4 Simple Ways to Prevent Tomato Rot From Ruining Your Harvest

4 Simple Ways to Prevent Tomato Rot From Ruining Your Harvest

When growing your own tomatoes, one of the most common problems you may encounter is blossom end rot. All seems well while you’re watching those tiny fruits grow larger by the day and slowly ripen. But then you notice a soft spot on the bottom side of a tomato that turns black. Blossom end rot has struck. Tomato lovers take heart, this isn’t the end of the story. Sure, you may have to toss already affected fruit into your compost pile. But still developing tomatoes on healthy plants can become perfect slicers for your next BLT with these four tips.

blossom-end rot on immature tomatoes on plant

What causes blossom end rot?

The culprit of blossom end rot in tomatoes is not a bug or a disease. This tomato problem, also known as bottom rot, is caused by a lack of calcium brought on by dry conditions. Tomato plants need calcium in all actively growing parts, from the roots to the fruits. Calcium is transported from place to place by water. When water is in short supply, such as during a drought, calcium can’t get all the way from the roots to developing fruit so blossom end rot occurs.

Maybe you’ve heard of calcium-boosting home remedies like planting your tomatoes with antacid tablets or egg shells in the holes to avoid blossom end rot. While these items won’t hurt your plants, it’s not likely to make much of a difference because most soil has plenty of calcium already. The bigger issue is not enough water to move the calcium to the fruit. However, a soil test will reveal if calcium or other essential plant nutrients are lacking.

The first tomatoes of the season are most susceptible because all parts of the plant are rapidly growing so calcium is in high demand. As the plant moves calcium up from its roots, stems and leaves will use it up first, so occasionally there won’t be enough left for the ripening fruit, resulting in black, mushy blossom end rot.

How to Prevent Blossom End Rot

The bright side of blossom end rot is that it’s not a disease that spells the end of your much anticipated tomato harvest. It’s not contagious; a symptomatic tomato will not “share” the problem with a neighbor. No chemical control, such as fungicide, is effective. This type of tomato rot is simply a condition that usually resolves when your plants get consistent soil moisture. Use these 4 tips to help prevent blossom end rot.

1. Keep tomato plants well watered.

Tomatoes grow best with about an inch of water a week from rainfall or irrigation. Supplement rainfall when needed by watering with a soaker hose or a watering can. This is especially important when growing tomatoes in containers, where they tend to dry out faster.

Test Garden Tip: To discourage leaf diseases, avoid getting foliage wet as you water. Yes, rain will obviously get your plants wet, which does help diseases spread. The more you can keep leaves dry, the better.

2. Add mulch around tomato plants.

Spread a 2-inch-thick layer of organic mulch around the base of your plants. Materials such as straw, grass clippings, chopped leaves, or shredded bark all work well. Mulch helps the soil retain moisture, so your plants won’t dry out as fast between waterings or rains. Plus, it helps smother weeds.

3. Don’t over fertilize.

Too much fertilizer can cause plants to grow faster than they can get calcium to where they need it for healthy growth. Fast growth can lead to blossom end rot. The best way to boost soil nutrients is to add a 2-inch-thick layer of well-decomposed compost to the soil prior to planting in spring. The compost will slowly release nutrients and improve the soil structure at the same time. Only apply fertilizer if recommended by a soil test, and make sure to follow label directions exactly.

4. Care for the roots.

Roots are essential for absorbing the calcium that prevents blossom end rot. Avoid disturbing a tomato plant’s root zone so it can absorb maximum calcium. Avoid hoeing and digging in a plant’s root zone and keep weeds at bay with a layer of mulch.

Most Popular Flowers & Plants in the USA

RegionPopular FlowersPopular Plants
Northeast (e.g., New York, Massachusetts)Rose, Purple Lilac, Mountain LaurelSugar Maple, American Elm, White Pine
Southeast (e.g., Florida, Georgia)Orange Blossom, Cherokee Rose, Southern MagnoliaLive Oak, Spanish Moss, Saw Palmetto
Midwest (e.g., Ohio, Illinois)Carnation, Violet, Purple ConeflowerBur Oak, Prairie Grasses, Wild Bergamot
Southwest (e.g., Texas, Arizona)Bluebonnet, Saguaro Cactus Flower, Indian PaintbrushJoshua Tree, Agave, Mesquite
West (e.g., California, Washington)California Poppy, Coast Rhododendron, BitterrootGiant Sequoia, Redwood, Manzanita
Rocky Mountain (e.g., Colorado, Montana)Rocky Mountain Columbine, Bitterroot, Indian PaintbrushBlue Spruce, Aspen, Sagebrush
Great Plains (e.g., Kansas, Nebraska)Sunflower, Goldenrod, Purple ConeflowerCottonwood, Bluestem Grasses, Buffalo Grass
Pacific Northwest (e.g., Oregon, Alaska)Oregon Grape, Forget-me-not, Pacific RhododendronDouglas Fir, Western Hemlock, Ferns

This table includes the most popular flowers and plants in the USA by region, which considers a range of botanical species, including native and widely cultivated varieties.

Most Popular Flowers & Plants in Australia

RegionPopular FlowersPopular Plants
New South WalesWaratah, Bottlebrush, Flannel FlowerEucalyptus, Acacia, Banksia
VictoriaCommon Heath, Waxflower, Pink HeathMountain Ash, Silver Wattle, Victorian Blue Gum
QueenslandCooktown Orchid, Golden Penda, Umbrella Tree FlowerMoreton Bay Fig, Macadamia Nut, Queensland Bottle Tree
South AustraliaSturt's Desert Pea, Kangaroo Paw, Eucalyptus BlossomAdelaide Blue Gum, South Australian Blue Gum, Saltbush
Western AustraliaRed and Green Kangaroo Paw, Mangles Kangaroo Paw, Swan River DaisyJarrah, Marri, Karri
TasmaniaTasmanian Blue Gum, Leatherwood Flower, Tasmanian WaratahHuon Pine, Tasmanian Oak, Myrtle Beech
Northern TerritorySturt's Desert Rose, Frangipani, Desert RoseBoab, Gidgee, Spinifex
Australian Capital TerritoryRoyal Bluebell, Australian Daisy, CorreaSnow Gum, River Red Gum, Black Mountain

This table offers a basic overview of popular flowers and plants in each Australian region, focusing on a combination of state flowers, native species, and other characteristic plants. It's important to note that specific species' popularity and prevalence can vary. This table is a simplified representation. Consulting local botanical gardens or regional horticultural societies in Australia would be ideal for more detailed and accurate information.

Charlotte Gammon

By Charlotte Gammon

Meet Charlotte Gammon, our expert and author. She's our true treasure, as she has got 20+ years of experience in gardening, winery and house design. In early 2000s, she worked for today.com magazine and was in charge of the gaardening section. Later on, Charlotte opened her own designer agency and worked as a designer and decorator. We are happy to have Charlotte with us, as she is our good friend. We value her experience and we're sure you will love the articles she created for our blog.