Nothing quite brings a garden together like a big, healthy tomato plant. While one of the most popular outdoor plants, growing tomatoes indoors is seen by many as daunting and difficult. That view is unfortunate as the strict requirements for light and temperature that tomatoes need means their outdoor growing season is limited. Today we hope to answer some common questions and show you it’s definitely possible to start growing tomatoes indoors.
First off it’s important to be realistic and set expectations for your tomatoes. While it’s possible to grow tomatoes indoors, they generally don’t grow as big as those grown outdoors nor do they produce fruit as fast. This is generally due to lack of proper temperature and light indoors. If you have the means to provide the right environment (like in a greenhouse) then indoor tomatoes can compete with outdoors grown ones, but this isn’t practical for most growers.
Tomatoes are also very finicky plants and can be tricky to grow. Don’t get discouraged if it takes a few tries to get it right, it’s well worth the effort in the end.
Lastly, it’s also important to note that there are a variety of different tomatoes you can grow. For indoor growth, look for ones labeled as “micro dwarf” as they are bred to grow in small spaces. You also have the option to overwinter tomatoes from outdoors to extend their growing time. You can opt to take the whole plant, or take a cutting and transplant that to a new pot.
Planting and Container
When choosing a container the most important thing is to make sure it has good drainage and can adequately “breath”. In most cases, it’s recommended to use clay pots as they provide both of the above. Other containers and pots will work, but you need to take extra care that the soil doesn’t remain too wet which can lead to root rot.
You can always start your tomato plants from seedlings, but many gardeners opt to start from seeds. Many indoor growers will plant multiple batches of plants a few weeks apart. This gives them the best chance of a successful plant, as well as giving them flexibility to try out different varieties.
When starting from seeds, place them about ¼” deep into the soil and gently cover. Put them in a warm spot that gets lots of sunlight while keeping the soil moist, using a heat mat can help with this. Once the plant germinates you can carefully move them to a larger pot and their final home. This can take up to a month for certain varieties so patience is a must.
Sunlight and Location
By far the two most important aspects of growing tomatoes, indoors or out, is sunlight and temperature. Without the correct amount of each the tomato will fail to produce fruit and ultimately die.
For sunlight, look to get at least 8+ hours of bright light each day if not more. This is often the main issue for growing tomatoes indoors as it can be difficult to reach that amount of light in many homes. If you can’t then look to supplement with grow lights and aim to hit 10+. This is often a requirement in the winter as the sunlight is less intense.
For temperature, you’ll want to keep your plants in a location that never falls below 65°F, but ideally closer to 75°F. Tomatoes do the best in warm environments, so keeping the temperature up is important. This is often easy enough in the summer as the sunlight will naturally heat the area, but during the winter can be a bit of a concern. Overnighting a bit cooler is fine, but never let the temperature drop too low or it can damage your plant.
Watering and Feeding
You’ll want to keep the soil moist but never soaked. Our common advice is to check the top 1-2” of the soil and water when it is dry, and that advice holds true here. You’ll likely end up watering your plant every couple of days, usually a bit more in the summer.
Look to fertilize your plant every 2 weeks. You can dilute down a liquid fertilizer with water and feed your plants with that. Slow release capsules are also another good option, just don’t go overboard. During the winter you can cut back on fertilizing as the plant will go dormant and not be actively growing. You may also notice during this time that you water less, and that’s perfectly natural and okay.
One unique concern when growing indoors is the lack of wind or bugs to pollinate your plant. Luckily, it’s pretty easy to do so yourself.
Simply gently tap the flowers as they begin to bloom to get the pollen moving around the plant. You can also take a cotton swam and gently brush the inside of the flowers to move the pollen around. While not strictly necessary it does help your plant in producing fruit. If you move the plant outside during the summer days then this will be taken care of naturally by visiting insects and the wind.
Harvesting is very easy, and should be done just before the fruits are fully ripe. Look to harvest when the tomato is about 3/4 red with a little green still visible. When harvesting at this time you’ll have a few days where the fruit will ripen up. You can leave your tomato out on the counter, and it will be completely ripe over the next few days.
To harvest, simply grab the tomato near the step and gently twist it until it pops off. Done correctly, this will not damage the plant. If properly cared for, a single plant will produce several harvests worth of fruit.
Growing Tomatoes Indoors
While tomatoes are not the easiest plant to grow indoors they are far from impossible. With a little bit of effort and knowledge you can start growing tomatoes indoors in no time at all. Best of all, you’ll be able to enjoy delicious, fresh tomatoes year round!
Will Tomatoes Grow Indoors During The Winter?
Yes, tomatoes can be grown indoors during the winter. Just be sure to keep up the necessary lighting and temperature to help your plants thrive.
Why Are My Tomato Plants Not Producing Fruit?
The biggest culprit is often lack of light followed by the temperature being too low. Tomatoes need a lot of light, and will not produce any fruits if they don’t get enough.
Which Variety Should I Grow Indoors?
Look for micro-dwarfs or others that take less room. This makes them overall easier to manage and they are better suited for indoor growth. While you can grow full-sized tomatoes indoors, this requires more room and care.
How Long Does It Take To Harvest Tomatoes?
Under proper conditions it takes about 60-80 days after your seeds have sprouted or from seedling. This may be a bit longer depending on the variety, or if your indoor environment is not completely ideal.