The taste of homegrown tomatoes is the reason many people begin a garden. In the United States, it is said that more gardeners grow tomatoes than any other vegetable. Entire books have been written about growing tomatoes, but these 10 tips will fast-track you to tomato-growing success. Wondering about how to grow tomatoes in Arizona, the low desert and other hot climates? Keep reading, there is plenty of information for you too!

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How to grow tomatoes in Arizona - 10 tips for growing tomatoes #tomatoes #arizonagardening #howtogrowtomatoes

10 Tips for How to Grow Tomatoes

Tip #1 for Growing Tomatoes: Choose a tomato variety suited for your tastebuds and climate

Decide which type of tomato you want to eat. Different types of tomatoes are suited for eating fresh, canning, making salsa, or cooking

For the best chance of success, choose a type of tomato suited to your climate as well. Because of the heat of Arizona summers, we have a short growing season. Look for plants with a short (60-90) days to maturity. These are often types with small to medium fruit or Roma or paste varieties. Varieties highly recommended for desert climates like Arizona include Punta Banda, Celebrity, Pearson, and Cherokee Purple. 

Different climates have other considerations and growing conditions. Ask a local grower for varieties that do well in your area.

How to grow tomatoes in Arizona - 10 tips for growing tomatoes #tomatoes #arizonagardening #howtogrowtomatoes

Tip #2 for How to Grow Tomatoes: Plant tomatoes at the correct time

To give tomato plants the best chance for success, plant tomatoes right after the last spring frost date. For the low desert of Arizona, this is usually around February 15th Once planted, if necessary, protect plants from cold nighttime temperatures. Plant tomatoes in the morning, so tomatoes have the day to settle in before cooler nighttime temperatures. 

There is a second (monsoon) planting window for planting tomatoes in the low desert of Arizona at the end of July through mid August. Once planted protect plants from high daytime temperatures with shade cloth. Plant tomatoes in the evening, so tomatoes have the cooler evening to settle in before hot daytime temperatures. 

Tomatoes grow best in temperatures of 70℉ to 90℉ with nighttime temperatures consistently above 55℉. In Arizona, you want tomatoes to flower and set fruit before it gets too hot. Once temperatures reach 90℉, tomato pollen is not viable. Fruit that has set will continue to mature, but new fruit will not set if pollen is not viable. 

How to grow tomatoes in Arizona - 10 tips for growing tomatoes #tomatoes #arizonagardening #howtogrowtomatoes

Tip #3 for Growing Tomatoes: Plant tomatoes in the right location

  • The most important requirement for productive tomatoes is plenty of sunshine.
  • Give tomatoes full sun for the entire plant with adequate growing space around each plant for air circulation.
  • Allow 2 feet between each plant for healthy and productive plants.
  • Do not plant tomatoes in the same location year after year. Rotate the location to prevent build-up of disease in soil.  
How to grow tomatoes in Arizona - 10 tips for growing tomatoes #tomatoes #arizonagardening #howtogrowtomatoes

Tip #4 for How to Grow Tomatoes: Prepare soil correctly

Tomatoes prefer well-drained loam, which is a mix of sand, silt and clay. Good drainage is important as an area with standing or puddling water invites disease. Tomatoes need soil rich in organic matter; make a habit of amending your soil with compost. Prepare your soil correctly and your plants will thank you. If you are growing tomatoes in raised beds, this article talks about the best soil for raised beds

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Tip #5 for Growing Tomatoes: Plant tomato seedlings deeply

Planting deeply encourages a more extensive root system and a healthier plant.

  • Remove the bottom 2/3 of leaves on the tomato transplant.
  • Dig a shallow trench or deep hole (depending on depth of planting bed) and plant transplant so that only top leaves are above the ground.
  • Roots will grow along the entire stem of the plant.
  • Bear in mind that after planting the tomato, plants may appear to do nothing for a bit- but they are growing roots.
How to grow tomatoes in Arizona - 10 tips for growing tomatoes #tomatoes #arizonagardening #howtogrowtomatoes
Tomato transplant with intact leaves
How to grow tomatoes in Arizona - 10 tips for growing tomatoes #tomatoes #arizonagardening #howtogrowtomatoes
Pinch off all leaves below the top leaves
How to grow tomatoes in Arizona - 10 tips for growing tomatoes #tomatoes #arizonagardening #howtogrowtomatoes
Plant transplant deeply, leaving only top leaves above ground

Tip #6 for How to Grow Tomatoes: Mulch tomato plants well

Use compost, straw, leaves, or pine needles to reduce evaporation and insulate the soil from extreme hot and cold temperatures; soil will stay at a more even temperature. 

Mulching helps control weeds, and plants will not have to compete with weeds for water and nutrients. Most mulch ultimately becomes fertilizer as it decomposes into the soil around the plant.

Tip #7 for Growing Tomatoes: Water tomato plants correctly

  • Water early in the day to prevent excessive evaporation.
  • It’s best to water at the soil level so leaves do not get wet. Wet leaves encourage disease.
  • Water to a depth of at least 12 inches to encourage roots to grow deep in the soil to find nutrients and moisture. 
  • Water slowly and deeply.
  • Deep, extensive roots help plants withstand dry spells.
  • Water regularly as needed, but do not allow plants to become soggy as plant roots need oxygen.
How to grow tomatoes in Arizona - 10 tips for growing tomatoes #tomatoes #arizonagardening #howtogrowtomatoes

Tip #8 for How to Grow Tomatoes: Feed tomato plants

When planting, it’s important to provide a source of phosphorus (bone meal or rock phosphorus) and again as plants begin to bloom and produce fruit. Without proper fertilization, plants do not produce well and are prone to weeds (which invite pests and other diseases).

Once tomatoes set fruit feed them every two-three weeks. Tomatoes do best with regular feeding from organic sources of fertilizer with a balanced supply of nitrogen, phosphorus, and potassium. Use a granular fertilizer like this one, or use a liquid fertilizer like this one

How to grow tomatoes in Arizona - 10 tips for growing tomatoes #tomatoes #arizonagardening #howtogrowtomatoes

Tip #9 for Growing Tomatoes: Provide support for growing tomato plants

It’s important to encourage tomatoes to grow vertically.

  • Growing tomatoes vertically keeps the plant upright, and prevents the stems from breaking from heavy fruit or wind.
  • Trellising tomatoes also keeps the leaves off the ground which helps reduce diseases.
  • Fruit is easier to harvest when it is off the ground as well. 
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The Vertex tomato cage from Gardener’s is a great option for trellising tomatoes. 

Tip #10 for Growing Tomatoes: Provide shade for tomato plants in extreme climates like Arizona

How to grow tomatoes in Arizona - 10 tips for growing tomatoes #tomatoes #arizonagardening #howtogrowtomatoes
Provide shade for tomatoes in extreme heat

Your plants may need a little help to get through a long, hot summer in the low desert of Arizona.

  •  Shade can reduce the air temperature for tomatoes by several degrees, and it also extends the growing season.
  • Providing shade in desert climates helps reduce stress on tomato plants, and can prevent sunscald on ripening tomatoes.
  • Shaded tomato plants are more likely to survive the extreme heat of the desert, and may perform better when cooler temperatures return in the fall.
How to grow tomatoes in Arizona - 10 tips for growing tomatoes #tomatoes #arizonagardening #howtogrowtomatoes
Sun scald on tomatoes

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How to grow tomatoes in Arizona - 10 tips for growing tomatoes #tomatoes #arizonagardening #howtogrowtomatoes
How to grow tomatoes in Arizona - 10 tips for growing tomatoes #tomatoes #arizonagardening #howtogrowtomatoes
How to grow tomatoes in Arizona - 10 tips for growing tomatoes #tomatoes #arizonagardening #howtogrowtomatoes
How to grow tomatoes in Arizona - 10 tips for growing tomatoes #tomatoes #arizonagardening #howtogrowtomatoes

Want more information about gardening in Arizona? This blog post shares 7 tips for  how to grow a vegetable garden in Arizona

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25 Comments on How to Grow Tomatoes in Arizona – 10 Tips for Growing Tomatoes

  1. Is it possible to plant tomato seeds (a desert variety of cherry tomatoes) directly into outside containers now – late July / early August in AZ, or is it too late? Thanks!

    • Tomatoes do best started from transplant outdoors. That being said, I’ve had several volunteer tomato plants sprout from seed throughout my garden through the years. Keep the seeds germinated until they sprout and give it a try.

    • The nice thing about raised beds is they have good drainage which is a great way to prevent root rot. Adding organic matter also helps with root rot. If you have root rot, let soil dry out and dispose of damaged plants.

  2. I stared my tomatoes indoor… as the seedlings started growing I notice that at the bottom of the leaves they had a purple color… has this happened to you??

    • Purple leaves are a sign of a phosphorus deficiency. Feed them with a diluted seaweed emulsion fertilizer.

  3. Hi, Angela! I love your site. As an AZ gardener, it’s great to have your site since our climate is so different. I’m wondering at what predicted nighttime temp do you cover tomatoes at night?

  4. We have some bigger plants from costco in the larger black containers. Can they be grown for the season in those – or – can they be transplanted to another pot? (larger – not black) … or is it really best to find a spot and dig up the grass to plant? The way our yard is laid out, leaving them in pots would work best for us. Thoughts?

    • I would plant them in larger containers. The more soil and water they have access to the better. Use good potting soil.

  5. I have worms inside my raised beds can I add fish liquid fertilizer to my tomatoes or will it kill the worms ??

  6. We bought tomato plants and have transplanted them to containers. I read th.at removing the blossoms will let the plant focus on root development, so that is what I did. Now we are going to hit the 90’s this week! Have I destroyed our ability to get tomatoes until the fall?
    Can we try indoor growing under grow lights for the summer and get fruit? I’m not finding answers so far with web browsing

    • Until we are consistently hot tomatoes will continue to set fruit. We still have several weeks (hopefully!) before temperatures are too hot for tomato pollen.

  7. I planted small plants in February they’re blooming but not setting. I’ve grown Tom’s for years this has never happened before. What am I missing?

    • That’s frustrating. We’ve had strange weather this spring for sure. Give the blossoms a little tickle to distribute the pollen. Hopefully they will set soon. Today’s wind may help 🙂

  8. Hi Angela, thank you so much for all you do!

    In Phoenix, for the tomatoes (and peppers) transplanted back in Feb and Mar, can we just let those hang out in the garden until July and Aug if they are still alive. Or is it best to cut them off at the base, after they stop producing, and replant new ones in in July/Aug?

    Thanks so much!

    • If they are still alive and look relatively healthy, absolutely. Often most of mine are a little worse for wear after our long summers and I replant. If you leave them in place, give them a good trim, a good dose of fertilizer (https://amzn.to/34CBOLP) and a good drink of water.

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