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Large cores

Posted: Fri Aug 02, 2024 9:26 am
by Vanman
All of my tomatoes this year have larger than normal cores. So far production is way down also and the plants are not nearly as "bushy" as usual. By this time they are usually a jungle. The only pruning we do is no limbs within about 15 inches of the ground and remove any diseased limbs.

Re: Large cores

Posted: Fri Aug 02, 2024 10:07 am
by karstopography
Explain or do you have a photo of a large core? I can’t ever remember having a tomato where an inedible or woody core extended very much below the stem scar. I generally cut a cone shaped section just beyond the margins of the stem scar and that takes care of most or all of the inedible parts. Tomatoes with cat facing and zippering also get a good amount of trimming. Late season tomatoes late in the season here can get some wider than typical stem scars.

Some flatter oblate tomatoes like dester I like to slice vertically right through the stem scar and then trim away the stem area on each half.

There are way at the end of my season a few nasty, deeply cracked, wrinkly, green shouldered, sunburnt that basically nothing is particularly edible, but those are rare outliers.

Re: Large cores

Posted: Fri Aug 02, 2024 10:14 am
by Ken4230
Vanman wrote: Fri Aug 02, 2024 9:26 am All of my tomatoes this year have larger than normal cores. So far production is way down also and the plants are not nearly as "bushy" as usual. By this time they are usually a jungle. The only pruning we do is no limbs within about 15 inches of the ground and remove any diseased limbs.
You are pruning just about the same way I do, I may be a little more aggressive because by the end of the year I have no leaves on the bottom 3' of my tomatoes. With all of the rain and heat we have endured, I'm thinking that we are lucky to have had any kind of successful garden. Even with all the rain, heat and critters my garden has been somewhat productive.


Thank goodness I staggered my plantings this year because my old faithful heirlooms are beginning to die back. Have a boatload of pruning to do eventually. I do have a dozen or so plants with a lot of small tomatoes on them.

Re: Large cores

Posted: Fri Aug 02, 2024 11:10 am
by Ken4230
karstopography wrote: Fri Aug 02, 2024 10:07 am Explain or do you have a photo of a large core? I can’t ever remember having a tomato where an inedible or woody core extended very much below the stem scar. I generally cut a cone shaped section just beyond the margins of the stem scar and that takes care of most or all of the inedible parts. Tomatoes with cat facing and zippering also get a good amount of trimming. Late season tomatoes late in the season here can get some wider than typical stem scars.
I have a few this year with some soft pale white extending down below the core about an inch or less. The white is V shaped and edible, at least to me. Mostly I have seen this on Better Boys and a couple of the other hybrids I grow. As far as the larger cores, I can't say because most of the tomatoes I grow have large cores anyway. Kentucky Cabin has a smaller core than the others. I'm just happy to have had a fairly successful garden this year.

I use the little serrated corer that is found where canning supplies are sold. Cheap and effective. Unless I am making a BLT I slice vertical and trim off any bad spots.

Re: Large cores

Posted: Fri Aug 02, 2024 12:13 pm
by Vanman
Ken4230 wrote: Fri Aug 02, 2024 11:10 am
karstopography wrote: Fri Aug 02, 2024 10:07 am Explain or do you have a photo of a large core? I can’t ever remember having a tomato where an inedible or woody core extended very much below the stem scar. I generally cut a cone shaped section just beyond the margins of the stem scar and that takes care of most or all of the inedible parts. Tomatoes with cat facing and zippering also get a good amount of trimming. Late season tomatoes late in the season here can get some wider than typical stem scars.
I have a few this year with some soft pale white extending down below the core about an inch or less. The white is V shaped and edible, at least to me. Mostly I have seen this on Better Boys and a couple of the other hybrids I grow. As far as the larger cores, I can't say because most of the tomatoes I grow have large cores anyway. Kentucky Cabin has a smaller core than the others. I'm just happy to have had a fairly successful garden this year.

I use the little serrated corer that is found where canning supplies are sold. Cheap and effective. Unless I am making a BLT I slice vertical and trim off any bad spots.
The soft pale white pretty much describes what I am seeing this year. Big Beef has it as well as the two SOO I have eaten so far. GGWT has it but not as bad as the others.

Re: Large cores

Posted: Fri Aug 02, 2024 12:22 pm
by Uncle_Feist
White flesh and large woody cores are caused by a potassium deficiency.

Re: Large cores

Posted: Fri Aug 02, 2024 1:12 pm
by Ken4230
Uncle_Feist wrote: Fri Aug 02, 2024 12:22 pm White flesh and large woody cores are caused by a potassium deficiency.
As much rain as I have had, there is no telling how many nutrients are now deficient in my raised beds and containers. I will have to do some heavy amending this fall. I've not seen any cores that I would consider woody and only a handful of the tomatoes have had the soft white below the core. Before the rain set in, I was already using a water soluble Bloom Booster. Once I figured out that the rain was here to stay I added a granular 13-13-13.
I have some really good compost that I intend to top off my beds with this fall.

Thanks for the heads up on that, did not know that specifically but I did know that rain was not good on raised beds.

Re: Large cores

Posted: Fri Aug 02, 2024 1:44 pm
by Seven Bends
This article from the Utah State University extension service https://www.heraldextra.com/lifestyles/ ... -tomatoes/ mentions these causes:
  • High temperatures during the ripening period
  • Problems with soil fertility and the fertilizer program
  • Insect damage
  • Some varieties are more prone to this problem
For fertility and the fertilizer program, they say it can be caused by:
  • Inadequate potassium (mentioned above by @Uncle_Feist)
  • High potassium combined with low nitrogen (nitrogen should be applied regularly in smaller doses rather than in large, infrequent doses)
Not sure why the article randomly starts talking about pomegranates, but the first part is about tomatoes.

I'm having trouble with cores in about half my varieties this year, when normally we get very little of it. We've had record high temperatures most of the summer, so I think that's the main problem. Fertilizer issues also could be a factor. We have good potassium levels in our soil and fertilized with a balanced fertilizer at planting but haven't fertilized since then due to the extreme heat and drought. The plants are very stressed.

One thing I've noticed this year is that some of the varieties develop a large, hard central core, and others develop a dispersed core that's like fingers or claws extending down into the tomato around the center, not in the center. Those are the worst -- very hard to remove.

Re: Large cores

Posted: Fri Aug 02, 2024 2:28 pm
by Uncle_Feist
Higher temps, drier conditions and the July sun intensity make it worse. Even if there are adequate K levels in the soil a plant stressed by inadequate soil moisture levels can't use it.

I had an older book about growing commercial greenhouse tomato crops in the 60's and it really stressed the importance of over applying potassium because of its importance in fruit quality.

Re: Large cores

Posted: Fri Aug 02, 2024 2:43 pm
by karstopography
Is there any way or any particular soil or region where the tomato grower can set up the soil with the necessary nutrients just prior to transplant time, but not do any subsequent fertilization and still expect to get quality tomatoes for the duration of the season?

I side dress granular and/or liquid feed and/or foliar feed my tomatoes periodically, especially as they begin to flower and set fruit. And it isn’t like I transplant the tomatoes into infertile soil.

Re: Large cores

Posted: Fri Aug 02, 2024 3:07 pm
by Uncle_Feist
When I was younger tomatoes were planted into a once fertilized row and allowed to sprawl and do their thing. We always had a huge crop for canning using that method.

I noticed the Veggie Boys channel on YouTube also let their plants sprawl, although on plastic mulch.

Re: Large cores

Posted: Fri Aug 02, 2024 3:11 pm
by Vanman
I have been guilty of under fertilizing this year. Time to apply more and hope to get better tomatoes later in the season.

Re: Large cores

Posted: Fri Aug 02, 2024 3:17 pm
by Ken4230
Seven Bends wrote: Fri Aug 02, 2024 1:44 pm This article from the Utah State University extension service https://www.heraldextra.com/lifestyles/ ... -tomatoes/ mentions these causes:
  • High temperatures during the ripening period
  • Problems with soil fertility and the fertilizer program
  • Insect damage
  • Some varieties are more prone to this problem
For fertility and the fertilizer program, they say it can be caused by:
  • Inadequate potassium (mentioned above by @Uncle_Feist)
  • High potassium combined with low nitrogen (nitrogen should be applied regularly in smaller doses rather than in large, infrequent doses)
Not sure why the article randomly starts talking about pomegranates, but the first part is about tomatoes.

I'm having trouble with cores in about half my varieties this year, when normally we get very little of it. We've had record high temperatures most of the summer, so I think that's the main problem. Fertilizer issues also could be a factor. We have good potassium levels in our soil and fertilized with a balanced fertilizer at planting but haven't fertilized since then due to the extreme heat and drought. The plants are very stressed.

One thing I've noticed this year is that some of the varieties develop a large, hard central core, and others develop a dispersed core that's like fingers or claws extending down into the tomato around the center, not in the center. Those are the worst -- very hard to remove.


I will gladly trade you 30" of rain for a month of your drought. :lol: Extension people are different from normal people, in my travels I've met some strange ones. We had an excellent one near-by until the tornado destroyed it a couple of years ago. Spent many a day there for seminars and Field Days. The only time I have seen woody cores was when a neighbor brought some over. The cores looked like the logs drying out at a sawmill. I think it's called checkering. If I remember right the cores were hard like wood.

No matter how long someone has done this, there's always someone with more and better information. I learn something just about every day that I didn't have a clue about.

Re: Large cores

Posted: Fri Aug 02, 2024 3:43 pm
by bower
Interactions between genetics and environment make it all crazy difficult to parse out, but it is a fact I've read time and again, potassium absorption is really sensitive to conditions. Stressful weather too hot, too cold, not enough light, too much light, pH to high, too low,... it goes on and on.
All we can really do is provide the basics and then try to simulate the goldilocks conditions or hope for it if we can't control.

Re: Large cores

Posted: Fri Aug 02, 2024 4:01 pm
by Ken4230
Uncle_Feist wrote: Fri Aug 02, 2024 3:07 pm When I was younger tomatoes were planted into a once fertilized row and allowed to sprawl and do their thing. We always had a huge crop for canning using that method.

I noticed the Veggie Boys channel on YouTube also let their plants sprawl, although on plastic mulch.
My grandparents had a 15-16 acre garden where they sold everything associated with a garden. I don't remember them ever tying up tomatoes. Grandpa had a couple of wagon loads of old growth Cyprus planks that was used to keep most of the tomatoes out of the mud. Cardboard was still pretty rare, so it was almost like gold. As we both got older I wound up with the job of laying the planks out. I think sprawling tomatoes are more productive even with the losses.

Re: Large cores

Posted: Sat Aug 03, 2024 12:29 am
by MissS
High doses of potassium or high doses of nitrogen can lead to larger cores.

Calcium and Potassium need to be balanced because they will fight with each other if there is too much of one or the other. High doses of potassium can also lead to a calcium deficiency which will cause blossom end rot.

Given this, it is best to have a soil sample done before your next planting. You can then learn what you need to do to balance out your soil and avoid this from happening next year.