How to water herbs growing in pots and containers

We all want our herbs and plants to grow and thrive. Learning how to water herbs and plants correctly plays a major role in our success or failure.

It is not unusual to spend time deciding on the correct potting soil mix for our herbs and plants. 

But when it comes to watering these same herbs we often just water “like we always do” without any thought or plan. We simply assume that dry soil is bad and damp soil is good.

Did you come here looking for information on growing herbs in water? Please refer to our beginners guide to hydroponic herbs including guides on how to build DWC (with and without air) and Ebb and Flow Hydroponics.

But if you want to grow herbs and plants successfully you should take a step back and re-evaluate.

Often we water too much or not enough simply because we do not know the difference. And any pattern of consistent watering where some herbs or plants get more and others less should be avoided.

This article will start by looking at 5 reasons we water our herbs too much. We then move on to 3 common reasons we do not water our plants enough.

Finally I will share 7 actionable tips that you can use to teach yourself to manage watering and moisture levels for your herbs better.

Overwatering when growing herbs

Judging from the questions I get, overwatering seems to be a problem for many garden enthusiasts. And it seems to be a problem for gardeners with indoor herb gardens as well as outdoor herb gardens.

And it is a fact that herbs will not survive if you water them too much or too often. Excess water may collect at the bottom of the pot and lead to root rot and all kinds of problems. Too frequent watering may in turn force herbs to grow roots that are too shallow.

I also have to admit that I struggled to find a balance when I first started growing herbs and vegetables. I would always have a few thriving plants but found some herbs “difficult”. It did not occur to me that many herbs have specific needs and wants.

After all, we all like our herbs and we do not want them to be “thirsty”. It is very easy to end up overwatering in our quest to take care of our herbs. 

Overwatering happens for many reasons. Below I list 5 reasons why you may be giving your herbs too much water. And yes, I do speak from experience as I have over watered many of my own herbs over the years.

1. Do not water every single pot the same

Before we water we need to check every pot individually to decide if it is needed. It is important to keep the herb’s stage of development as well as type of herb or plant in mind instead of just watering everything.

You also need to factor in conditions such as full vs partial sunlight and exposure to wind.

Seeds need moisture to germinate but a developing plant may need to dry out before we water again. Rosemary and oregano are two prime examples of herbs that like to dry out between watering. 

Watering your rosemary and oregano pots every three to four weeks may be enough to keep the plant happy. Overwatering for example an oregano plant may result in yellowing leaves and even root rot.

Parsley, fresh basil and coriander (cilantro) and are on the other hand examples of herbs that are soft leaf and wilt more easily.

Basil is a soft leaf herb that needs moist soil
Basil wants moist soil and more frequent watering than for example rosemary or tarragon

Rule of thumb: herbs with thick wooden stems need less watering than more tender and soft leaf herbs with delicate leaves.

2. Make sure to provide proper drainage

It is always difficult to speak in absolutes but herbs prefer a well drained growing environment.

A loose and well drained soil mix will allow the rooting process to develop strong and healthy roots.

Always use a well drained soil mix and a pot with drainage holes.

3. Keep a herb garden journal

It is easy to become a creature of habit. And it is not always easy to remember what we did three days ago. Keeping a herb garden journal will allow you to note down details like when you watered which plant and how much.

I keep a journal with separate entries for my indoor herb garden and the herbs that I grow outdoors. And it is great if you are trying different methods like exchanging tap water for distilled water or testing a different potting mix for some pots.

And if there are several people looking after the pots chances are your herb garden journal will prevent mistakes where you otherwise may “double up”.

4. Using the wrong type of pots

Always use pots with drainage holes and keep the material in mind when watering.

Terracotta pots breathe and absorb water whereas plastic pots will keep the moisture inside the pot longer.

Metal conducts heat extremely well but does not breathe. If you water a metal pot too much you may burn or boil your root system if placed in a sunny windowsill with full sun. 

5. Placing pots outdoors and forgetting to account for rain

It is fun to grow herbs indoors. But it is also a great feeling to move herbs outdoors. We germinate the seeds, develop the seedlings or herb cuttings and then spend time hardening the plant. 

But when we move herbs outdoors we need to account for rain and help the pot if there is too much precipitation.

And herbs planted outdoors are often placed in pots on saucers to avoid the pots being in direct contact with the ground or leave marks on the surface where they are placed.

These same saucers will collect rain as it drains through the soil and can leave the pot sitting in constant wet. Keep an eye on your pots outdoors and be prepared to shield them from excessive rain. 

Underwatering – not providing enough water

We all know that our pots need to be watered. Pots are a closed ecosystems and we need to control the level of water and moisture if we want our herbs to thrive. 

Underwatering is often simply a matter of forgetfulness or making one wrong decision and being unable to cope with or handle the consequences.

1. Forget to water pots in outdoor herb garden

When we grow indoors we do our daily walk-throughs and watch our herbs grow. The first couple of weeks are especially exciting and we watch first leaves emerge (cotyledons) and true leaves take form.

When the new plants develop we then move the herbs outdoors. Here it is easy to forget to water these new additions to our garden. And remember, these herbs growing outdoors are now exposed to the elements including water and wind.

When we grow herbs we are also often forced to move pots around. Any given herb may get too much sun or may need to be shielded from the wind. And when we do, it is easy to forget to water our pots and containers in the new locations.

2. Choosing the wrong pot for herb plants

Pots made from organic materials and breathable fabrics absorb water. Terracotta pots, grow bags, peat and bamboo pots are some good examples. But these materials also leak water as the water they absorb evaporates. And when the water evaporates more water is drawn from the soil inside the pot.

Consequently all pots that breathe need to be watered more often than materials such as plastic, composites and metal.

Follow our guide to make grow bags from breathable material at home. It is not difficult and will save you money compared to buying large pots and containers.

Metal on the other hand conducts heat, why root systems can overheat and die if over exposed to sunlight. Always keep a close eye on pots placed in places with full sun.

Choose the material based on the need of your plant. Some herbs require direct sunlight while other herbs want a warm environment but do not tolerate too much direct sun.

3. Placing pots in the wrong location 

Be careful of putting pots in locations where the temperature will get really hot. Young plants and seedlings may grow tall and leggy and you will end up with weak roots and no new growth.

This is especially true for pots from materials that do not breathe such as metal, plastic and composites. Herbs run the risk of drying out as well as overheating.

But it is also true for terracotta pots and pots from organic materials as the water they absorb will evaporate quickly leading to an increased risk of dry outs.

Avoid placing your herbs in locations that get too hot. And remember to check the temperature during the hottest time of the day.

7 tips to help you water your herbs and pot plants

These 7 tips will help you understand how to water your herbs and pot plants.

And maybe more importantly, they will let you understand where you may be going wrong today.

1. Keep a garden journal

Keeping a garden journal is extremely helpful when we try to learn what works.

It is more important to start a journal than to try to start the perfect journal from day 1. 

Take a notepad and start writing when you water and how much. No need to be exact, just use measures and time units that will make sense to you. 

Keeping tabs on watering can be as simple as writing down the date and time and if you used top or bottom watering or maybe watered using a spray bottle.

Your journal will take form over time and it will help you as you over time will include more and more information.

2. The larger the pot the longer you can wait to water

All pots will not need to be watered at the same time.  Pots that are larger will hold more soil that will retain moisture longer. 

Remember to also factor in the material of the pot and do not go too big to make it “easy” on yourself. Many herbs and vegetables prefers to develop in a smaller environment to develop a strong and compact root system. One of the best examples are chillies but I would argue that it holds true for most seedlings.

3. Plant two pots and water one as usual and one more seldom

Do you find it difficult to follow instructions that talk about not watering too much or too often? And just with enough water for that particular herb or plant?

You are not alone. The solution is to start two pots whenever you plant new seeds. Then water one pot as you always do and the other pot every other time. Whereas guides and how-to tutorials will give you a lot of useful information you can take it one step further. 

Apply all you learn from the tutorials and then use the 2-pot system to hone in on what works best for you in your unique growing environment. 

4. It is ok for the soil to dry out on the surface

Thyme does not like constant daily watering
Thyme does not like daily watering

Do not panic every time the surface of the soil dries out.

Herbs and plants can and do survive mild surface dry outs. And some herbs like for example thyme, tarragon and oregano even thrives from it. 

You do not want the entire pot to dry out but it is perfectly fine to let the surface dry out every now and then. But do avoid dry outs in combination with high temperatures.

5. Use your finger to check the potting mix if unsure 

The surface of the soil does not tell you all you need to know about the level of moisture in the pot.

Make a hole with your finger and if it is dry 3 centimeters (1 inch) or so deep it is time to water. 

6. If in doubt do not water

If you cannot decide if you should water or not then do not water. Look at your plant. Most herbs will show you if they need water. More established plants will look lacklustre and weak. Fresh basil is a great example where you may even see yellowing leaves or discoloration.

And if you are unsure and there are no signs it is usually better to wait. Generally speaking a mild dry out is better than constant, albeit well meaning, over watering.

7. Water fresh herbs seldom and thoroughly

Lavender prefers thorough deep watering to encourage  healthy root growth
Lavender prefers thorough and deep watering less frequently

When you decide to water you should always water thoroughly.

Do not fall into the trap of watering a little every day out of habit. You do not want shallow root systems seeking surface moisture.

Instead water slowly until water is dripping out from the drain hole and make sure to let excess water drain off completely. Or if planted in your herb garden, make sure you water thoroughly and deep to encourage healthy deep root development.

Meet the author: Mattias is an experienced gardener spending most of his free time on his knees among herbs, plants and garden vegetables. For the past two years he has been sharing gardening projects and how-to tutorials on the NordicLavender website and YouTube channel.