Spring kind of got left in the dust in some parts of the country. Summer decided it wanted to be the boss. Fine by me. So, with the very warm weather already upon us, I wanted to write an article about keeping your Citrus happy through the dog days of Summer.
Many of these will cross over from in the ground to container grown, I will specify as need be.
Timely watering is essential for proper growth and fruiting. More trees are stunted or lost by drought stress than from any other cause, except maybe over watering. Make sure there is adequate moisture in the soil before wilting occurs. To avoid over watering, excess water must drain away. Hence a well draining soil, that retains some moisture, and a good amount of drainage holes are needed in a container.
Very hot days, and hot winds, which extract water from the leaves faster than the roots can draw it up from the soil, may cause temporary wilting. Even if there is ample water present, this can happen. A cool misting of the leaves will help alleviate this. Remember, a drastic swing from moist to dry, can cause blossoms and small fruit to drop. Larger fruit may be reduced in size or drop.
Another trick to use on container grown Citrus, when the temperatures are soaring, is to paint the town white. Get some of the white spray paint that is used on plastics and spray half of the pot. The best half to paint is the side that gets the most late afternoon sun, basically speaking, the West side. The reason for this is, the root zone of plants can easily reach 120 degrees in the sun, especially if using black containers. During the late Fall, Winter and early Spring, you can just turn the painted side to the North. This way the roots will stay a little warmer.
Mulches are beneficial. They conserve moisture, control soil temperatures, prevent soil compaction, reduce water runoff and control weed growth. Keep any mulch that tends to stay wet a few inches away from the trunk. Citrus are very susceptible to bark diseases encouraged by moisture at or near the soil level. Mulches CAN be used in containers! Just remember to keep it away from the trunk, this may not be very useful in smaller containers however.
There are twelve mineral elements citrus trees need in order to be healthy. The major ones are Nitrogen, Phosphorus, Potassium, Magnesium, Calcium, and Sulfur. These are needed in larger quantities. The so called, “Micro” nutrients are Iron, Zinc, Manganese, Molybdenum, Copper and Boron. These are not needed in as large a quantity. If you are going to grow Citrus in the ground it is best to do a soil test to see if you have any deficiencies. When Citrus is grown in containers they can easily be deficient in any of the above. Make sure you look for a fertilizer that contains as many, if not all, of these vital nutrients. Again, a soil test can be done if there is any doubt. If using a water soluble fertilizer, feed every two to three weeks when grown in containers. Probably once a month will be fine when in the ground.
Fish emulsion is a nice treat for your Citrus. A foliar feeding at least once a month will add extra Nitrogen, which of course, Citrus are heavy feeders of. If you want to spoil your citrus, more often will not hurt.
Don’t be alarmed if a few small immature fruits turn yellow and fall off. Citrus will naturally shed a number of fruit a month or so after blooming. Called the June drop, it is a natural process. If your tree is in a stressed state they can drop all the fruit. Follow the above suggestions and you should have no problems getting your Citrus trees through the “Dog Days” of Summer. Boy it's hot, anybody for a lemonade?