When Does Basil Grow? (Sonoran Desert)

When does basil grow in the Sonoran Desert, you ask?

As with most plants, there are many varieties of basil! Some are better-adapted for different regions and climates.

Some of these varieties may fall outside of the season I've laid out below, so always take these things with a grain of salt and experiment with different varieties yourself.

You never know what variety you'll find that does particularly well in your climate and microclimate!

What Conditions Does Basil Like to Grow In?

In general, basil likes warm and hot temperatures. This is a Mediterranean plant, after all! That means hot dry summers are often totally fine for basil.

When Can You Grow Basil in Tucson?

I've observed basil thriving in Tucson here from April through November. By mid-to-late-October and November, basil has usually gone to flower but will still have plenty of nice leaves for plucking.

The bees love the October / November basil flowers here, so do consider leaving them standing to help out your pollinators and ecosystem!

Do consider, though, that a bit of shade cloth or a shady spot can make a big difference for your basil in the midsummer desert heat. The Sonoran does get hotter and sunnier than the Mediterranean, so take this into account and help your basil out with a bit of shade.

When the cold snaps come in November or early-December, basil will turn black and quickly die off, so I suggest harvesting all you can by early November.

Basil does not like it when the nights drop down into the low-40's and high-30's.

Transplanting Basil

Like tomatoes, basil will grow new roots anywhere the stalks are exposed to water. This is the reason basil propagates so well in a glass of water on your window sill.

This means that when transplanting basil out into the garden, you have the option to bury it deeper than the original soil line.

If you choose to bury your basil deeper, be sure to strip the lower leaves / shoots off before doing so.

Burying your basil deeper than the original soil line will allow the basil to focus more energy on root expansion at first, having more stalk underground to produce roots from.

This focus on root production theoretically allows your basil plant to expand its moisture and nutrient uptake zones before focusing on leaf / shoot production. This should produce more basil eventually, with a delay initially - long-term thinking.

Have you tried burying your basil stems deeper? If so, we'd love to hear from you in the comments as to whether you think this did anything or not!

Common Basil Pests in the Sonoran Desert

I've noticed A lot of insect bites out of my sweet basil, which I believe to be from the increase in grasshoppers after the abundant 2021 monsoon.

I'm not sure if this guess is correct, however the basil seems to turn black around the bites and seems stunted and more curled under than usual. Could this be related to the insects eating the leaves?

Thrips can also be a problem on basil and will do a lot of damage if given the opportunity. Insecticidal soap can help with thrips in the greenhouse or seed-starting area, but I recommend against spraying it in the garden as it can kill beneficial insects too.