Salt water vegetable gardens

As sea levels rise coastal farming areas are being exposed to more salt water.  On top of that irrigation is the major cause of salinization of water and salted waste water from farms is dumped into local streams and ponds, causing damage to those biosystems. A use for this saline water can slow down the dumping. A food crop that grows in this water can help feed a hungry planet.

One option is to investigate halophytes as food sources.  Halophytes are plants that prefer or will only grow in saline water.  Many grow rapidly producing much more plant material per sqft of land than traditional land grown crops.  One plant under consideration is Saltwort ( aka beachwort aka Batis maritima ) which produces nutritional seeds providing both protein and oil.

Another option is to replace land biofuel crops with halophytes, and save the farm land for growing food crops.

Yet another possibility is to adapt our favorite foods to grow in saline water.  Tomatoes grown in salt water ( about 10% salt sea water, 90% fresh water ) produced more antioxdants than tomatoes grown in fresh water.

If we start farming in saltwater areas we can increase the world’s farming areas by as much as 50%.

See also:
Rice grown by Chinese scientists using seawater in Dubai’s deserts
Saline agriculture may be the future of farming
Tomatoes grow well in diluted seawater and produce more antioxidents ( news article )
Food vs Fuel: Saltwater crops may be key to solving Earth’s land crunch

Wondering about the soil in your new home?

A great source of soil information is the USDA Web Soil Survey You can zoom in on the map to your location and get all sorts of information about your soil.

Wander about the site, you’ll find enough data to spend an afternoon wandering.

Like most government sites the use is not intuitive or clearly explained.

Click the ‘Web Soil Survey’ link ( top right section of website )Web Soil Survey

Select ‘Navigate by Address’ and put in your address and click ‘View’

Now you must select an area of interest using the ‘aoi’ buttons on the top of the map. Click one of them and use it to select the area of the map you are interested in.

Once you have an area selected you can choose the ‘Soil Map’ and ‘Soil Data Explorer’ tabs to obtain information.

Rain water vs tap water for your plants vs bottled water

This is one of those things every knows but no one can tell you why. Everyone will tell you rain makes a garden grow. But I had to find out why.

There was no information to be found on rain water in Houston. If you are from another city you may or may not find some useful information online. I purchased an aquarium water test kit at the local per store and used it on the water.

Here in The Woodlands, and I imagine most of Houston, our tap water has a high kH. kH is the carbonate hardness of water. The higher the kH the more difficult it is to change the pH of the water and the more difficult it is to absorb or neutralize acid. Water kH can be increased by adding baking soda or reduced by adding CO2 ( you can purchase tabs to drop in water at the pet store ).

For your aquarium and pond plants a high kH is good. Over time this releases CO2 to the water which benefits the plants. When I switched from tap water to bottled in the aquarium the plants all died.

The pH of the tap water was 8.5 when I measured it, and the rain water was 6.5, which is where the bottled water I tested came in. pH is very important to plants. pH is a measure of the hydrogen in your soil. The scale runs from 0 to 14, 0-7 being acidic, 7 is neutral, and 7-14 is basic. You really want your garden soil and water pH to be between 5 and 7. More or less than that and most plants will have trouble getting the nutrients that are in the ground. This is why everything greens up after a rain. It is much easier for the plant to use the nutrients that are in the ground at that pH. At the pH of our tap water it is difficult for plants to get there nutrients. The nutrients may be there, but they can’t get in.

So is rain or tap water better for your plants? Both are, at least locally.

Some plants may be extremely sensitive to the fluoride and chlorine in tap water. You’ll know by the edges of the leaves or tips turning brown. Usually just a very thin brown edge and usually just on houseplants. If you have a plant that is sensitive to chemicals, cut your tap water with some bottled water when you water it.

You can help your soil pH by adding peat moss to your soil each year ( see article below ), but you are not likely to change it long term. You’ll see your plants leaves turn yellow while the veins stay green when the plant is unable to take up nutrients. Adding fertilizer, especially one you can spray onto the plant will help. Iron added to the soil around the plant also will help.

Though I am sure there are many other interesting differences between rain and tap water here in Houston, I’m still looking for information. Everything else I’ve been able to test came out the same for both.

More information:
pH soil and plants

Your plants need micronutrients too

Micronutrients are essential for plant growth but only in extremely small amounts. Usually just adding a little organic matter will take care of all your plants micro nutrients. This is more of an issue in food crops for humans and animals. Lack of micronutrients in food crops can cause diseases related to these deficiencies in humans and animals. So be especially sure your herb and vegetable garden get a bit of organic matter each year.

Signs of micronutrient deficiencies in plants:

Boron deficiency – newest buds die, stems may crack and split, young leaves are distorted in shape, crinkled, and discolored, plant may not set seed.  Often boron deficiency is a by product of putting adding too much lime to the soil.

Chloride deficiency – roots are highly branched with stubby tips, leaves wilt then become mottled and tip wilts.

Copper deficiency – leaves are very dark green, and crinkly, stunted growth plants wilt even when given sufficient water.  New leaves are small and uniformly yellow.  Older leaves curl upward and edges of leaves roll in toward center.  Plants are most likely to get fungal infections when copper is deficient. Copper sweetens and strengthens the flavor of fruits and vegetables.

Iron deficiency – yellow leaves with green veins, yellowing begins at center of leaf where it attaches to the stem

Molybdenum deficiency – older leaves yellow, newer leaves are light green

Zinc deficiency – yellow and brown mottling of leaves, green veins, also small leaves that are distorted can grow much closer together than they should. Black spots can appear on yellowed leaves.  Zinc deficiency often occurs when phosphorus levels are high and soil is alkaline.

An excess of one micronutrient usually causes a deficiency of another micronutrient.

Calcium, Magnesium and Sulfur are the secondary nutrients needed by plants

In the Houston area soil is poor for most of us. We either have sand or clay. Rare is the lucky soul with loam. To make matters worse we tend toward alkaline soil, the more north and west you go the worse it gets. Then the heat and humidity rapidly breaks down what little organic matter the soil contains. This means we see lots of nutrient problems with plants.  Plants need much more fertilizer here than anywhere else you’ve lived, but the biggest pollutant in our bayous is fertilizer run off.  So feed your plants lightly and frequently and watch for signs they may be missing something.

If you are seeing yellowing leaves with green veins you might want to check your plants secondary nutrients. Iron is usually but not always the cause of green veined, yellow leaves.  Sulfur deficiency effects new leaves first, calcium and magnesium effect older leaves first all have the same tell tale green veins and yellow leaves.

Calcium deficiency – Youngest leaves looked bleached, especially at the tips of the leaves. Leaf tips rolls and appear scorched. Along the edges of the leaves the veins remain green while leaf looks bleached out. New leaves may be distorted in shape. Old leaves turn brown and die. Growth is stunted, new buds don’t grow. In vegetables you get blossom end rot and black spots in things like celery, carrots and cabbage. Usually this only occurs in very acidic soil.

Calcium is needed to build plant cell walls, and to help move nutrients through out the plant.

Calcium is usually not a problem if your soil pH is between 6-8. Too much or too little water can also effect calcium levels in the plant. If calcium is low, soil is not properly buffered ( pH can swing rapidly making nutrient uptake difficult ). Around here blossom end rot on tomatoes is a common symptom.

Magnesium deficiency – Older leaves become yellow, while veins remain green. Leaves drop off plant. Leaves may curl up at edges and edges become red-brown-purple in color leaving a green arrowhead shape in the center of the leaf.

Magnesium is needed for photosynthesis it is the main element in the chlorophyll molecule. It helps the plant uptake iron and also to move nutrients around the plant.

Add epsom salts 1 teaspoon per gallon twice a year to fix a magnesium deficiency.

Sulfur deficiency – Youngest leaves yellow, veins remain green. Plant is slow growing. Leaves curl. Often sulfur is not deficient but rather just low compared to the amount of nitrogen in the soil. Sulfur deficiencies are rare. Adding sulfur will help lower your soil pH, slowly and lightly, so don’t be afraid to add some to your soil if your pH is higher than 7.0.

Too much of these nutrients are not usually a problem except that other nutrients can’t keep up. So too much of any of these may cause a deficiency in another nutrient.