Arizona Garden in March
March is a transition month in the low desert garden—cool-season crops are wrapping up, fruit trees are setting fruit, and warm-season planting is in full swing. Pruning frost-damaged plants, thinning fruit trees, and pulling weeds before they go to seed are just some essential tasks to keep your garden thriving before temperatures climb.
This is also one of the most beautiful months of the year in the garden. Wildflowers bloom, citrus trees are fragrant with blossoms, and mild temperatures make it the perfect time to enjoy your outdoor space. Many local gardens offer spring garden tours this month—these are a great way to see what’s thriving in Arizona landscapes and gather ideas for your garden.
Whether tending to fruit trees, refreshing raised beds, or planning your warm-season crops, this month’s garden checklist will help you stay on track.
Note: The low desert includes elevations below 3,500 feet in the Southwest, such as the Phoenix and Tucson metro areas.
“Spring makes its own statement, so loud and clear that the gardener seems to be only one of his instruments, not the composer.”
Geoffrey Charlesworth
Click on the title to jump to that section and learn more about what to do during March:
- March YouTube Videos
- Vegetable Gardening Tasks for March
- My March Garden Journals
- Garden Pests in March
- Container Gardening Tasks
- Flower Gardening Tasks
- Caring for Roses During March
- Herb Gardening
- Fruit Trees, Berries, and Citrus
- Landscape Plant Tasks During March
- Watering Your Garden and Landscape
March YouTube Videos:
Vegetable Gardening Tasks for March
March is a busy month for vegetable gardening in Arizona. While cool-season crops are finishing up, it’s time to prepare beds, maintain healthy soil, and establish warm-season crops before summer’s heat arrives.
If you’re wondering what to plant this month, check out my What to Plant in March blog post and my Arizona Planting Calendars for a complete guide.
Prepare Garden Beds for Spring Planting
A successful spring garden starts with healthy, nutrient-rich soil. March is a great time to refresh garden beds:
- Add compost and organic matter to improve soil structure and fertility.
- If your soil level has dropped, that’s a good sign—it means organic material has broken down and fed your plants. Now, top up your beds with worm castings, compost, and a raised bed mix. I get all of those things from Arizona Worm Farm.
- For beds with existing plants, feed them by layering compost and worm castings over the mulch, then water deeply to soak it in.
- Consider soil testing at least once a year to monitor nutrient levels and soil health. I use this soil test kit from Amazon. Add a balanced organic fertilizer if needed based on your soil test results.
For more soil-building tips, check out my guide to preparing your soil for planting.
Vermicomposting: Natural Fertilizer for Your Garden
I don’t use much fertilizer in my garden because my worms do the work for me!
- In-bed vermicomposting is one of the easiest ways to create nutrient-rich compost right where your plants need it.
- Worms break down kitchen scraps into a powerful natural fertilizer, improving soil structure and microbial life.
- If you haven’t started vermicomposting yet, now is a great time to add a worm bin to your raised bed.
Learn more about how to add in-bed worm bins to your garden beds in my Composting with Worms Guide.
My March Garden Journals
Twice a month, I send my personal garden journal to members of “Growing in the Garden Academy.” From the first seedling to the last harvest, you can follow my gardening adventures in Arizona’s unique low desert. Access the past three years of garden journals and monthly classes as a member.
Garden Pests in March
As temperatures rise, stressed winter crops attract pests. Instead of treating infestations, it’s often best to remove struggling plants—cut them off at the base to leave roots in place for soil health. Keep bolting herbs like dill and cilantro to attract beneficial insects that help control pests naturally.
- Aphids love tender new growth, but ladybeetles, lacewings, and hoverflies will take care of them if given time. Companion planting with alyssum, marigolds, and nasturtiums can also help.
- Genista caterpillars on Texas Mountain Laurels cause some defoliation but usually don’t harm the tree. If needed, treat with Bt (Bacillus thuringiensis) while caterpillars are small.
- Companion planting supports natural pest control—flowers like alyssum and marigolds attract predatory insects, while basil and cilantro deter pests. Learn about more warm-season companion plants in this guide.
Container Gardening Tasks
If you’re growing vegetables in containers, remember they typically need more frequent watering than in-ground beds. March is also a great time to fertilize containers, especially if you’ve noticed slowed growth or pale foliage.
Choosing the Right Container Size
- Bigger is better—for tomatoes, peppers, and other larger plants, at least 10 gallons is ideal, but 20 gallons is even better.
- Larger containers retain moisture longer and provide more root space, leading to healthier plants.
- Need help choosing the right size? Check out my Guide to Container Sizes.
Feeding Container Plants
- Worm castings are an excellent organic boost for container soil. If you harvest from your garden beds, mix them into your containers to support healthy microbes and plant growth.
- No worm castings? This organic fertilizer works well for container gardening.
Watering Containers Efficiently
Because containers dry out faster, check moisture levels often and adjust your watering schedule as temperatures rise. Instead of watering daily, I use oyas to keep containers evenly hydrated with minimal effort.
What Are Oyas & How Do They Help?
- Oyas are porous clay pots buried in the soil and filled with water. The water slowly seeps out as the soil dries, delivering deep, steady moisture directly to plant roots.
- This means less watering, less evaporation, and stronger, deeper roots. Perfect for hot, dry climates.
- Prevent overwatering: Pop off the lid—if it’s empty or the water level is low, it’s time to water. If there’s still plenty of water inside, the soil has enough moisture.
Want to try oyas in your container garden? Click here to purchase oyas.
Flower Gardening Tasks
March is a spectacular month for flowers in the low desert, with wildflowers in full bloom and cool-season hardy annuals blooming.
Wildflowers & Perennials in Bloom
- Fall-planted wildflowers—including poppies, lupine, and blue flax—will continue blooming through much of March. Enjoy the show!
- Purple lilac vine is in full bloom now. This Australian native thrives in Arizona winters and looks beautiful on a trellis or as ground cover. Its glossy green foliage remains even after the flowers fade.
Sunflowers: Long Blooming & Heat-Tolerant
- Sunflowers can be planted from February through July, meaning you can enjoy their blooms nearly year-round.
- These bright, cheerful flowers add color and variety to any summer garden. For growing tips, check out How to Grow Sunflowers.
Making the Transition to Warm-Season Annuals
- Avoid planting new cool-season annuals—their growing time is short, and heat will stress them soon. Instead, plant warm-season annuals as they become available at nurseries. Keep seedlings thinned for better blooms.
- Want to know which flowers to plant this month? Check out my Flower Planting Guide and Arizona Flower Planting Calendar for the best options!
Caring for Roses During March
March is a key month for pruning, fertilizing, and planting roses to ensure strong growth and beautiful spring blooms.
- Prune & Clean Up: If you didn’t prune in January, do it now. Remove dead or damaged branches, thin weak growth, and clean up fallen leaves to prevent pests and disease. For younger roses, prune lightly.
- Fertilize: Once new leaves appear, start feeding. Use liquid fish emulsion for newly planted roses and granular organic fertilizer for established ones. Always deep-water before and after fertilizing.
- Plant New Roses: Container-grown roses can be planted now to establish before the summer heat. I get mine from Heirloom Roses—use code GARDENAZ20 for 20% off through 2025.
- Mulch for Healthy Growth: A 2-4 inch layer of compost or wood chips helps retain moisture, suppress weeds, and prevent disease as temperatures rise.
For more detailed rose care, check out my Rose Growing Guide.
Herb Gardening
March is the perfect time to harvest, prune, plant, and divide herbs while temperatures are still mild. Taking care of your herbs now will keep them healthy, productive, and ready for the warmer months ahead.
- Let annual herbs like dill, cilantro, and fennel bolt—their flowers attract pollinators, and you can save seeds for next season.
- Remove bolted cool-season crops by cutting them at the base. This leaves the roots in place to enrich the soil and prevent soil disturbance. Spent plants can be composted or fed to chickens.
- Trim back woody herbs like oregano, rosemary, and thyme by about one-third. This promotes fresh growth—if you see dead wood at the base, cut just above where new green growth is emerging. Learn more in my Oregano Growing Guide.
- Pinch back basil once it has several sets of true leaves to encourage bushy, healthy growth.
- Harvest chamomile flowers when the petals begin to fall back. Dry them for homemade chamomile tea—use one teaspoon dried or two teaspoons fresh per cup of water. Read my Chamomile Growing Guide for more details.
- Harvest lavender as buds begin to open. Cut early in the morning and dry in a cool, shaded place. For tips on growing lavender in warm climates, check out this guide.
- Divide mint or lemon balm if they’ve outgrown their containers—this prevents overcrowding and encourages healthy regrowth.
- Lemongrass grows fast, and a good spring pruning keeps it manageable and healthy. Cut it back to about a foot tall, removing any dead or dried-out stalks. If your lemongrass is overcrowded, you can also divide it now. Read my Lemongrass Growing Guide for more details.
Fruit Trees, Berries, and Citrus
March is an important month for planting, fertilizing, and pruning fruit trees while preparing for the upcoming growing season.
Planting Fruit Trees & Citrus
- March is a great time to plant fruit and citrus trees before the summer heat arrives.
- Choose low-chill varieties (less than 400 chill hours) that mature early and are self-pollinating. See my Fruit Tree Planting Guide for recommended varieties.
- For citrus, select the right variety for your space and taste preferences. Learn more in my Citrus Growing Guide.
- Blackberries and grapes can also be planted this month.
Thinning Fruit for a Better Harvest
- Thin fruit on deciduous trees when it’s smaller than an inch in diameter, about a month after full bloom.
- Leave 4-6 inches between each fruit—this prevents small, crowded, lower-quality fruit. See my Guide to Thinning Fruit Trees for more details.
Fertilizing & Feeding
- After bud break, fertilize deciduous fruit trees and citrus with an organic fertilizer.
- Fertilize blackberries with a balanced fertilizer.
- Water deeply before and after fertilizing to help nutrients reach the roots.
Pruning & Cleaning Up Trees
- If you haven’t already, prune deciduous fruit trees and clean up fallen leaves and debris to prevent pests and disease. Learn how to prune fruit trees in this guide.
- Prune grapevines before they begin to leaf out if you didn’t do it in February.
- For citrus, prune lightly—only remove dead, damaged, or crossing branches.
- Avoid over-pruning citrus! Keep lower branches intact to shade the trunk and prevent sun damage. For more citrus care tips, check out 10 Common Citrus Growing Mistakes.
Properly thinning, fertilizing, and pruning will set your fruit trees up for a strong growing season and a better harvest.
Landscape Plant Tasks During March
March is the time to prune, plant, and control weeds before the heat arrives.
Weed Control: Remove Stinknet Now
- Pull weeds before they go to seed—use a hula hoe or weed torch, and avoid chemical sprays.
- Watch for stinknet! This invasive weed spreads fast, chokes out native plants, and triggers allergies. Remove stinknet before it flowers and bag it—don’t compost it.
Prune & Clean Up Frost-Damaged Plants
- Trim frost-tender plants like hibiscus and lantana to encourage fresh growth.
- Shape evergreen trees and shrubs and remove dead branches from cold-hardy trees.
- Check if struggling plants are alive—scratch the bark. Green? Give it time. Brown? Replace it.
Planting Trees & Shrubs
- Plant cold-tolerant trees, bushes, and perennials, including frost-sensitive plants like hibiscus and lantana.
- Add summer-flowering shrubs, but space them properly to prevent overcrowding.
- Do not prune or fertilize newly planted trees or shrubs—let them establish first.
Fertilizing Landscape Plants
- Fertilize only established trees and shrubs—native plants usually don’t need it.
- Boost plant recovery with Nutrient+ from Arizona Worm Farm:
- Apply 1 cup per 3-foot tree height directly to trees and water well.
- Dilute 4:1 for smaller plants.
Watering Your Garden and Landscape
Consistent, deep watering is essential for helping plants establish strong root systems and preparing your garden for the warmer months ahead.
- Use watering grids in raised beds to ensure even moisture, no dry spots, and no wasted water. Since they’re connected to irrigation, it’s easy to adjust watering as temperatures rise.
- Check your irrigation system and timer—run the system, inspect drips and sprinklers for leaks, and ensure proper coverage.
I use the garden grids from Garden in Minutes in all of my raised beds. Use code Angela10 to save $10 off $100 or GITG5 to save 5 percent on any size order.
- Deep water landscape plants this month to prepare for summer and flush excess salts from the soil.
- Annuals will need more frequent watering as temperatures rise. Water to a depth of 6 inches, letting the top of the soil dry out before watering again.
- Containers dry out faster—check moisture levels with a meter or feel the top inch of soil before watering.
- Water citrus trees once every 2-3 weeks and fruit trees every 7-10 days.
Check out my Watering and Water Conservation Resources for more details on efficient watering.
Your whole blog is stunning! Thank you for the excellent, accurate information and beautiful photos!
That is kind of you to say! Thank you so much, I’m glad it has been helpful.
Are artichokes planted from seed or transplants… Where do I find them..Thank you for your information..Your gardens are stunning..
Thank you. You can plant from either depending on the time of year. It’s generally easiest to grow them from transplant.
I plant per your calendar, but I seem to miss the “harvest” dates. Where do I look for “harvest tips”? For example, I planted potatoes, when you said to do so, I think they are about ready, but I’m not sure when to harvest. The tops are starting to die, but with my new compost came aphids, so I don’t know if they are ready or aphids got to the leaves.
Good question. For harvest tips read the individual blog posts about each crop to learn the signs of harvest readiness. That will help you determine when to harvest. The days to harvest number on the seed packet can also be a guide to approximate time. Hope that helps. For potatoes, you can dig down and check the size of the tubers. Once the plants die back I usually wait about 2 weeks to harvest.
Hello Angela
Firstly, I want you to know that I enjoy immensely all your videos and newsletters! You are my garden earth angel.
If you have addressed this and I have missed it I apologize. But my question is when do you cut back ornamental grasses please? Is it also a good time to fertilize it a week or two after you cut them down?
Thank you so very much for all you do to help us formerly northern gardeners become Arizona gardeners successfully.
Best time to cut them back is late December when they go dormant. Cut back to 6-8 inches.