Growing Basil

If you choose to grow just one herb at home this year, basil should be a top contender. Because this fragrant garden favorite is so easy to grow in the right conditions, you’ll be grateful for the time you spend growing basil.

Tropical areas of southeast Asia have been growing basil for over 5,000 years, and this aromatic herb can be used as a savory enhancer in a wide variety of dishes. You don’t have to limit yourself to pesto; spaghetti sauces, pizza, fish dishes and fresh tomatoes all taste incredible with a little basil mixed in.

As an added benefit, your homegrown basil will be far cheaper and healthier than anything you can find at the grocery store. So what are you waiting for?

Start Growing Basil

Basil grows as well in a sunny windowsill as it does in your garden. Follow these tips to have the best chance of success.

Understanding Seed Germination for Basil

Basil is naturally a tropical plant, meaning that it doesn’t grow well in cold climates. Your seeds will have trouble germinating unless you keep the soil temperatures above 60 degrees. Light is essential for basil seeds to germinate, so to have success you will need to plant your seeds shallow enough that either natural or artificial light can reach them.

It takes basil seeds between 5 to 14 days to germinate, depending on the soil temperature. Once sprouted, basil needs about 70 to 80 days to reach full maturity. However, you can snip off leaves to use before this time. In fact, keeping your basil plants trimmed back will help them to grow bushier and fuller in the long run.

Starting Seeds Indoors

You can start your basil seeds indoors about six to eight weeks before the last frost date. Using sterile plant soil is a smart idea to prevent contamination, and basil seeds do best with a little bit of lime (called dolomite) and sand mixed into their soil. This helps with drainage and maintaining proper pH levels. Simply pack soil into peat pots or soil blocks and plant two to three seeds about a quarter inch deep. Once your plants have developed three or four true leaves you can thin out the smallest ones.

Indoor Lighting Suggestions

Because basil seeds need heat and light to germinate, artificial lights and heating cables can be a big help. You want to give your basil seedlings at least six hours of sunlight a day, or 10 hours under fluorescent lights. It’s perfectly fine to alternate between the two types of light to maximize the amount of time your basil spends in natural light.

Preparing A Basil Bed

Basil thrives in raised bed setups that have a soil pH level between 6.0 and 7.5. Because it tends to be a heavy nitrogen feeder, you can prepare the bed with several inches of compost before planting. Also, make sure that your soil can drain well to prevent the basil roots from getting soggy. If you have thick clay soil, adding in some sand can make a big difference in drainage.

Moving Transplants Outdoors

Basil shouldn’t be transplanted outside until after the last frost of spring. Even a small amount of frost can cause basil leaves to droop and turn black, rendering them tasteless.

Basil is ready to be transplanted when each plant has four to six true leaves. To get your basil ready to move outside, take the time to “harden it off” by moving your plants outdoors for a few hours a day for a week before you plant it. This prevents you from killing or stunting your plants with the extreme environment change when they go outside permanently.

A key to success when planting basil is not to crowd your plants. Large leaf plants like ‘Lettuce Leaf‘ should be spaced a foot and a half apart, while the small leaf ‘Spicy Bush‘ can handle just a foot. This allows for air circulation that is necessary to keep your plants healthy, dry and fungus free. Also, be sure to keep your plants out of a windy area, as the plant’s fragile stems can easily snap in severe weather.

Direct Seeding

If you have a long enough summer season, you can skip the prep work and simply start your basil seeds directly in your garden. Once daytime temperatures reach 70 degrees, you can prepare planting rows spaced a foot apart and plant your basil seeds a quarter inch down with spacing that’s roughly eight seeds an inch. That may sound excessive, but basil is very picky about germinating in the great outdoors, and most of your seeds won’t come up. You can thin out the ones that do once they form true leaves.

Even a thin crusting of soil over the seeds can prevent them from sprouting, so a good idea is to keep the planting area lightly misted until they sprout. A light layer of vermiculite (a moisture-retentive mineral) on top of the seeds can also prevent this crusting.

Watering and Mulching Requirements

Weeds can quickly take over your basil patch, so keep them in check by mulching your bed and weeding regularly. You can mulch with grass clippings, chopped leaves or barley straw for the best effects on retaining moisture and suppressing weed growth.

Basil plants need lots of water, so be sure to keep their roots wet through a drip irrigation system. Be careful not to water excessively though, as too much water can make the leaves flavorless. You also don’t want your plants to get too hot in the sun (which can scorch their leaves) so try to keep your plants shaded during the harshest afternoon sun.

Companion Planting and Rotation Considerations

There are lots of rumors about the positive impacts basil can have in different garden locations. It has been reported to help repel thrips, mosquitoes and flies, so it might be worth planting some in more insect infested areas to see if you see an improvement.

As a companion plant, basil grows well around peppers, asparagus, oregano and petunias. Hot peppers are reported to help prevent root rot in basil. It’s not smart to plant rue next to basil, as basil will out-compete it and take over. It’s long been a rumor that tomatoes become more flavorful when planted next to basil, but even if this doesn’t hold true it doesn’t hurt to make this delicious pairing easily accessible together.

Common Pests and Diseases for Basil

Basil tends to be at risk for a wide variety of fungal diseases, including Fusarium wilt, black spot and gray mold. You can avoid the majority of these problems simply by waiting to plant until temperatures have warmed up enough for basil to handle them. Providing enough space between your plants will also help prevent the undersides of leaves from not drying out and getting moldy and will stop diseases from spreading from one plant to another.

If your plants contract any sort of fungus or root rot, the best thing you can do is dig up the infected plants and throw them away far away from your healthy plants, lest the rot spread throughout your bed.

Pests like aphids, slugs, and Japanese beetles can also cause damage by chewing on healthy leaves, leaving behind only thin veiny skeletons. The best way to organically control for these garden scourges is to simply hand pick them off the leaves of your plants.

Harvesting and Storing Basil

Basil leaves can be harvested continuously off of healthy plants, and you can start harvesting as soon as the plant is large enough to handle losing some leaves. Always harvest the top leaves first, and be sure to slice the stems off with a knife right below a joint so that you encourage the plant to send out new growth.

Basil leaves need to be handled delicately so that they won’t bruise or blacken before you can eat them. The leaves will keep for a few days in your refrigerator if you stick the stems in a glass of water (don’t let the leaves get wet because they will turn black). For long term storage, you can dehydrate or freeze leaves in airtight containers. Another option is to make pesto and freeze it in individual servings for your favorite pasta dishes.

If you want to have the goodness of fresh basil all winter long, you can cut off some stems from your fall garden and stick them in water. The stems will soon form roots, and you can plant them in containers to grow indoors.

Saving Basil Seeds

You can save your basil seeds if you grow open pollinated “heirloom” varieties. Unfortunately, most disease resistant varieties are hybrids, meaning the seeds won’t stay true to form for the next year.

To save your basil seeds, let your basil plant develop flowers and go to seed in the fall. When these these flowers have dried on the plant, you can pick them and lay them out on a baking sheet. Let them sit for several days, and then lightly tap on the tray until the seeds become separated from the pan. Next, tilt the pan to collect these seeds in an envelope, which should be stored in a cool, dry place.

Choosing the Best Basil Seeds for Your Climate

If you live in a colder climate, some varieties are well suited to withstanding chillier temperatures. You can visit your local seed distributor to get some personalized suggestions for your growing conditions. Cold tolerant basil doesn’t tend to get as tall as tropical varieties, usually averaging a foot tall instead of almost two feet.

Organic seed varieties of basil tend to be somewhat limited, but sweet basil is the most common organic variety you will find.




Additional Growing Tips for Growing Basil

If you follow the strategies above, your basil crop should be impressive this year. For some extra help fulfilling all your pesto needs, you can follow these tips.

  • You can eat the basil plants you thin. Simply wash the roots off before sticking the young seedlings into a fragrant salad.
  • If you see your basil starting to flower, pinch off the flowers and the tops of the plant. Once the plant produces flowers it will stop trying to stimulate new growth, which is the opposite of what you want to happen.
  • So long as you fertilize your garden plot before planting your basil, you won’t need to top dress the soil throughout the season. That being said, if you think your plants need a boost, you can spray the leaves with a liquid organic leaf spray to stimulate the plant to produce more plant sugars, resulting in a better tasting leaf.