How To Start, Develop, and Grow an Indoor Vegetable or Herb Garden - Seed To Harvest
Growing and maintaining an indoor garden is easy, fun, rewarding, and soothing. Creating life, watching it grow, and eating its organic fruits is an experience far too few people in today’s day and age are allowing themselves. What a shame. You can do better!
Basil - Thyme
Basil - Parsley
There are several ways of getting started with an indoor garden and you should choose one that is in line with your ambitions and budget. The most basic and cheapest approach is to make use of everyday items for your grow. There are a couple of things that you definitely need but these essentials are cheap and available both online and offline.
Cucumbers, basil, arugula, nasturtium.
1. Seeds. Choose the type of plant you want to grow (we give suggestion further down in this article) and find a place that sells seeds.
Amazon offers seeds online but if you have a physical store nearby it's usually better to buy in person and get tips and hints from professionals. Most plants have at least some characteristics that you'll want to know about (light, water, space requirements, etc) to set up your grow for success. You’ll find specific grow instructions for your selected plants on the seed packaging.
Seed package instructions.
2. Soil. A soil type with little or no nutrients is recommended for seeds and younglings as too much nutrients could burn the fragile little darlings. Once it's time to replant the younglings to larger pots, typically when they are about 2 inches (5 cm) tall (after 2-3 weeks for quick growing plants), a potting mix soil with nutrients is recommended. Taking soil from outside is rarely a good idea as it often has different pests and diseases that you don’t want to bring inside.
Seeds and soil are literally the only things you need to buy IF you have a well-lit area for your grow. A window sill, balcony (assuming it's warm enough), or under any artificial light source with enough light output (we'll talk more about this further down) is a suitable place for your indoor growing project.
You'll also need (but already have at home):
3. Containers/pots. You can re-use any type of milk, juice, or similar carton or plastic package assuming you make a couple of holes in the bottom for drainage. Buying pots is, of course, also an option.
Microgreens & chilli.
4. Tray/tarp: to keep your indoor garden area clean and prevent drain water to make a mess, it's a good idea to have some kind of protection under the pots. You can use a plate or any kind of tray. Alternatively, you can purchase a tabletop tarp.
A tarp or tray can also come in handy when replanting.
5. Watering can. Here you can get creative. The easiest way is to fill a glass with tap water and then get cracking. Poking holes through a soda bottle's lid is also an option. Buying a watering can is, of course, the ideal way to go about this but we want to show that you can get by without barely spending any money.
These are the items and equipment you need to grow common and everyday vegetables, herbs, and spices in the comfort of your home.
6. Light. In many cases, the natural light from the sun is an optimal light source for your plants. If your grow area does not have access to natural light, you'll need to use an external light source. The type of light you need is primarily determined by your grow area. You need a light that produces enough light footprint to cover the area with your plants. Most indoor vegetables need relatively little light. A small grow area with just a couple of small sized pots is usually illuminated well by a T5 fluorescent lamp or a light strip.
A more efficient alternative is an LED grow light. The right LED light delivers light with optimized color spectrum and high light output. Growing inside of a grow tent, as pictured below, makes LED lights a good light source. Adjust the lamp's distance to plants so they get the right light intensity (PPFD).
The more light of good quality you give your plants, the better and faster they will grow, to some extent.
We dive deeper into plants' light requirement in the next article.
Again, Basil - Thyme
Basil - Parsley.
Basil, chilli, tomato, arugula, thyme, rosemary, cucumber grown with LEDTonic Z5 LED grow light.
7. Space. This is quite straightforward. You'll need to put your plants somewhere. Some plants grow well in small containers whereas others need either deep or wide pots. Consider how much space you can set aside for your indoor garden then choose plants that can thrive in your specific conditions.
Peas, microgreens grow on a window sill.
8. Seedling/seed starter tray: by far the best and safest choice to start seeds. Some plants (certain tomatoes, for instance) are very particular about their container size when developing from seed to seedling. A too large container will confuse the plant and it won’t grow properly. On the other hand, other plants, certain chilli types, for example, care less about the size of their pot and could essentially be planted in a small plastic cup (Solo cup) with a drainage hole in the bottom.
Chilli (red chili peppers).
9. Nutrients. Need for nutrients is plant-specific. A good potting mix soil will already be packed with nutrients but the soil’s nutrient supply only lasts about 4 weeks. Some plants we list further down are ready to be harvested within a month of planting and will not require additional nutrients if the soil is already rich. Other plants may take months to fully develop and those will definitely need nutrients to thrive, which is why the nutrients part is in our “Optional” category. Indoor plant/herb nutrients can be bought online (search for “indoor plant nutrients”) or offline, in your local gardening shop. Nutrients usually come in liquid form and are to be mixed with the water you'll use to water your plants.
Want to take it to the next level? Step up your grow!
Grow tents are great if you want a confined space where you easily regulate temperature, humidity, and contain your light. Using a large artificial light outside a tent may not be convenient or preferable if it’s within your daily living area. Setting up a light in a tent, however, will capsule the light and won’t be noticeable from outside the tent.
Basil, chilli, tomato, arugula, thyme, rosemary, cucumber.
Temperature and humidity meter. Once again, some vegetables require specific temperatures and humidity levels to thrive. To monitor these levels and to give your plants ideal growing conditions, a meter is a useful tool.
Here's the list of vegetables you can grow indoors year-round.
We’ll summarize the most essential information for some of our favorite plants but such short summaries don’t paint the entire picture. It’s enough if you’re starting your first grow and want to keep things simple but as you grow as a grower ;-) you’ll want to absorb more knowledge to maximize your plants’ full potential. It’s also important to remember that species are different from one another. We give general advice but you should take a good look at the seeds’ package which will tell you exactly what requirements the species you selected has.
1. Lettuce and Other Salad Greens
Lettuce is easy to grow and shallow rooted. It does not require a deep container, a 2-4” (5-10 cm) deep will do. Lettuce seeds prefer a chilly environment and will develop best in a temperature between 40 - 60 °F (5 - 15 °C). The starting pots can be placed in a refrigerator for the first couple of days for a better germination success rate. It is important to keep the soil moist at all times, but not too wet. Misting the soil daily with a mister or spray bottle is a good way to go about it.
“Loose leaf” salad types can be harvested continuously as they grow. Other types of salad form a head as they grow and should be harvested once the head is fully developed. Head forming salads are generally a bit more difficult to grow than loose leaf, especially indoors.
Cucumbers are highly rewarding to grow as the typical cucumber species grows quickly and is ready for harvest in 2-3 months. Normally, the flowers need pollination to start producing cucumbers, but if you choose a parthenocarpic variety there will be no need for that as they produce fruit asexually. Place seeds ½” (1 cm) deep in a small pot containing moist seed starting mix. Seeds sprout in room temperature in 5-8 days. Transplant to a bigger pot with richer soil once the seedling reaches 1.5 inches (4 cm). Be careful, as their roots are very sensitive. The final pot should be at least 2.5 gallons (10 liters).
Cucumber plant. 2.5 weeks old.
Cucumbers love to get at least 6-10 hours of light each day. When you give the plant what it wants and needs, it can grow over an inch every day. You might need to have some bamboo sticks ready to stake up the plant. Having strings tied up for it to climb on will also work. Be sure to look for ripe cucumbers often and don’t hesitate to pick them when they are ready. If they stay on for too long, it will alter the taste. Look at the back of your seed package for harvesting instructions, as it differs slightly between different varieties.
Cucumber plant from above. 2.5 weeks old.
Basil is one of the most popular herbs for indoor gardeners and a very easy plant to grow. There are over 50 types of basil. They love heat, light, and nutritious soil.
Basil is one of the plants that doesn’t necessarily need to be planted in a starting tray and then transplanted. It can be planted straight into a long term pot right away. The denser the seeds are planted, the shorter each plant will be as they fight for nutrients, light, and water. At a minimum, an inch (2.5 cm) between the seeds is recommended.
A healthy basil plant. 1.5 months old.
Use a starting mix soil if you intend to start of the seeds in a starter tray. If you prefer planting in a large pot right away, use starting mix soil as a top layer in which you plant your seeds. Below this approximately 1” (2.5 cm) layer, use potting mix/soil (not gardening soil) in which the roots will eventually grow. Placing seeds ¼” (0.5 cm) deep in a seed starting mix.
Seeds will usually sprout between 3-15 days, depending on what kind you choose to grow. Keep the soil moist and in room temperature, and wait for sprouting. If you started them off in a starter tray, transplant to a bigger pot and nutritious soil (potting mix) when the second set of leaves is showing. Make sure the plants get a lot of light right away when they are breaking the surface of the soil.
At four sets of leaves, you can start harvesting! You can pick the leaves with your fingers but a clean and sharp set of scissors is even better. The less damage is done to the plant the quicker it will recover.
After six sets of leaves, the basil will definitely need to be pruned to prevent it from flowering. Cut the stem with a clean knife or scissors above the first or second pair of leaves to prevent it from transitioning into flowering phase. A flowering plant will put its energy into producing flowers instead of leaves.
Basil plants cut to prevent flowering.
As long as you give your plant the right amount of light and nutrients, it will keep growing for up to a year, giving you plenty of leaves to harvest!
Three basil plants at different phases.
Microgreens are tiny sprouts of basically any plant. Seeds are germinated and grown until the younglings reach 1-4” (3-10 cm), then harvested. They have a crisp texture and are packed with nutrients. Microgreens have become popular among both chefs and home growers in the last decade. They are one of the fastest and easiest greens to grow indoors and they don’t need much soil to give plenty of yield. A 2” (5 cm) deep tray is enough and recycling any old food packaging or styrofoam container is a good idea for this type of grow.
Microgreens, broccoli, 3-day-old.
In general, seeds should be planted at a depth of two times the width, or diameter, of the seed. For example, if you have a seed that's about 1/16 inch thick, it should be planted about 1/8 inch deep. Promote healthy growth by keeping the soil and plants medium damp. Once or twice a day, use a mister or spraying bottle, dampen the surface with a good squirt of water.
Normally, microgreens both germinate quickly and grow fast. They are usually ready for harvest already after 7-14 days but some sprouts can take a little longer to mature. A good sign of harvesting is when the second pair of leaves are showing, although this can differ between species.
Three popular microgreens to grow are radish, sunflower, and broccoli.
Here we are growing broccoli microgreens and recording a time lapse.
Tomato plants love heat and light, up to 86 °F (30 °C). Planting them indoors makes it possible for them to grow all year long. There are a couple of thousand tomato species and they could be divided into two groups: bush tomatoes and vine tomatoes.
Four different species of tomatoes.
Ramino F1 Bush Tomato, 1-month-old (largest)
Tigrette Cherry Tomato, 1-month-old (lime green)
Bitonto Cherry Tomato, 1-month-old (second largest),
Tiny Tim Cherry Tomato 2.5 weeks-old (smallest)
Bush tomatoes will grow compact, typically under 1.5 feet (45 cm). A perfect choice when growing on a window sill.
Vine tomatoes can continue to grow even after reaching 4 feet (1.2 m). Some even reach heights above 10 feet (3 m). Staking and tying is necessary when growing vine tomatoes. In other words, they need more space and work to thrive.
The seeds germinate within 5-10 days in room temperature. Ripe tomatoes come in all different shapes and colors, depending on what tomato plant you choose to grow.
Tomato plants grow best with a lot of light and when the soil remains evenly moist. Both too much or too little water can be harmful to plants.
Check the soil often for dryness by sticking your finger into the soil 1” (2.5 cm) below the surface. A large plastic pot can keep the soil moist for about a week whereas a plant growing in a small clay pot will need to be watered every day or every other day. Room temperature and humidity naturally play a lot into how much water your plants require.
Tomato plant under LED grow light, 1-month-old.
As each tomato species have unique features, their development time varies. Some grow and bear fruit quickly, others take a longer time. The general tomato plant will be ready for harvest 100-150 days after its seeds are planted.
Arugula is perfect to grow indoors and great for beginners. It thrives in a partly sunny environment but will also tolerate full sun, although the taste will be a bit milder in a partly shaded environment. It is fast growing and easy to set up. It grows to 4-6” (10-15 cm) in height and that is also when its leaves are ready to be harvested, usually after 25-30 days.
Arugula growing under LED grow light, 8-day-old.
Arugula seeds are not as sensitive as many other seeds and will germinate in 5 to 7 days in temperatures as low as 40 - 55 °F (5 - 10 °C). In room temperature 70 °F (21 °C) or so, they will germinate even quicker. Keep soil moist by misting on a regular basis. Arugula needs continuous moisture or else it won’t have its typical fresh taste. New seeds can be planted every now and then for a steady supply of fresh leaves, but make sure to add some fertilizer or nutrients in the soil between rounds.
Arugula almost ready for harvest, 12-day-old.
Four steps to set up your indoor garden
Do you have everything ready? If so, then let's get started...
1. Plant the seeds in a small starting/seedling pots with no or very little nutrients in the soil. Starting mix soil is the ideal choice for most seeds. Water sparsely. The soil should be moist, not saturated. Cover the pot or tray with a plastic film to keep the humidity high and to maintain a moist soil.
Alternatively, place the seeds in a damp paper towel and put the damp towel in an enclosed and dark space. For instance, between two plates or a zip-lock bag and then in a kitchen cabinet. The seeds will typically germinate in 1-3 days. Once the seedling is an inch (2.5 cm), plant it as mentioned above.
Thai basil, cucumber, tomatoes.
2. Light. After the seedlings penetrate the soil they will need light. In the beginning, when they are small and fragile, most species only need very limited light. Exposing them to a heavy artificial light or direct sunlight can burn or hurt the younglings. A windowsill with a few hours of light per day is ideal. Artificial light is also an option but if your lamp/bulb is strong, make sure the light is some distance from the small plants. Different lights have different light output. It's nearly impossible to accurately say how much of a distance you'll need without knowing your lamp's specifications. But to give you an idea, here are two examples. Please take them lightly though.
A T5 fluorescent light should be about 6-15 inches (15-35 cm) from the younglings, depending on the light's light output.
A LED grow light which consumes 50W should be 20-30 inches (50-75 cm). This is, of course, a very general rule of thumb as different lights have different efficiency and light output. If your lamp has so-called PPFD specifications, aim to position your light so your younglings get about 100 PPFD. A more mature plant can handle twice or three times as much.
As the younglings grow and develop, they will be able to handle more light which means they will want to be closer to the light source and/or get more hours of light per day.
3. Re-plant the little ones. Different vegetables and plants will develop at a different pace. Some plants will grow to 2 inches (5 cm) above the soil in a matter of days. Others may take weeks. When purchasing seeds, their package or the salesperson (or website) should tell you how that particular species grows.
Most plants will need to be replanted when they reach about 2 inches (5 cm) above ground from their small starting pots to their long term pot. The size of the long term pot also depends on what you grow.
4. Maintain the grow. Water your plants, give them nutrients, adjust the light they receive, and give them some love. Sooner or later they will develop enough for you to harvest and reap your reward.
Basil leaves harvest.
To round off the article we’d like to once again say that just like humans, plants are very different. Different vegetables grow at different pace and different lengths. They have different light requirements as well as water requirements. Some plants grow well in small pots, others need large, deep, or wide containers. Even different species may have vastly different preferences.
We try to give a fair overview of how to get started with an indoor garden but be sure to do your homework and read the instructions of the seeds you select.
With that said, we truly believe that anyone can start their own grow. There are plants for every occasion and every taste. Growing your own food is a project you can be proud of and one that may turn into a healthy hobby. Get started today!