Want fresh, peppery greens all year round? Learning how to grow arugula indoors is a fantastic way to start. It’s one of the easiest and most rewarding plants for your kitchen garden.
You don’t need a lot of space or experience. With just a few basic supplies, you can have a continuous harvest right on your windowsill. This guide walks you through every step, from seed to salad bowl.
How To Grow Arugula Indoors
Growing arugula inside is straightforward. The key is mimicking its preferred cool-weather conditions. You’ll focus on four main things: light, water, soil, and temperature.
Let’s get your indoor garden started.
What You’ll Need to Get Started
Gathering your supplies first makes the process smooth. Here’s your simple shopping list:
- Containers: Pots or window boxes at least 6 inches deep. They must have drainage holes.
- Potting Mix: Use a high-quality, well-draining potting soil. Avoid garden soil, which is too heavy.
- Seeds: Standard arugula seeds. You can find them at any garden center.
- Light Source: A sunny south-facing window or a grow light.
- Watering Can: One with a narrow spout for gentle watering.
- Optional: A small fan for air circulation and organic fertilizer.
Choosing the Perfect Spot and Light
Arugula needs plenty of light to grow fast and taste great. A south-facing window is the best natural option. It should get at least 4-6 hours of direct sun daily.
If your windows are dim, don’t worry. Grow lights are a perfect solution. Use LED or fluorescent bulbs placed 4-6 inches above the plants. Keep the lights on for 12-14 hours a day. A simple timer can automate this for you.
Planting Your Arugula Seeds
Now for the fun part. Follow these steps to plant your seeds correctly.
- Fill your container with moist potting mix, leaving an inch of space at the top.
- Sprinkle the seeds evenly over the soil surface. Try for about 1 inch apart.
- Cover the seeds with a very thin layer of soil—about 1/4 inch deep.
- Gently mist the soil with water so you don’t disturb the seeds.
- Place the pot in its warm spot. You should see sprouts in 5-7 days.
You can sow new seeds every 2-3 weeks for a non-stop harvest. This is called succession planting.
Watering and Feeding Your Plants
Consistent moisture is crucial. Arugula likes its soil to be like a wrung-out sponge—damp but not soggy.
Check the soil daily by sticking your finger in an inch deep. If it feels dry, it’s time to water. Water slowly at the base until it runs out the drainage holes. Always empty the saucer underneath to prevent root rot.
For feeding, arugula isn’t a heavy feeder. But for lush growth, use a half-strength liquid organic fertilizer every two weeks after the first true leaves appear.
Common Watering Mistakes
Overwatering is the biggest issue for indoor gardeners. Yellowing leaves can be a sign. Let the top inch of soil dry slightly between waterings. Underwatering causes slow growth and a very sharp, bitter taste.
Ideal Temperature and Humidity
Arugula prefers cooler temps, between 50-70°F (10-21°C). It can bolt (flower and go to seed) quickly if it gets to hot. Keep it away from heat vents and direct blasts from heaters.
Average indoor humidity is usually fine. If your air is very dry, a small humidifier nearby helps. Good air circulation from a fan also strengthens the plants and prevents mold.
Harvesting Your Homegrown Arugula
You can start harvesting in as little as 4 weeks! There are two main methods:
- Baby Greens: Snip off individual leaves with scissors when they are 2-3 inches long. Cut from the outer leaves first.
- Cut-and-Come-Again: Harvest by cutting all the leaves about an inch above the soil. The plant will often regrow for a second, smaller harvest.
Always harvest in the morning when leaves are most crisp. Rinse them gently and enjoy immediately for the best flavor.
Troubleshooting Common Problems
Even easy plants can have issues. Here’s how to fix common problems.
Leggy, Thin Seedlings
This means not enough light. Move them to a brighter window or bring your grow lights closer. Seedlings will stretch desperately toward a light source.
Yellowing Leaves
Often a sign of overwatering. Check your drainage and let the soil dry a bit more. It could also indicate a need for fertilizer.
Small Holes in Leaves
While pests are rare indoors, you might see aphids or fungus gnats. For aphids, a spray of water and a drop of dish soap works. For fungus gnats, let the soil surface dry out more between waterings.
Bolting is when the plant sends up a flower stalk. The leaves become bitter. If you see a stalk forming, harvest the entire plant immediately. To delay bolting, keep the plants as cool as possible.
Tips for the Best Flavor
For that perfect peppery zing, follow these tips. Cooler temperatures produce sweeter leaves. Hot conditions increase the spicy bite.
Regular harvesting encourages tender new growth. The younger leaves are milder, while older leaves are more pungent. Try a leaf every few days to see how the flavor changes.
FAQ: Your Arugula Questions Answered
Can I grow arugula indoors all year?
Yes! That’s the main advantage. You control the environment, so you can grow it in any season.
How long does it take to grow arugula inside?
From seed to first harvest, it typically takes 4 to 6 weeks for baby leaves.
Do I need to thin my arugula seedlings?
If you sown to thickly, yes. Thin them to about 3 inches apart to give each plant room to grow. You can eat the thinnings as microgreens.
What are the best containers for indoor arugula?
Any container with drainage holes works. Shallow, wide pots or window boxes are excellent because arugula roots don’t go extremely deep.
Why is my indoor arugula bitter?
Bitterness is usually caused by heat stress (bolting) or underwatering. Harvest younger leaves and keep the plants well-watered and cool for a milder taste.
Starting your indoor arugula garden is that simple. With consistent light and water, you’ll have a steady supply of fresh greens. There’s nothing quite like adding your own homegrown greens to a meal. Give it a try—you might just find a new favorite hobby.