9 Tips for Growing Abundant Herbs in Raised Beds

Is a garden complete without herbs? I don’t think so! Strolling out into your garden and picking a few sprigs of dill for dinner or mint for a cocktail is an experience everyone should be able to enjoy. Trust me, evening herb harvesting will quickly become one of your favorite summertime rituals.

Fortunately, most herbs are easy to grow at home, including in raised beds. That means they’re an excellent option if you live in an apartment with a patio garden or have a single raised bed in your small backyard. And if you’re working with multiple raised beds, you can experiment with various types of herbs.

If you’re worried about taking up your precious raised bed space with herbs, I get it. It can be difficult to know how to mix them in with your vegetables, flowers, and whatever else you’re growing. I’ll share some tips for growing herbs in raised beds that will make you a prepared and confident gardener.

Know Whether Herbs Are Annuals or Perennials

I’d say that about three-quarters of herbs are perennials that come back year after year. Think of plants like rosemary, sage, thyme, and oregano. Other plants like cilantro, basil, and dill are annuals that germinate and flower all in the same growing season. And some others are biennials, meaning they grow leaves in their first year and flower in their second year.

Here are some examples of popular herbs and their life-cycle:

Knowing the growth habit of each herb allows you to plant it in an area of your raised bed that makes sense. For example, you probably don’t want to plant oregano right in the middle of your bed since it will stick around for years to come. While it may grow well with its current lettuce neighbors, future plantings of tomatoes or peppers will quickly shade out this sun-loving plant. Edges of raised beds are better spots for perennial herbs.

Annual herbs offer a more flexible planting option than perennials, allowing you to experiment with their placement in your raised bed. While they can still be overshadowed by other plants, you only need to consider their current neighbors, not future ones. This is because herbs like cilantro and basil have a lifespan similar to lettuce or tomatoes, providing you with a reassuring level of flexibility in your herb garden.

Knowing whether herbs are annuals or perennials also allows you to plan for future seedling purchases and seed starting. You’ll only need to purchase perennial herbs once (as long as you take care of them). However, plan on continually starting annual seeds or purchasing annual herb seedlings.

Keep Succession Planting in Mind

Annual herbs like cilantro and dill are great candidates for succession planting. I find that many gardeners pop a dill seedling or cilantro seeds in the ground in the spring and expect their herbs to last all summer. But this isn’t the case!

The long days and warm weather of summer cause these plants to shift their focus from vegetative growth to flower production. After all, the plant’s goal is to produce seed! Flowering helps the plants produce offspring, but it doesn’t bode well for gardeners hoping to enjoy the fragrant leaves in salads and dressings. While you can’t stop plants from flowering, succession planting allows you to enjoy tender herbs throughout the summer.

I like to plant cilantro and dill seeds every two to three weeks from the late spring through early fall. When an old succession starts to flower, a new planting will be ready to harvest. Both of these crops are great candidates for direct sowing, but you can also plant the seeds indoors and then transplant them into your garden.

Although basil is another popular annual herb, you don’t have to worry about succession planting. That’s because a healthy plant will continue to produce new leaves for multiple months. If you’re worried about your plants succumbing to downy mildew or another fungal disease, plant one round of basil in the late spring and another in the beginning to middle of summer.

Get Your Spacing Right

If you’re working with limited space, it’s tempting to pack your plants tightly together. How else would you fit all the different herbs, veggies, and flowers you want to grow? But before you go wild with planting, remember that a handful of healthy plants are better than dozens of unhealthy ones!

Proper plant spacing is essential for maintaining proper plant health and growth. Packing plants close together causes the plants to compete against each other for water, nutrients, and sunlight. Plus, it leads to limited airflow and increases susceptibility to fungal diseases like powdery mildew and septoria leaf spot.

The ideal spacing for herbs depends on the type of plant. Chives and parsley are happy with ten-inch spacing, but large rosemary and sage plants will do better if you leave at least 18 inches between plants. If you’re not sure about the ideal spacing for your plants, look up the information for the herb you’re planting.

Don’t Be Afraid to Interplant

Sometimes these aromatic plants fall to the end of our planting lists. Although we know fresh basil will brighten our Caprese salads and dill will make our potato salad pop, glamorous crops like tomatoes and peppers take center stage, making them the supporting actors in our garden productions. Fortunately, herbs grow well with many other plants!

I like to tuck short annuals like dill and cilantro beside greens like lettuce and arugula. These greens are small enough to allow adequate sun to reach the herbs, and the two grow together nicely. If you’re working with small perennials like thyme and chives, try planting shorter crops like lettuce, carrots, and bush beans nearby.

Another trick is to plant quick-growing herbs alongside slower-growing veggies. For example, I like to plant a row of cilantro on either side of my tomato and pepper rows while leaving about a foot of space between the herbs and larger plants. By the time the veggies outgrow the herbs, they’ll be about done growing and starting to flower.

Take Advantage of Flowering Herbs

One of my favorite things about herb plants is their beautiful flowers. While most people plant herbs for their fragrant and flavorful foliage, their flowers are a bonus. Bright yellow dill umbels, purple sage spikes, and lacy white cilantro flowers all add beauty to the garden.

Since most people are after herbs’ foliage, watching your plants go to flower can be disappointing because it often coincides with the end of leaf production. But don’t pull out your flowering herbs! The flowers not only add beauty to the garden, but they also provide food and an environment for beneficial insects.

The flowers’ nectar and pollen provide food for pollinators like bees and butterflies and predatory insects like green lacewings, ladybugs, and hoverflies. These good bugs feed on common pests like aphids and thrips, so having them in your garden is a big win. Small herb flowers like cilantro, dill, bronze fennel, and thyme are especially attractive to tiny parasitic wasps and hoverflies that face difficulties feeding on larger flowers.

Sticks Herbs in Shorter Raised Beds

One of the great things about many types of herbs is their shallow root systems. While mature rosemary and sage plants can develop deep roots, many can happily grow in less than a foot of soil. Therefore, they’re a great option for elevated planters and raised beds that aren’t deep enough to properly accommodate plants like tomatoes, potatoes, and broccoli.

You can even tuck many in small pots if you don’t have the space or budget for larger raised beds. Some herbs that grow well in pots include thyme, lavender, sage, chamomile, and basil. Plant a single herb in an eight-inch pot, or plant a few in a larger container.

While many herbs grow well in smaller raised beds, feel free to tuck them in deeper beds. Their flexibility means you can grow them just about anywhere!

Remember that Raised Beds Get Colder than Native Soil

Although many are perennial, that doesn’t mean all of them can withstand conditions that would make a polar bear shiver. Some perennials like thyme and sage can withstand the winter in zone four or five, which means they can survive temperatures as low as -20°F (-29°C) to -30°F (-34°C). However, herbs like rosemary and some types of lavender can only tolerate winter temperatures as low as 10°F (-12°C).

So, what does all this have to do with raised beds? Well, the soil in raised beds often get colder than native soil. Since the sides are exposed to the air, the soil temperature drops more quickly. The soil found in the ground traps heat during warmer days and holds it during nights and cold spells, resulting in soil that’s often warmer than the air temperatures.

Therefore, you should take extra precautions when overwintering perennial herbs like rosemary, lavender, lemon verbena, and bay laurel in raised beds. If air temperatures remain near freezing, you don’t have to worry. But if you’re expecting an unusual cold spell, take measures to protect your plants.

Insulating the base of the plants with a layer of mulch is a great place to start. Wood chips, straw, and shredded leaves will act as a blanket that helps keep the plant’s roots warm. You can also drape a layer or two of row cover over your bed. Just remember to remove the covers once warm weather returns.

Prune Regularly for Robust Growth

No matter where you’re growing herbs, pruning is an essential part of maintaining healthy and robust plants. Perennial herbs, including thyme, rosemary, lemon verbena, and lavender, all benefit from annual pruning. While you may be hesitant to chop off some of the herb’s beautiful growth, know that this herbal haircut will encourage your plants to produce new lush growth.

Pruning off any old and diseased growth, as well as a portion of healthy growth, allows the plants to put their energy into producing healthy root systems and new stems and leaves. It also allows for good airflow, which helps decrease the chances that fungal diseases will take over your plants. Finally, pruning encourages flowering herbs to produce more flowers!

The ideal pruning method depends on the herb you’re working with. However, you should always start with extra sharp and sanitized tools. Sharp tools make a clean cut with as little exposed surface as possible, and sanitization prevents you from spreading diseases between plants.

Most woody herbs prefer to be pruned in the late spring or early summer. You’re looking for the time just after flowers have fallen from the plants. This timing ensures that you’re not removing any desirable flowers before they appear while also giving the plants enough time to recover when the frost arrives. I recommend learning about how to prune each type of herb, but a good rule of thumb is to remove the top quarter of the plants’ stems.

Choose a Long-Lasting Raised Bed

If you know you want to grow herbs but don’t have a raised bed at the ready, don’t just buy the first or cheapest garden bed you see! High-quality raised beds can last for multiple decades, and cheap beds can fall apart in a few growing seasons, so spending a few minutes researching your options is worth your time.

First, think about what size you’d like. Shallow beds work well for most herbs, but deeper beds allow you to grow a wider array of crops. You should also consider whether you want a bed that sits on the ground or an elevated bed that makes gardening more accessible.

Next, think about the material. If you’re interested in the natural look of wood, consider cedar. This wood is naturally rot-resistant, so you can enjoy long-lasting beds without worrying about synthetic chemicals. Plus, it looks and smells great! Metal is another popular option due to its durability, light weight, and sleek appearance.

After you’ve selected one you love, fill it with a suitable material. If you’re working with an extra-tall bed, you can fill the bottom with logs and sticks to improve drainage and save some money on soil.