Top 10 Best Organic Potting Soils for Herbs – GWC Mag

Like many people, you may be under the impression that dirt is just dirt and it doesn’t matter which type you use. In reality, there are three main types of soil, and only one of them is ideal for growing herbs in pots.

As the name suggests, topsoil comes from the top 3-10 inches of land. In its undisturbed state, topsoil contains high levels of nutrients and organic matter.

The main source for commercial topsoil, however, tends to be poor soil from construction sites. Although its composition depends on where the producers collected it, it doesn’t contain much organic matter, and plants won’t readily grow in it. You can use it for lawn care or landscaping projects, however.

Richer than topsoil, manufacturers often amend garden soil with organic matter. It often has little wood chips or fine mulch mixed in. This type of soil is best for outdoor gardens or raised beds and can be tricky to find in the spring when demand for gardening supplies increases. You could probably get away with using garden soil for potted plants, but it’s not ideal.

Usually composed of half garden soil and half peat moss or coconut fiber, this is the best soil type to use for growing plants in pots, whether indoors or out.

It often contains a small amount of perlite or vermiculite to increase aeration and structural integrity. It may also come with slow-release nutrient additives like rock dust, alfalfa meal, canola meal and rock phosphate.

There are numerous types of potting soil, and different herbs have unique soil type requirements based on their geographic origin. Therefore, it’s important to buy specific types of potting soil depending on the herbs you want to grow.

Mediterranean herbs with woody stems include sage, lavender, rosemary, oregano and thyme, among many others. These plants typically thrive in gritty soil with good drainage and less moisture around their roots, so make sure the pots you use to grow these herbs have holes in the bottom.

Mediterranean herbs need well-aerated soil with medium fertility, which prevents them from getting root rot and preserves their flavors. If you plant woody-stemmed herbs in rich soil, they’ll have a lower flavor and may be more vulnerable to pests.

Look for a potting soil with around 70% peat-free compost and 30% horticultural sand and grit. You may need to create this mix yourself, but it’s easy to do. Simply buy the compost and grit separately and combine them at home.

Avoid planting Mediterranean herbs in any soil containing manure, wetting agents or ericaceous compost. At the same time, don’t swing to the other extreme and plant them in pure sand or gravel. They need a balanced mix of organic and inorganic matter.

Mint, chives, cilantro, parsley, fennel and basil lack woody stems. Instead, they have soft green stems that draw in water to help the plants maintain their shape. These herbs prefer more moisture, so potting soil without sand is the best bet. Always plant them in pots with holes in the bottom.

Choose multipurpose compost to provide nutrients, retain some moisture and still allow for good drainage. Since it’s already so rich, you don’t need to mix it with additional materials. Avoid amending the potting soil with sand, grit, coffee grounds or manure.

Many warm-weather herbs prefer soil around 60 degrees Fahrenheit to thrive. However, this preference varies widely between species, so it’s best to look up specific guidelines for each type of herb you plant.

The temperature of your house or outdoor air temperatures will affect the temperature of the soil. In general, however, moist, packed soils are typically warmer than loose, dry soils. You can measure the temperature of your soil with a soil thermometer.

Now that you have an idea of which type of potting soil you need, it’s time to buy some from a reputable brand. Purchase a ready-to-plant soil or mix and match different kinds to create the perfect blend.

1. Dr. Earth Pot of Gold All Purpose Potting Soil

With kelp meal, composted green waste, aged fir bark, sawdust, fish bone meal and alfalfa meal among the ingredients, this organic, non-GMO potting soil is perfect for growing herbs in containers.

It features beneficial microbes and mycorrhizae to give your plants the best chance of growing up healthy. It’s also pet safe. You can use it for indoor or outdoor gardening. At $20 a bag, it isn’t cheap, but it is high quality.

2. Espoma Organic Potting Mix

Vegetables, herbs and flowers thrive in this organic soil specially formulated for container gardens. It contains mycorrhizae, sphagnum peat moss, humus and perlite enhanced with alfalfa meal, kelp meal, feather meal and earthworm castings for extra nutrients. It doesn’t contain any synthetic plant foods or chemicals. It’s also pet safe.

3. Foxfarm Ocean Forest Potting Soil

This robust organic soil blend is lightweight and well-aerated. It contains sphagnum moss, bat guano, fish meal, crab meal, forest humus and more. Its pH sits at 6.3-6.8 to optimize fertilizer uptake by your plants’ roots and is perfect for a container garden.

Foxfarm’s organic soil is pricey, but the high-quality ingredients seem to justify the expense—it has very good ratings and reviews on Amazon.

4. Burpee Organic Premium Potting Mix

This potting soil comes enriched with slow-release plant food to nourish your growing herb garden for up to three months. It also includes coconut coir to maintain moisture between waterings.

This potting mix is perfect for an indoor or outdoor container garden and is certified organic. It contains bone meal, earthworm castings, alfalfa meal and kelp meal to provide nutrients.

5. Gardener’s Supply Company Organic Potting Mix

This bioactive soil is perfect for helping you grow herbs indoors or out. It contains composted manure and plant material, sphagnum peat moss, perlite and nutrient amendments. It also contains mycorrhizae to bolster your herbs’ roots against stress. Additionally, it’s weed-free and pH balanced.

6. Back to the Roots Organic Potting Mix

This potting mix is much more affordable than most. It comes with mycorrhizae, coconut coir and yucca extract to help retain moisture and provide nutrients to your herbs. It also includes pH-balancing dolomitic limestone to provide calcium carbonate and magnesium carbonate, which reduce acidity and prevent nutrient deficiencies.

You can easily use this mix for an indoor or outdoor potted herb garden. Plus, it’s peat-free, so it doesn’t contribute to mining peatlands and releasing carbon dioxide emissions, and made in the U.S.

7. Black Gold Natural and Organic Potting Soil Plus Fertilizer

This rich, loamy soil has a completely organic base made of earthworm castings and sphagnum peat moss. It also contains compost and forest humus alongside pumice and perlite to promote aeration.

8. Good Earth Organics Zen Blend Premium Potting Soil

Fortified with exotic ingredients, among them seabird guano, glacial rock dust and crustacean meal, this organic potting soil is great for all growing environments, making it perfect for indoor or outdoor planting. It has a 0.2% total nitrogen content and contains soil-amending humic acid from humic shale ore.

Good Earth Organics is a small business, so its prices aren’t as low as you’d get from big-name brands, but its potting soil has excellent reviews overall.

9. Kellogg Organics Raised Bed and Potting Mix

Specially formulated for large outdoor containers and raised beds, this organic soil mix has added nutrients from poultry manure, earthworm castings and kelp meal. It also contains bat guano, recycled forest products, peat moss and feather meal to enrich your herb garden.

10. Wonder Soil Premium Organic Potting Soil Mix

Wonder Soil’s potting mix includes humus, worm castings, kelp, mycorrhizae and more to give your herbs the best shot. It’s peat free, organic and pet safe. It comes compressed in a resealable bag but expands to four times its size once you add water.

This soil offers excellent water retention and drainage. You can transfer herbs into it after they sprout or use it directly for germinating your garden.

Growing your own herbs is a great way to combine a passion for cooking and gardening. Many herbs thrive indoors, smell fragrant and brighten up your home in addition to their culinary qualities.

When looking for potting soil, first decide which types of herbs you want to grow and if you want to grow them indoors or out. Then you can choose from reputable brands to give your plants exactly what they need. Just be prepared—soon enough, people will be asking you for recipes!

Feature image: Markus Spiske; Image 1: Natalie Sym; Image 2: Rich Smith