Starting Asparagus from Seed Indoors: Step-by-Step Guide

Growing asparagus from seed indoors gives gardeners a head start on establishing productive, long-lived beds. While crowns offer faster harvests, starting seeds indoors allows control over germination, variety selection, and early-season growth. With over 30 years of experience growing asparagus, I’ve refined a step-by-step approach to ensure healthy seedlings ready for transplanting outdoors.

Table of Contents

Step 1: Select Seeds and Containers

Choose Varieties: Pick disease-resistant, high-yielding types such as ‘Jersey Knight’ or ‘Purple Passion.’
Containers: Use seed trays, pots, or any shallow container with drainage holes.

Step 2: Prepare the Growing Medium

Soil Mix: Use a light, well-draining seed-starting mix.
Moisture: Moisten the soil before sowing seeds, ensuring it’s damp but not soggy.

Step 3: Sow the Seeds

Depth: Plant seeds ½ inch deep.
Spacing: Leave 1–2 inches between seeds to reduce overcrowding.
Labeling: Mark varieties and sowing date for reference.

Step 4: Provide Optimal Conditions

Temperature: Maintain 70–75°F for germination.
Light: Place under grow lights or in a sunny window for 12–16 hours per day.
Humidity: Cover with a clear lid or plastic wrap to retain moisture until seedlings emerge.

Step 5: Care for Seedlings

Watering: Keep soil consistently moist but avoid waterlogging.
Thinning: When seedlings have two true leaves, thin to the strongest plants.
Hardening Off: Gradually acclimate seedlings to outdoor conditions 1–2 weeks before transplanting.

Step 6: Transplanting Outdoors

Timing: Plant in prepared, well-drained soil after the last frost.
Depth: Set crowns or seedlings so roots are fully covered and crowns sit just below soil surface.
Spacing: Space 12–18 inches apart in rows 3–4 feet apart.

My Experience and Key Takeaways

Starting asparagus from seed indoors ensures uniform, healthy plants ready for outdoor beds. Patience, consistent moisture, and proper light are key to strong seedlings that will produce productive, long-lived asparagus crowns.