7 Indoor Gardening Mistakes Beginners Make (And How to Fix Them)
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If your first indoor herbs struggled, you are in good company. Indoor plants tend to fail for a short list of reasons, and once you know them, most problems are easy to catch early. Here are the seven that come up most, with the signs to look for and the fix for each.
1. Overwatering
The mistake: watering on a schedule, or watering whenever the plant looks a little sad.
Why it matters: Iowa State University Extension explains that roots sitting for long periods in wet soil develop root rot, and lists yellowing or browning leaves, leaf drop and wilting as symptoms. Wilting from rot looks a lot like wilting from thirst, which is why people often water an overwatered plant even more.
The fix:
- Push a finger about an inch into the mix before watering. Water only if it feels dry.
- Water until it drains from the bottom, then empty the saucer after a few minutes.
- Expect to water less in winter and in lower light, when plants use less water.
Many herbs prefer to stay on the slightly dry side, as Michigan State University Extension notes. Basil is an exception that dislikes drying out completely, so check it more often.
2. Insufficient light
The mistake: choosing a spot because it is convenient or looks bright to you.
Why it matters: Iowa State Extension calls light the most limiting factor for herbs grown indoors, and most herbs need around six to eight hours of direct light a day.
Signs: thin stems that lean hard toward the window, long gaps between leaves, pale new growth and stalled growth.
The fix: move herbs to your sunniest window, start with more forgiving herbs like chives and mint, or add a grow light 6 to 12 inches above the leaves on a 12 to 16 hour timer. How Much Light Do Indoor Herbs Actually Need? explains how to check your windows.
3. Poor drainage
The mistake: planting in a decorative pot with no hole, using garden soil, or leaving pots standing in full saucers or outer sleeves.
Why it matters: University of Illinois Extension says herbs can grow in any container as long as it has drainage holes. Iowa State Extension lists missing drainage holes, old compacted soil and pots left sitting in water as causes of root rot.
The fix:
- Use pots with drainage holes. Keep a decorative pot as an outer cover only.
- Use bagged potting mix made for containers, never garden soil.
- For extra drainage, University of Maryland Extension suggests two parts soilless mix to one part perlite for indoor herbs.
4. Incorrect pot sizes
Too small: roots fill the pot quickly and the mix dries out within hours. University of Illinois Extension recommends herb pots of 6 inches or bigger and warns that basil quickly outgrows a 3 inch pot.
Too big: a large pot holds far more wet mix than a small plant can use, so the soil stays soggy. Iowa State Extension advises using a container of the appropriate size, not too big.
The fix: start most herbs in a 6 to 8 inch pot. When roots grow through the drainage hole, move up one size rather than jumping to a much larger pot. Penn State Extension recommends repotting when roots come through the drainage hole, ideally in early spring.
5. Overcrowding
The mistake: packing several herbs into one container, or leaving a grocery store pot of basil as one dense clump.
Why it matters: crowded stems compete for light, water and nutrients, and air cannot move between the leaves. Different herbs also want different amounts of water and light. Michigan State University Extension suggests keeping herbs in separate pots where room allows so you can monitor the light and water each one gets.
The fix: give each herb its own pot, or group only herbs with similar needs. Split crowded grocery store basil into two or three smaller pots, and thin seedlings to the strongest one or two per small pot.
6. Improper feeding
The mistake: reaching for fertilizer to fix every problem, or feeding heavily all year.
Why it matters: a struggling plant is usually short on light or overwatered, not underfed. Iowa State Extension notes that excess fertilizer leaves salts that can damage roots, causing lanky growth, yellowing or browning leaves and a white crust on the soil or pot. University of Illinois Extension warns plainly: do not over fertilize herbs.
The fix:
- Check light and watering before you feed.
- Fresh bagged mix often contains fertilizer already, so new plants may not need any for a while.
- When you do feed, use a diluted water soluble fertilizer as the label directs. Iowa State suggests feeding from early spring through summer and avoiding fertilizer in winter.
- If you see a salt crust, flush the pot with plenty of water or repot in fresh mix.
7. Ignoring early warning signs
The mistake: noticing a change but waiting to see whether it gets better.
Why it matters: most indoor problems are easy to fix early and hard to fix late. By the time a whole plant collapses, root rot or pests are usually well established.
A quick diagnosis guide:
| What you see | Likely cause | First step |
|---|---|---|
| Tall, thin, leaning stems | Not enough light | Brighter spot or a grow light |
| Yellow lower leaves, wet mix | Overwatering or poor drainage | Let the top inch dry, empty the saucer |
| Wilting, dry mix | Underwatering | Water thoroughly until it drains |
| Wilting, wet mix | Root damage from soggy soil | Stop watering, check roots, repot in fresh mix if they are brown and mushy |
| White crust on soil or pot | Fertilizer salt buildup | Flush with water or repot |
| Small bitter basil leaves | Flowering | Pinch off the flower buds |
| Tiny flies around the pot | Fungus gnats from constantly wet mix | Let the mix dry between waterings |
| Fine webbing or sticky leaves | Spider mites or aphids | Isolate the plant and rinse the leaves |
The fix: take thirty seconds each week to look closely at every plant: the newest leaves, the undersides of leaves, the soil surface and the drainage hole. A short weekly check catches nearly every problem while it is still small.
What to expect
Every home is different, and results depend on your light, temperature, plant variety and care. Avoiding these seven mistakes will not guarantee a perfect harvest, but it removes the most common reasons indoor herbs fail.
Keep learning
Our book Grow More From the Space You Have includes a troubleshooting guide for eleven common indoor plant problems and a weekly garden check. For a specific herb, start with How to Grow Basil Indoors in an Apartment, or plan a low cost setup with How to Start an Indoor Herb Garden on a $25 Budget.
The easiest way to avoid mistake number two is to check your light before you buy anything. The free 7 Day Indoor Garden Starter walks you through it, one short task a day.
Sources
- Iowa State University Extension: Diagnosing Houseplant Problems Related to Poor Culture
- Iowa State University Extension: Growing Herbs Indoors
- Michigan State University Extension: Growing Culinary Herbs Indoors
- University of Illinois Extension: Container Gardening, Herbs
- University of Illinois Extension: Growing Herbs in Containers
- Penn State Extension: Growing Herbs Indoors
- University of Maryland Extension: Growing Herbs in Containers and Indoors
