11 Mistakes to Avoid When Growing Herbs Indoors
A little indoor herb garden is aesthetic and convenient, but it may not always turn out the way photos look on Pinterest. When growing herbs indoors, it’s easy to make several mistakes that stunt or kill your plants. Most culinary herbs have different requirements than houseplants, and some require major adjustments to transition from an outdoor environment.
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A little indoor herb garden is aesthetic and convenient, but it may not always turn out how photos look on Pinterest. When growing herbs indoors, it’s easy to make several mistakes that stunt or kill your plants.
Most culinary herbs have different requirements than houseplants, and some require major adjustments to transition from an outdoor environment.
If your indoor garden is struggling, here are 11 common mistakes we’ve all made and how to fix them.
Lack of Sunlight
Insufficient lighting is the most common mistake across all indoor gardening methods, but it is especially problematic for herbs. While it may seem nice to brighten up a dark corner with some greenery, herbs (and most houseplants) tend to suffer without bright sunlight.
Basil, cilantro, parsley, mint, chives, rosemary, and lavender are particularly finicky about their lighting needs. These plants need 6-8 hours of sunlight daily, preferably from a west or south-facing window.
Choosing the Wrong Species
Some plants just aren’t meant to be grown indoors. It’s not that they’re impossible to grow in your home; rather, they are difficult to please in a windowsill container. If you have extra time, space, and supplemental lighting on your hands, give these plants a go! But if you want a lowkey indoor herb garden, pick species that willingly adapt to growing inside. We have a list of 15 herbs you should avoid growing indoors, including:
You may have some luck if you start these plants in outdoor containers and bring them inside for winter. The avid indoor grower can certainly pull off growing the above species, but beginners should opt for easier indoor herbs like:
Generally, the best herbs for growing as houseplants have these attributes:
- Compact size
- Tolerate lower light conditions
- Provide continuous harvest
- Enjoy moderate room temperatures
Choosing the Wrong Pot Size
Container size is absolutely crucial for successful indoor plants. If you select a pot that is too large, the soil can hold excess water and cause root rot. But if you use a pot that is too small, the herb can quickly suffocate and become rootbound. A happy medium is necessary, and you may need to up-pot on a semi-regular basis to keep your plants happy.
A pot should generally be 1.5 to 2 times the size of an existing plant’s root ball. This allows ample space for the roots to expand without creating a soggy, waterlogged mess of excess soil.
If you are growing from seed, it’s best to start small. You can always up-pot later, and most herbs are tolerant of transplanting.
Lack of Drainage
There are millions of adorable pots and planters on the market today. The problem is that many of them don’t have drainage holes. To successfully grow herbs indoors, you must start with containers that can drain water out of the bottom. Without a drainage hole, water has nowhere to go and can pool up in the pot’s base.
As you’ll see, this mistake is closely intertwined with overwatering and improper soil selection. All three of these factors can spell disaster for your windowsill garden. Only purchase pots with one or more drainage holes in the bottom.
Classic terracotta pots with saucers are great for windowsills. If you find a container you love that doesn’t have a drainage hole, consider drilling one with a diamond-tipped drill bit. Depending on the material, you should be able to modify the container to remain functional for your herbs while still matching your interior decor.
Planting in the Wrong Soil
Most container-grown plants require extra well-drained potting soil. Because the roots are confined in a smaller space than they would be in the ground, the soil needs to drain water more efficiently.
If you plant indoor herbs in heavy or poorly drained soil, you may notice:
- Yellowing leaves (a sign of overwatering)
- Droopy or dead leaves
- Slime or mold growing on the soil surface
- Mildew growing on the leaves
- A rotten smell from the roots (a sign of root rot)
If there isn’t a pest or disease issue, most plants can be saved by repotting with a quality soil mix. Look for blends that include:
- Perlite: This is the most valuable resource for an indoor gardener. This puffed volcanic mineral improves drainage.
- Vermiculite: Like perlite, this material improves aeration and can help fluff up soil mix.
- Compost: Compost improves drainage while simultaneously helping the soil hold onto water. Overall, it’s a great texturizer.
- Peat moss or coco coir: This shredded organic material adds more air space between soil particles and slowly releases water into the root zone.
- Vermicompost: Worm castings are great for herbs like basil or oregano that enjoy an extra nutrient boost.
- Pea gravel and sand: These gritty materials are best for Mediterranean herbs like thyme, lavender, or rosemary.
Overwatering
It’s easy to give your plants a little too much love. Overwatering is a super common mistake typically caused by misinformation. Many people think irrigation should happen on a set schedule (for example, a rule that says, “Water your cilantro every other day”), but that’s not how plants work.
Because light, humidity, temperature, and growth patterns always change, you can’t reliably water herbs in conjunction with your calendar. Watering without checking the soil typically leads to overwatering and a host of other issues.
Overwatering can look like:
- Droopy, wilted leaves (it seems counterintuitive, but excess water suffocates roots, which means less water can reach the leaves)
- Yellow leaves (especially between the veins)
- Stunted growth (your herbs just won’t get bigger)
- Soggy, water soaked lesions on leaves
- Mold or mildew diseases
- A bad smell in the soil
- Super dark colored soil
- Fungus gnats hovering near the soil surface
- Root rot (slimy, mushy roots)
Herbs strongly dislike sitting in waterlogged soil (most plants do unless they are wetland species). But container plants are especially susceptible to overwatering because you don’t always know what is happening to the water in the bottom of the pot.
To avoid this mistake:
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- Always check your soil before watering.
- Stick your finger 2-3 inches into the soil in the pot.
- If your finger comes out clean and dry, it’s time to water.
- If your finger comes out covered in soil or damp/wet, don’t add more moisture.
Of course, the watering needs will depend on the specific plant. But generally, potted herbs should not be watered excessively. Only irrigate until water comes out of the bottom of the pot into the saucer, and then stop.
Alternatively, you can “bottom water” by placing pots in a saucer or shallow bowl of water for a little while and allowing the roots to suck up moisture from below. If doing this method, limit the time the pot is spent sitting in the water to an hour or less. This prevents the soil from absorbing too much moisture!
Underwatering
The opposite of the overzealous indoor gardener is the plant parent who completely forgets about their herbs. If you go on a weekend trip and return to depressing wilted herbs, it’s probably due to underwatering.
Plants in small pots dry out more quickly than those in large pots or those growing in the ground. Depending on the soil type, herb species, humidity, and air circulation in your home, some species are especially prone to losing moisture.
Underwatering can sometimes look like overwatering, but plants are more likely to perk up after a drink. Symptoms include:
- Wilting
- Dry, crispy leaves
- Yellowing leaves (starting from tips to center)
- Leaves dropping off the plant or dead leaves
- Drooping, withered stems
- Leathery, brown leaves
- Dry, dusty soil
- Compacted soil
To avoid underwatering, check your kitchen herbs every couple of days by sticking your finger in the soil. Any time you harvest a few sprigs of thyme for soup, it’s a great time to ensure all your herbs have the water they need.
Neglecting Pruning and Harvest
Regularly pruning your herbs promotes bushier growth and more harvests. If your herbs seem leggy (elongated, wimpy stems) or aren’t putting up new growth, it may be because you’re not harvesting them enough.
Once cilantro, parsley, basil, chives, thyme, oregano, mint, and others reach a certain size, they actually benefit from being harvested. Don’t be afraid to snip leaves every week! A haircut keeps the plant healthy and prevents it from going to seed.
Harvest stems near a node (where leaves meet the stem) to encourage quicker regeneration and bushy growth. For chives, simply cut across the top with kitchen shears, leaving at least 3-4 inches of growth at the base.
Poor Air Circulation
If the air around your herbs is stagnant or the leaves are crowded together, it can quickly ruin your seasoning harvests. Proper airflow prevents fungal diseases like powdery mildew from contaminating your herbs. Many kitchens don’t have ceiling fans, so it’s helpful to occasionally open a window or turn on the vent above your stove.
Pruning and spacing are two other important ways to avoid this mistake. If your plants start to look overcrowded inside their pots, or your pots are crammed closely together, it’s time to spread things out and let air flow through to keep them healthy.
Improper Fertilization
Unlike herbs grown outside in the garden, indoor herbs cannot access the natural minerals in your native soil. Nutrients deplete more quickly in containers and need to be replenished regularly.
Some plants can get by on just the organic material from compost, but others benefit from a slow-release balanced organic fertilizer that can provide nutrients over time. Under-fertilized herbs may grow slowly, appear yellow or pale, or look dull and sad.
On the other hand, too much nitrogen can cause excessive leafy growth without much flavor. This is especially annoying with fragrant leafy herbs that we grow precisely for their aroma and taste in our favorite dishes. Over-fertilizing can also lead to salt buildup inside containers, potentially killing plants over time.
Ignoring Pest Problems
In an ideal world, our homes would be protected from the pesky insects that attack outdoor plants. But alas, indoor plants are still susceptible to pests. If you forget to check for pests regularly, they can quickly spread between containers and contaminate your entire indoor herb collection.
The most common potted herb pests include:
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- Fungus gnats (closely linked with overwatering or soggy soils)
- Aphids (they hang out under leaves)
- Whiteflies (they fly in the air when you shake an infested leaf)
- Spider mites (almost invisible, but cause yellow leaves)
- Mealybugs (hang out in leaf axils and stem joints)
- Thrips (cause discoloration and distorted leaves)
Monitor your plants closely and remove leaves or stems where you notice pests. If things get exceptionally out of hand, consider using a homemade neem oil spray or a horticultural soap to remove them.
While these are organic measures, you may want to wait a week or so after application to ensure the pests and the treatment are gone. Wash your herb leaves thoroughly after harvesting. Neem does not taste very good in basil pesto!
Final Thoughts
Many common houseplant tactics crossover into the edible herb gardening realm. As general rules of thumb, ensure your herbs receive 6-8 hours of sunlight, well-drained potting soil, and consistently moist soil that is never soggy. Check out our grow guides for specific details about each unique species. Most importantly, don’t overwater or keep your herbs in the dark!
