Lime in potted tomato plants

[gratiotknight]

I have tomato plants in large pots. I used dolomite lime in the soil, and put more in when the plants initially blossomed about a month later.
Should I add more once again, and if so...when?

 

[Chuck]

I have tomato plants in large pots. I used dolomite lime in the soil, and put more in when the plants initially blossomed about a month later.
Should I add more once again, and if so...when?

What is the original soil? Potting soil, compost....what? Potting soil and compost, if commercially made, is usually close to neutral Ph, or 7. By adding lime you will raise the Ph of the soil. Why are you adding any lime at all? Tomato plants do best in slightly acidic soil, about 6.8 or 6.9. What are you fertilizing with and what is the NPK of this fertilizer

 

[gratiotknight]

What is the original soil? Potting soil, compost....what? Potting soil and compost, if commercially made, is usually close to neutral Ph, or 7. By adding lime you will raise the Ph of the soil. Why are you adding any lime at all? Tomato plants do best in slightly acidic soil, about 6.8 or 6.9. What are you fertilizing with and what is the NPK of this fertilizer

Potting soil. I've added the lime to prevent blossom end rot, which has happened in the past.

 

[Chuck]

Potting soil. I've added the lime to prevent blossom end rot, which has happened in the past.

Dolomite lime is about 20% calcium and Blossom End Rot is caused by either a deficiency of calcium or a plants inability to uptake calcium. If you add lime at time of planting and again when plant is blooming that should be more than enough calcium. Have you tried sprinkling a big handful of Epsom Salts around the base of the plant. My soil is extremely alkaline with an overabundance of calcium and ES works very well for me. What are you fertilizing with? You need NPK and trace minerals.

 

[gratiotknight]

I've read potted plants lose fertilizer and lime through the constant watering. Wasn't sure if the two rounds of the lime would last due to watering them so much.
How much lime is effectively too much, then?

 

[Chuck]

I've read potted plants lose fertilizer and lime through the constant watering. Wasn't sure if the two rounds of the lime would last due to watering them so much.
How much lime is effectively too much, then?

Impossible to say exactly but I will say this. Organic fertilizer molecules are positively charged and synthetic fertilizer molecules are negatively charged. Soil molecules are negatively charged. Organic fertilizers are attracted to soil. That is, the molecules of the fertilizer are attracted to and adhere to the soil molecules, thus making organic fertilizers much less susceptible to leaching away. You can research this if you want by just googleing Cation Exchange Capacity. If you are using organic fertilizers you probably have enough calcium when you added it the first time and more than likely a second application is superfluous. That is why I wanted to know what you are fertilizing with and its NPK value. If you are using synthetics all I can do is give you a semi-educated guess as I never use synthetics but up until about 30 years ago synthetics was all we had and I had to use it then and way before that too.

 

[gratiotknight]

Soil and fertilizers miracle grow brand.

 

[Chuck]

Soil and fertilizers miracle grow brand.

Is it the product in the black bag? The Performance label?

 

[gratiotknight]

Miracle grow potting mix
Yellow with green lettering

 

[Chuck]

Miracle grow potting mix
Yellow with green lettering

That is synthetic. If it is what I am fairly sure it is, it is a very high nitrogen content plant food with a NPK of 24-8-16. This fertilizer has no calcium but the potting mix does have a very slight amount. Adding too much calcium will cause a magnesium uptake deficiency. In a large container I would add no more than a tablespoon of lime.