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Growing Cosmos in Tehran

🇮🇷 Zone 6 Planting Guide · Cold semi-arid climate

USDA Zone 6 240 frost-free days 50-60 days to harvest

Quick Answer: Growing Cosmos in Tehran

Yes, you can grow Cosmos in Tehran, IR! Plant during Mar, Apr, May, Jun for best results. Tehran is in USDA Zone 6 with a Cold semi-arid climate, offering 240 frost-free days per year. The difficulty level is easy, and Cosmos takes 50-60 days to harvest. Cosmos needs full sun and low watering.

Climate Match Analysis

Moderate Match Tehran + Cosmos

Tehran's climate requires careful timing. Winter lows (-1°C) drop below Cosmos's minimum (5°C), so avoid cold months. Summer highs (36°C) exceed Cosmos's maximum (35°C), so plant early or provide shade. Follow the recommended planting months for success.

Cosmos tolerates 5°C to 35°C
Optimal: 15°C - 28°C
Tehran range -1°C to 36°C

Tehran Climate Data

USDA Zone
6
Frost-Free
240days
Winter Low
-1°C
Summer High
36°C
Rainfall
228mm/yr
Climate
BSk
Cold semi-arid

Cosmos Planting Calendar for Tehran

Green months show the best time to plant Cosmos in Tehran

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

Cosmos Growing Requirements

☀️

Sunlight

Full Sun

6+ hours direct sunlight

💧

Water

Low

Drought tolerant, water sparingly

📅

Days to Harvest

50-60

From planting to first harvest

📊

Difficulty

easy

Great for beginners

💡 Growing Tips for Cosmos

Direct sow. Thrives on neglect -- don't fertilize. Wait until soil warms to at least 15°C before transplanting outdoors — cold soil stunts growth and can invite root rot. Overwatering is the most common mistake. Let soil dry out between waterings and ensure drainage is excellent.

Frost tolerance: Cosmos is NOT frost tolerant — wait until after the last frost in Tehran.

How to Grow Cosmos in Tehran

Tehran, IR is in USDA Hardiness Zone 6 with a Cold semi-arid climate (Köppen BSk). With winter lows of -1°C and summer highs of 36°C, the growing season spans approximately 240 frost-free days. Cosmos is one of the easiest plants to grow in this climate.

Cosmos thrives in temperatures between 15°C and 28°C, requiring full sun and low watering. In Tehran, the best months to plant Cosmos are March, April, May, June. Cosmos is not frost tolerant, so it's important to wait until after the last spring frost before transplanting outdoors. Expect to harvest in approximately 50-60 days after planting.

Tehran receives only 228mm of annual rainfall, so consistent irrigation will be essential for growing Cosmos successfully.

Other Plants That Grow in Tehran

More plants you can grow alongside Cosmos in Tehran

Keep Exploring

Frequently Asked Questions

Can I grow cosmos in Tehran?

Yes! Cosmos can be successfully grown in Tehran, IR. Tehran is in USDA Hardiness Zone 6 with a Cold semi-arid climate. The difficulty level for growing Cosmos here is rated "easy". The best months to plant are March, April, May, June.

When should I plant cosmos in Tehran?

In Tehran, the recommended planting months for Cosmos are March, April, May, June. Tehran has 240 frost-free days per year, with winter lows of -1°C and summer highs of 36°C. Since Cosmos is not frost tolerant, make sure to plant after the last frost date.

How long does cosmos take to grow in Tehran?

Cosmos typically takes 50-60 days from planting to harvest. In Tehran's Cold semi-arid climate with 240 frost-free days, you have plenty of time to grow Cosmos to maturity. Direct sow. Thrives on neglect -- don't fertilize. Wait until soil warms to at least 15°C before transplanting outdoors — cold soil stunts growth and can invite root rot. Overwatering is the most common mistake. Let soil dry out between waterings and ensure drainage is excellent.

Can I grow cosmos indoors in Tehran?

Cosmos can potentially be grown indoors in Tehran 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 Mar, Apr, May, Jun outdoor planting window. Use containers with good drainage and low watering.

What month do I plant cosmos in Tehran?

Plant Cosmos in Tehran during March, April, May, June. These are the optimal months based on Tehran's USDA Zone 6 climate, 240 frost-free days, and temperature range of -1°C to 36°C.

Is cosmos hard to grow in Tehran?

Cosmos is rated "easy" to grow in Tehran. This is a great choice for beginners — it is forgiving and adapts well to this climate. The climate match for Cosmos in Tehran is Moderate.

What grows well with cosmos in Tehran?

In Tehran, you can grow many companion plants alongside Cosmos. Good options from the same planting window include Tomato, Basil, Lettuce, Carrot and 2 more. These plants share similar planting months and thrive in Tehran's Zone 6 climate.

Does cosmos need full sun in Tehran?

Cosmos requires full sun. In Tehran, provide at least 6 hours of direct sunlight daily. During peak summer heat, some afternoon shade can help prevent heat stress.

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

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