[lfouquette]

I have several kinds of heirloom tomatoes which are doing well, but many of my Cherokee Purples start rotting around the end opposite the stem before they get ripe. It's happening to the plants both in the greenhouse and outside beds. It isn't from lying on the ground, as fruits higher up are affected. The other varieties of tomatoes don't seen to be affected. Most of my plants (all varieties) are from seeds I saved from plants I grew last year.

Mudbug, I read that you have this variety. Any words of wisdom from anyone?

Thanks -- Lynne

[foodnfoto]

What you describe is known as "blossom end rot". It is caused by a fungus that grows in the soil. Often it occurs during very hot weather and when plants are watered in the evening or nightime. Extreme variations of moisture and temperature are the prime causes of this fungus. The cooler air at night, plus the added moisture allow the fungus a prime growing medium, thus affecting your plants. Heirloom plants also tend to be more susceptible to this problem. Hybrids tend to have resistence bred into them.
Strive to achieve a balance of moisture and temperature in your soil. You can also apply a fungicide on your soil (arghhh!) or water early in the morning when the plants will better absorb the water and strengthen for the heat of the day.
This fall, build up the strength of your soil through organic methods and work in natural anti-fungal elements (check with your favorite organic farmer or garden center.)
There is probably little you can do at this point in the season, though.

[mudbug]

Hi Lynne,

foodnfoto's response is good - although I'm not sure I completely agree with it being caused by fungus in the soil. It is the sign of a calcium deficiency. But simply adding calcium is not the answer. The plant has to have a balance of nutrients to be able to take up the calcium and use it optimally.

I personally have not had blossom end rot affect my Cherokee Purple's. There is very little you can do at this point other than to try to pick as close to possible when ripe while being able to enjoy healthy fruit and cut off the bottom. Prepare your soil with organic matter instead of fertilizers this fall, so it will be ready for planting in the spring. The healthier your soil, the healthier your plants will be.

Here is information on Blossom End Rot

[lfouquette]

Thanks to both of you! I have been watering in the mornings, but we have had very hot weather. The only thing I've used to ammend the beds is steer manure. I'll do a little research on calcium and what nutrients are needed along with it and call our extension office to ask about natural antifungals. Thanks for the great advice!
Lynne

[lfouquette]

Aha! I just read that to avoid blossom-end rot, one should "avoid ammoniacal forms of nitrogen that compete with calcium during uptake from the soil." (http://ianrpubs.unl.edu/horticulture/nf43.htm).

AND -- "Nitrogen is present in manure in a variety of forms, most of which gradually converts to ammonium and nitrate nitrogen." (http://www.ecochem.com/t_manure_fert.html).

SO perhaps steer manure isn't the best thing for my vegetables. I'm doing some research so find a more suitable ammendment. Thanks for your guidance!
Lynne

[mudbug]

Very interesting. Thank you for providing the further information.

So if you incorporate your manure in the fall, it should be more acceptable by spring.