Indoor Gardening for Beginners: Grow Food Year-Round

Indoor gardening comes down to three things: enough light, a pot that drains, and watering only when the soil needs it. Get those right and you can grow sprouts, microgreens, salad greens and herbs all year, even in a small apartment. If you have no yard, it’s the easiest way into gardening.

Light is where most beginners go wrong, so this guide spends the most time there. You’ll learn which light to buy, how far above the leaves to hang it and how long to run it. You’ll also get a short list of seeds to start with, so you know exactly what to buy.

As an Amazon Associate I earn from qualifying purchases.

In this guide

1. What you need to start indoor gardening
2. What can you grow indoors year-round?
3. How to grow sprouts in a jar
4. How to grow microgreens on a windowsill
5. How much light do indoor plants need?
6. Which grow light to buy and how far to hang it
7. Best room temperature for indoor herbs and greens
8. Containers and potting mix
9. How often to water indoor plants
10. How to fertilize indoor herbs and greens
11. How much of an herb can you harvest at once?
12. When to repot, divide or replace herbs
13. Common indoor plant pests and what to do
14. Is a hydroponic herb garden worth it for beginners?
15. Can indoor herbs go outside in summer?
16. Common indoor gardening mistakes
17. Where to go next
18. Frequently asked questions

What you need to start indoor gardening

You don’t need much. Here is the short list:

• A light source. A bright window, a grow light, or both.
• Containers with drainage holes. At least 6 inches deep for herbs and greens.
• Fresh potting mix. Not garden soil from outside.
• Seeds or starter plants. Pick crops that suit your light.
• A timer. Plants need a steady schedule, and timers don’t forget.
• Fertilizer. A liquid feed for herbs and greens once they’re growing.

What can you grow indoors year-round?

Start with the crops that need the least light and grow the fastest. The University of Tennessee Extension says microgreens and baby greens are the quickest indoor crops and need the least light. Leafy vegetables come next, then herbs. Fruiting crops like tomatoes and peppers need more light than any of these, so save them for later.

Which seeds to buy first

• Microgreens: radish, pea, broccoli and sunflower. They are common, easy to find as microgreen seed, and simple to grow in a tray.
• Salad greens: loose-leaf lettuce is the easy pick. You cut the outer leaves and the plant keeps growing. Arugula is another good choice.
• Herbs: chives, mint, parsley and basil. Chives and mint are forgiving. Parsley is slow to start but steady once it’s up. Basil wants the most light of the four.

How much light and time each crop needs

Why two numbers for herbs? UT Extension gives 4 to 6 hours as the minimum for herbs and leafy vegetables. Iowa State says most herbs need 8 or more. So treat 4 to 6 hours as enough for greens and the bare floor for herbs. If you want bushy basil, plan on 8 hours.

My plan for a first indoor garden is simple. Grow sprouts this week. Start a tray of radish or pea microgreens next. Add a pot of loose-leaf lettuce, then move on to herbs once your light is sorted.

How to grow sprouts in a jar

Sprouts need no soil and no light. You need a clean glass jar, a mesh sprouting lid or a piece of cheesecloth with a rubber band, and seeds sold for sprouting.

1. Put a small layer of seeds in the jar. They swell a lot, so leave plenty of room.
2. Cover with cool water and soak them for several hours or overnight.
3. Drain through the lid, rinse with fresh water and drain again.
4. Tip the jar upside down at an angle in a bowl so water runs out and air gets in.
5. Rinse and drain every morning and evening. Never leave them sitting in water.
6. Eat them when the shoots are the size you like, usually 2 to 5 days. Store them in the fridge.

A food safety note. The US Food and Drug Administration warns that raw and lightly cooked sprouts can carry bacteria that cause foodborne illness, because the warm, wet conditions sprouts need also suit bacteria. The FDA advises children, older adults, pregnant people and anyone with a weakened immune system to avoid raw sprouts. Cooking them reduces the risk. Rinsing at home does not remove it.

How to grow microgreens on a windowsill

Microgreens are seedlings cut young. They grow in a shallow tray of potting mix and are a good next step after sprouts. Radish and broccoli are small seeds that are easy to scatter. Pea and sunflower are larger seeds that give bigger, crunchier shoots.

1. Tray: Use a shallow tray with drainage holes, set inside a second tray to catch water.
2. Mix: Fill it with moist potting mix and level the surface gently.
3. Seeding: Scatter the seed thickly so the seeds sit close together in a single layer, without piling on top of each other. Press them lightly into the mix.
4. Germination: Mist the surface and keep it moist until the seeds sprout.
5. Light: Once they’re up, put the tray in your brightest window or under a grow light, so the stems don’t stretch and flop.
6. Cutting: When the first true leaves open above the seed leaves, cut the stems with clean scissors just above the mix. Rinse and eat.

Most microgreens don’t regrow after cutting. Compost the used mix and sow a new tray. If you sow a fresh tray every week or so, you keep a steady supply.

How much light do indoor plants need?

Usually more than a window gives, especially in winter. Iowa State University Extension says most herbs need 8 or more hours of direct light a day. A window with a few hours of sun is fine for greens but won’t keep basil bushy.

Don’t trust your eyes here. The University of Florida IFAS notes that judging light by eye is unreliable and suggests a light meter or a phone app. UF/IFAS also advises against grouping low-light and high-light plants together. A basil plant and a fern want very different spots.

If your home is dim, read my guide to low light indoor plants, or the one on plants for rooms with zero sunlight. Food crops won’t thrive in those spots without a grow light.

Which grow light to buy and how far to hang it

Most beginner guides skip this part. Here is a clear plan.

You don’t need a special grow light

Mississippi State University Extension says ordinary LED or fluorescent shop fixtures work. You don’t have to buy anything labeled “grow light” unless you want to.

Match the light to the size of your garden

Iowa State’s advice is to use a compact fluorescent bulb in a task lamp for a few plants and a plug-in 4-foot LED shop light for more. CFLs are now hard to find in most US stores, so I’d use a full-spectrum LED bulb in the task lamp instead. It fills the same small role, and it fits Mississippi State’s point that ordinary LEDs work.

The distance and hours both come from Iowa State. For a shelf, linkable bars are easy to fit. The Barrina T5 2-foot 5000K full spectrum grow lights come in a 4-pack that links together, which matches the shop-light style the extension services describe. If you want the timer built in, the Barrina T5 2-foot 30W grow light has 4, 9 and 14-hour settings plus reflectors. The 14-hour setting sits inside Iowa State’s range.

How long to run the light

Iowa State Extension recommends 12 to 16 hours a day, on a timer. Other guides land in the same zone: Planet Natural says most vegetables do best with 14 to 16 hours, and Gardenary suggests 12 to 14 hours of artificial light in winter. I’d start at 14 hours, which fits all three, and then watch the plants. Leggy, stretched stems usually mean the light is too far away. Lower it toward the 6-inch mark before you add hours.

Best room temperature for indoor herbs and greens

Herbs and greens are comfortable in the same rooms you are. Lawn Love’s beginner guide gives 70 to 80°F by day and 65 to 70°F at night. Planet Natural gives 65 to 75°F, with about 10°F either way still acceptable. A normal heated home in winter fits inside those ranges.

Humidity is harder. Lawn Love suggests 40 to 50%, and notes that most homes sit at 10 to 20%. Dry air is one more reason to check the soil often in winter.

The bigger risk is moving air. The University of Tennessee Extension says to keep plants out of the airflow from heating and cooling vents. Hot or cold air blowing across leaves dries them out fast, so move pots away from vents and drafty doors.

Containers and potting mix

Gardenary recommends containers at least 6 inches deep with a good drainage hole for herbs and salad greens. Without that hole, water pools at the bottom and the roots rot.

Use a bagged potting mix, not soil dug from outside. A bag like Miracle-Gro Houseplant Potting Mix (4 quart) is a manageable size for a few pots. If you’re short on space, my guides to small space container gardening and small indoor plants have more ideas for fitting pots onto sills and shelves.

How often to water indoor plants

Water by touch, not by the calendar. UF/IFAS advises against a fixed weekly schedule. Check the soil every couple of days instead.

1. Push a finger about 1 inch into the mix. Lawn Love uses this same finger test.
2. If it feels moist at that depth, skip watering.
3. If the top is dry, water until a little drains out the bottom.
4. Empty the saucer so the pot doesn’t sit in water.

The University of Tennessee Extension puts it simply: water when the top of the mix is dry, but before the whole pot dries out.

How to fertilize indoor herbs and greens

Here is what to do, step by step.

1. Skip sprouts and microgreens. They’re eaten within days or a few weeks, so I don’t feed them.
2. Check your potting mix bag. Some mixes already contain fertilizer. If yours does, follow the bag on how long to wait before you start feeding.
3. Pick a liquid fertilizer. Use one labeled for houseplants, herbs or vegetables, and mix it at the rate printed on the label. Liquid feeds are easy to mix into your watering can.
4. Feed once or twice a month. That’s the UT Extension guidance for indoor herbs and greens.
5. Hydroponic units are different. UT Extension says to use fertilizer made for hydroponics in those systems, not regular plant food.

How much of an herb can you harvest at once?

Lawn Love’s guide says to prune no more than 25% of a plant at a time. So snip a few stems from the tips, leave most of the leaves in place, and let the plant regrow before the next big cut. Regular light snipping keeps basil and mint bushy.

When to repot, divide or replace herbs

Lawn Love suggests repotting tabletop plants every 12 to 18 months, going up no more than 2 inches in pot size. Herbs often need attention sooner, and each one has its own answer.

• Signs an herb is rootbound: roots circle the inside of the pot or poke out of the drainage hole, water runs straight through, and the plant wilts soon after watering.
• Mint: it fills a pot quickly. Tip it out, cut the root mass into a few pieces with a clean knife, and replant one piece in fresh mix. Give the spares away or start new pots.
• Chives: they grow in a clump. Pull the clump apart into smaller bunches and replant each one in fresh mix.
• Basil: it’s an annual. Once it turns woody or keeps trying to flower, it won’t recover well in a bigger pot. Start a new pot from seed, or root a few stem tips in water, and retire the old plant.

Common indoor plant pests and what to do

Two pests you’re likely to meet indoors are fungus gnats and aphids. Here is what I’d do if they show up.

Fungus gnats

These are tiny dark flies that hover around the pot and run across the soil. Their larvae live in damp potting mix, so the first fix is to keep the mix less wet.

• Let the top of the mix dry out between waterings.
• Empty saucers so pots never sit in water.
• Stick yellow sticky cards in the pot to catch the adults.
• Use fresh bagged mix for new pots rather than reusing old, soggy mix.

Aphids

These are small soft-bodied insects that cluster on new growth and the undersides of leaves. Leaves may curl or feel sticky.

• Look at the undersides of leaves when you water.
• Rinse them off with a gentle spray of water in the sink, or wipe them off by hand.
• Snip off badly affected tips.
• Keep the plant apart from your other pots until it stays clean.

If a problem keeps coming back, your county extension office can identify the pest and suggest next steps.

Is a hydroponic herb garden worth it for beginners?

A countertop hydroponic unit grows plants in water instead of soil, with the light and timer in one box. The ScienGarden 12-pod hydroponic indoor herb garden is one example, with its own grow light built in. Before you buy it or any other unit, hold the listing up against the checklist below.

What to look for

• Adjustable light height. The light should rise as plants grow, so you can keep it close to the leaves. A fixed light can end up too far from seedlings or too close to tall basil.
• Reservoir size. A bigger reservoir means topping up less often. A small one can run low over a long weekend away.
• Pod count. More pods means more plants, but large herbs like basil crowd their neighbors. Plan for fewer plants than the pod count suggests.
• Replacement seed pods. Check whether refill pods are easy to get, and whether the unit accepts empty pods you can fill with your own seeds.

Downsides of all-in-one hydroponic units

With pots and a shop light, you can swap any part. A sealed unit is different. If the built-in light is too weak for herbs, you can’t easily upgrade it. If the pump or light fails, you need a replacement from the maker. If the unit only takes branded pods, you buy seeds from the maker too. You also need hydroponic fertilizer, as UT Extension notes.

Who should skip it

Skip it if you want to grow a lot of greens, since a tray of microgreens or a few pots under a shop light give you more room. Skip it if you’d rather not keep buying pods. And skip it if you enjoy soil and pots, because the jar, tray and pot methods above cover the same crops.

Can indoor herbs go outside in summer?

Yes, potted herbs and salad greens can spend the warm months on a patio or balcony. Wait until nights are reliably warm before you move basil out. This is for your food crops. UF/IFAS warns against moving ornamental houseplants outdoors, because many can become invasive.

Ease the move. Leaves grown indoors are soft and can scorch in full sun. Planet Natural recommends hardening plants off over 7 to 10 days. Start with 3 to 4 hours in shade, then add 1 to 2 hours a day. My guide to a balcony vegetable garden covers setting up pots outside.

Bringing herbs back in without bringing pests

1. Bring pots in before the first cold nights, not after.
2. Check the undersides of leaves and the soil surface for aphids and other insects.
3. Rinse the foliage with a gentle spray of water.
4. Clean the outside and base of the pot.
5. Keep the plants away from your other indoor pots for a while, then check them again before grouping them.
6. Greens that have bolted or turned bitter are better composted than brought in. Sow fresh ones indoors instead.

Common indoor gardening mistakes

• Relying on a window alone for herbs in winter.
• Hanging the light too high above the leaves.
• Running lights without a timer.
• Watering on a schedule instead of checking the soil.
• Keeping the mix soggy.
• Cutting more than 25% of an herb at once.
• Using pots with no drainage hole.
• Grouping sun lovers with shade plants.
• Parking plants next to a heating vent.

Where to go next

Once your first pots are growing, you can build upward. My guide to indoor wall plants and vertical gardens shows how to fit more green into a small room. Start small, get the light right, and add a new crop each month.

Frequently asked questions

How many hours should a grow light run?

Iowa State University Extension recommends 12 to 16 hours a day for indoor herbs, set on a timer. Fourteen hours is a good place to start because it sits near the middle of that range. If stems stretch, lower the light before adding hours.

How far should a grow light be from plants?

Iowa State University Extension says to keep supplemental lights 6 to 12 inches from the leaves. If seedlings look tall and stretched, move the light closer to the 6-inch end.

What vegetables can I grow indoors year-round?

Microgreens, baby greens, salad greens like loose-leaf lettuce, and herbs are the best picks. The University of Tennessee Extension says microgreens and baby greens are the quickest crops and need the least light. Fruiting crops like tomatoes need more light and are harder indoors.

Do I need a special grow light for indoor gardening?

No. Mississippi State University Extension says ordinary LED or fluorescent shop fixtures work. For a few pots, a full-spectrum LED bulb in a task lamp is enough. For a shelf of plants, a 4-foot LED shop light works well.

How often should I water indoor plants?

Check the soil every couple of days instead of following a weekly schedule, as UF/IFAS advises. Water when the top of the mix is dry, before the whole pot dries out. If it still feels moist about 1 inch down, skip watering.

How much can I cut from an indoor herb at once?

Lawn Love’s beginner guide says to prune no more than 25% of a plant at a time. Snip from the tips, leave most of the leaves in place, and let the plant regrow before the next big harvest.