growers never bother.
Can I grow microgreens without soil?
Yes. Soilless grow mats and coconut coir both work well, and both are cleaner than soil-based mix. Hydroponic trays with a mat and a shallow reservoir are also an option, though they need a little more attention to water levels. The sowing and harvesting steps are the same whichever medium you choose.
How much do microgreens cost to grow?
A first tray costs little more than the seeds and a bag of growing medium, and each follow-up tray costs mainly the seeds. A single packet of radish or broccoli microgreen seed, which costs very little, sows several trays. Grown weekly, a windowsill tray works out far cheaper per serving than buying cut microgreens, and you avoid the plastic packaging as well.
Are microgreens safe for children and older people?
Microgreens grown at home from untreated seed, in fresh medium, in clean trays, and harvested with clean scissors are a normal fresh food. As with any raw produce, people who have been advised to avoid raw foods for medical reasons should follow their clinician's advice. The key safety habits are the same ones in this guide: seeds sold for microgreens, fresh medium, clean trays, and no eating from a tray that smells off or shows mould.
Why did my microgreens go mouldy?
Mould usually comes from a combination of overwatering, overcrowding and still air. The fix is to sow a little less densely, water from below, improve airflow around the tray, and discard any tray that is already badly affected rather than trying to rescue it. Clean the tray thoroughly before the next batch.
Can I grow microgreens all year round?
Yes, that is one of their biggest advantages. A windowsill tray works in every season. In summer, move trays out of direct midday sun and water a little more often. In winter, give them your brightest window and consider a small LED light. The weekly sowing rhythm stays the same all year.
A small tray, a steady habit
Microgreens are not a project that asks for a garden, a budget or a season. They ask for one bright windowsill, ten minutes a week, and a little patience while the first tray germinates. In return, they give you the fastest harvest in gardening, fresh flavour in the months when the outdoor garden offers least, and a small daily reminder that growing food can be simple.
Start this October with one tray of radish or broccoli. Sow it, cover it, give it light, and cut it in about ten days. Then sow another. By the time the first frosts arrive, the windowsill will be doing what the garden cannot: producing fresh greens, every week, all winter long.
