Plus, which herbs are easiest to grow at home.
According to a recent article in the Washington Post, seeds are poised, along with Zoom and sourdough starter, to be one of the big winners of the coronavirus pandemic. Both as a hobby and for being able to provide one’s own sustenance, people are taking on the cultivation of edible plants with enthusiasm. If you’ve caught the green thumb this month (and hopefully little else), an herb garden can be an easy way to dabble in the agricultural arts, providing big flavor, and quickly, for relatively little effort. If you’ve ever thrilled to the overnight progress in your jar of regenerating scallions, imagine the potential joy sparked by an abundance of fresh basil, brought about by your own handiwork.
Whether you are working with a yard, patio, or even just a sunny windowsill, here are all of the elements to consider for ushering your personal herb garden into existence, from seed to harvest, with success.
To Seed or Not to Seed
If you’d like to enjoy your herbs sooner rather than later, and to ensure ongoing engagement with your new project, Ann Whitman, author of “Organic Gardening for Dummies,” recommends beginning with young plants, rather than seeds. A few herbs such as basil, chervil, and cilantro can be more easily cultivated from seeds, and some such as basil and mint can also be rooted from cuttings placed in a glass of water.
Whitman recommends the following herbs for beginning gardeners: basil, bay laurel, chervil, chives, mint, oregano, parsley, rosemary, and thyme. See the appendix at the end of this article for the particular nuances of growing these, and many other herbs.
Soil & Drainage
Indoors or outdoors, high-quality organic gardening soil with good drainage is a must, specifically potting soil if growing indoors, and it should be rich, loamy, and not compacted. Well drained soil should always appear grainy or crumbly, even when wet. You can add perlite to increase drainage at a ratio of 1 part perlite to 25 parts soil.
Resist using natural outdoor soil for indoor plants to avoid inviting unwanted guests that can coexist in a natural ecosystem but will be disruptive in a controlled environment.
Pots for Indoor Herbs
Rule number one: Your pots must have drainage holes, ideally with saucers underneath or a double bottom for collecting excess water and protecting your surfaces. Terra cotta is a good material to look for; because of its porous nature, it takes in air and prevents soil from becoming too wet. Good air circulation is also key for growing the herbs you’re intending to, and not other organisms like fungus.
Bigger is better when it comes to size: more space promotes better growing conditions than less. For individual herbs, the pots should be no smaller than 6 inches in diameter. To grow multiple herbs together, you’ll want to put two or three in a pot that is about 10 inches in diameter and about 8 inches deep.
Light is the most important aspect of growing any green thing, and many people don’t have enough. A sign that your herbs aren’t getting enough light is that the stems are getting longer without producing abundant leaves.
Most experts agree that six to eight hours of light per day is optimal, which can be achieved naturally or superficially. For outdoor plots, avoid areas that are too shady during the day, under trees or against a wall with mostly northern exposure.
For indoor herbs, “a southwestern-facing window is your best bet for good light,” says Diane Stahl, owner of Urban Roots, a Denver-based city garden store and greenscape installation company specializing in small urban spaces. Rotate your pots occasionally so that they don’t start to lean toward the sun.
If you can’t get light from the sun, get a few clamp-on reflector lights with compact fluorescent bulbs, which should be placed very close to the plants, about four to six inches away. But also be wary of too much light. While a rare scenario, brown spots on the foliage can indicate that the leaves are actually burning,
“Overwatering is the biggest mistake people make trying to grow herbs inside,” says John Lingle, owner of Lingle’s Herbs, a nursery specializing in organic herbs located in Long Beach, California. Herbs need less water than you might think, and you need to learn to read your plants and let them tell you when they’re ready for water.
“The rule of thumb is to let all the herbs dry out completely,” says Urban Roots’ Stahl. She also says that though plants don’t like a lot of water, they do like consistent watering, so it’s best to check the soil for dryness daily to help develop a regular schedule for when your herbs likely require watering.
To water your indoor herbs, put the plants in the sink and water the base where the stem meets the dirt, not the leaves, letting the water soak through, doing this twice. Let them drain completely and put them back in their saucers. Never leave standing water in the saucer or you’ll rot the plant’s roots. Like light, there is such a thing as too much hydration. Yellowing leaves are an indication that your herbs might be getting too much water.
Feeding Herbs: What Your Food Eats
Herbs are fairly hearty, but they still like to be fed a good organic fertilizer like fish emulsion (be aware: it stinks) or liquid seaweed. You’re growing herbs for their leaves, not their flowers, so find a fertilizer that doesn’t promote blooming. That means the fertilizer needs to have a low level of phosphorus. Lingle suggests getting a gallon jug and filling it with water and one tablespoon of fish emulsion to make a very weak organic fertilizer solution. Water the herbs with it, and then you won’t have to worry about when to feed them. You can even make your own fish emulsion!
The plants will let you know if they need to be fed. If they seem to have stopped growing, they probably need food. If the plants are turning yellow and you’ve already ruled out watering issues, this may also mean they need feeding.
The lime in eggshells can also be beneficial for Mediterranean plants like rosemary, thyme, and basil. Rose Marie Nichols McGee, coauthor of “Bountiful Container” and co-owner of Nichols Garden Nursery in Albany, Oregon, suggests putting the shells into a food processor with a little water and putting a spoonful into each pot when prepping the soil for planting.
How to Harvest Herbs
Proof positive that herbs were made for human enjoyment: Cutting your herbs encourages growth. Prune from the top, pinching off leaves where the leaf meets the stem:
Remove no more than a third of the volume at a time, and you’ll activate a virtuous circle that ensures ongoing enjoyment of your herb-growing labors.
Appendix: The Ins and Outs of Particular Herbs
Herbs That Are Easy to Grow
Bay Tree: A very slow grower. Be sure you pick up a Laurus nobilis, Nichols McGee; the Laurus nobilis is best for cooking with. Bay tree can become infested with scale if it gets too dry—use dishwashing detergent to wash off the leaves, then rinse them thoroughly.
Chive: Doesn’t require as much light as some other herbs. The Grolau variety was bred for growing indoors.
Related Reading: What Is the Difference Between Chives, Scallions, and Green Onions?
Kaffir Lime Tree: Kaffir lime leaves are often used in Thai cooking. Be sure you give this plant special citrus food.
Lemongrass: A good way to cheat, because it requires no soil; you can just use a stalk you get at the market. Make sure it has a good amount of stem and the bottom is intact; trim the top and put it in a container with a couple of inches of water. Connie Campbell, a New Hampshire–based master gardener, says, “It will send out roots and new sprouts and many, many new stalks from the bottom, and you can just cut those off and use them.”
Related Reading: How to Prepare and Cook with Lemongrass
Mint: Very invasive, so it needs its own pot. Peppermint is great for teas, and you’ll only need a little of it. You usually need a lot of spearmint for recipes, so it may not be worth growing in a container.
Parsley: It doesn’t need much sun, says Carole Ottesen, author of “The New American Garden,” but it’s a slow grower so may not yield a whole lot.
Vietnamese Coriander: Almost identical in taste to cilantro, says Campbell, and very reliable.
Herbs That Are a Bit More Difficult to Grow
Oregano: Try the Greek variety. Needs a lot of light.
Rosemary: Keep it on the dry side and look for an upright variety like Tuscan Blue or Blue Spire. It needs a very sunny window and probably supplemental light. Since you don’t need a lot of it for cooking, it’s a good herb to grow. It’s very sensitive to overwatering.
Thyme: It will likely need supplemental light. Look for lemon thyme, which has a unique flavor and can’t easily be purchased in markets.
The Hardest Herbs to Grow Successfully
Basil: It’s a favorite to cook with, but it’s a tough one to grow. Your best shot is to grow it during the warm, bright summer months. Campbell suggests the Spicy Globe or African Blue variety, the latter of which is more like Thai basil and does well indoors.
Cilantro: Cilantro is the name for the stems and leaves of the coriander plant. It often bolts, meaning it starts growing flowers and seeds instead of leaves. Leslie Land, gardening columnist and blogger, sows coriander seeds in a shallow flat (a plastic tray), then eats them as sprouts, root and all. “Sow the coriander seeds quite thickly, like almost paving but not quite. Only let seedlings get about four to five inches tall, then pull them up, roots and all, and wash them.” To make this economical, she says, just pick up coriander seeds in bulk at a health food store.
Sage: Nichols McGee says that sage is more susceptible to mildew and is very sensitive to overwatering. If you want to try it, though, Campbell says to go for the dwarf sage, which is more compact than regular sage.