First, some good news: Indoor gardening offers a significant advantage over traditional outdoor gardens – pests are much less common because your plants grow in a controlled environment and lack natural entry points for pests. Most Everleaf users never experience this problem. If something does appear, there's no need to panic – with a little attention and the right approach, you can easily get it under control.
The castile soap bath – your most important tool
Before we get to the individual pests, let's briefly discuss your most important tool: the castile soap bath. It's used against most pests and works reliably – so we'll explain it in detail right here.
What you need: 1 tablespoon of castile soap + 1 liter of warm water in a bowl or bucket. Please only use castile soap – no dish soap, no hand soap, no other soap. Castile soap is biodegradable, safe for humans and animals, and leaves no harmful residue.
Here's how to proceed:
- Harvest as much as possible first – less plant mass means fewer hiding places for pests.
- Cut off heavily infested leaves with scissors and dispose of them.
- Briefly rinse the plant in the sink to wash away any initial pests.
- Then immerse the plant upside down in the castile soap solution until it is just below the substrate, leave it in for 10–20 seconds, and shake it gently.
- Remove and gently pat dry with a cloth.
- Turn off the light for 4 hours afterwards – otherwise the still-damp leaves will burn under the lamp.
- Rinse vegetables briefly with water before eating.
Why multiple times? Pests have a life cycle – eggs, larvae, adults. A single bath only kills one stage. By repeating the treatment regularly, you break the cycle at every stage.
Here's how to prevent it
The most effective protection against pests is to avoid inviting them in the first place – and a few small habits are enough to achieve this:
- Wash your hands and roll up your sleeves before touching your plants – pests can also travel on clothing, especially if you have been working outside in the garden.
- Check briefly once a week – especially under the leaves, on stems, and at new growth. Those who spot problems early have a much easier time dealing with them.
- Keep your distance from windows and doors that are often open, from pets (who like to bring things in), and from freshly bought fruit and vegetables from the supermarket.
- Regularly remove dead or yellow leaves – they are breeding grounds and hiding places for pests.
- Keep other potted plants at a distance – pests can live in their soil and jump from there to your garden.
The 5 most common pests
🪲 Aphids — easy to control
Aphids are annoying, but one of the easiest pests to get rid of. With consistent treatment, you'll have them gone in just a few weeks.
How to recognize them: Sticky, shiny residue on the leaves, deformed or wilted shoots. The aphids themselves often sit in groups on stems or the undersides of leaves – depending on the species, they are greenish, black, or reddish.
What you do:
- Remove and dispose of heavily infested plants or leaves.
- Then the castile soap bath (instructions above) – repeat every 4 days, at least 4 times.
- The treatment therefore lasts about two weeks – after which the infestation should be gone.
If you still see aphids after the fourth bath, you can either continue (then every 7-10 days instead of every 4) or dispose of all plants, thoroughly clean the system and restart.
🕷️ Spider mites — persistent, but solvable
Spider mites are the most challenging of common pests. They are small, reproduce quickly, and require consistent treatment. With patience, however, they can be controlled – and those who act early have a significantly easier time.
How to recognize them: Fine cobwebs on the underside of the leaves, yellowish or silvery-dull spots on the upper side of the leaves. The mites themselves are tiny (reddish-brown or pale) and barely visible to the naked eye.
What you do:
First harvest and cut off heavily infested leaves, then:
In case of light infestation: Rinse the plant thoroughly in the sink, then soak it in castile soap every 4-5 days – at least 4 times.
In case of severe infestation: Dispose of heavily infested plants completely. Rinse the remaining plants and soak them in a castile soap bath every 4–5 days – at least 6 times (approx. 3.5 weeks). If you see no improvement after two weeks, it is more effective to discard all plants, thoroughly clean the system, pause for 3–4 weeks, and then start again.
Tip: Predatory mites (more on this below) are particularly effective against spider mites.
🦗 Thrips — requires some patience, but solvable
Thrips are somewhat more persistent than aphids, but can be controlled well with regular treatment.
How to recognize them: Silvery-white streaks or mottled light patches on the leaves, small black dots (feces) on the leaf surface. The thrips themselves are very small, narrow, and pale yellow to brownish – you often only see them when you look very closely.
What you do:
First harvest and cut off heavily infested leaves, then:
In case of light infestation: Rinse the plant thoroughly in the sink, then soak it in castile soap every 4-5 days – at least 4 times.
In case of severe infestation: Discard heavily infested plants. Rinse remaining plants and soak them in a castile soap bath every 4–5 days – at least 6 times. If you see no improvement after two weeks, discard all plants, clean the system, pause for 3–4 weeks, and restart.
Tip: Predatory mites (more on this below) can be a good alternative to a castile soap bath.
🪰 Whiteflies — combat them with two measures at once
Whiteflies are manageable – you just need to know that they have two life stages that must be tackled simultaneously: the adult flies and their larvae. Trying to control only one stage will only make things worse.
How to recognize them: Small white flies that rise when you touch a plant. Sticky or shiny leaves, weakened, pale growth.
What you do:
First harvest and cut off heavily infested leaves. Then you fight on two fronts at once:
Against adult flies (with wings, visibly flying):
- Hang up yellow sticky traps – they catch flies before they can lay new eggs. Available at any garden center or online.
- Additionally, spray the plants with a castile soap solution every 4 days (1 tablespoon of castile soap / 1 liter of water in a spray bottle), making sure to spray both the tops and bottoms of the leaves. Then turn off the lights for 4 hours. Continue until no more flies are visible.
Against the larvae (invisible, they stick to the undersides of leaves):
- Give them a castile soap bath every 4-5 days (instructions above) – at least 4 times. The intensive immersion reaches the larvae where a spray cannot.
Ideally, you should do the spray and the bath on consecutive days – this way you have two days of treatment in a row and interrupt the life cycle even more effectively.
🦟 Fungus gnats — easy to control
Fungus gnats look worse than they are. The small black flies that fly around the soil are harmless themselves – the real problem is their larvae in the soil, which feed on the roots. However, this can be dealt with quickly and easily with the right product.
How to recognize them: Small black gnats flying around the substrate. You can sometimes see the larvae themselves on the surface of the substrate.
What you do:
- Hang up yellow sticky traps to catch adult gnats before they can lay more eggs.
- Add BTI tablets (e.g., Culinex Tab Plus , available online) directly to the water tank – one tablet every two weeks. BTI is a natural strain of bacteria that specifically targets and kills the larvae without harming you, your plants, or your vegetables. You can continue harvesting and eating as usual throughout the entire treatment.
Important: Always use yellow sticky traps and BTI at the same time – otherwise new gnats will immediately lay eggs again, and you will only be fighting half the population.
Predatory mites – the natural boost
Predatory mites may sound strange at first, but they are one of the most effective and gentle methods of pest control. They are invisible to the naked eye, do not spread throughout the home, and are completely harmless to humans and animals.
How they work: Predatory mites are natural enemies of pests like thrips and spider mites. You buy them in small sachets, simply hang them on your plants – and the mites do the rest by eating pests and their eggs.
Important: If you are using predatory mites, pause the castile soap bath and all spray treatments – these would also kill the predatory mites. Instead, let them do their work undisturbed. You can find predatory mites in garden centers or online (e.g., as "Phytoseiulus persimilis" against spider mites or "Amblyseius cucumeris" against thrips).
Which varieties are more frequently affected – and which are not?
Not all plants are equally susceptible. If you're starting over after an infestation or want to play it safe from the beginning, it's worth making a conscious choice of plants.
Aphids frequently infest: snack peppers, chili peppers, jalapeños, mini eggplants, cherry tomatoes, kale, endive.
Spider mites frequently infest: snack cucumbers, snack peppers, chili peppers, jalapeños, mini eggplants, cherry tomatoes, wild strawberries.
Thrips frequently infest: snack peppers, chili peppers, jalapeños, mini eggplants, pak choi, endive.
Whiteflies frequently infest: snack peppers, chili peppers, jalapeño, mini eggplants, cherry tomatoes, pak choi.
If you take a break after an infestation and start again, choose varieties for the first cycle that are generally more robust and less likely to attract pests. Herbs like mint, thyme, and chives are not only robust – their scent also acts as a deterrent to many pests, making them good companion plants for more susceptible varieties.
