Growing Marshmallow from seed:

• Marshmallow plants, scientifically known as Althaea officinalis, are fascinating herbs with a rich history.

• They were once used to make the original marshmallows, and today, they are still valued for their medicinal properties.

• Growing marshmallow plants from seed is a rewarding experience, and with a little care, you can enjoy the benefits of this versatile herb.
  

Quick Guide

Start Indoors:

• Timing: 6-8 weeks before last spring frost

• Seed Depth: 1/4"

• Germination time: 14-21 days

• Transplant out: after last frost date

Direct Sow:

• Timing: after the last frost, when soil temperatures have warmed,

• Seed Depth: 1/4"

• Spacing: 18" - 24"

Plant Specifications

Light Preference

Plant Height

Plant Spacing

Hardiness

Full Sun

36-40"

18-24"

Perennial

zones 3-7

Step-by-Step Instructions - Starting Seeds Indoors

Collect Supplies:

• Seeds

• Seed starting trays or pots

• Seed starting mix (sterile)

• Labels and a marker

• Plastic wrap or a humidity dome

• Spray bottle or watering can with a fine nozzle

• Grow lights or a sunny windowsill

  Timing

  • When to Start: Begin the process about 6-8 weeks before the last expected frost date in your area.

  Preparation

  • Clean Containers: Sterilize your seed starting trays or pots to prevent disease.

  • Moisten Seed Mix: Slightly moisten your seed starting mix so it's damp but not soggy.

  Planting Seeds

  • Fill Trays: Fill each cell in the seed tray with the moist seed starting mix.

  • Sow Seeds: Place 1-2 seeds in each cell.

  • Label Trays: Label each tray or pot with the variety and the planting date.

  Germination

  • Cover Seeds: Cover with 1/4" of soil.

  • Moisten Surface: Use a spray bottle to mist the top of the soil.

  • Create Humidity: Cover the seed trays with plastic wrap or a humidity dome to maintain moisture.

  • Warmth: Place the trays in a warm location (70-75°F or 21-24°C). A heat mat can help.

  Light and Watering

  • Lighting: Once the seeds germinate (about 14-21 days), remove the cover and place the seedlings under grow lights or in a sunny windowsill. Provide 12-16 hours of light per day.

  • Watering: Keep the soil moist but not waterlogged. Water from the bottom if possible to prevent damping-off disease.

  Take Care of Seedlings

  • Thinning: Once seedlings have two sets of true leaves, thin them to one plant per cell or pot.

  • Hardening Off: About a week before transplanting outdoors, start to harden off your seedlings by gradually exposing them to outdoor conditions for increasing time periods each day.

  Transplanting Outdoors

  • Timing: Transplant the seedlings outdoors after all danger of frost has passed.

  • Soil Preparation: Choose a sunny spot with well-draining soil. Amend with compost if needed.

  • Planting: Plant seedlings 18-24 inches apart, depending on the variety. Use netting or a trellis to support plants for straight cut flower stems.

  • Watering: Water thoroughly after planting.