bottom-rot tomatoes

In CO it is a lot less likely to have Ca deficiencies, more likely to have irregular watering, also causing BER. Wood ash is an excellent source of Ca, but any compost will also be a very good source.

I don't know the soils in Colorado, but BER is more often caused by stress. This can be due to a lack of any of several nutients even by water deprivation (drought). Some varieties (cultivars) are very prone to BER while others are relatively unaffected. Check your soil pH. Most soils contain sufficient calcium, but high acidity can impede the uptake into the plant. Ground limestone (prefereably dolomite which also contains magnesium) is the best long term solution. Crushed seashells, eggshells etc also are primarily calcium carbonate and work the same . Wood ashes are a great source of potasium not calcium but will quickly but temporarily raise the soil pH.

actually wood ash is in all cases 30 to 50% Ca. In fact, Ca is the most abundant nutrient in wood ash. All you have to do is a web search to find out. that is one of the reasons why it is so good for tomatoes, cabbage and lettuce amonst others. It has both (K-Ca), plus it helps raise the pH.

Google on "blossom end rot" for copious information. Look for .edu sites indicating a university agricultural program. BER has a number of "causes" and, fortunately, often appears only on early fruit and straightens out by itself further into the season. BTW, it's a

Thanks for the many replies. We will look further into the situation and have our soil tested. We appreciate your advice.