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The best time to plant herbs in Phoenix is during the cooler months, specifically from October through March.
This window avoids the brutal summer heat that can quickly kill tender seedlings and herbs.
If you’ve been wondering when to plant herbs in Phoenix, the short answer is that you have two prime growing seasons: fall and spring.
Phoenix’s desert climate makes timing everything, as our scorching summers are simply too intense for most culinary herbs.
By planting in the fall, you give your herbs a head start to establish deep roots before winter’s mild temperatures arrive.
In this post, we’ll cover the best times to plant herbs in Phoenix, which herbs thrive in each season, and practical tips to help you succeed.
Let’s dig into the desert gardener’s calendar.
When to Plant Herbs in Phoenix: The Core Window
The most reliable answer to when to plant herbs in Phoenix is October through November for the fall crop and February through March for the spring crop.
These months offer mild daytime temperatures ranging from the 60s to 80s, which herbs absolutely love.
You can plant herbs in Phoenix during these windows, and they’ll grow vigorously without the stress of extreme heat.
Our unique low-desert climate (USDA zone 9b-10a) means you have a long growing season, but the summer months from June through August are a hard no-go for most herbs.
During the summer, temperatures routinely exceed 100°F, which causes herbs to bolt, wilt, or simply fry in the sun.
So, when to plant herbs in Phoenix really boils down to working around those extreme heat events.
1. Fall Planting: October through November
Fall is arguably the best time to plant herbs in Phoenix because the soil is still warm, but the air is cooling down.
Warm soil encourages strong root development, which is critical for herbs to survive the mild winter.
When you plant herbs in Phoenix during the fall, you can enjoy fresh harvests all winter long.
Perennial herbs like rosemary, thyme, and sage thrive when planted in October.
Annual herbs like cilantro, dill, and parsley also do spectacularly well in this window.
The key is to plant them early enough in October so they establish before the coldest nights in December and January.
If you miss October, November still works, but you’ll need to keep an eye on any unexpected frost.
Phoenix rarely gets hard freezes, but young herbs are sensitive, so a light frost cloth can help.
2. Spring Planting: February through March
The second best answer to when to plant herbs in Phoenix is late winter to early spring.
By February, the danger of freezing temperatures has mostly passed, and the days start to warm up.
Planting herbs in Phoenix in February gives them a full window to grow before the summer heat bakes in.
You want to get them in the ground by early March at the latest.
Herbs like basil, oregano, and mint love the spring warmth, but they must be harvested heavily before June.
Once the temperature consistently hits the mid-90s, these herbs will start to struggle.
So, if you want a big spring crop, plant herbs in Phoenix in February or March.
This timing also aligns with longer daylight hours, which boosts photosynthesis and leaf production.
Best Herbs to Plant in Phoenix by Season
Knowing when to plant herbs in Phoenix is only half the battle, you also need to pick the right herbs for each season.
Not all herbs are created equal in a desert climate.
1. Cool-Season Herbs for Fall and Winter
Cilantro is a must-have for fall planting, as it bolts instantly in the heat.
Parsley, both flat-leaf and curly, thrives in winter temperatures.
Dill, fennel, and arugula (if you count it as an herb) all love the cool season.
Chives and green onions are also perfect for planting herbs in Phoenix during the fall.
These cool-season herbs can handle night temps down to the 30s without any issues.
You can even plant them in containers and move them around for optimal sunlight.
2. Warm-Season Herbs for Spring
Basil is the star of spring planting in Phoenix, but it needs to be in the ground by early March.
Oregano, marjoram, and thyme also do well when planted in late February.
Sage and rosemary are technically perennial, but they appreciate the spring window too.
Mint is a vigorous grower, but it needs partial shade in the summer, so plant it early.
When you plant herbs in Phoenix in the spring, just be prepared to give them extra shade cloth by May.
The goal is to harvest as much as possible before the monsoons and heat waves arrive.
Tips for Planting Herbs in Phoenix Successfully
To get the most out of your planting schedule, you need to adapt your soil and watering techniques to the desert.
Phoenix soil is typically alkaline and low in organic matter, so you always need to amend it.
1. Amend Your Soil with Compost
Before you plant herbs in Phoenix, mix in 2-3 inches of compost or aged manure.
This improves drainage, adds nutrients, and helps the soil retain moisture.
Herbs like well-draining soil, so avoid heavy clay or overly sandy conditions.
Raised beds are a fantastic option for controlling soil quality.
2. Water Deeply but Infrequently
Herbs prefer a consistent moisture level, but they hate soggy roots.
Water deeply right after planting, then let the top inch of soil dry out before watering again.
In the cooler months, you might only need to water once or twice a week.
As temperatures rise in spring, you’ll need to water more frequently.
Using drip irrigation is the best way to keep moisture at the roots without wetting the leaves.
3. Provide Afternoon Shade
Even in the fall and spring, Phoenix sun can be intense.
Plant your herbs where they get morning sun and afternoon shade, especially in March and April.
You can also use a 30-40% shade cloth to protect tender spring herbs.
This little trick will extend your harvest by several weeks.
So, When Should You Plant Herbs in Phoenix?
When to plant herbs in Phoenix is all about avoiding the scorching summer extremes.
You should plant herbs in Phoenix during the fall months of October and November, and again in late winter from February through March.
These are the windows where your herbs will flourish with minimal stress.
Fall is the premier season, as you get months of harvest through the mild winter.
Spring is your second chance, but you must stay on top of harvesting and shading.
If you follow this schedule, you’ll have fresh herbs almost year-round in the Valley of the Sun.
And if you find yourself itching to plant in the summer, stick to heat-loving varieties like lemongrass or Mexican tarragon, but know that they’re the exception.
For everything else, stick to the cool windows.
So, mark your calendar for October and February, that’s when to plant herbs in Phoenix.
Your taste buds will thank you when you’re snipping fresh rosemary in January.
Happy planting, and here’s to a bountiful herb garden in the desert.