Growing fresh tomatoes indoors may seem impossible, but with the right techniques and care it can be easy and rewarding! Windowsill gardening allows anyone, even those without an outdoor garden, to enjoy homegrown tomatoes year-round. Follow these simple steps to grow happy, healthy cherry tomatoes or even full-sized varieties inside your home
Choosing the Right Tomato Variety
When selecting tomato varieties for indoor growing, prioritize dwarf compact types that do well in containers. Cherry tomatoes are always a safe bet since they stay small. Try grape cerise, or mini Roma varieties like Red Robin or Sweet ‘n’ Neat. For full-sized slicing tomatoes, look for “patio” or “pot” in the name, like Patio Princess or Pot Luck. Determinate varieties that stay short also work better than tall indeterminates.
Some of the best varieties for windowsill growing include:
- Micro Tom – The world’s tiniest tomato, only 4-5 inches tall!
- Window Box Roma – Mini Roma perfect for containers
- Sweet ‘n’ Neat – Cherry tomato with great sweet flavor
- Tiny Tim – An iconic dwarf tomato variety, just 10-12 inches tall
- Salad Cocktail – Prolific producer of red and yellow cherry tomatoes
Starting Seeds Indoors
Tomato seeds can be started indoors 6-8 weeks before the desired harvest. Sow seeds 1⁄4 inch deep in seed starting mix or potting soil, water gently, and place in a warm spot with plenty of light. A seedling heat mat can provide the ideal soil temperature of 80-90°F. Once sprouted, move to the sunniest window in your home. Add grow lights to provide at least 6 hours of daily sunlight.
When the seedlings have 2-4 true leaves transplant each one into a 3-4 inch pot filled with potting mix. Let them grow until the roots fill the pot before transplanting into a larger container. Hardening off is not necessary since they will stay indoors.
Choosing the Right Containers and Soil
For windowsill gardening, use the largest container possible, at least 6 inches deep. This gives tomatoes adequate room for their roots to spread out. Clay, plastic, wood, and ceramic pots all work fine as long as there are drainage holes. Self-watering containers and upside-down planters like Topsy Turvy are also options.
Use quality potting soil not garden soil, which is too heavy. Mix in compost or worm castings to enrich the soil. Adding slow-release tomato fertilizer at planting provides nutrients for the full season.
Caring for Indoor Tomato Plants
Sunlight, temperature, water, and fertilizer are the keys to keeping indoor tomatoes happy in their pots.
Sunlight: Tomatoes need at least 6 hours of sun per day. South or west-facing windows are ideal. Rotate plants frequently so all sides get sun. Grow lights can supplement natural light, especially in winter.
Temperature: Daytime temps of 70-80°F and nighttime temps above 60°F are best. Keep away from drafty spots. Use a space heater or seedling heat mat if needed.
Water: Check soil daily to keep it evenly moist. Wait until the top inch is dry to water again. Keep the soil consistently moist, but well-drained.
Fertilizer: Use soluble tomato fertilizer every 2-3 weeks according to label rates. An occasional compost or fish emulsion feeding provides micronutrients.
Pollinating and Supporting Your Plants
Outdoors, wind and bees spread pollen so tomatoes set fruit. Indoors you need to hand pollinate by gently shaking or tapping tomato blossoms daily. You can also use a small brush or cotton swab to transfer pollen.
As indoor tomatoes grow, tie them loosely to bamboo stakes or tomato cages for support. Prune suckers (small branches between stems and leaves) to keep plants tidy and focused on fruiting.
Troubleshooting Common Problems
Growing tomatoes on the windowsill comes with some challenges. Here are solutions to common issues:
- Leggy growth – Insufficient sunlight, increase hours under grow lights
- Poor fruit set – Lack of pollination, tap blossoms daily
- Leaf spots – Fungal diseases from humidity, improve air circulation
- Wilting – Under or overwatering, check soil and adjust watering
- Slow growth – Low temperatures or inadequate fertilizer, move to warmer area and fertilize
- Whiteflies/aphids – Insect pests, spray with insecticidal soap
- Blossom end rot – Irregular watering, maintain consistent moisture
Enjoying the Harvest
Once your indoor tomatoes start ripening, check plants daily for ready-to-pick fruits. Gently twist to remove, leaving stems attached. Cherry types ripen prolifically over a long period. Slicing tomatoes produce over a shorter timeframe.
The sweet taste of homegrown tomatoes in winter is a real treat. Enjoy them fresh in salads and sandwiches, cooked into sauces and soups, or preserved by canning or freezing. With the right care, windowsill gardening can yield a mini tomato harvest for months of indoor enjoyment!
How many plants do you typically grow at once?
Usually at least 2 of each variety. I might start a 3rd if I find that tomato tastes really good!
Do you use grow lights or a windowsill to grow your micro tomatoes?
I actually don’t own any grow lights. I am lucky that a sunny windowsill is enough to grow all my micro tomatoes in. The indirect light they get from the southeast facing window is enough to keep them happy.
Grow tomatoes indoors on a windowsill using FREE home made light tubes. This is how I do it.
FAQ
Can I grow tomatoes on a windowsill?
A particularly sunny windowsill is a great spot for growing tomatoes! Dwarf varieties are better for small spaces as full-sized tomato plants can grow tall.Jul 19, 2023
Can you grow tomatoes indoors by a window?
Yes, I mainly grow these tomatoes to harvest them indoors. This gives me just enough of tomatoes for my sandwiches and spring salads. Then I plant my windowsill tomatoes in pots outside instead.
Where is the best place to grow tomatoes indoors?
Find the Perfect Place: Tomatoes won’t effectively grow indoors unless the conditions are like those of an outdoor garden. The plants need a good eight hours of sunlight per day and a surrounding temperature of around 70 degrees Fahrenheit or higher. Consider a spot on a window sill or near a screen door.
Is it good to grow tomatoes inside the house?
Small tomato’s like the Cherry variety , are perfect for indoor growing, for their size. The actual plant and fruit stay small throughout the growing process. You will need to keep temperatures between 60–80 degrees fahrenheit, and give the plants 10–15 hours of light daily.