Useful Tips for How to Grow an Indoor Vegetable Garden

How to grow your own food all year round in your indoor vegetable garden. In this piece, you’ll learn which vegetables are best to grow indoors and how to grow food hydroponically or in potting mix. You’ll also get tips on lighting, nutrients, and water requirements, pests to look out for, and tools.

Growing your own food is something that we tend to think of as always being outside. But what if the season is too cold or you don’t have much outdoor space to garden? Creating an indoor vegetable garden lets you grow food year-round, no matter what your circumstances. Whether you have a windowsill, a conservatory, or a dark apartment, it’s time to get sowing, growing, and enjoy all the benefits of homegrown fruit and veg.

Growing food inside is a little different from growing it conventionally. It presents different challenges and opportunities, so if you already have some gardening experience, you’ll need to think about it differently. You’ll need to hand-pollinate fruit, create the right humidity and temperature, know which crops grow well indoors, and learn how to grow them. You’ll also need a different set of equipment and materials.

However, if you do it well, growing your own food need not be restricted by the season, your climate, or the availability of outdoor space. You could have fresh herbs or veggies all year round!

Ways to Grow an Indoor Vegetable Garden

Growing edible plants indoors can be simple and fun or complicated, depending on what you choose to grow. You can sprout seeds in jars, grow microgreens in mini trays and cloches, or try larger plants like tomatoes and chilis. You could also stick to more traditional methods of sowing seeds in pots, modules, or seed trays, and just simply enjoy the wonder of watching them germinate indoors. There are also many easy-to-grow vegetables that will grow both indoors and in the garden.

You can grow an indoor vegetable garden in potting mix, much like you would do in an outdoor garden. If you are feeling more adventurous, you can even grow food without any soil at all, hydroponically, by channeling water and nutrients directly to plant roots. I’ve also seen people set up small greenhouses indoors, and even grow rooms dedicated to providing the light and conditions that plants need.

Humidity is something that needs monitoring, both in the seedling stage and when mature. The air inside the home tends to be drier than outdoors, so you can use plastic covers (propagators), misters, and other techniques to keep plants happy.

You’ll also need to keep an eye on lighting, potting mix moisture, and indoor pests. If your crops need pollinating, you might need to give them a hand. With no pollinators inside your house, some fruit flowers will need you to spread pollen from one flower to the next. It’s not that complicated since you can use a small artist’s paintbrush to brush pollen from one flower to the next.

Vegetables to Grow Indoors

Indoor growing isn’t suited to all vegetables, but some do great! Ideally, prolific cropping of petite plants is best so they take up minimal space. Chilies, microgreens, tomatoes, and greens such as salad leaves and spinach provide abundant harvests that can keep you gardening indoors all year round, even if the weather outside is not prime. And of course, a kitchen cannot be without herbs! See below for recommended varieties and how to look after your indoor vegetable garden.

Herbs	January-April is a great time to sow herbs, though you can grow them year-round. Rosemary, mint, basil, chives, oregano, and parsley can all be grown in pots on a windowsill. Sow in small batches for continuous crops, and evergreen rosemary will just keep on going with little intervention.	Grow in a bright area. No feed is required. Many herbs are drought-tolerant, so bi-weekly watering should be enough, but keep a close eye on basil as it needs more water than other herbs.
Microgreens	Microgreens are a healthy addition to salads and sandwiches since they are packed with nutrients. Grow in small pots or a propagator, any time of year. These fast-growing superfoods can be on your plate in two-three weeks. Try pea shoots, kale, basil ‘dark opal’ or rocket ‘Victoria.’	Mist or water from the base, but do not keep it too wet, or the roots may rot off. Go easy on the amount of seeds you use to avoid overcrowding. Keep aerated. No feed is required as they mature so quickly.
Sweet peppers	‘Mini Belle’ and ‘Mohawk’ are great compact varieties. Sow seeds from February to March in a propagator. The stem may need support as the plant matures.	Peppers love light and warmth. Water little and often and boost weekly with a high-potash feed once flowers appear.
Lettuce	Cut-and-come-again salad greens can be sown from February. Try rocket,  mizuna, lollo rosa, salad bowl, baby oakleaf, and compact butterhead Tom Thumb. Succession sowing in pots will ensure you always have a fresh crop. Sow seeds little and often.	Grow by a south-facing window for plenty of light, but take care not to scorch leaves in summer. Lettuce is particularly suited to growing under grow lights or hydroponics. Water twice a week to keep it moist. Check that it does not dry out. Feed every couple of weeks with a high-nitrogen fertilizer to promote healthy green foliage.
Chilies	Chilies need a long growing season to produce fruits—about six months from seed to maturity. Sow in January and nurture the young plants under grow lights. Larger plants may need support.  Varieties vary in heat strength. See the Scoville scale. Try mild pimento, banana pepper, medium jalapeños, Serrano, Numex Twilight, Cayenne, Apache, and Compact Prairie Fire, or Scotch bonnet and habanero if your taste buds want to be tested!	Chilies like heat and humidity. The plants will need a good light source. Air can be kept moist by placing a water bowl on a nearby radiator. Chilies will require artificial light during winter. In hot weather, you may need to water two-three times a week, less in winter. Feed weekly with a high-potash fertilizer.
Radishes	Sow in spring through to autumn in a deep container. Radishes are quick to mature, so keep sowing little and often for a continuous crop. The green leaves are edible too. Thin seedlings. Grow ‘Caro,’ ‘Cherry Belle,’ ‘D’Avignon,’ or ‘Early French Breakfast.’	Place in a bright area with at least six hours of sunlight a day. Water two to three times a week, do not constantly soak or roots will rot, feed with an organic all-round fertilizer like seaweed every couple of weeks.
Tomatoes	Bush toms are compact for containers. Try dwarf ‘Tumbling Tom’ and ‘Tiny Tim’ or, if more space is available, grow cherry tomatoes like ‘Sungold,’ ‘Sweet Million’ and ‘SuperSweet100.’ All are good indoor croppers. Fruits are small and plentiful, but the plants will need support as they can grow to 3 feet (1 meter) tall.	Grow by a south-facing window for maximum light. If growing through winter, you may need artificial light to aid growth. Feed and water weekly with high-potash formula to promote fruit growth—organic seaweed is ideal. Better to give a good, long soak rather than multiply brief sprinkles.
Spinach	Grow spinach in a well-drained container with potting mix or hydroponically. Sow March-April. Try baby leaf sweet ‘Monnopa’, disease-resistant, slow to bolt ‘Toscane,’ exquisite ‘Rubino’ for colorful foliage, or perpetual spinach for larger, perennial plants.	Place in a bright spot but not direct sun. Keep the growing medium watered but not wet to avoid root rot and fungal disease. Feed every two weeks with a nitrogen-based fertilizer, like nettle tea, to promote green leaves.
Citrus fruits	Dwarf citrus trees are excellent for indoor growing. Try dwarf lemons ‘Meyer’ or ‘Ponderosa,’ limes, tangerines, and nectarines. Best to buy root-grafted dwarf trees.	Citrus trees like lots of light and cool roots, so avoid dark pots, which absorb heat. Choose free-draining citrus potting compost to keep roots moist but not soggy and feed with a citrus fertilizer.

Indoor Gardening in Potting Mix

There are various challenges with growing vegetables indoors, and many of them have to do with what the roots grow in. For indoor gardens, buy quality peat-free potting mix and use perlite, vermiculite, or coir to help retain moisture, aerate the soil, and improve drainage. You can use up to 33% of these additional materials.

Whatever you do, make sure not to use garden soil. Firstly, it compacts and dries out very quickly in containers. It will also contain fungi, weeds, diseases, and microorganisms, and possibly even worms. All of which will not be beneficial or necessary for an indoor vegetable garden. The downside of not using your own homemade compost is that you have to purchase a premade product, usually in a plastic bag, and remember to mind your back when lifting.

Growing Food Hydroponically

Hydroponic gardening involves growing plants without soil. Instead, water and nutrients are delivered directly to the plant’s roots, supported in a growing medium such as rockwool or hydrocorn, vermiculite, perlite, or sand. On the whole, growing hydroponically can be advantageous.

First off, it’s a successful way to grow an indoor vegetable garden practically anywhere. Increased oxygen to roots promotes growth, yield, and health, and by delivering feed in liquid form, nutrients are quickly absorbed with minimal energy. This can produce healthy, strong plants that are less prone to pests and diseases. Hydroponic gardening can be expensive and has an environmental impact, though. There’s also a big debate on whether it can even be considered organic.

Light Requirements for Indoor Vegetables

Germinating seeds in summer is easy. Pop your pot near a bright window or conservatory, and your new seedlings will receive all the natural light they need. However, if you are starting seeds indoors and/or in winter, you may need to boost your plants’ daily exposure to light with grow lights. There just isn’t enough daylight during winter to ensure the plants can photosynthesize enough to grow strong and healthy.

Grow lights will provide your plants with their lighting requirements, but at a cost both financially and potentially in energy use. I know that my electricity bill goes up a bit when I’m starting seeds and seedlings indoors, so that’s something to consider. The type of light you use makes a big difference, though, and fluorescent (CFLs) will be less efficient than light-emitting diodes (LEDs).

Nutrient Requirements for Indoor Vegetables

Like plants growing outdoors, the crops in your indoor vegetable garden will need nutrients. They include nitrogen, phosphorus, and potassium (NPK) as well as trace minerals. Outdoors, much of this comes from compost mulch that you apply to the soil, but it can also come from the soil itself. Though potting mix initially contains a good balance of these nutrients, it depletes quickly, and you will often need to feed indoor crops. Some of them may have an odor, though, so make sure that the ones you use don’t offend your senses.

Liquid seaweed is a great natural fertilizer all-rounder for the indoor vegetable garden. However, homemade nettle tea can encourage healthy leaf development, and for fruit, use potassium-rich comfrey tea. All three are concentrated liquids that you dilute in water, but they can be a little stinky.

Alternatively, you can dig granular fertilizers into the potting mix. These are solid pellets or granules that you can mix in before planting or sprinkle onto the surface afterward.

Liquid fertilizers are preferable for indoor vegetable gardens and hydroponics, though. With them, there is a lower risk of pipes clogging than with powdered or granular fertilizers. And rather than buying premade fertilizers, there is, of course, the option of making your own DIY organic fertilizers.

Watering Indoor Vegetables

Watering must be tightly monitored when growing an indoor vegetable garden. Too much water can lead to fungal and pest issues, as well as swamping your plants, which may cause them to die. Too little and they can dry out and die, too.

Because tap water contains additives that plants don’t respond well to, it’s best that you always water them with rainwater or filtered water. It’s best to avoid watering the top of the potting mix and instead water plant pots from the base. That way, the roots can draw up water directly from a saucer or tray without getting the top of the potting mix wet. This stops erosion but reduces the chance of getting fungus gnats.

One method you could try is to set plant pots in a sink shallowlly filled with water. Once they’re in, leave them a few minutes before pulling the plug and leaving them in the sink. That way, they’re able to absorb water but the excess will drain out.

If you water the top of the potting mix it can, in time, rot the stem or wash away the soil and expose fine roots on the surface. If you’ve ever seen houseplants with shriveled or wilted leaves it could be due to root exposure damage. Watering from the top also creates a crust, which can be difficult for young seedlings to grow through. It’s not a big deal for larger plants, but something to think about if you’re germinating trays of seeds.

When it comes to watering, you also need to think about the moisture in the air. The humidity inside our homes is 40-60% less than what plants tend to thrive in and it can contribute to leaves wilting, yellowing, developing brown edges, and generally looking sick. One way to increase humidity around your plants is by misting them with a plant mister. Water evaporating from leaves creates a temporary change in humidity. You could also use a humidifier or set a bowl of water above an active radiator.

Dealing with Fungus Gnats

Fungus gnats are tiny dark flies with transparent wings, which can be found, on the surface of pots, and seed trays or flying around indoor plants. They bear an uncanny resemblance to tiny mosquitoes but don’t bite.

Fungus gnats thrive in damp compost and relish people who overwater their plants. They can be an utter pest in hydroponic systems too. Although the adults don’t particularly pose a direct problem with your plants or home, the larvae en masse can damage roots and hinder plant growth.

So how to avoid them or get rid of fungus gnats if they have set up residence in your home? You can sterilize your potting mix, don’t allow fungi to breed, or use a pebble mulch to deter female flies from laying eggs on the potting compost surface. Some people have success with popping chunks of raw potato in an infected pot because the larvae are drawn to the chunks and then can be removed. You can also hang up sticky traps to reduce the number of adult flies.

For biological control, you can apply Nematode Steinernema feltiae or bacteria Bacillus thuringiensis to destroy the fungus gnat larvae or apply a fungus gnat mulch top dressing to deter egg-laying.

Indoor Gardening Products and Kits

The gardening industry has recognized the growing desire for people who want to grow food in their houses. Sometimes the gadgets are a little expensive and perhaps unnecessary and sometimes they’re absolutely brilliant! Here are some that I found online:

• AeroGarden Harvest is a compact unit that facilitates growing herbs and vegetables all year round. It has the capacity to grow six plants at a time under a 20-watt LED lighting system so is both compact and productive.
• The Complete mason jar sprouting kit is a genius germination kit, which provides you with everything you need to sprout seeds in one space-saving device. It allows you to easily grow and harvest mung beans, alfalfa and broccoli, and other high nutrient microgreens.
• If you have the budget and are serious about creating a modern indoor vegetable garden, the Vertical hydroponic grow kit by Aerospring might be up your street. It can grow 27 plants at the same time so can keep you well-stocked in greens all year round.

Benefits of Growing an Indoor Vegetable Garden

Growing an indoor vegetable garden has tremendous benefits because it can keep you in homegrown veg regardless of outdoor space. It also ensures you can keep gardening throughout the cold winter months even when the soil outside is frozen.

Having herbs and vegetables in close proximity to the kitchen is always a win, but especially so if you can’t grow outdoors! Just snip off herbs and veg as you need them; ingredients do not get fresher. You could even try growing tropical crops like pineapple.

Indoor Gardening Inspiration

Now you are raring to set up your indoor vegetable garden, check out these useful ideas. They include additional reading about edible houseplants, toxic houseplants to avoid if you have pets and helpful tips to help you get the best out of growing your own veg.

• Houseplants that are Toxic to Cats
• Guide to Edible Houseplants
• How to Plant a Winter Vegetable Garden
• Don’t Make these Common Gardening Mistakes