I am glad we got out of that cold spell we were in last week. This time of year gets a little tough on us gardeners. While I was stuck inside, I cleaned the garden room -- well, I started it any way. I am not sure how so much stuff gets collected in one space, valuable stuff of course. The cold weather also gave me time to catch up on some reading, about gardening naturally.
One of the things I was reading about was calcium in the soil. Calcium is essential for the formation of roots, stems and new growth in plants. The nutrient forms calcium pectate, which plants use to construct cell walls and membranes. Consequently, calcium helps provide plants' rigidity.
Calcium also benefits your garden soil. It is interesting the way it improves soil structure; one way is by helping soil particles stick together, or it can improve tilth by reducing the stickiness and clinging ability of soils containing clay. Somehow, it knows the difference.
Although calcium deficiency has recognizable symptoms in plants, a soil test is the best way to tell if you have adequate calcium in your garden. Symptoms of calcium deficiency in plants usually appear on new growth. The typical symptoms include stunted growth, distorted leaves and pale yellow patches between the leaf veins. The leaves may also be cupped. Weak stems and dying stem and root tips are some more signs of calcium deficiency in plants. In certain vegetables like tomatoes, calcium deficiency causes a disorder called blossom end rot. A watery spot appears at the blossom end of the tomato, and the spot grows wider and darker as the fruit enlarges. Finally, the spot sinks or flattens, and the surface becomes firm. This is why it is an old custom to bury an egg shell with your tomato plant.
Some garden crops, such as tomatoes, peas and beans, have a high calcium requirement but do best in slightly acid soil. In this case, calcium can be provided in the form of a gypsum soil amendment (calcium sulfate). Agricultural gypsum is a good source of both calcium and sulfur, yet has little effect on soil pH. If your soil is a little too acidic, adding limestone helps increase alkalinity. For example, if your soil pH is below 5.5, add 2-3 pounds of dolomitic lime per 100 square feet to raise the pH. Most garden plants like a pH of 6.5-6.7 Once again a soil test is best to determine its pH. Work the lime in a couple of weeks to a month before planting your vegetables or other plants to allow time for it to dissolve into the soil.
You can improve the availability of calcium in soil and reduce the risk of blossom-end rot with a few simple techniques. Excessive amounts of potassium, nitrogen and magnesium from fertilizer can inhibit a plant's ability to use the calcium in soil. Excessive shoot growth is one indicator a plant received too much fertilizer, and it may be an early sign of blossom-end rot. If you notice blossom-end rot on your plants, you can apply a premixed calcium spray designed for plants. Using the spray can support other measures designed to add calcium to the soil to correct problems caused by calcium deficiency.
I know this all sounds a little complicated, but it's really not. Just plant something, and if things start going wrong, start asking questions. Experience is a gardener's best friend.
Happy gardening!
Peter Sutter is a life-long gardening enthusiast and a participant in the MU Extension's Master Gardener program. Gardening questions can be sent to [email protected].