dragonlady
Newly Registered
Posts: 5
Joined: Wed May 30, 2007 3:18 pm
Location: SOUTHWEST ONTARIO CANADA

Black spots on bottom of tomatoes

Growing beefsteak tomatoes in containers. One plant's tomatoes has black spots on the bottom. Is this a calcium deficiency? If so, how do I remedy it? Will diluting milk with water and using this help? And also, are these tomatoes worth saving?

User avatar
Jess
Greener Thumb
Posts: 1023
Joined: Mon Mar 19, 2007 7:50 pm
Location: England

Hi dragonlady :D

Could be "blossom end rot" depending on which end of a tomato you call the bottom. :lol:
Google for info to see if this is what they are suffering from as there is lots about this problem online.

opabinia51
Super Green Thumb
Posts: 4659
Joined: Thu Oct 21, 2004 5:58 pm
Location: Victoria, BC

We come across this question each year, this is definately blossom end rot. The way to combat the problem is to

a) place crushed eggshells in the soil around your plants (or bone meal)

b) Use a calcium spray (available from any local nursery) and spray undamaged tomatoes with the spray.


The reason being is that the fungal infection that insues during blossom end rot is brought on by a calcium deficiency in the soil.

The short term solution would be the spray but, to nip the prolem in the bud, place crushed eggshells in the soil where you intend to grow your tomatoes.

Inamon
Full Member
Posts: 59
Joined: Wed May 16, 2007 8:30 am
Location: PA, USA

opabinia51 wrote:The reason being is that the fungal infection that insues during blossom end rot is brought on by a calcium deficiency in the soil.
Blossom end rot is caused by a calcium deficiency. This leaves soft tissue that often is infected by fungal spores, often resulting of total loss of that particular fruit.
End rot is a totally physiological condition occuring most often in the early fruit. Mostly due to calcium deficiency but can also occur because plant has been hardened to fast, weather conditions are cooler during early growth (sometimes in late cooler summers).

"If your calcium is off add limestone (for acid soils with a pH below 6), or gypsum when the soil pH is in the 6 to 7 range. If calcium levels are okay, the next most important control is to maintain optimum soil moisture. When tomatoes experience the slightest bit of drought, BER may result. Using mulches will usually significantly decrease BER as excessive evaporation from soil is reduced. If growing on bare ground, avoid cultivating too close to plants to prevent root damage and the need to maintain deep root development. Varieties will vary in their susceptibility so if you have a problem with a particular variety, choose a new one next year. When side-dressing plants, using a nitrate type fertilizer like calcium nitrate is preferable to ammonium based ones like urea. Finally, don't bother to use calcium sprays. They are worthless in combating the problem. The same problem can occur on pepper and eggplant." As per Thomas A. Zitter, Professor, Department of Plant Pathology, Cornell University, Ithaca, NY, and Steve Reiners, Associate Professor, Horticultural Sciences, NYSAES, Geneva, NY

Good luck :D

opabinia51
Super Green Thumb
Posts: 4659
Joined: Thu Oct 21, 2004 5:58 pm
Location: Victoria, BC

Thanks Inamon!



Return to “TOMATO FORUM”