Zinnias are excellent to start from seed indoors or direct sow because:

• They have a fast germination rate and are easy to grow, making them perfect for both beginners and experienced gardeners.

• They quickly establish themselves, with blooms appearing in as little as 60 days, providing a rapid payoff.

• Are hardy and not very demanding in terms of soil conditions, thriving in full sun and well-drained soil.

• Direct sowing ensures they develop strong root systems and eliminates the need for transplanting, which can sometimes stress the plants.

Direct Sowing:

• Timing: 1-2 weeks after last frost

• Seed Depth: 1/4'

• Germination time: 7-10 days

• Row Spacing: 8-12"

Quick Guide

Starting Indoors:

• Timing: 4-6 weeks before last spring frost

• Seed Depth: 1/4'

• Germination time: 7-10 days

• Transplant out: 2 weeks after last frost

Plant Specifications

Light Preference

Plant Height

Plant Spacing

Hardiness

Full Sun

Variety Specific

9-12"

Annual

Step-by-Step Instructions - Starting Seeds Indoors

Collect Supplies:

• Zinnia 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

1. Timing

   • When to Start: Begin the process about 4 to 6 weeks before the last expected frost date in your area.

2. 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.

3. Planting Seeds

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

   • Sow Seeds: Place 1-2 zinnia seeds in each cell. Zinnias should be sown about ¼ inch deep.

   • Label Trays: Label each tray or pot with the type of zinnia and the planting date.

4. Germination

   • Cover Seeds: Lightly cover the seeds with more seed starting mix. Optionally, add a layer of vermiculite to prevent algae growth on soil surface.

   • 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.

5. Light and Watering

   • Lighting: Once the seeds germinate (about 7-10 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.

6. 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.

7. Transplanting Outdoors

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

   • Conditioning Transplants: Over the course of a week, slowly transition tender seedlings outdoors by gradually exposing them to the elements.

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

   • Planting: Plant seedlings 9-12 inches apart, depending on the variety.

   • Watering: Water thoroughly after planting.