How to Grow Tomatoes in Hot Climates (Even In the Arizona Desert)

When you think of gardening the first plant everyone wants to grow are tomatoes. It’s just the thing to do and for good reason. Tomatoes taste ten times better fresh off the vine then anything you’ll ever get at a supermarket.

If you live in hot, dry climates like where I reside in the Arizona desert, you may be thinking that growing tomatoes just isn’t doable. Well, if you have a basic understanding of gardening in hot climates, then you’ll be harvesting amazing tomatoes in no time.

Utilize Raised Beds

For those of us living in a hot climate, like the Southwest U.S., one of the first things you may notice when you think about gardening is the soil. It’s not that rich, fertile, black soil that you typically think of when growing things. It’s a hard, dry, brown, compacted soil.

Our soil is generally a clay type soil that has some pros, but the main concern is the lack of organic matter. It makes it hard for plants like tomatoes to take up the needed nutrients. So growing in the ground is going to be a major challenge, especially for newbie gardeners.

Your best bet for successfully growing tomatoes in a hot climate is to build a raised bed. If you’re unsure what a raised bed is or how to build one. Here are a couple of my related posts to get you started:

Raised Bed Gardening for Hot Climates

Getting Your Raised Bed Ready for Planting Season

Growing in a raised bed allows you to have better control over the soil. I highly recommend using a high-quality sandy-loam type soil. I purchase mine by the cubic yard from local sources. The cheaper bag soil commonly found in the big box stores will produce cheap results.

I also recommend adding worm castings, coconut coir, and compost or manure. I utilize my rabbit manure compost which supplies a steady stream of food for my tomatoes throughout the entire growing season. I’ve seen huge results with rabbit manure.

Seeds or Transplants

For beginners, your best bet will be going with transplants. I do grow some tomatoes from seed, but still, prefer transplants. Again go to a reputable nursery that sells plants suited for your area and knows your climate. Growing from seed adds the element of acclimating them to the outdoors or “hardening them off.”

This can cause the plant to suffer or even kill the plant if not done correctly. When starting seeds, I generally start mine around New Years in Arizona. You want at least 6 weeks for the seeds to establish a decent root system and enough top growth to be ready to plant outdoors.

Many varieties do well here, but you want to look for varieties that produce in the shortest amount of time. It’s a race to beat the heat! I look for varieties that produce in 80 days or less. Here are some varieties to consider:

Early Girl (My Favorite)
Juliet
Roma
Celebrity
Black Cherry
Sungold
Columbia
Cherokee Purple
Rosa
Summer Girl
Other Cherry Tomato Varieties

Time to Plant

This is what trips up a lot of gardeners that have migrated to the Southwest from other areas. Gardening in areas that have extreme winter tends to start later in the year than in the warmer climates. In the Phoenix, Arizona area it’s generally recommended to start planting in mid-Feb.

Although we do tend to get a late cold snap towards the end of Feb, so keep this in mind. Tomatoes are cold/frost sensitive so if you plant too early you risk losing your plants if left unprotected during a cold spell.

You can also plant towards the end of summer in our second growing season to try to beat the cold, but I prefer to stick with growing tomatoes in the Spring to early Summer months.

Utilize Support

Tomato plants can get quite large and need support to grow upright without toppling over. Simple cages can work, but when the plants are loaded with fruit the weight can cause them to tip. A square cage has more of a base which can provide more stability. This is my favorite cage option over on Amazon, click here.

Consistency with Watering

It’s important to stick with a consistent watering schedule with tomatoes. They like a consistent watering regimen versus being allowed to dry out or being overly wet for periods of time. It’s best to water deeply to encourage the roots to go deep into the soil. Adding a thick layer of mulch is a great way to conserve moisture.

Problems with Blossom End Rot

Blossom End Rot is a common problem growing tomatoes in our area. This is when the end of the tomato can become brown and mushy. Half the tomato is still edible and the end with the rot needs to be cut off.

It detracts from the tomatoes beauty and can be frustrating for the tomato grower. Blossom end rot occurs when a calcium deficiency is present, due to the plant’s inability to take up the needed calcium from the roots.

Ways to Combat Blossom End Root

High PH– Our city water tends to elevate the PH levels in the soil and our native soil is high in PH. Utilizing compost, worm castings, and even soil sulfur or peat moss can help keep the PH down.
Fluctuations in Soil moisture– This is where coconut coir and peat moss can help retain some moisture so your soil isn’t completely drying out. Setting up a consistent watering schedule also helps, but also being careful not to over or underwater.
High Salts– Another problem with using city water in areas that lack rainfall is that it’s high in salts. Combat this by deep watering through a slow drip. This pushes the salts deep and away from the root system. Shallow watering keeps the salts towards the surface.
Epsom Salt– Many people claim that Epsom salt or magnesium sulfate can help with blossom end rot by mixing it into the soil at planting.

Sun Exposure and Heat

It’s literally a race to beat the heat when growing tomatoes in hot climates. Growing tomato plants in climates where temps soar above 95 degrees Fahrenheit for long periods of time, like here in Arizona, can be problematic.

When temps are this high it affects the pollen so fruit stops. Long periods of high heat and sun exposure can also cause the plants to suffer. I tend to harvest all the tomatoes I can in the months of May, June, sometimes July than remove all my plants.

Some utilize shade structures and things to help get their plants through the hot summer, but in my opinion, it’s not worth it. Tomato plants do like sun and warmth, so even in our hot climate, you don’t want to fully shade them or give them too much shade.

An ideal spot is where they will get sun until 2 or 3, then shaded by trees or foliage around them the rest of the day. This will help prolong the plants through more of the summer. If planted in full all day sun, they’ll struggle more when our temp’s spike.

Pruning

Some people prune tomato plants to help increase yields, keep the plant looking clean, and hopefully speed up ripening. I’ve personally never done anything to prune my tomatoes. I’ve always had more than enough tomatoes for my family, neighbors, friends, and the birds. It’s never been a big deal for me when my tomato plants become a dense looking jungle.

If you’re only growing a plant or two or just looking to try something new, then it may be beneficial to look into pruning techniques. Here is a post from Bonnie Plants that shows you exactly how to prune.

Pests

The main problem I have with pests is cutworm. They will eat through the base of your young plant literally sawing it in half. I tend to occasionally lose a plant to these ruthless pests.

Try adding a teaspoon of any of these essential oils (orange, thyme, sage, or cedarwood) as an organic way to get rid of cutworm. If you find any worms or caterpillars immediately remove them. Aphids aren’t a major problem for tomato plants. Whiteflies can be reduced with insecticidal soap or neem oil.

Time to Harvest

As your tomatoes start to get some color it’s time to start picking them. Tomatoes will ripen if picked early and sometimes this is the best time to harvest them. If you’re having problems with birds or other things eating your tomatoes, beat them to it.

Varieties that produce other colors, besides red, typically take a bit longer to change. If you wait too long the tomatoes will over ripen and become too mushy. Grow some cherry tomatoes! Your kids will love them and they’re great to snack on while you’re out in the garden. Check out the video below for one of my harvests: