A broccoli plant

Planting MethodActivityRecommended Dates
Spring PlantingIndoor Seed StartingDecember 1 – January 15
Transplant OutdoorsJanuary 15 – February 15
Direct SowingJanuary 15 – February 15
Fall PlantingIndoor Seed StartingAugust 1 – September 1
Transplant OutdoorsSeptember 1 – October 1
Direct SowingSeptember 1 – October 1

Understanding Arizona’s Climate

Arizona’s climate ranges from USDA Hardiness Zones 4b to 10b, significantly impacting planting schedules. The state experiences hot summers and mild winters, making precise timing essential.

Arizona hardiness zone map

Starting Broccoli Indoors

Example: In Phoenix, AZ (Zone 9b), start broccoli seeds indoors from early December to mid-January. This allows you to transplant seedlings outside in mid-January to mid-February.

  • What You’ll Need: Seed trays, high-quality potting mix, grow lights or a sunny window, and a consistent watering schedule.
  • How to Do It: Fill seed trays with potting mix, sow seeds about ¼ inch deep, keep the soil moist, and ensure they get plenty of light.

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Useful Tools for Starting Broccoli 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 broccoli the best chance to thrive from the very beginning.
Seeds Image
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Planting Trays

Planting trays help you organize your seedlings and ensure they have enough space to grow before you transplant them outdoors. This makes the process more efficient and increases the chances of strong, healthy plants.
Planting Trays Image
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Grow Lights

Grow lights are essential if you don’t have enough natural sunlight. They provide your seedlings with the light they need to grow strong and healthy, even in less-than-ideal conditions.
Grow Lights Image
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Seed Starting Soil

Using light, fine soil specifically designed for seed starting helps young roots establish quickly and promotes healthy growth. It’s an easy way to give your seedlings the best start possible.
Seed Starting Soil Image
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Garden Tools and Fertilizer

Garden Trowel

A garden trowel is a handy tool that makes transplanting your seedlings easier and more precise, ensuring that each plant is placed at the right depth without damaging the roots.
Garden Trowel Image
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Soil and Fertilizer

Fertilizer is essential for enhancing growth, especially if your soil is nutrient-poor. By enriching the soil, you give your broccoli plants the nutrients they need to grow robust and produce a bountiful harvest.
Fertilizer Image
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Direct Sowing in the Soil

Example: In Tucson, AZ (Zone 9a), you can sow seeds directly in the garden from mid-January to mid-February for a spring crop, and from early September to early October for a fall crop.

  • Preparing the Soil: Work the soil until it’s fine, mix in some compost, and make sure good drainage.
  • Sowing Seeds: Plant seeds ½ inch deep, spaced about 3 inches apart. Once seedlings have a few true leaves, thin them to 12-18 inches apart.

Transplanting Broccoli Seedlings

Example: For gardeners in Flagstaff, AZ (Zone 6b), start seeds indoors in early December and transplant them into the garden in mid-January.

  • Preparing the Garden Bed: Make sure the soil is rich in organic matter and has a pH between 6.0 and 7.0.
  • Transplanting Technique: Space seedlings 18-24 inches apart in rows 24-36 inches apart. Water thoroughly after transplanting and apply mulch to keep moisture.

Other planting guides for Arizona:

Any questions on growing broccoli? Visit our forum to discuss: Growing Broccoli



General Care and Maintenance

Watering and Feeding: Broccoli requires consistent moisture, especially during dry spells. Water at the base to avoid wetting the leaves, and use a balanced vegetable fertilizer as needed.

Pest and Disease Management: Be aware of pests like aphids and cabbage worms. Use floating row covers and organic pesticides if necessary. Rotate crops and remove plant debris to prevent disease.

Harvesting Broccoli: Harvest the heads when they are firm and tight, before the flowers start to open. Cut the main head with part of the stem attached, and the plant will often produce smaller side shoots for a continued harvest.

BeeJay