Bowl of Arugula

Arugula is also known as rocket. It’s a leafy green full of nutrients like vitamins A, C, and K, as well as calcium and iron. This peppery green is popular in the kitchen and used in salads, sandwiches, and pasta dishes.

Best Planting Times

Planting MethodActivityRecommended Dates
Outdoor PlantingDirect SowingMarch 1 – June 1
Succession PlantingEvery 2-3 weeks during spring and early fall
Greenhouse PlantingYear-roundAdjust planting based on temperature control in the greenhouse

Planting Conditions

Arugula Planting Conditions

The climate here allows for a diverse growing environment with moderate temperatures, which is ideal for arugula cultivation. With USDA Hardiness Zones ranging from 5 to 9, understanding the best planting conditions is essential for healthy growth.


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Useful Tools for Starting Arugula Indoors

Using the right tools can save you time and increase your success rate.

Seeds

Quality seeds lead to better germination and healthier plants. Starting with high-quality seeds gives your crop the best chance to thrive from the very beginning.

For perennial plants, look for the wild rocket types, which are somewhat spicier but will return year after year.

The most widely used type is the Astro variant, known for being vigorous, all-season, and offering a nutty flavor with long, silky leaves.


You can find Astro Arugula Seeds on Amazon here: https://amzn.to/4gTTIgT

Planting Trays

Planting trays help organize seedlings and ensure they have enough space to grow before being transplanted outdoors, improving efficiency and plant health.
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Grow Lights

Grow lights are essential if you lack sufficient natural sunlight. They provide key light for growing strong seedlings, even in less-than-ideal conditions.
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Seed Starting Soil

Using light, fine soil designed for seed starting helps roots establish quickly and promotes healthy growth. It’s an effective way to kickstart your seedlings.
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Average First Frost Dates in Washington’s Major Cities

To ensure optimal growth and flavor, plant arugula outdoors in Washington approximately 2-4 weeks before the expected first frost date in late autumn.

CityAverage First Frost Date
SeattleNovember 15
SpokaneOctober 15
TacomaNovember 5
VancouverNovember 10
BellinghamOctober 25

Disclaimer: Frost dates are average estimates, and actual conditions may vary. It is recommended to monitor local forecasts and adapt planting decisions accordingly.

Greenhouse Growing

Utilizing a greenhouse in Washington can provide protection against unexpected cold temperatures and frost, making it easier to grow arugula. This controlled environment allows for year-round cultivation, ensuring a consistent temperature beneficial for growth during the cooler months.

This 10×12 FT Greenhouse from HOWE can be found at Amazon for $999.00 right now.
Greenhouse Image 1
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Fertilizer

For optimal growth, consider supplementing with fertilizer to ensure abundant and healthy harvests. Quality fertilizer replenishes soil nutrients and encourages vigorous plant growth.
Fertilizer Image
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Other planting guides for Washington:

Broccoli Planting in Washington

Kale Planting in Washington

Pumpkin Planting in Washington

Any questions on growing arugula? Visit our forum to discuss: Gardening Forum.

Starting Arugula Indoors

In Washington (Zone 8), begin indoor arugula seed starting from February 15 to March 15. This timeline ensures healthy seedlings ready for outdoor transplantation starting from mid-March to early April, once the risk of frost has passed.

Transplanting Arugula Seedlings

Transplant arugula seedlings outdoors from April 1 to April 15, ensuring the soil temperature is above 50°F consistently. Space the seedlings 6-12 inches apart in rows with at least 12 inches between rows for optimal growth.

General Care and Maintenance

Watering

  • Provide consistent and deep watering to maintain evenly moist soil. Washington’s variable climate means regular monitoring of soil moisture is essential.
  • Water at the base of plants to avoid leaf wetness, which helps prevent fungal diseases.

Fertilizing

  • Apply a balanced fertilizer at planting time and again when the plants start to develop leaves. Incorporating compost before planting can improve soil fertility and structure.

Pest and Disease Management

  • Regularly monitor for common pests like aphids and slugs. Washington’s mild climate can foster these pests, making vigilance essential.
  • Utilize organic or integrated pest management techniques to safeguard arugula plants from pests and diseases.

Harvesting

  • Harvest arugula leaves when they reach a desirable size, typically around 4-6 inches long. Frequent harvesting encourages new leaf growth and prolongs the harvest period.

The importance of good soil

Before starting to grow it is important to take a step back and find the condition of the soil in your garden,The optimal soil is a blend that includes the mineral-rich dirt along with organicrich organic matter that plants need to thrive.


In my garden I try to compost as mutch as possible, so I can mix in the nutrient ritch compost in my soil. I use both hot composting of food scraps and cold composting of all organic garden “waste”..
If you dont have the time or space for composting, it is possible to get compost ready to use in garden centers and Community Composting.
You can read more on Community Composting here: https://www.epa.gov/sustainable-management-food/community-composting

If you are uncertain of the quality of your soil, you can get easy to use soil tests at amazon for 17 dollars. Check latest prices here: Soil testing kit.

Also remember to check out how much sunlight your growing area gets, and that the rain drains well. If you treat your soil well and plan you crops according to your climate you will succeed with any plant you want.

When is the best time to plant arugula?

The best time to plant arugula is in early spring or late summer to early fall when temperatures are cooler.

Can arugula be grown in winter?

Arugula can be grown in winter using a cold frame or indoor growing setup that provides adequate light and warmth.

How long does it take for arugula to grow?

Arugula typically takes about 30 to 40 days to reach maturity, depending on the variety and growing conditions.

Is it possible to plant arugula directly in the ground?

Yes, arugula can be sown directly in the ground as soon as the soil can be worked and temperatures are suitable.

What are the signs that arugula is ready to harvest?

Arugula is ready to harvest when the leaves are about 3 to 6 inches long, with a vibrant green color.

BeeJay