Your Complete Guide to Growing Ashitaba


Ashitaba (Angelica keiskei), a unique herb native to Japan, is renowned for its rapid regeneration and numerous health benefits. Also known as “tomorrow’s leaf,” this plant has been used traditionally for its supposed medicinal properties. The plant is part of the carrot family and features dark, glossy leaves and small white flowers.

Ashitaba is not only appreciated for its culinary uses but also for its rich nutritional content. It contains an abundance of vitamins, minerals, and antioxidants. Traditionally, it has been used in Japanese medicine to treat various ailments and to promote overall health.

Growing Ashitaba can be a rewarding endeavor, providing you with a continuous supply of this beneficial herb. Whether you are an experienced gardener or a beginner, this guide will help you understand the essential steps and conditions needed to cultivate Ashitaba successfully. From seed germination to harvesting, you will learn how to care for and maintain this remarkable plant, ensuring it thrives in your garden or home.

I. Ashitaba Plant Information

1. Description and Characteristics

Plant TypeHerbaceous perennial
FamilyApiaceae (Carrot/Parsley family)
Growth HabitUpright, spreading
Mature Height3-5 feet (90-150 cm) tall
Sunlight RequirementsFull sun to partial shade
Soil RequirementsRich, well-draining soil
Water NeedsConsistently moist soil
Temperature RangeHardy to USDA Zones 6-9
Planting TimeSpring or fall
Spacing2-3 feet (60-90 cm) apart
PropagationDivision or seed
Harvest TimeLeaves can be harvested year-round
LeavesDark, glossy, evergreen
FlowersSmall, white, in umbels
Unique FeaturesRapid leaf regeneration

2. Health Benefits and Traditional Uses

  • Nutritional Content: Rich in vitamins, minerals, and antioxidants.
  • Medicinal Uses: Traditionally used in Japanese medicine for treating ailments and promoting health.
  • Unique Compound: Contains chalcones, which are believed to have various health benefits.

II. Seed Germination and Planting

1. Fresh Seeds and Germination Process

Freshly harvested Ashitaba seeds have a much higher chance of germination compared to older seeds. There’s no need for extra work such as soaking or refrigeration when using fresh seeds. Simply plant them and keep the soil consistently moist. Germination typically takes about 3-4 weeks. High humidity is crucial during this period, so using a dome or cover to maintain moisture can significantly improve success rates.

2. Soil Preferences

Ashitaba thrives in rich organic matter. Ideal soil amendments include compost, worm castings, biochar, and rock dust. The soil should remain moist but well-drained to prevent waterlogging and root rot. Adding perlite to the soil mix can help create a light, fluffy texture that enhances drainage and aeration.

3. Planting Location

In regions with strong sunlight, such as Southern California, it’s best to grow Ashitaba in part shade to prevent leaf burn. In cooler climates, the plant can tolerate full sun but should be introduced to these conditions gradually to avoid shock. A transition from full shade to full sun over time helps the plant acclimate without damaging the leaves.

4. Detailed Planting Steps

  1. Fill seed trays or pots with a well-draining potting mix enriched with compost or worm castings. Sow the seeds on the soil surface and press them lightly into the mix. Water gently to ensure the soil is moist but not waterlogged.
  2. Cover the trays or pots with a humidity dome or plastic wrap to retain moisture. Place them in a warm location with indirect sunlight.
  3. Check the soil regularly and keep it consistently moist. Once the seeds germinate (in about 3-4 weeks), gradually remove the cover to acclimate the seedlings to lower humidity.
  4. When the seedlings are large enough to handle, transplant them into individual pots or directly into the garden. For pots, use containers that are at least 12 inches (30 cm) in diameter. Choose a location with part shade if growing in a hot climate or full sun in cooler climates.
  5. Prepare the planting site or pots by incorporating organic matter into the soil. Transplant the seedlings, spacing them about 18 inches (45 cm) apart in the garden, or one seedling per pot. Water thoroughly and maintain moist, well-drained soil. Gradually introduce the plants to more sunlight to prevent shock and leaf burn.

III. Care and Maintenance

1. Watering and Soil

Ashitaba requires regular watering to keep the soil consistently moist but not waterlogged. It is important to prevent root rot by ensuring good drainage. Whether grown in pots or in the garden, the soil should be rich in organic matter and well-draining. Adding perlite to the soil mix can help improve aeration and drainage.

2. Fertilizing

Feed Ashitaba with fresh compost every month or two to provide essential nutrients. Organic fertilizers such as cattle horn shavings or dung are ideal. Commercial fertilizers can be used sparingly if necessary. Ensure that the plants receive a balanced mix of nutrients to support healthy growth.

3. Climate and Light

Ashitaba prefers cool, damp conditions and may slow its growth during hot, dry months. The plant can grow in semi-shade or full sun, but it requires at least 6 hours of sunlight per day. Gradually introduce the plants to more sunlight to avoid shock and leaf burn.

4. Pruning and Plant Health

a. Pruning Ashitaba Plants

  • Timing: Prune Ashitaba plants in early spring or late fall to promote healthy growth and shape the plant.
  • Tools: Use clean, sharp pruning shears to make precise cuts and avoid damaging the plant. Always clean pruning tools before and after use to prevent the spread of diseases. Disinfect with a solution of one part bleach to nine parts water.
  • Method: Cut back any dead or damaged leaves and stems. For shaping, trim back overgrown areas to maintain the desired size and shape.
  • Leaf Harvesting: Regularly harvest the leaves by cutting them at the base of the stem. This not only provides you with fresh leaves but also encourages new growth.
  • Flowering Control: To prevent the plant from flowering (which can reduce leaf production), remove flower buds as they appear. This helps the plant focus energy on leaf production.
  • Rejuvenation: Every few years, perform a more extensive pruning to rejuvenate older plants. Cut back the plant by about one-third to stimulate new growth and remove any old, woody stems.

b. Maintaining Plant Health

  • Regular Inspection: Regularly check plants for signs of pests, diseases, or nutrient deficiencies. Early detection and treatment can prevent major issues.
  • Balanced Feeding: Feed plants with a balanced organic fertilizer to maintain nutrient levels. Avoid over-fertilizing, which can lead to excessive foliage at the expense of root development.
  • Proper Watering: Ensure consistent moisture without waterlogging the soil. Adjust watering based on weather conditions and plant needs.
General Tips
  • Refrigerate seeds for a month before sowing to improve germination rates.
  • Protect plants from strong sunlight and winds, especially in hotter climates.
  • Regularly renew mulch or compost to maintain soil moisture and nutrients.
  • Monitor for pests and diseases, and take appropriate measures to keep the plants healthy.
  • Ensure good air circulation around the plants to prevent fungal issues.

IV. Harvesting and Usage

1. When and How to Harvest

  • Timing: Ashitaba leaves can be harvested year-round, but the best time to harvest is in the morning when the leaves are fresh and full of nutrients.
  • Method: Use sharp, clean scissors or pruning shears to cut the leaves at the base of the stem. This encourages new growth and prevents damage to the plant.
  • Leaf Selection: Select mature, healthy leaves for harvesting. Avoid leaves that are damaged, yellowing, or diseased.
  • Frequency: Regularly harvesting the leaves promotes continuous growth. If you have multiple plants, rotate your harvesting to ensure each plant has time to regenerate.

2. Preparing Ashitaba for Consumption

  • Fresh Use: Rinse the harvested leaves under running water to remove any dirt or pests. Pat them dry with a clean towel.
  • Drying: To dry Ashitaba leaves for tea or storage, tie them in small bundles and hang them upside down in a cool, dry, and well-ventilated area. Alternatively, use a dehydrator set to a low temperature.
  • Grinding: Once dried, the leaves can be ground into a powder using a mortar and pestle or a spice grinder. This powder can be used in teas, smoothies, or as a seasoning.

3. Storage

  • Fresh Leaves: Store fresh Ashitaba leaves in a sealed plastic bag or airtight container in the refrigerator. They can last up to a week when stored properly.
  • Dried Leaves: Store dried leaves in an airtight container in a cool, dark place. They can retain their potency for up to a year if kept away from light and moisture.
  • Powdered Ashitaba: Store the powdered form in an airtight container, preferably in the refrigerator or freezer to maintain its freshness and potency. Use within six months for the best results.
Ashitaba flowers in bloom
Ashitaba flowers in full bloom.

V. Common Issues and Solutions

1. Germination Challenges

  • Low Germination Rate: Ensure seeds are fresh. Use high humidity environments and well-draining soil to improve germination success.
  • Long Germination Period: Be patient, as Ashitaba seeds can take 3-4 weeks to germinate. Maintain consistent moisture and humidity levels.

2. Environmental Stress

  • Sunlight Stress: Gradually acclimate plants to full sun to prevent leaf burn. Use shade cloths in extremely hot climates.
  • Temperature Extremes: Protect plants from frost by bringing them indoors or using row covers. In high heat, ensure adequate watering and shade.

3. Overwatering and Underwatering

  • Overwatering: Ensure well-draining soil to prevent root rot. Avoid waterlogged conditions by allowing the top layer of soil to dry out slightly between waterings.
  • Underwatering: Keep the soil consistently moist, especially during hot and dry periods. Use mulch to retain soil moisture.

4. Pest and Disease Management

  • Aphids: Spray plants with a mixture of water and mild soap. Introduce beneficial insects like ladybugs to control aphid populations.
  • Powdery Mildew: Improve air circulation by spacing plants properly. Apply a solution of baking soda and water (1 tablespoon per gallon) to affected areas.
  • Root Rot: Ensure proper drainage and avoid overwatering. Remove affected plants and treat the soil with a natural fungicide like neem oil.
  • Snails and Slugs: Use beer traps or diatomaceous earth around plants. Handpick and remove snails and slugs in the early morning or evening.

5. FAQ

Why are my Ashitaba seeds not germinating?

Fresh seeds have higher viability. Ensure high humidity and consistent moisture. Be patient, as germination can take up to 4 weeks.

How can I prevent my Ashitaba leaves from burning?

Gradually acclimate plants to full sun. Provide part shade in hot climates and ensure consistent watering.

What should I do if my Ashitaba plant gets root rot?

Improve soil drainage, reduce watering frequency, and treat the soil with neem oil or other organic fungicides.

How do I control aphids on my Ashitaba plants?

Use a water and soap spray or introduce beneficial insects like ladybugs to naturally reduce aphid populations.


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