Ask a Master Gardener: Monday, October 3, 2011

The Master Gardeners had an "Ask the Master Gardeners" day in July at the County Extension Office, where the public could stop by and ask questions about anything gardening related. It was a great success.

Now our group is going to publish questions and answers monthly that are appropriate for the time of year based on your calls and questions.

Q. My pine trees are around 6 years old. They have been doing great. The last few weeks, the needles started to turn brown and are falling from the tree at a fast rate. Is this normal?

A. Though pines and most other conifers are called evergreens, their needles do not stay alive and green forever. Generally, new needles are produced every spring or summer depending on the variety. So, as the tree grows larger year-by-year, newer needles are always at the branch end and older needles are father back in the crown. As needles age, they become less efficient at producing food for the tree. They also become more shaded by the newer needles. For these reasons, old needles finally turn brown and drop off. This is a natural occurrence. Do be concerned if there is yellowing or dieback at the tips of the branches. One possibility is a watering problem. Proper watering should be done at the drip line; an imaginary vertical line extended from the outermost branch tips of a tree to the soil directly below. The most efficient way to water is slowly and deeply. You can either use a drip irrigation system or make a well all the way around the tree at the drip line. If you make a well, you will need to fill it more than once. The water needs to penetrate the soil three to four feet. To determine how deeply you have watered, use a piece of rebar or other metal rod. Insert it into the soil at the drip line. When it becomes very difficult to push in, you have reached dry soil. For established trees, if the temperature is above 100 degrees, check your soil moisture every three to four days. Between 80 and 100 degrees, check the moisture every five to seven days during the summer months. During winter months, check them every week, however they will probably not need additional watering more than once a month. A more frequent watering pattern is necessary for immature/newly planted trees. Keeping your trees watered correctly will prevent them from becoming stressed. Stressed trees are a target for insects and diseases.

Q. I have cactus that I just planted last spring. How do I water them this winter?

A. Starting in mid September, stop watering your cacti. This will allow them to start hardening off for winter. When the weather gets cold and the cacti are waterlogged, the pads are prone to freeze and split. Excess water could also cause them to rot at the base. Most of our native cacti do not need watering after they are established.

Q. My tomatoes and peppers have been flowering. Then the flower just falls off. No fruit.

A. When we have sustained temperatures above 94 degrees, most of the vegetable blossoms have a high likelihood of falling off. It is also possible they were not pollinated, making bees and butterflies a valuable asset. Still another possibility is improper watering. Water slowly, deeply and consistently. Try not to put your plants in stress by water logging their roots or allowing them to completely dry out.

Q. When Do I plant bulbs?

A. September and October are ideal months to plant your bulbs, even transplant rhizomes. Remember to put hyacinths and tulips in the refrigerator for six weeks before planting. This will stimulate larger blooms.

To submit questions, please email the Kingman Area Master Gardeners at mohavece@cals.arizona.edu