When to Plant Artichokes [Zones 3-11]
If you’ve only ever had artichokes from the store, you’re really missing out. This year I decided to plant artichokes in our yard as an ornamental and edible plant. I like to call it foodscaping (edible landscaping). When I started to research information, I quickly became frustrated by the lack of information about when to plant my artichokes.
There was the usual generic information (which can’t be the same for everyone. I mean someone in Indiana is not going to plant artichokes at the same time as me in Southern California, right? And then there was the really bad inaccurate information. I do have a Master Gardner’s textbook at home after all.
So in this article, I’m going to document my experience and share with you when to plant artichokes based on where you live.
What Zone Do Artichokes Grow In
Artichokes grow in USDA zones 3 through 11. However, they only grow as perennials in zones 7 through 11. In these zones, artichokes can live and produce edible heads for up to five years.
In zones 3 through 6, they will only grow as annuals so you’ll have to replant them each year. But the good news is you can still grow them!
Best Way to Plant Artichokes
The first thing you should know is there are multiple ways to plant artichokes. You can plant them from a seed (which is what I did) or you can plant them from rooted shoots growing from existing plants. Artichokes produce rooted shoots like many succulents do and you can pull those apart with the root ball and propagate them. How cool, right?
Depending on whether you are planting seeds or planting shoots, it will change when you plant them in the ground. I’ll discuss both throughout the article.
Most universities agree that planting with seeds results in higher heads of artichokes per plant. Furthermore, you can only propagate artichokes from shoots in zones 7 through 11 where they grow as perennials.
Soil Temperature for Planting Artichokes
The main consideration for when to plant artichokes is soil temperature. Artichokes are a mild-weather plant. They like a little bit of cold, a little beat of heat, but no extremes on either side. This is why planning is so important to determine when you plant your seeds.
In order for seeds to germinate, the soil temperature must be between 60 and 80 degrees Fahrenheit.
Artichoke plants also need at least 200 chill hours in order to set buds. That’s 200 hours at temperatures between 35 degrees and 45 degrees Fahrenheit. If they don’t get at least 200 hours, you’ll end up with a fern-looking plant, but no artichokes.
For best production, I suggest closer to 1,200 chill hours. If you don’t get enough chill hours (this happens sometimes where I live because our winters are very mild), you can place ice around the base of the plant to simulate the same effect.
Can Artichokes Survive Frost
They can tolerate mild, occasional freezing as low as 25 degrees Fahrenheit (at least that’s what I’ve observed personally), but anything below 34 degrees will stress your plant. It’s not ideal.
Can Artichokes Tolerate Heat
Also, while artichokes can withstand temperatures above 85 degrees Fahrenheit, the flower heads start to become hard and difficult to eat. Warmer temperatures will also encourage the plant to bloom early.
So the optimal temperature for artichokes is between 50 and 85 degrees, with some chill hours between 35 and 45 degrees.
Artichokes take almost half a year to mature so depending on where you live, you may have to sow seeds indoors in order to avoid excessive heat leading to premature bloom.
When to Plant Artichoke Seeds
Now that we’ve discussed temperatures, let’s talk about when you should plant your artichoke seeds. Artichokes are planted at vastly different times of the year depending on where you live. Here in Southern California, I’ll plant artichokes in late summer, or early fall.
But someone in the Pacific Northwest would most likely plant them in late winter or early spring.
In zones 3 through 6, where artichokes are grown as annuals, you’ll plant them in the spring. In zones 7 through 11, where they are grown as perennials, you can plant them in late summer or by mid-fall.
Regardless of where you live, you don’t want to plant them too late into the summer because they won’t get the required chill hours. No chill hours means no buds, which means no artichokes.
When to Plant Artichoke Seeds Indoors
If you live in a climate where you don’t have a month of 60 to 80-degree Fahrenheit weather followed by a few weeks of weather between 35 to 45 degrees, and then another 4 to 5 months of temperatures between 50 and 80 degrees, sowing seeds indoors will give you the runway you need.
With the exception of locations in California, most of the country has to start their seeds indoors using a heat mat to get their artichokes to germinate. Seeds will only germinate in soils between 60 and 80 degrees Fahrenheit.
If you don’t have a heat mat, you can also try placing the tray on top of a refrigerator or on a warm window sill. I do find a heat mat to be the most predictable way to control the soil temperature though.
For most locations, you’ll start your seeds in late winter or early spring. Sow seeds 8 to 10 weeks before your last frost date. You want to target transplanting after the threat of frost has disappeared, but when there are still at least 2 to 8 weeks of cool temperatures between 35 and 45 degrees Fahrenheit.
When nighttime temperatures are consistently around 50 degrees, it’s usually safe to transplant them outside.
When to Plant Artichoke Shoots
If you live in zones 7 through 11 where artichokes are a perennial, you’ll notice offshoots around your plants in the second or third year. You can carefully separate these shoots from the mother plant and replant them into a new plant.
When propagating artichoke shoots, plan them in the late winter or early spring 2 weeks before your last frost.
When to Plant Artichokes in California
You can plant artichoke seeds from fall through early spring in California. I like to plant mine in late September or early October. This allows for warm enough soils that my seeds will germinate outside without transplanting.
And then with our mild winters in Southern California, by mid-November, the plant starts to get enough chill hours to produce buds. Within 3 to 4 months I start to notice buds and they are ready for harvest by April of the following year.
The plant will then go dormant during the summer.
If you live at higher elevations or in Northern California, you can follow the same advice, planting seeds from fall through early spring. Some people have even said that light, occasional frosts sweeten the taste.
The best place to grow artichokes in California is the Central Coast. The weather there is ideal and mild. But they can be grown throughout the state. The bread basket or Central Valley is one of the largest producers of artichokes. I live in the Inland area and they grow great here too.
In fact, commercial production of artichokes in the United States is almost exclusively found in California. Outside of that, most of the world’s artichokes come from Italy, Egypt, Spain, and Peru.
The most common variety of artichokes in California is the Green Globe.
When to Plant Artichokes in Arizona
Artichokes do well in Arizona; however, the Green Globe which is grown in California may not perform as well in Arizona’s summer heat - especially in the low desert regions. Rather, the Imperial Star variety which was developed by the California Cooperative Extension may be better suited for Arizona.
Most areas in Arizona start seeds indoors in December or January and transplant them outside after the last frost date has passed. This is usually in late February or early March.
By late April or early May, buds will start to appear and you can harvest them sometime in June before the summer heat really picks up and makes your plant flower.
When to Plant Artichokes in Texas
Texas A&M recommends planting seeds indoors in mid-August for Central Texas and early August for North and West Texas. In mid-October, you can transplant those seeds outdoors into your garden to start soaking in those chill hours it needs to form a bud.
Similar to California, the Green Globe grows well in Texas, especially Central Texas.
When to Plant Artichokes in Zone 6
Artichokes are easy to grow in Zone 6 and can even be grown as a perennial if overwintered. It’s best to sow seeds indoors in late February or early March. In early May, you can transplant your seedlings outdoors. By the end of summer, you’ll have delicious artichokes straight from your garden.
When to Plant Artichokes in Zone 7
For most of Zone 7, follow the same advice as Zone 6. Sow seeds indoors in late February or early March and transplant outdoors by the end of May.
When to Plant Artichokes in Zone 8
In Zone 8, you can start seeds indoors in early January. By the end of March or early April, it’s usually safe to transplant the seedlings outdoors (after the last frost date).
Overwintering Artichokes
If you want to grow artichokes as perennials, enjoying the flowers and edible hearts year after year, here’s how.
In Zones 8 through 11, cut the plants back to soil level and cover them with organic straw or a similar mulch. You’ll want to use at least four inches.
In Zones 6 and 7, cut your plants down to 12 inches after your last fall harvest and add an organic mulch around the base. Then cover them with a burlap sack or garden fabric. Both will protect your plant from cold winters and still allow it to breathe. My grandma used to use a styrofoam cooler-like item to cover her plants for the winter. While less environmentally friendly, that would work too.
In Zones 3 through 5 it’s really hard to overwinter artichokes. Short of growing them in 20-inch diameter pots (or larger) and bringing them indoors, your best bet is to follow the instructions for Zones 6 and 7 and pray for a mild winter.
When to Plant Artichokes Conclusion
Artichokes are a thistle from the Mediterranean. They are adapted to cool weather climates with coastal fog. In the US, they can grow in Zones 3 through 11.
In Zones 7 through 11 artichokes grow as perennials and can produce for up to 5 years.
Artichokes thrive in temperatures between 50 and 80 degrees Fahrenheit and require at least 200 chill hours to produce buds.
In mild climates like California, artichokes are planted in late fall for harvest before the intense summer heat arrives.
In cooler climates, seeds are started indoors using a heat mat in late winter to early spring and then transplanted outside after the last frost date.
