Grower’s Reference Guide: Spinach

Introduction

Spinach is a fast-growing, nutrient-dense leafy green that thrives in cool weather and is well-suited for organic gardening. Its rich vitamin and mineral content makes it a favorite among home gardeners and commercial growers alike. Growing spinach organically enhances its flavor, reduces exposure to synthetic chemicals, and supports sustainable agriculture.

Fun Fact

Did you know that spinach was ranked #2 on the Dirty Dozen list of foods with the highest pesticide residues? This means store-bought spinach is often contaminated with chemicals, making it one of the best crops to grow yourself—100% organic and toxin-free!

Scientific Information

• Scientific Name: Spinacia oleracea (Common spinach), Basella rubra (Red Malabar spinach)
• Key Characteristics: Dark green or red-veined leaves; grows in a rosette pattern; cool-season crop.
• Common Uses: Salads, smoothies, soups, sautéed dishes, juicing, and as a cooked side dish.

Growth Overview

• Annual or Perennial? Annual (biennial in some climates if allowed to overwinter); Malabar spinach (Basella rubra) is a perennial vine in warm climates.
• Growth Form: Low-growing leafy vegetable (Spinacia oleracea), climbing vine (Basella rubra).
• Toxicity: Non-toxic to humans and pets
• Edibility: Fully edible (leaves and stems)
• Size & Growth Rate: Spinacia oleracea grows up to 12 inches tall; matures in 30-45 days. Basella rubra can grow up to 10 feet as a climbing vine and thrives in warm weather.

Varieties

• ‘Bloomsdale’: Heirloom variety with crinkled, thick leaves and excellent flavor.
• ‘Giant Noble’: Large, smooth-leafed variety known for its high yield.
• ‘Tyee’: Hybrid variety resistant to bolting and mildew.
• ‘Space’: Compact variety suitable for small gardens and containers.
• ‘Red Cardinal’: Unique red-veined variety with a slightly sweeter taste.
• ‘Red Malabar’ (Basella rubra): A heat-tolerant, vining variety with thick, glossy, red-tinged leaves and a mild, slightly mucilaginous texture, ideal for tropical climates.

Growing Conditions

Ecosystem/Climate

• Spinacia oleracea: Prefers cool temperatures; ideal for spring and fall planting.
• Basella rubra: Thrives in warm and humid climates; can be grown year-round in tropical regions.
• Grows best in temperate climates but can be cultivated in colder areas with protection.

Soil & pH

• Rich, well-draining soil with high organic matter.
• Optimal pH: 6.0-7.0.
• Organic amendments: Compost, aged manure, worm castings.

Temperature & Hardiness

• Spinacia oleracea: Optimal growing temperature: 50-70°F (10-21°C). Hardy to light frosts but struggles in heat (above 75°F/24°C).
• Basella rubra: Prefers temperatures above 70°F (21°C) and thrives in hot weather.

Moisture & Humidity

• Requires consistent moisture but should not be waterlogged.
• Mulching helps retain soil moisture and regulate temperature.

Season

• Spinach: Best planted in early spring and fall.
• Malabar spinach: Grows best in summer and tropical climates year-round.

Pests & Diseases

Common Issues

• Spinach: Susceptible to downy mildew, aphids, and leaf miners.
• Malabar spinach: Generally resistant to most pests but may attract spider mites in dry conditions.

Health Benefits & Nutrition

• Spinach is #2 on the Dirty Dozen list, meaning it’s one of the most pesticide-contaminated crops when purchased conventionally.
• Growing your own organic spinach eliminates exposure to harmful residues.
• Packed with vitamins A, C, K, and iron, boosting immune and heart health.

By following these organic practices, you can grow fresh, nutritious spinach—free of harmful pesticides—right in your own garden while promoting a sustainable and eco-friendly approach to gardening.