A bountiful herb garden is a timeless luxury. The ability to step outside one’s door and harvest a handful of fresh, fragrant herbs can be the difference between a tasty meal and a culinary masterpiece. And what herb garden is complete without at least one beautiful, bountiful basil plant?
This wonderfully fragrant herb in the mint family has historically been popularly used in cuisines including Italian and Asian. This herb can be dried and preserved, but it truly is most flavorful when eaten fresh.
Basil is a relatively easy plant to grow, and has moderate sunlight and watering needs. It also happens to be a great plant to grow in containers, making it accessible even for those without a garden bed to plant it in.
If you’re interested in growing a patio herb garden or just want to keep your basil easily transportable, here are some tips for keeping your basil healthy and happy in its container.
Plant At the Right Time
Basil can be planted from seed, and young plant starts are commonly available for purchase at most nurseries and even many grocery stores. Depending on the variety you want to grow, availability may be limited in terms of plant starts. Fortunately, basil is easy to grow from seed and there are a number of different varieties that are widely available in this form.
Planting starts should take place any time from two weeks after the last frost until mid-May. Direct sowing seeds can start as early as March as long as there isn’t a risk of snapback frosts in your region.
It’s a good idea to germinate seeds indoors, as the optimal germination temperature is between 75°-85°. A bright sunny window is a great place to start basil seeds. Once your seeds have reached a few inches tall and have at least one set of mature leaves, transplant them into your container.
Choose the Right Container
Basil plants need a little space between plants. So, if you are planning on planting more than one plant, you’ll need a container that accommodates them.
The Epic Lined Grow bags make great containers for plants that need constant moisture, paired with good drainage. Their unique liner system encourages a stronger roots system, and they come in a variety of sizes that can accommodate from one to three plants at a time.
I personally like to grow my herbs in vertical tower planters, like the GreenStalk Tiered Vertical Planters. Each plant gets its own space in these convenient planters, and because they stack on top of each other, they take up very little space.
If you have limited space but want to grow an amazing herb garden, I highly recommend these. Whichever type of container you choose, make sure it has proper drainage, as basil will not thrive in soggy soil.
Choose Your Variety
There are about 100 species of basil and many more varieties. Not all basils are good for culinary use. For example, African Blue Basil is an amazing pollinator attractor.
Bees and butterflies adore their flowers, but their leaves are a little bit lackluster in the flavor department. Most varieties of culinary Basil are cultivars of Ocimum basilicum or Sweet Basil.
Basil plants are members of the mint family. They are fragrant, herbaceous, annual plants that are most flavorful when used fresh, but they can be dried as well.
Boxwood Basil is a wonderful, shrubby cultivar with tiny leaves and a pungent flavor. Dark opal is a gorgeous deep purple Basil with a spicy flavor that looks absolutely stunning in a caprese salad alongside some plump tomatoes and burrata mozzarella.
The most traditional and widely sold cultivar is Genovese basil. This tasty plant can grow rather large and boasts large, shiny, fragrant leaves with a spicy, anise-type flavor. I love to trim off some basil stems to add to cut flowers on my dining room table. Besides being beautiful, the aroma of fresh basil is simply mouthwatering.
Use the Right Soil
Basil likes high-quality, loamy soil with a high concentration of organic matter. Vegetable and herb potting mixes are typically a healthy mixture of soil with compost and sphagnum moss. These provide the nutrients basil needs to thrive, and they don’t compact as easily as standard potting mix, which will damage basil’s roots.
Because basil needs proper drainage, a potting blend that’s optimized for container growing is ideal. A blend that contains mycorrhizal additives can be beneficial for plant root systems. If you are mixing your own soil with a base of your native backyard soil, blend in a lot of compost and a small amount of coarse sand.
Lots of Sun
The amount of sun your basil needs will depend on the climate in which it is planted. Typically, basil likes full sun, which means 6-8 hours of direct sunlight per day. Basil will not grow in the shade. However, in areas where the summer is particularly hot, it’s a good idea to give your plants some shelter from the hot afternoon sun.
Like most plants, basil prefers the morning sun because it has all the same benefits of the afternoon sun without the searing, intense heat. The ideal light situation for basil is to get those 6-8 hours as early in the day as possible.
Too much afternoon sun can lead to leaf scorch, making those leaves unusable. Leaf scorch, often called sunscald, shows up on basil leaves in the form of dry, brown patches. This is an indication that your plant needs more water or less intense sunlight. If you’re growing in pots or grow bags, consider moving plants to some afternoon shade on the hottest days.
If growing your basil in a GreenStalk, ensure all sides of the tower receive good sun exposure. Basil does need that full sun for optimal growth.
Sow From Seeds or Starts
Basil seeds can be directly sown outdoors or started indoors, depending on the weather. If you are going to direct sow, it’s important to wait until the weather warms up a bit in spring. If you’re planting in a container, there is some good news related to direct sowing.
Because raised beds help the soil to warm faster, you can plant your basil earlier in the season to get a head start. You want to wait until at least two weeks after the last chance of frost. The same goes for basil starts. Whether you’ve grown them yourself or purchased them, wait until two weeks after the last frost to plant them outdoors.
Protect it From the Cold
Basil begins to suffer from cold temperatures in the range of 40°F, but it can still bounce back from nights this cold as long as the days are warmer. If the temperature drops to freezing, basil plants need extra protection from the cold.
If you encounter some unexpectedly cold weather after you’ve planted your basil, the nice thing about planting in moveable containers is that they can be brought under shelter and even grown indoors to protect the plants.
When basil plants are in raised beds or otherwise not transportable, a layer of compost or mulch will help to insulate the roots, and the tops of the plants can be covered to offer them some insulation from the cold.
Give it Some Space
Give your basil plants a bit of space to spread their roots. If you are planting your basil in individual containers, aim for a pot that is at least 8” deep. Having that deeper root zone will give your plant the space it needs to set strong roots and produce a bigger, healthier plant overall.
In terms of spacing, leave 12”-16” of space between plants in the same container. This means that in a 12” container, you can have a maximum of 2 basil plants, and that could be cramped as they mature. This is another reason I recommend vertical planters, as each plant has its own space, and it doesn’t eat up much floor space in the garden.
Basil likes a fair amount of water. In the ground, one inch per week is typically the recommendation. However, the soil will dry faster in containers, so they need to be watered more often. I water my basil thoroughly every other day.
If you forget to water, your basil plants will let you know when they are in need. Their broad leaves are somewhat delicate and soft, so when the plant lacks hydration, the leaves will lose a lot of their body and start to droop and wither.
While it’s best to prevent the soil from drying completely, most basil plants will make a decent comeback if you forget them once or twice, but make a habit of it, and you’re going to sacrifice the quality of your harvest.
Just a Pinch
If you want to keep your basil growing and branching, the best practice is to pinch off the tops of the stems on a regular basis. When the stems are pinched just above a set of leaves, the plant responds by branching, resulting in a fuller, bushier plant over time.
This is a very simple practice that doesn’t require any special tools. You can use your fingers to pinch the stems off. In fact, any time you want to harvest some of your basil, this is the perfect way to do it. That’s not to say that using a pair of shears or scissors will hurt the plant, just that you don’t have to if you don’t have a pair handy.
Like most herbs, basil benefits from occasional fertilizing. Typically, a balanced granular organic fertilizer is ideal for container-grown basil. Granular organic fertilizers are made up of ingredients such as kelp meal, feather meal, guano, and so on. These take a while to take effect as they must decompose to allow their nutrients to become plant-available, so add fertilizer to your soil blend when planting and work a little extra into the top of the soil around your plants every month.
Liquid organic fertilizers are also an option but opt for one that’s higher in nitrogen than in any other ingredient. With a liquid fertilizer, you’re dealing with a soluble ingredient and will need to fertilize more often because you’re watering more often. Soluble fertilizers can easily be flushed out of the soil, especially nitrogen. As basil is producing primarily leaves and stems, it needs that little extra nitrogen to ensure it’s got what it needs to produce more foliage.
Consider Propagating More
Did you know that you can coax basil cuttings into taking root? If you have a particularly-healthy plant, consider popping a cutting into water. Change the water daily so it’s always well-oxygenated, and wait for the cutting to develop at least 1″ long roots.
Once the cutting produces a reasonable amount of root mass, prepare another container with pre-moistened potting mix and gently tuck the cutting in place, being careful not to damage the roots. Ensure it gets extra watering until you see new growth developing, then gradually ease back the extra water until you’re on the same schedule as your other basil plants.
We talked about pinching back the tips of your basil plants to encourage branching. A nice, bushy basil plant produces plenty of tasty herbs to last the season. So when I say harvest often, this is more or less the same thing. Trimming the tops off of basil plants encourages them to grow.
Another reason it is good to harvest the tops of your basil regularly is to prevent flowering. Some types of basil are mostly ornamental and make wonderful pollinator plants, in which case you want the plant to produce flowers.
Bees and other pollinators adore basil flowers. But allowing your culinary basil to flower or “bolt” will affect the leaves’ flavor, and not in a good way. By harvesting the tops of your basil stems regularly, you keep the leaves fresh and tasty.
The third reason is that basil is truly an herb that is best when used fresh. It doesn’t last very long in the refrigerator, a week at most, before it begins to wilt and turn gray. A great way to keep your cut basil fresh is to place the stems in a jar of water like a bouquet of flowers. This will keep them fresh for longer.
Don’t Prune Too Far Back
When you prune your basil, try not to prune it back to the woody portion of the stems. It is possible to prevent the stems from becoming woody altogether if you harvest them often. When the plant goes to flower, the stems will turn woody, and the leaves will become bitter. It is best to pinch stems down to just above a set of healthy leaves on flexible stem tissue.
If you miss the window and your basil begins to flower, pluck the flowers off as soon as you see them. Most of the damage is done when they go to seed, so if the flowers just popped up, you still have a chance of preserving the flavor of your herbs.
Keep an Eye Out for Pests
The three main pests that go after basil are slugs, Japanese beetles, and aphids. Aphids are easy to diagnose. There are typically a great number of small green or yellow bugs that cluster on the young, most tender growth and suck all of the fluid out of them, leaving a shriveled mess.
Aphids can be dealt with using neem oil. If your plant is in bloom, avoid using neem oil during the day, as it is harmful to pollinators when wet. Late afternoon, such as sunset, is usually the safest time to treat with neem oil as most pollinators have already taken shelter for the night at that point, and the neem will dry on the plant overnight.
Japanese beetles feed on the soft portions of the leaves, leaving behind a leaf skeleton of sorts. These pests come around in the summer and stay for about a month. These can’t be treated with insecticidal oils like neem oil as effectively as aphids can. A better solution for the treatment of these beetles while they’re active is pyrethrin spray, an organic pesticide derived from the pyrethrin daisy.
However, Japanese beetles are also a seasonal pest, and a much better solution would be to apply beneficial nematodes to the soil in your yard. The nematodes will consume the beetle grubs while they’re still in the soil, reducing the incidence of beetles in your garden the following year.
Slugs are also fond of basil and climb the stems and eat ragged holes in your plant’s leaves. Slugs are also attracted to the moist soil that basil enjoys. To ward off slugs safely and naturally, consider an organic slug and snail bait. These are made to be appealing to snails and slugs, and they will consume the pelletized bait and die off.
Growing basil in containers is easy and convenient, making a beautiful herb garden accessible to anyone with a little space, a sunny spot, and the time to do a bit of tending. Basil is a wonderful addition to any herb garden, and its fragrant and tasty foliage will add a spicy zest to home-cooked meals.