The Sustainable Garden
Powered by
🍅 What's Wrong With My Tomatoes?
Every Tomato Plant Tells a Story
One day your tomato plants look beautiful...
The next, you notice yellow leaves.
Dark spots appear.
A tomato suddenly splits open after a rainstorm.
Sound familiar?
The good news is that most tomato problems aren't fatal. In fact, your plants are usually trying to tell you exactly what they need.
This week we're decoding those signals so you can spend less time worrying—and more time harvesting delicious tomatoes.
🌱 In This Week's Issue
Why leaves develop brown spots
What blossom end rot really means
Why tomatoes crack after rain
Easy ways to keep plants healthy all season
Simple prevention tips that save future harvests
🍃 Spotty Leaves?
Brown spots surrounded by yellow halos usually point to fungal diseases like Early Blight or Septoria Leaf Spot.
What causes it?
• Humid weather
• Water splashing soil onto leaves
• Poor air circulation
• Older lower foliage
What to do
✅ Remove infected leaves
✅ Water only at the base
✅ Mulch around plants to prevent soil splash
✅ Prune lower branches for better airflow
💡 Bloom Tip: Never compost heavily diseased tomato foliage.
🍅 Blossom End Rot
That black leathery spot on the bottom of a tomato isn't actually a disease.
It's usually caused by the plant being unable to move enough calcium into developing fruit.
Most often the culprit is:
• Inconsistent watering
• Drought stress
• Root damage
The Fix
Keep soil evenly moist
Add organic mulch
Avoid letting plants dry out between waterings
Your next tomatoes will often develop normally once watering becomes consistent.
🍂 Why Are My Leaves Turning Yellow?
Yellow leaves can have several causes.
Check these first:
✔ Too much water
✔ Too little water
✔ Nitrogen deficiency
✔ Poor drainage
✔ Natural aging of lower leaves
Feed with a balanced tomato fertilizer every 3–4 weeks, but don't overdo nitrogen or you'll grow lots of leaves and very few tomatoes.
🍅 Why Did My Tomato Split?
Few things are more frustrating than seeing a nearly perfect tomato crack overnight.
This usually happens after:
Heavy rain following dry weather
Deep watering after drought stress
Rapid fruit growth
Prevent cracking
Water consistently
Mulch 2–3 inches deep
Harvest ripe tomatoes before major storms if possible
Even cracked tomatoes are perfectly edible if used quickly.
🌿 Five Habits of Healthy Tomato Plants
💧 Water Consistently
Deep watering on a regular schedule encourages strong roots.
🌿 Feed Regularly
Use a balanced tomato fertilizer every 3–4 weeks during the growing season.
✂ Improve Airflow
Prune lower leaves and avoid overcrowding plants.
🌾 Mulch Well
Organic mulch keeps soil cooler, reduces evaporation, and helps prevent disease.
🔎 Check Often
A quick weekly inspection catches small problems before they become major ones.
🌼 Bloom Gardens Tip of the Week
Healthy tomatoes aren't the result of luck.
They're the result of consistent care.
Small improvements—watering on schedule, improving airflow, and keeping the soil healthy—can make the difference between a few tomatoes and baskets full of them.
📚 Learn More
Looking for more practical gardening tips?
Explore our growing collection of:
Vegetable gardening guides
Water-wise landscaping ideas
Native plants
Sustainable gardening practices
Mountain West gardening resources
Visit BloomGardens.org
Trouble viewing Bloom Gardens Magazine? Go to: https://bloomgardens.org/magazine/summer-2026/
Featured in this Issue:
*Woodstuff Landscape Supply
955 S 1950 W Springville Utah 84663
(801) 489-4777
Click on Ad to enlarge
July Tips & Checklist
Start enjoying the tomato harvest.
Fertilize potatoes with nitrogen in early July.
Harvest summer squash and zucchini when they are still small and tender.
Deep water established trees and shrubs about once a month during the heat of summer.
Deadhead (cut off) spent blossoms of perennial and annual flowers.
Divide crowded iris or daylilies once they have finished blooming.
Visit alpine areas for wildflower displays.
Remove water sprouts (vertical shoots in the canopy) on fruit trees to discourage regrowth.
Renovate perennial strawberry beds by tearing out old crowns (mother plants) and applying fertilizer to stimulate new runners.
Remember that turfgrass only needs 1½ to 2 inches of irrigation per week. Learn about irrigation needs in your area.
Pests and Problems:
Check under leaves of pumpkins, melons, and squash plants for squash bugs.
Watch for mosaic virus in vine crops, such as cucumbers and watermelons, and remove infected plants to reduce spreading.
Watch for holes from tobacco budworm feeding in the leaves of petunias, nicotiana, geraniums, and other annual flowers.
Protect black locust trees (not honey locust) with a registered chemical to prevent locust borer damage.
Control codling moth in apples and pears to reduce wormy fruit. For specific timing see our Utah Pests Advisories.
Control walnut husk fly in walnuts, peaches, and apricots, typically on August 1st and 15th.
Learn how to identify a hobo spider.
Control European paper wasp with traps this time of year.
Monitor for damaging turfgrass insects.
The Sustainable Garden Newsletter is provided by Bloom Gardens
Happy Gardening!
Ramona
Bloom Gardens www.bloomgardens.org
