Published on May 21st, 2019 | by Sarah Dephillips

Why Are My Potted Herbs Dying? 5 Common Mistakes of Container Growers

Growing herbs in your kitchen is an overall fantastic idea – it’s aesthetic, healthy, and adds flair to your cooking. Maybe you saw a cute kitchen herb garden idea on Pinterest and went for it – that’s great! But now your oh-so-cute container herb garden is droopy, scraggly, yellow, stunted, or worse – dead. If you’re asking, “Why are my potted herbs dying?” don’t worry, herbs are resilient. They recover or regrow quickly. You don’t have to have a green thumb to grow a thriving container herb garden.

Why Grow Herbs in the First Place?

Growing your own kitchen herbs has health benefits AND environmental benefits. Here are just a few:

Growing your own herbs allows you to ensure they’re organic – no pesticides or herbicides.
You eliminate shipping (fossil fuels) and packaging (paper, plastic, glass waste) when they’re sitting right in your kitchen.
Fresh herbs have better flavor and higher nutrient contents.
Many fresh herbs have medicinal properties that can be used on minor ailments.
House plants clean your indoor air quality.
Herbs generally require less nutrients and maintenance than vegetables, making them ideal for kitchen container gardens.

So what if you’ve tried and turned out to be an herb killer? See if you’ve made one of these common mistakes and try again!

Mistake 1 – Improper Drainage

This is the most common mistake I see in kitchen herb gardens. Plant roots not only need water and soil, they also need air. If your herbs are planted in a mug or a mason jar, chances are their roots are rotting. Even though it’s cute to have a plant growing out of a teacup, if that container doesn’t have a hole at the bottom, managing the soil moisture for good root health is going to be a nightmare. If you’re a beginner, make sure your containers have holes at the bottom to let the water drain out. And beside that, make sure you’ve got a dish underneath to catch the water when it comes out the bottom!

Mistake 2 – Inadequate Pot Size

Even though you don’t see them, roots are a vital part of plant health. Just like the top of your herb, the roots need space to grow and thrive. How much space? A good rule of thumb for beginners is to imagine the root system getting as big as the above-ground part of the adult plant. It has to support those stems and leaves, somehow! Here’s a quick reference chart for common kitchen herbs and their ideal pot depth.

Most herbs require an 8” deep pot at least! Sorry, no, the teacups just won’t work long term.

Mistake 3 – Overcrowding

You’ve got your little seed packet, and there’s so many tiny, tiny seeds. How many herbs should you have per pot? In most cases – ONE. Even though the seeds are minuscule now, a mature herb plant likes to have its own soil, water, and light without competition from its siblings. Sure, you can plant a pinch of seeds in each pot and watch them all germinate into cute, tiny plants. But as they grow bigger, you need to do what’s called thinning. As you use them in your cooking, harvest the smaller, weaker, and more crowded plants at the ground level. One healthy, mature herb will give you a much better harvest than 25 weak scraggly ones competing for light and nutrients.

Mistake 4 – Improper Harvesting

Many people don’t want to harm their beloved plants, so they gently pick off a leaf or two here and there when they want to use them. It’s a good sentiment, but this type of harvesting actually causes most herbs to become tall, scraggly, and eventually top heavy. Cutting a whole stem will actually stimulate bushy growth, giving your herb a nicer shape and more leaves for future harvesting. To harvest basil, cut the stem just above two leaves. This will cause two branches to form below the cut. Thyme, oregano, rosemary, parsley, marjoram, and many other common kitchen herbs have multiple stems. Cut stems close to the base with sharp scissors or a knife, not taking more than ⅓ of the plant’s green leaves at one time. Pinching off flowers will also direct the plant’s energy toward more leaf growth.

Mistake 5 – No Sunlight

Herbs are a great indoor choice because many don’t require full sun. But they do need some natural light to photosynthesize. If you have a window that gets some sunshine, put them there. If not, they need to be in a place that gets good ambient or reflected sunlight to survive.

Your herbs were thriving but are now dying:

Maybe you’ve had a thriving container herb garden but now your plants are looking sick or tired. While many herbs are perennial (living for many years), some are annual. Cilantro and dill for example will generally only live one season before they go to seed and die. Save some seeds and replant these. Note whether your seeds or herbs are annual or perennial when you buy them.

If you have a perennial herb that’s a year or more old and not looking so good, its roots may be suffering. Plants can sap all the nutrients out of potting soil, or roots can become crowded and start to choke each other. Take your herb outside and gently pull it out of the pot. If the roots were smashed against the pot and are starting to coil around in the pot’s shape, loosen them up and replant your herb in a bigger pot with new, fresh soil. If you want to use the same pot, prune the roots with sharp clippers so they’re not growing in a circular pattern any more and repot with fresh soil. Add some organic fertilizer such as compost to your perennial herbs annually to give them a nutrient boost. This can be done during repotting and/or root pruning, or can just be added to the top of the soil, which is called “topdressing.”

If you haven’t started yet, here’s a list of the 5 best herbs to grow indoors.