Arugula is a fast-growing leafy green vegetable that packs a peppery punch. It is often included in mesclun mixes at the grocery store. In this article, you’ll learn how to grow arugula and enjoy a bountiful harvest of salad greens all season long.
Growing arugula requires nothing more than cool weather, rich soil, and a sunny location in your garden. Arugula plants are remarkably low-maintenance after they become established, making them a very beginner-friendly crop to grow. It’s even possible to grow your own arugula right on your kitchen windowsill.
Fresh and brightly tangy arugula leaves are an excellent way to spice up summer salads. Microgreens are ready to harvest in just a few weeks. Baby arugula leaves have a milder flavor and a more tender texture than the larger leaves. Be sure to pick arugula before the plants begin flowering, as the leaves quickly turn too bitter to eat.
Best Tips for Planting Arugula
What is arugula? This leafy green is a vegetable of many names. Eruca vesicaria ssp. sativa is its botanical name, and it also goes by “rocket” or “roquette” in some parts of the world.
It’s part of the Brassica plant family, along with bok choy, broccoli, cabbage, cauliflower, kale, kohlrabi, mustard, radishes, and turnips.
The tender leaves have a rich, peppery flavor that adds an exciting kick to your summer veggie palette. Arugula flowers are also edible and have a milder flavor. If you’ve never tried topping your salads with freshly picked edible flowers before, it’s a real treat.
Like most other types of leafy greens, including collard greens or kale, arugula grows best in cool weather between 45-65℉. It’s relatively frost-tolerant and survives temperatures as low as 25℉.
Some gardeners even report their arugula plants growing throughout the entire winter in a cold frame or unheated greenhouse.
However, when summer temperatures rise above 80℉, the plants may bolt, which is when they prematurely send up a flower stalk and begin to produce seeds, similar to growing bok choy. Pinch off any flower buds as soon they emerge to slow down the bolting process.
Remove arugula plants that have already bolted. Succession planting, or sowing seeds every two to three weeks throughout the growing season, is an excellent strategy for a continuous supply of fresh salad greens.
One of the best things about growing a vegetable garden at home is the opportunity to try unusual varieties that aren’t commonly available at the grocery store or farmer’s market.
Wild arugula cultivars have thinner, oak-shaped leaves and generally pack a more potent peppery punch. Standard arugula strains have larger, wider leaves and a milder flavor. Here are a few of the leading varieties for planting arugula in your garden.
How to Grow Arugula from Seeds
Since it’s a cool-weather crop, the best time for planting arugula seeds for an early summer harvest is in early spring, as soon as you can work the soil. This is similar to planting cauliflower. Arugula grows best when seeds are directly sown in the garden beds.
Since they’re such fast growers, there’s no significant advantage to starting seeds indoors or purchasing nursery-grown seedlings, which don’t tend to transplant well.
Arugula seeds germinate at temperatures as low as 40℉, but germination is significantly quicker when the soil temperature is between 60-70℉.
To warm the earth ahead of planting, the best way to grow lettuce or arugula is to cover your garden bed with a thick layer of dark-colored mulch, organic compost, or a sheet of black plastic for five to seven days.
Sow seeds a quarter-inch deep and spaced an inch or two apart in moist, rich soil. To ensure that the plants have all the nutrients they need to start growing, amend your soil with organic compost or all-purpose fertilizer before planting arugula seeds.
Germination usually takes about seven to ten days. To speed up the germination time, soak the seeds in water overnight before planting them to begin breaking down their protective outer coating. Keep the soil moist but not oversaturated while your arugula seeds are germinating.
Once the seedlings reach three or four inches tall, thin out the weaker ones so that your arugula plant spacing is about six inches.
If desired, transplant the seedlings you thin out to other areas of your garden. Otherwise, use them in the kitchen as microgreens or add them to your compost pile.
For a fall harvest, plant another round of arugula seeds in late summer once the weather begins cooling down. Sow seeds six to eight weeks ahead of the typical first frost in your area.
Lengthen Your Growing Season with a Cold Frame
An outstanding way to extend your growing season for several weeks in the spring and fall is by using a cold frame to protect cool-season crops from a hard frost.
Cold frames are portable solar greenhouses that allow gardeners to grow cool-weather crop varieties earlier and later in the year.
They’re also helpful for hardening off warm-season plants started indoors or purchased from your local plant nursery. In addition, they’re extraordinarily straightforward to make using repurposed materials.
Decide on the dimensions for your finished cold frame. Some gardeners use a cold frame early in the season to cover their raised beds.
Others employ them as portable mini-greenhouses throughout the growing season. Feel free to customize your cold frame design to suit your particular situation.
Cut your 2×6 pieces to match the dimensions of the lid. It’s advantageous to design your cold frame with the back taller than the front to drain excess water and maximize daily sunlight hours.
Cut one of the 2×6 pieces diagonally so that you end up with two triangular pieces for the sloped sidewalls. Secure the sideboards to the corner posts with two wood screws each.
Attach the narrow point of the triangular top panels to the board below with a vertically placed screw. Repeat with the front and back walls to complete the box.
Position the lid on top of your frame and attach hinges to the back. If you aren’t using repurposed windows or a shower door, construct the frame for the lid and attach greenhouse plastic or a sheet of polycarbonate.
For a large cold frame, use a series of several hinges along the length of your cover to ensure it’s completely secure.
Connect the lid supports. First, place a long 1×1 piece in each of the front corners of your cold frame to hold up the sides of the lid at various heights.
Then, on the front edge of the frame, position two shorter supports on either side. These pieces keep the top ajar for ventilation.
Attach the side supports with wood screws on the inside of the frame. Ensure that they’re just loose enough to swivel into position but tight enough to stay in place when supporting the lid.
By using a cold frame, it’s possible to enjoy your spring harvest up to two weeks earlier. Similarly, cold frames prolong the growing season considerably in the fall and even throughout the winter in some climates.
Best Soil for Growing Arugula
Since they have shallow root systems, it’s crucial to grow arugula in loose, well-draining soil rich in organic matter.
A week or two before planting arugula seeds, work several inches of compost or well-rotted manure into your garden soil. Also, ensure that the planting area is free from rocks and other obstructions.
Arugula thrives in consistently moist soil, but it shouldn’t stay waterlogged. It’s helpful to water more often during dry periods to prevent bolting. Arugula grows best in soil with a neutral to slightly acidic pH level, between 6.0-7.0.
Use organic materials like straw, leaf litter, grass clippings, or pine needles between plants as mulch to retain moisture, minimize weed growth, and keep the soil temperature cooler.
Choosing the Right Fertilizer
Plant fertilizer contains three vital macronutrients: nitrogen (N), phosphorus (P), and potassium (K). Nitrogen encourages prolific leaf growth, phosphorus promotes robust root systems, and potassium stimulates the plants’ fruiting and flowering processes.
Leafy greens like arugula benefit from regular applications of high-nitrogen fertilizer. Coffee grounds, composted manure, fish emulsion, and grass clippings are effective natural and organic lettuce plant fertilizer amendments that add nitrogen to your garden soil.
It’s crucial to use well-rotted manure in your garden. Most types of raw manure have such high nitrogen levels that it “burns” the plants.
Fertilizer burn results in brown, crispy leaves and damage to the root system from an excessive buildup of salts that don’t get flushed out quickly enough.
The only types of manure that are safe to use “cold,” or raw, are alpaca, llama, and rabbit. Other manure sources like chicken, cow, goat, horse, and sheep must get composted for at least six months first.
Ideal Growing Conditions for Arugula
For best results, plant arugula seeds in an area with full sun, meaning six or more hours of direct sunlight daily. However, arugula also grows in partial shade and benefits from a little bit of protection from intense afternoon sun in warmer weather.
For optimal leaf production, feed your plants with slow-release organic arugula plant fertilizer every three or four weeks according to the instructions listed on the product label.
In mild climates, growing arugula throughout the entire growing season is possible by succession planting seeds every two to three weeks.
On average, arugula plants require between one and two inches of water per week, depending on natural rainfall levels. However, be sure not to overwater.
If the soil stays waterlogged too long, the plant root systems cannot absorb oxygen and nutrients from the soil and may rot or develop fungal diseases.
Harvesting and Storing Arugula
After planting seeds and caring for the seedlings, how long do arugula take to grow? It depends on the variety. Generally, expect microgreens to be ready for picking in about three weeks and fully mature arugula leaves in five or six weeks.
The best way to harvest arugula is to cut the outer leaves from the plant, leaving the new leaves to continue growing. When to pick arugula for baby greens is once the plant forms a rosette of at least six or eight leaves two or three inches long.
Harvesting your arugula before the plant begins producing seeds is crucial, as the leaves quickly become bitter and inedible when the plant starts flowering.
Once you begin to see flower buds forming, cut the whole plant at its base, remove the remaining leaves if their flavor is still palatable, or gently uproot it, taking care not to disturb the surrounding plants.
If you’d like to save seeds for planting next year, allow a few of your plants to continue flowering. Once the seed pods dry out, remove them from the plant and store them in a cool, dry place until the following spring.
Arugula stays fresh in the refrigerator for up to ten days. After harvesting, rinse and dry the leaves and store them in a lidded container in the crisper drawer of your refrigerator.
Keep your leafy greens away from fruits that produce ethylene gas like apples, avocados, pears, and peaches. Ethylene gas is a naturally occurring chemical that speeds up the ripening process and causes leafy greens to wilt faster.
Solutions for Common Pest and Disease Problems
Although growing arugula is generally straightforward, it’s vital to regularly monitor your plants for signs of pest and disease problems.
They’re much more susceptible to attacks from insects and pathogens when they’re stressed, so keep your plants as healthy as possible by supplying appropriate amounts of light, nutrients, and water.
Aphids, flea beetles, leaf miners, slugs, and snails are some of the most commonplace insects that feed on arugula plants. In addition to damaging the tender leaves, these insects often transfer diseases like mosaic virus between plants.
Organic insecticides like neem oil, horticultural oil, and insecticidal soap are effective against soft-bodied insects like aphids, cabbage worms, flea beetles, and leaf miners. Make a natural bug spray for lettuce and arugula with neem oil, dish soap and water and spray the entire plant, taking care to cover the undersides of the leaves where insects like to hide.
Apply a dusting of diatomaceous earth to kill slugs and snails. Use floating row covers over your newly sprouted arugula plants to prevent insects from laying eggs on the tender young leaves.
Some of the most prevalent plant diseases that affect arugula are bacterial leaf spot, downy mildew, powdery mildew, and mosaic virus.
Treat affected plants with an organic copper or sulfur fungicide. If you’ve had plant disease problems in the past, practice regular crop rotation to prevent pathogens from building up in the soil.
Companion Planting with Arugula
Companion planting is a strategic garden design technique that gardeners have used for generations. The idea is to utilize the advantages of specific plant pairings and create a healthy and sustainable garden ecosystem.
Certain plants attract pollinators and predatory insects, and others deter various garden pests. Some plants reportedly enhance one another’s growth and flavor when grown together.
However, a few species must be planted far apart because they have detrimental effects on one another’s growth.
Legumes like beans and peas have a unique ability to fix nitrogen in the surrounding soil through a symbiotic relationship with soil bacteria, so they make exceptional companion plants for leafy salad greens.
Root vegetables like beets, carrots, and parsnips don’t compete for soil space with shallow-rooted arugula plants. They make great arugula companion plants. These root veggies fit nicely together to maximize your available planting space. They also share similar preferences for cool weather and soil moisture.
Aromatic herbs like basil, catnip, cilantro, and mint repel numerous pests, including aphids, cabbage worms, flea beetles, and slugs. Borage, chamomile, calendula, dill, feverfew, and tansy are wonderful flowers for attracting beneficial predatory insects as well as pollinators.
Members of the Allium plant family, including chives, garlic, and onions, deter numerous pests like aphids, cabbage worms, flea beetles, slugs, spider mites, deer, and rodents through their strong scent.
Avoid planting arugula near strawberries. They reportedly stunt the growth of Brassica plants like arugula, broccoli, kale, turnips, and radishes.
In addition, it’s a good idea to grow your Brassicas in separate areas of the garden. Pest and disease problems spread much faster between similarly vulnerable plant pairings.
Planting arugula in your garden is a fantastic way to spice up your cool-season veggie collection. These peppery salad greens grow best in partial shade to full sun and require moist, rich soil.
Be sure to harvest the whole plant before it begins bolting and the leaves become too bitter to eat. Use a cold frame to prolong your growing season by several weeks in the spring and fall.
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