Dealing with calcium in Antelope Valley soil
Calcium is a nutrient that is required in high amounts by plants. As we know, plants do not have bones. But what gives plants their strength is almost every plant cell is covered with a layer of calcium. In some cells, there are several layers of calcium. The strength of each cell combines to give the plants its strength.
The soil across the Antelope Valley is consistent, and in most cases, you can grow just about any plant that can climatically grow here. What we can find is there are areas of the valley that are very high in calcium. In fact, most of the valley is high in calcium.
A common visual characteristic of very high-calcium soil is that it is very light to white. These areas of high-calcium soil will form into a rock called limestone or caliche. In the rest of the Antelope Valley, if we dig a hole, we might see small white or gray (pea-size or smaller) blocks of calcium have cemented itself together.
Most of us have enough calcium in the soil for plants to use as a source of calcium needed as a nutrient. However, the more calcium in your soil, the higher the pH of your soil can become, which can cause other problems.
Where we have problems with the lack of calcium as a nutrient is in raised beds or especially in pots using artificial potting soil. If you make your own raised-bed potting soil with very high levels of organic matter, you can have calcium problems.
A common problem with tomatoes is if the end on the tomatoes opposite of the stem turns brown or rots, that is a symptom that your plants are lacking calcium.
I have had only heirloom tomatoes growing in containers ever get blossom rot. If I grow heirloom tomatoes in the native soil, I seldom get blossom end rot. If I grow the more modern varieties of tomatoes in the ground or in containers, the tomatoes do not get blossom end rot.
With all this said, I never add any specialized calcium fertilizer to my landscape or vegetable garden planted in native soil. I will add calcium fertilizer to my container grown vegetables only if needed.
Commonly people add eggshells to their soil or compost pile to furnish calcium. I normally do not recommend it, but if you feel you need to, it is best if you grind up first. Adding eggshells to the compost is more about pH control than plant nutrition.
Garden centers sell fertilizer specifically for tomatoes that contain calcium. I always look for the calcium content in the fertilizer. I have found general-purpose fertilizer that contains more calcium and a lower cost than tomato fertilizer. You can also add bone meal which is high in calcium.
Never use fireplace ash. Although high in calcium, once the calcium is heated, it becomes a product called burnt lime. In ancient times, burnt lime was used for concrete and mortar — not good for your soil.
Adding too much of any plant nutrient can cause problems in your soil. If you needed more sodium in your diet and added a bunch of table salt to your soup, you may make your soup inedible because it is too salty.
Adding too much calcium to your soil could kill your plants because it raises the soil pH to a level that plants cannot survive growing in.