How Do I Stop My Tomatoes from Cracking?

How do I stop my tomatoes from cracking? There are several ways to end this problem.

“Stop my tomatoes from cracking! Last year even though the weather was optimal with sun and rain my cherry tomatoes continued to split as they grew and most were not edible as the bugs got into them as soon as they split. Is there a way to stop them from splitting like that?” Question from Sylvia of Belle Plaine, Minnesota

Answer: There are several things that you can do. Let me start by explaining what causes tomato splitting. Splitting occurs when a tomato is ripe and full of natural sugars and then it rains significantly. Tomato plants take up water fast, and due to a natural process called osmosis, the water is attracted to the plant parts with the most sugar–ripe fruits. So essentially, those sugary tomatoes fill up with too much water too fast and split. Here are the three best solutions to keep this from happening.

Ways to Stop My Tomatoes from Cracking

1. Choose crack-resistant tomato varieties. Some tomatoes either naturally resist cracking or were bred to be crack-resistant. The sweet cherry tomatoes ‘Ladybug‘ and ‘Jasper‘ are just two of many that are reliably crack resistant. You may see a crack here and there, but they are infrequent when compared to average cherries. ‘Baby Cakes’ salad tomato is tasty and both crack- and disease-resistant. And ‘Big Rainbow’ is a beautiful heirloom with great taste and crack resistance. And, if you like delicious orange slicers, ‘Chef’s Choice Orange‘ cannot be beaten for flavor and crack resistance. These are just a few of many options.

2. Give your tomatoes maximum drainage. Amend your vegetable garden soil well, and berm it up in your tomato beds to facilitate the best drainage possible. Excellent soil drainage will keep your tomatoes from taking up as much water as fast. Our best vegetable garden soil amendments include Black Gold Canadian Sphagnum Peat Moss, Garden Soil, and Garden Compost Blend. Till these in and then rake up the bed areas into wide berms where you plant your tomatoes. (Click here to read our top 10 essential tips for vegetable gardening success for more bed prep tips.)

3. Pick tomatoes just before they are fully ripe. If you pick tomatoes just before they are fully ripe and allow them to ripen in a bag or on a windowsill, you can avoid the cracking problem. Slightly underripe tomatoes lack the full-sugar load that causes cracking.

For further tips on growing beautiful tomatoes, I recommend you watch our video about growing tomatoes from seed to harvest below.

Happy gardening,

Jessie Keith

Black Gold Horticulturist

Overwintering Outdoor Ceramic Containers

With 150+ potted containers throughout my garden, it is important that I overwinter them well. Living on the relatively mild western slope of Oregon’s Willamette Valley, our winters do not compare with those in colder parts of the country, but we do get freezing temperatures. Almost every winter, we will have some nights when the temperatures dip into the low 20’s and sometimes into the high teens. While we also have our fair share of rain during the winter months, we often get a few days of snow and ice, which can wreak havoc on containers.

Protecting Wintering Containers

This snow-covered Italian Terracotta flower pot will likely weather through the winter.

Plants in containers are exposed to the elements more than those in the ground. Pots do not offer roots as much insulation or protection, but each is different in its protection and durability, whether glazed ceramic, concrete, plastic, Terracotta, or stone.  (In this article, we will cover ceramic pots, which are what I use.) Just like the hot summer sun can quickly dry soil in a container, especially with Terracotta pots, cold temperatures, and winter wind can freeze the soil. The ice expands, and as it does, it often has enough force to crack certain pots, especially if the soil is moist.

The question is, what ceramic containers endure winter cold without cracking? In our climate, it would be very unusual for a container not to have soil wet from the winter rain and then potentially freeze. So, having the right container is an important necessity.

Over the years, I have learned through trial and error what pots work. The conclusions that I have reached are not scientific but based on my own experience in dealing with different types of pottery from different places. Some behave poorly outdoors and are better reserved for indoor plantings.

Pots for Indoor Use

Mexican pottery is fantastically pretty but cracks easily outdoors in freezing winters.

First, bear in mind that some manufacturers add elements to their clay to make pots more winter hardy, and some don’t. Thickness and firing temperature can also help prevent cracking. Generally, I have found that Terracotta-based Mexican pottery, glazed or unglazed, will not survive a cold winter without cracking. Likewise, most pottery from China is variable, but the thin pots tend to crack. Some of the most beautiful pottery that I have seen is from Thailand, but it tends to be thin-walled and is poor for outdoor planting.

Thin-walled ceramic pots tend to crack while thicker-walled pots don’t.

We do have some pots from Thailand in our garden, though. These tend to have unique designs and colors and create much interest from visitors. We use Thai pots as pieces of garden art with nothing planted in them. There are holes in the bottom for the rain to drain through, so there is no concern about cracking.

If you choose to grow summer annuals in pots that are not reliably frost-proof, take out the soil when you remove the annuals. Or, if your containers are mobile, move them into a garage to protect them.

Pots for Outdoor Use

Thick-walled, high-fired Vietnamese pottery survives the winter very well for me.

Containers from Italy seem to go through our winters just fine, but those that consistently weather through without cracking are from Vietnam. In our area, the Vietnamese pots sold in local garden centers are thick-walled, highly glazed and fired, very heavy, and frost proof. I have some pots from Vietnam on our deck that we have had for 15 plus years, and they have never cracked. These pots are exposed to winter winds, rain, freezing; they have no protection from the elements.

Thick, high-fired Italian pottery also withstands winter cracking better.

Another important factor when a purchasing pot is getting the right pot for the right location. Check the selection of winter-hardy pots at your local garden center for colors, sizes, and styles with good thickness, high fire, and thick glaze. I have found that the right colorful containers scattered throughout the garden are permanent additions that also serve as garden art.

Microclimates play a role, too. Try to protect your outdoor pots through winter by placing them below overhangs or patios close to the house. Not only can this further help protect them from cracking, it helps the shrubs or perennials they hold.