How to grow herbs – 13 mistakes to avoid (and what to do)

I get a lot of questions about how to grow herbs and vegetables from friends, family, and fellow enthusiasts.

Today I will share the top 13 mistakes I see people making when they grow herbs at home.

1. Buying herbs at the supermarket

Be patient and see the beauty in the process.

Grow your herbs from seeds unless you are in a real hurry. There is no reason to buy herbs in pots at the supermarket unless they are for immediate consumption.

It may seem like a quick fix to buy a potted herb plant at the supermarket. But why?

It is not difficult to grow herbs from seeds.

It is much more complicated to keep a store-bought plant alive and well. These plants have often been driven hard under extreme conditions to make it to the supermarket shelf as fast as possible. 

How will you replicate this environment?

There are however exceptions to the rule. Basil is one herb that can be started by taking cuttings to grow more basil plants with ease.

2. Using old seeds

When people ask me how to grow seeds at home, I give them basic information about pots, soil, seed, light, and water.

I often get the response that they think they have some bags of seeds in a drawer somewhere at home. 

This is not the right way to start.

It is possible to store most seeds for several years if stored properly. 

Seeds must be stored in a cool, dry place with no direct sunlight and a somewhat constant temperature. 

If you are unsure that your seeds are healthy, you should always buy new seeds to maximize your chances of germination.

And if you insist on using leftover seeds – always pre-germinate your seeds before planting. This way, you will know that you are only working with viable seeds.

3. Watering too much 

It is easy to love our plants a bit too much.

And from experience, more herbs are killed by watering too much than by not watering enough.

There are many different ways to gauge when you need to water your herbs.

Your herbs may need extra water if the weather has been scorching and sunny. To be sure, you can insert your finger in the soil; if it is dry 3 centimeters (1 inch) down, it is time to water.

You can also buy a Soil Moisture Meter that will show if the soil is dry, moist, or wet.

My best tips are to remember three things:

  1. Dry on the surface does not automatically mean time to water
  2. Water thoroughly and seldom rather than a little three times a day
  3. If you are unsure, do not water. Most herbs prefer a mild dry out to soaking wet soil.

4. Using big pots

There is no need to use big pots and lots of soil when we plant seeds. Instead, start your seeds in small starter pots. 

Smaller pots make it easier to control moisture levels. Water using a spray bottle and cover the pots with a translucent cover.

Let the seeds germinate and grow first and true leaves before even thinking about transplanting the seedling to a larger pot.

Smaller pots mean less soil and more control. And this is a good thing.

5. Do not plant one seed per pot 

We have all seen the photos on social media. A pot with a solitary seedling growing proudly in the middle.

Why?

First of all, not all seeds are guaranteed to germinate.

And when seedlings develop, they give each other support as they grow.

Furthermore, even if you end up with too many seedlings, it is easy to thin out the plants and add the harvest to your next meal.

My advice is to plant 5-10 seeds in a pot. 

Most herbs take well to growing in bunches. Examples are basil, parsley, thyme, chives, oregano, and dill, to mention a few. 

6. Trim and harvest continuously

Herbs will grow long and top-heavy if left alone.

Instead, continuously harvest (remove) leaves to shape a healthier, bushier, and more compact plant. 

Do not always trim the most prominent and oldest leaves on top of the plant. These leaves are your solar panels feeding the growth of your plant.

Harvest the younger leaves and, most importantly, look at the plant before you harvest leaves. You will see where it makes the most sense to harvest at any given time.

Another tip is to harvest 10-15 centimeter (4 to 6  inches) long cuttings from your herb plant. 

How to grow basil from cuttings
Basil cuttings setting new white roots

Harvest the lower leaves and leave the top crown intact. Place the stem in a glass of water; in 1-4 weeks, you will see new roots forming.

Now plant the cuttings, and you have started a new plant. Try it with basil or sage if you are new to the method, but it is very straightforward.

Make sure to replace the water at least every other day.

7. Are you providing enough light?

Herb plants need light to grow and thrive. 

Make sure you place your herb plants in a place with access to sunlight. 

A window sill can be an ideal place.

If you are growing herbs indoors during the darker periods of the year, you should consider using grow lights.

I use a timer to give my herbs additional light from midnight to 8 AM as the electricity is cheaper at night where I live. This also means that any natural light during the day is a welcome bonus.

8. Watering the wrong way

Seeds and seedlings are fragile and need to be treated gently.

When we water from the top, we risk flooding the planted seeds. Seeds planted on the surface will be displaced and often end up in the same place.

Seedlings showing first or even true leaves will also be flooded, and we risk exposing roots as the soil shifts. The leaves can also be weighted down and pushed into the soil.

My tip is to always water seeds with a spray bottle. Seedlings are, on the other hand, watered from underneath using a water bath.

Watering from underneath will allow the soil to absorb moisture while leaving the surface intact and undisturbed.

9. Using the wrong soil 

Sometimes more is not better. And this is true for planting seeds and the use of fertilizer.

Seeds and seedlings do not need much nutrition to develop during their first stages.

If you use regular garden soil, you risk using too much fertilizer. This is not necessary. 

Regular garden soil is also often too dense. You want looser soil to allow the seeds and seedlings to grow and develop.

Ideally, you buy or mix your potting soil. If you do not want to spend money, you can use 2 parts of regular garden soil mixed with 1 part of coarse sand.

Throwing in a handful of gravel will also help make the soil more porous, if available.

10. Allowing herbs to flower

You should never let your herbs bolt or flower.

Unless, of course, you are planning to harvest edible flowers or seeds for the next growing season.

When herb plants set flowers, a couple of things happen. The two most important to us are:

  1. The taste of the herb changes. Sometimes the herb will lose some of its characteristic taste and smell. Other times the taste may change and turn bitter.
  2. The plant will now use all its energy to produce flowers rather than the leaves we are looking to harvest.

My tip is to trim any buds or flowers as soon as they appear. 

If an annual herb has started to bolt, it is impossible to reverse the process. But we can delay it by removing buds and flowers as soon as we see them.

11. Not growing seeds in batches at different time intervals

If you want to have fresh herbs in your kitchen garden year-round, do not sow all your seeds at the same time.

Instead, sow seeds in batches every 3 to 4 weeks. That way, you will have many different herbs growing at different stages. You will have a constant source of fresh herbs year-round.

12. Buying the same seeds and same varieties

Having too much of one particular type of herb can become a little boring. And you may run out of ideas on how to create different dishes or beverages using the same herb all the time. 

Instead, try different varieties of the same herb (for example, common basil, Thai basil, and cinnamon basil) or try different herbs. 

You may be surprised at just how many types of seeds are available for herbs you may never have heard of before – and specific herbs that may not be available in your local market.

13. Buying seeds for the wrong reasons

Growing herbs from seeds require attention to detail and a bit of time. 

Do not spend money on seeds unless you are willing to:

  • Invest your time in the growing process
  • Look after your plants
  • Use your herbs in your kitchen for dishes or beverages

I have seen friends who want to fill pots with fragrant kitchen herbs but are unwilling to care for them, let alone use them. 

You will end up with a sad, wilted collection of neglected pots on your window sill.

Mattias Magnusson: Hello, I'm Mattias, a passionate and experienced gardening enthusiast. I am the creator of MattMagnusson.com, your guide to year-round herb and veggie growing. Let's simplify green living, no matter your space or location.