Is there anything better than the spicy, floral scent of basil? Working in the plants, watching the bees go crazy in the small white or purple flowers, cutting some sprigs for a homemade pizza–it’s the essence of the summer garden.
And then—the first cold snap turns your lovely basil into a dark slimy mess.
What if there was a way to keep your basil harvest going indefinitely through the winter and even into the next spring and summer?
Basil is tender, which means as soon as the temperature drops your outside basil is gone, along with all your dreams of pesto and basil chiffonade.
It’s easy to grow basil indoors all year, and you can also use this technique to multiply your plants, start your summer garden with big healthy basil plants, and keep yourself in pesto all year.
Basil grows well from cuttings, which is an easy way to turn one plant into a whole lot of plants to grow in pots indoors or on the patio.
We just harvested a big bowl of basil from a single container, at the end of January in Colorado. That one January harvest yielded enough for a batch of pesto and a batch of basil simple syrup from the trimmings.
With some simple care you can grow enough basil to make whatever you like, even in the very dead of winter.
Everyone knows you can eat basil leaves. But fewer people know about the other basil plant parts you can eat.
Leaves: Basil leaves go into garnishes, pesto, pretty much any basil recipe ever. Depending on the variety, basil leaves taste sweeter or more like licorice or citrus.
Stems: Tender young stems can be used in pesto and recipes just like the leaves. Tougher stems can be infused as described below.
Flowers: Basil flowers are entirely edible. You can add them to salads or make scented vinegars and teas.
Seeds: Basil seeds are soaked and used like chia seeds. They are called tukmaria or sabja in recipes, usually as a thickener. But since basil is an annual that dies after it sets seed, remove the flowers and seeds to keep the basil growing through the winter. Green seed heads can be chopped and used in recipes like leaves
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Is basil an annual or a perennial?
In zones below zone 10 basil is grown as an annual. Basil is a terribly tender plant that turns into black slime as soon as it gets cold. There’s no such thing as “kissed by frost” with basil.
In zones 10 and above basil is considered a short-lived perennial. That means that it can grow for 3-5 years before dying. Typically the plant reseeds itself so that there are always new plants coming up.
For our application, you can keep basil going indoors in pots all year as long as you keep the seeds head pruned. Inside, basil will be a tender perennial that keeps growing as long as you protect it from cold temperatures.
When to plant basil indoors
The quickest way to get a good stand of basil is to start with cuttings. But to take cuttings you need a plant.
You can start basil from seed if you don’t have a basil plant to start with but it takes many weeks before basil plants grow large enough to harvest.
I like basil seeds from Seeds Now or Botanical Interests.
To start a basil plant to grow outside, start seeds 12 weeks before the last frost and transplant outdoors after all danger of frost has passed, or grow the plant indoors in a pot.
To grow basil from cuttings, either start with plants from the garden, start with a starter plant from the nursery, or take cuttings from a live basil plant from the grocery store. You know the ones, they come in plastic with bare roots.
Take cuttings from the garden well before the danger of first frost.
Don’t know when to expect first or last frost? Try this calculator from Morning Chores. Put in your zip code and find the earliest and latest frost dates for where you live.
I recommend you take your cuttings slightly before the earliest first frost date in the range because basil is extremely tender. You won’t be sorry to start your cuttings early.
Materials to grow basil all year long
It doesn’t take much to get a basil pot going all year. You probably have most of what you have around the house already.
For the cuttings
- Basil plant: You can use a basil plant from your garden or a friend’s garden, from a nursery, a live basil plant from the grocery store or start with one grown from seed.
- Sharp paring knife: You’ll want a sharp cut. Scissors might crush the stems so I prefer a sharp knife.
- Container to root cuttings: Just a tall glass that you can spare for a few weeks.
- Filtered water (or tap water left out overnight): My cuttings have grown no matter what the water source but some people think unchlorinated water is better.
For the basil pot
- Container about 12” deep with drainage holes: Any container that’s large enough will do, even a bucket with drilled holes.
- Saucer: Something to catch overflow when you water.
- Potting soil: Choose a sustainable and organic potting soil brand that’s free of peat moss and chemical fertilizers.
- Liquid fertilizer: Use a liquid fertilizer like sea kelp fertilizer or the liquid from your worm bin or bokashi bin.
- Sunny spot indoors or on a protected frost free patio: Since basil is so tender, it will do better in a warmer place with a lot of light.
Nice to have
- Moisture meter: A moisture meter will let you know if the pot needs to be watered.
- Grow lights: If you lack a sunny window, grow lights help. I like grow lights with an adjustable height so you can raise them as the plants grow.
- Timer: for use with a grow light.
Grow new basil plants from cuttings
Basil is a culinary and medicinal herb of the mint family (Lamiaceae). The mint family is characterized by square stems and opposite leaves, small flowers and strong fragrance.
Basil grows with side stems arranged opposite on the central stem. PIC. To take a cutting, cut off the central stem above a node where the two side stems emerge.
Always take a cutting with a sharp knife so the stem isn’t crushed. This is the same way you’d prune basil to keep it bushy and keep it from flowering.
Remove any leaves from the bottom third of the stem. Put your stems in a glass of water and keep the ends under water.
After a few weeks, you should start to see roots emerge from the stem. I have found it takes longer for the cuttings to root on a cold windowsill compared to when the temperature is warmer.
The roots will get longer and less fragile over the course of several weeks. When they start to get long and to look more brown than white they are pretty strong and ready to transplant.
Put it all together: grow basil indoors in pots
- Clean your container: Since you’re going to be growing in this container for a while, be sure it’s clean before you start. A quick scrub with mild soap should suffice.
- Fill with potting soil: Fill to a level about 1” below the rim. The soil will compact over time, so start with a little more soil than you think you need, while leaving room for watering.
- Plant the cuttings: Make holes large enough to fit the rooted cuttings without crowding. Tamp down the soil so the cuttings are held firmly in place.
- Water well: Be sure the cuttings are kept moist for the first few days while they recover from transplanting. Afterwards, keep the soil moist but not wet.
- Fertilizer: Once a week, fertilize the pot with a dilute liquid fertilizer when you do your regular watering.
- Moisture meter: If you’re using a moisture meter, check it periodically to tell when your pot needs watering. Or feel the soil for dryness.
- Grow lights: Keep the grow lights an inch or two above your growing plants. Raise the grow lights as needed to be sure the plants don’t grow out of their light zone.
- Pruning: Basil gets lanky and unproductive if it isn’t pruned. Prune basil by cutting the central stem just like when you took the cuttings. If the basil tries to flower and set seed, prune the flowerheads to keep the energy going into foliage. Use these prunings to cook or start new cuttings.
- Harvest: Start a light harvest when the plants are established and have healthy growth. Within a few weeks the plants should be able to support a heavier harvest.
- Grow new cuttings: When the plants are large, take some new cuttings to start a new batch when the pot starts to look like it’s had better days.
- Refresh the pot: Cut the older plants back to the lowest node, leaving the roots intact and some side stems to keep growing. Make a few holes and plant your new cuttings to refresh the pot.
What type of basil should you grow indoors?
So, now that you know how to grow basil indoors, what type should you choose? For indoors, I prefer to grow the familiar sweet basil with large leaves, but there are a whole lot of types you can choose. Many of them are pretty enough to be houseplants in their own right. They each have their own uses and flavor profiles. Here’s a rundown of some of the popular varieties:
Sweet basil: This is the common basil that you see in grocery stores. This type of basil has a slightly sweeter taste, with large and tender leaves.
Purple basil: This beautiful plant will add to your home and patio. It tastes slightly spicy, with a light licorice flavor.
Holy basil: Holy basil is used medicinally in Chinese and Ayurvedic practices for bronchitis, the common cold and lots of other ailments. The flowers, leaves and seeds are all used medicinally.
Thai basil: This basil has a small habit, with narrow leaves and pink flowers. Thai basil has a stronger flavor profile than sweet basil, with more anice and licorice notes.
Lemon basil: This basil is used extensively in Indonesian cooking. Lemon basil has a strong distinct lemon scent, which is strongest right after harvest.
African blue: This basil can only be propagated through cuttings. It grows like a shrub and has a strong camphor scent. It is used both medicinally and in cooking, but is best used in dishes that can handle its distinctive taste.
Cinnamon basil: This is also called Mexican Spice basil. It contains cinnamite, which gives it a cinnamon-y taste.
How to use and preserve your homegrown basil
Garnish and Chiffonade: At first, while your plants are getting established, you can pick the larger leaves for use. The classic way to cut basil is to make a chiffonade. Stack the leaves, roll them into a tube and slice them to make ribbons.
Pesto: When your plants are well established and getting too big for the pot or growing past the grow lights, you can harvest enough to make pesto. Cut larger stems at a node and strip the leaves and tender stems from tougher stems. In a food processor, chop the basil with olive oil, salt, lemon, garlic and if desired, grated parmesan cheese to taste.
Basil simple syrup: Don’t discard those tough stems or any flowers, damaged leaves or seed heads that you won’t otherwise use. Make a simple syrup with one part granulated sugar to one part water. Add the basil stems and seed heads and boil for one minute. Leave the plant material in the syrup for at least 30 minutes, until the syrup takes on a floral basil taste. Use as a flavoring in cocktails, fruit salad or custards.
Preserve: I like to preserve basil by making pesto and then freezing the pesto in one tablespoon portions. You can also choose to dry it or keep it in the refrigerator in olive oil.
Growing basil indoors is worth it
If you have basil in the garden, it’s a no-brainer to start some cuttings to grow indoors. Even if you start with only one grocery store plant, or a smaller plant you started from seed, you can multiply that plant easily until you have a plentiful supply all through the winter and year-round.
Imagine what it will be like when you have a flourishing pot of green basil pot giving you fresh herbs all winter. It feels like getting something for nothing. You might even multiply enough to have multiple pots going at once.
It’s pretty fun to sip a summer-scented basil cocktail while the snow flies and add some basil chiffonade to your morning eggs straight from your windowsill.
I’d love to hear how it goes! Let me know in the comments, or send me a message. I’m always happy to answer questions.
All the best to you and yours,
Susan
P.S. If you like indoor kitchen gardening check out these posts on How to Grow Microgreens at Home and How to Grow Garlic Indoors.
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