Skip to content
🥬 Vegetable hard

Growing Corn in Johannesburg

🇿🇦 Zone 7 Planting Guide · Subtropical highland climate

USDA Zone 7 290 frost-free days 60-100 days to harvest

Quick Answer: Growing Corn in Johannesburg

Yes, you can grow Corn in Johannesburg, ZA! Plant during Aug, Sep, Oct, Nov for best results. Johannesburg is in USDA Zone 7 with a Subtropical highland climate, offering 290 frost-free days per year. The difficulty level is hard, and Corn takes 60-100 days to harvest. Corn needs full sun and regular watering.

Climate Match Analysis

Moderate Match Johannesburg + Corn

Johannesburg's climate requires careful timing. Winter lows (4°C) drop below Corn's minimum (10°C), so avoid cold months. Follow the recommended planting months for success.

Corn tolerates 10°C to 35°C
Optimal: 18°C - 30°C
Johannesburg range 4°C to 26°C

Johannesburg Climate Data

USDA Zone
7
Frost-Free
290days
Winter Low
4°C
Summer High
26°C
Rainfall
713mm/yr
Climate
Cwb
Subtropical highland

Corn Planting Calendar for Johannesburg

Green months show the best time to plant Corn in Johannesburg

Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Plant Corn Not recommended

Corn Growing Requirements

☀️

Sunlight

Full Sun

6+ hours direct sunlight

💧

Water

Regular

Consistent moisture, 1-2 inches/week

📅

Days to Harvest

60-100

From planting to first harvest

📊

Difficulty

hard

For experienced growers

💡 Growing Tips for Corn

Minimum 4x4 block for pollination. Heavy feeder -- needs nitrogen-rich soil. Wait until soil warms to at least 18°C before transplanting outdoors — cold soil stunts growth and can invite root rot. Aim for about 2.5 cm of water per week, adjusting for rainfall. Organic mulch around the base helps maintain even moisture.

Frost tolerance: Corn is NOT frost tolerant — wait until after the last frost in Johannesburg.

🤝

Companion Plants for Corn

Find out which plants grow best alongside Corn — and which to keep apart

How to Grow Corn in Johannesburg

Johannesburg, ZA is in USDA Hardiness Zone 7 with a Subtropical highland climate (Köppen Cwb). With winter lows of 4°C and summer highs of 26°C, the growing season spans approximately 290 frost-free days. Corn requires more experience to grow successfully in this climate.

Corn thrives in temperatures between 18°C and 30°C, requiring full sun and regular watering. In Johannesburg, the best months to plant Corn are August, September, October, November. Corn is not frost tolerant, so it's important to wait until after the last spring frost before transplanting outdoors. Expect to harvest in approximately 60-100 days after planting.

With 713mm of annual rainfall, Johannesburg provides moderate natural moisture. You'll likely need to supplement with regular watering, especially during the growing season.

Other Plants That Grow in Johannesburg

More plants you can grow alongside Corn in Johannesburg

Keep Exploring

Frequently Asked Questions

Can I grow corn in Johannesburg?

Yes! Corn can be successfully grown in Johannesburg, ZA. Johannesburg is in USDA Hardiness Zone 7 with a Subtropical highland climate. The difficulty level for growing Corn here is rated "hard". The best months to plant are August, September, October, November.

When should I plant corn in Johannesburg?

In Johannesburg, the recommended planting months for Corn are August, September, October, November. Johannesburg has 290 frost-free days per year, with winter lows of 4°C and summer highs of 26°C. Since Corn is not frost tolerant, make sure to plant after the last frost date.

How long does corn take to grow in Johannesburg?

Corn typically takes 60-100 days from planting to harvest. In Johannesburg's Subtropical highland climate with 290 frost-free days, you have plenty of time to grow Corn to maturity. Minimum 4x4 block for pollination. Heavy feeder -- needs nitrogen-rich soil. Wait until soil warms to at least 18°C before transplanting outdoors — cold soil stunts growth and can invite root rot. Aim for about 2.5 cm of water per week, adjusting for rainfall. Organic mulch around the base helps maintain even moisture.

Can I grow corn indoors in Johannesburg?

Corn can potentially be grown indoors in Johannesburg with proper conditions. It requires full sun (6+ hours of direct light — a south-facing window or grow lights recommended). Indoor growing extends your season beyond the Aug, Sep, Oct, Nov outdoor planting window. Use containers with good drainage and regular watering.

What month do I plant corn in Johannesburg?

Plant Corn in Johannesburg during August, September, October, November. These are the optimal months based on Johannesburg's USDA Zone 7 climate, 290 frost-free days, and temperature range of 4°C to 26°C.

Is corn hard to grow in Johannesburg?

Corn is rated "hard" to grow in Johannesburg. This is challenging in this climate. Experienced growers will have the best success with careful attention to temperature and moisture. The climate match for Corn in Johannesburg is Moderate.

What grows well with corn in Johannesburg?

In Johannesburg, you can grow many companion plants alongside Corn. Good options from the same planting window include Tomato, Basil, Lettuce, Carrot and 2 more. These plants share similar planting months and thrive in Johannesburg's Zone 7 climate.

Does corn need full sun in Johannesburg?

Corn requires full sun. In Johannesburg, provide at least 6 hours of direct sunlight daily. Most garden locations with southern exposure will work well.

Last updated: March 2026 · Climate data from NOAA, FAO, USDA

See an error? Report it