How to Care for Your Herb Garden
Jules Walters • First published: Oct 24, 2023
Before diving into the detail of caring for your herb garden, first things first. You want to be sure your herb garden is in the right place.
Location, location, location
Herbs need three things above all else to survive and thrive: water, a healthy growing medium, and light; ideally direct sunlight. If you don’t get light sorted from the outset, no amount of water or expensive compost is going to give you healthy herbs.
So, if you’re lucky enough to have a choice of outdoor spaces, establish your herb garden in the spot that receives the most sunlight. And bear in mind, most herbs do best in full sun. That’s at least 6 to 8 hours of direct sunlight per day.
All is not lost if, like most of us in urban environments, you get less than full sun outdoors. You may struggle with lavender and thyme, both of which would rather die than live in a shady spot. But there are other herbs that do well in a combination of sun and partial shade. Think: coriander, mint, and parsley.
If you don’t have any suitable outdoor spaces, take a look at my blog on starting an indoor vertical garden for some other ideas. You’ll find an option there for even the smallest of indoor spaces.
Growing herbs in pots, raised beds, or in the ground
If you do have a sunny patch of ground to spare, or an established plant bed, these are nice choices to have. Should I create my herb garden in the ground, in raised beds, or in planters?
Here’s a few things to help you decide.
If you have limited space, growing herbs in pots allows for flexibility – and you can move them around as the seasons change. That flexibility will matter more if space is tight, and if you’ll need to move your plants around to catch more sunlight.
Raised beds are ideal for medium-sized spaces, while in-ground planting is more suited to larger areas and more permanent planting.
Potted herbs have the great advantage of movability. That makes potting a great choice if you need to relocate frequently, or bring your herbs indoors during the winter; or even take them with you on vacation now and again!
In containers and raised beds, you have greater control over soil quality, drainage, and pH levels. This can be especially helpful if your native soil isn’t ideal for herb growth.
In-ground planting needs soil preparation and additions, such as well rotted organic matter, to ensure the right conditions for your herbs to grow happily. If you have poor soil to begin with, or if it’s too acid or alkaline, that can take time to get right.
Maintenance and access
Growing herbs in raised beds or pots usually calls for less bending and kneeling compared to in-ground planting. This can be a big advantage for people who find it hard to get up and down, or those who just prefer gardening higher off the ground.
For more on this, see my article on How to Begin an Indoor Vertical Garden.
Watering and drainage
Potted herbs will need more frequent watering, as the soil tends to dry out faster than ground soil. Pots or planters should have drainage holes in the bottom so the plants don’t become water logged. Then, as part of your maintenance program, check every now and then that the holes haven’t become blocked, either by an impacted root ball, or by rocks or soil. If your plant is full of water, something is not right.
Remember that raised beds also tend to dry out more quickly compared to in-ground planting.
In-the-ground herbs benefit from natural drainage, so they should need less watering.
Herbs by design
Think about the overall look and design you would like for your gardening space.
Potted herbs can be arranged creatively, such as a mixture of rosemary, thyme and sage. Or, you might go for a group of pots all the same. Raised beds are versatile and offer a structured, organized garden design. In-ground planting might be preferable for a more natural, traditional garden look.
Herbs do vary in their growing needs, as well as their natural lifespans.
- Rosemary, for example, is a perennial plant, which means it continues to grow year after year. In the right conditions – principally a sunny spot and warm, well-drained soil – rosemary will gradually grow as big as you’ll let it. That suits it well to all types of planting.
- Mint, on the other hand, while also perennial, spreads through its roots and can easily end up dominating other plants, which is why it’s deemed invasive. Knowing that, I recommend giving your mint plants their own dedicated planters, so they have ample space to grow – but only so far, and no further!
- Basil is only a perennial in the warmest climates, as it can’t tolerate temperatures below around 40F (5C). In the US, that makes it an annual plant anywhere outside USDA zones 10 to 11. So, basil is best planted in a pot or planter that you can bring inside when a cold snap is due. Or, you could grow it inside permanently, on a windowsill that gets direct sunlight, complemented by an LED grow light fixed overhead.
- Some other culinary herbs, like basil, are known as tender perennials for the same reason; dill, for example. Cilantro (aka coriander) is a tender annual, with weak stems and feathery leaves, so it easily collapses if it gets too wet or too cold. All of these herbs are likely to be better off in small pots or planters that you can easily move under cover as needed.
Summary: pots, raised beds, or grounded?
To summarize: each planting method has its advantages. So, as well as your own preferences, consider your available outdoor space; where and whether you’re willing to get down on your hands and knees; and the distinctive qualities and needs of the herbs you plan to grow.
If, like me, you enjoy having fresh herbs in easy reach, you may want to have an indoor herb planter too. Take a look at my article on the best vertical hydroponic gardens if you want a readymade system for growing your herbs – either indoors or outside.
If you want to plant herbs from seeds, plan to germinate the herb seedlings indoors in early spring. Then plant out the seedlings outdoors once they’re established and you can be sure the last frost has gone.
If you’re buying young plants and skipping the herb seeds stage, you can plant them in your outdoor containers or beds after the last expected frost.
Check your seed or herb plant supplier’s recommendations on spacing to ensure they have enough growing room.
And, if you’re repotting herb plants to allow for future growth, be sure to give them at least half as much space again in the new container as they had in the old one.
Watering and feeding
Ensure your herb garden is watered regularly, but not too much. Test the soil in each bed or container regularly with a fingertip, and water deeply whenever the top inch or so feels dry.
The best water for herbs is rainwater, either straight from the sky or freshly collected in a covered water butt. In most places, tap water is an OK next best thing, but preferably not straight from the tap.
In many places in the US , for example, your tap water will have had chlorine added, which can be very harmful to plants. The remedy is to draw the water off into a bucket or watering can and leave it to sit for a day; allowing all the chlorine to evaporate. If you can’t wait that long, you can boil the water for 15 to 20 minutes instead.
Then, at least monthly during the growing season, add a slow-release organic fertilizer or liquid fertilizer to give your herbs the nutrients they need.
Check your herbs at least weekly for signs of pests or diseases.
Prune back the outliers to encourage more growth. And be sure to harvest herbs frequently, to promote new growth, hold their flavor and prevent them going to seed prematurely. You can cut up to a third off most plants – trimmed from the crown – without harm to the plant.
Testing the soil
Most plants like the pH of their soil to be slightly acid. That’s a pH level of between 6.0 and 7.0. Testing the pH of soil is relatively simple and can be done using a soil pH testing kit, or by sending a soil sample to a lab for analysis.
Once you know the pH, adjustments can be made, such as adding lime to raise the pH, or sulfur to lower it.
Perlite and vermiculite
Perlite and vermiculite are commonly used in gardening and horticulture. Their purpose is to improve the soil structure and boost its moisture-retaining capacity.
Perlite, seen above, is a type of volcanic glass that’s heated and expanded, creating a lightweight and porous material. When added to soil, perlite improves aeration and drainage by preventing compaction. It helps loosen heavy clay soil in particular, which makes it easier for roots to penetrate and allows excess water to drain more readily.
Vermiculite, shown here, is a natural mineral that expands when heated. It has excellent water-holding capacity, which helps to keep moisture in the soil. The main use for Horticultural vermiculite is to prevent soil from drying out too quickly, and thereby enable a more consistent water supply to plant roots.
Just a word of warning: don’t mix up vermiculite insulation granules, found in hardware stores, with horticultural vermiculite. They’re not the same thing!
Frequently asked questions
Should you water herbs everyday?
It’s good to have a routine, but it’s just as easy to over-water as to water too little. And daily watering can be too much. The time to water is when the top inch or so of soil is completely dry to the touch.
In a hot spell, this may be once a day at around the same time; ideally in the early morning or early evening, when your herbs are in shade. Avoid watering in the late evening, as this can result in your herbs having wet roots overnight that then get very cold, or even freeze solid on the coldest nights.
What does pH stand for? What does it mean, and why does it matter?
The letters ‘pH’ are short for ‘potential hydrogen’, and the pH scale indicates the concentration of hydrogen ions in a soil solution.
The pH level of soil is crucial for successful herb growth because it affects the availability of essential nutrients to plants. Different herbs have different preferences for soil pH, and they thrive best within specific pH ranges. As a general rule, most herbs prefer a slightly acidic to neutral pH level (around 6 to 7), though some may tolerate slightly alkaline conditions.
Soil pH directly affects nutrient uptake by plant roots. If the pH is not within the preferred range, some nutrients might become less available or even toxic to the plants.
Which are the most aromatic plants in herb garden?
We refer to many of the most fragrant as Mediterranean herbs. And you’ll certainly find them growing widely throughout the coastal regions of Southern Europe and beyond.
Top among them for fragrance, I would include: basil, bay, cilantro (coriander), dill, fennel, lavender, lemon balm, marjoram, mint, oregano, parsley, rosemary, tarragon and thyme.
Despite their Mediterranean label, these herbs grow successfully across large parts of the world.
What if I don’t have space for garden beds?
Don’t worry! There are plenty of alternatives to in-the-ground planting or a raised bed. If you have nothing more than a blank wall or border fence available, you can have a vertical herb garden. You can even have a miniature kitchen garden in a hanging basket, or a sunny outside windowsill.
Some other vertical garden options include:
- Hanging baskets
- Hanging pots
- Window boxes
- Recycled containers
Or if outdoors is out of bounds, then have you considered growing herbs indoors?
You can get more herb garden ideas in my blog on starting an indoor vertical garden.