Fig Fruit Production Not on/off Switch

Q. Would a fig tree produce figs if it got sun in the spring, fall and summer months but not the winter? I have lots of spots to plant trees but a house blocks winter sun.

The amount of light and the quality of light is important in flower and fruit production as well as increasing the branching of some plants. All plants have a minimum amount of light required to flower and maintain fruit production. The amount needed varies among plants but generally most of flowering and fruiting plants need at least 6 hours of direct sunlight every day

A. Success depends on how much sunlight plants get when leaves are out. When leaves are gone, sunlight is not nearly as important. Winter sunlight is not terribly important for trees in our climate because it is cold and the plant is dormant or "resting". But light during spring and summer months, when leaves are out, is very important. That is when sunlight is critical.

            Fruit production is usually not controlled by an "on and off" switch. As the total amount of light decreases, the amount of fruit produced also decreases. At some point, if the plant does not receive enough light, flowering and fruiting stops. The amount of sunlight needed for flowering and fruiting varies somewhat among plants but fruit trees generally need a minimum of 6 hours of direct sunlight. If sunlight continues to decline during months when leaves are out, at some point, there won’t be enough light for the plant to make flowers and produce fruit. It stops producing fruit, only leaves and stems.
 

Foliage plant, and interior plant that produces only leaves and stems, growing under very low light conditions in the Amsterdam airport men's bathroom. This plant was selected because it requires a very low light levels to produce leaves and stems and can take a very tough conditions.

            If a fig tree is getting a minimum of 6 hours of sunlight when leaves are present, it will probably produce decent fruit. Not all this light has to be direct sunlight. Reflected light also counts but not as much.In direct light, light from bright reflecting surfaces, will contribute to flowering and fruit production but more indirect light is needed than direct light. Much of this depends on the total amount of light as measured in footcandles per hour or watts per square meter per hour. The quality of light, the color, is also important because it can trigger some types of behavior in plants.

            Fruit production also depends on the “quality” of reflected light. If light is reflected off shiny or white surfaces, then plants receive more light than light reflected from darker or variously colored surfaces.

Roundup Does Not Cause Root Damage of Saguaro If Properly Applied

Q. My Saguaro cactus is beginning to lean and I’m afraid it will fall over. Landscapers were spraying weeds with Roundup on top of the soil near it. Will Roundup hurt my Saguaro and Prickly Pear cacti?  Did the Roundup make the Saguaro lean by hurting its roots? Do you know anyone in the Coachella Valley who can put a brace on it so it doesn’t fall over?

A. To kill or damage plants, Roundup must be sprayed onto the green parts of the plant. Older parts of the plant which are not green or no longer green won’t absorb any. If your gardeners sprayed the ground surrounding the Saguaro there should be no problem for the Saguaro.

            There is an exception. Roundup can move in water and cause damage. Never spray Roundup where there is moving water.

            Any pesticide including Roundup can move with wind or significant air movement. Never spray when there is air movement over 2 mph. never spray the hot surface of a soil or rock because pesticides can volatilize, move upwards with warm air and damage plants.

             As long as landscapers or applicators are careful around plants there should be no problems.

            In my opinion, the reason your Saguaro started leaning is because of how it’s irrigated. Saguaros support themselves with roots that extend long distances from the plant. This stabilizes it as it gets taller.

            If irrigation is applied close to the trunk and there is no other water available then roots will not grow very far. As it gets larger, it gets top-heavy and these short routes can no longer keep it upright.

            What to do? I sent you a picture of how to properly support a Saguaro after it has been planted and until I can get established. Install other plants with drip irrigation at several distances away from the Saguaro. If the soil is wet, the roots of the Saguaro will find this water and grow further from the trunk.

Fall Planting Fig No Problem If They Don't Freeze

Q. Can I plant fig trees in the Fall or should I wait to buy these trees in the spring?

A. Plant in the Fall. Fall is the best time to plant all fruit trees including figs. The problem is finding varieties of fruit trees that you want. But if you find the tree you want, if it is not sensitive to freezing temperatures, plant it. Figs handles temperatures down to about 10°F or -12°C.

            The best time for planting freeze tolerant plants is in the Fall. Begin planting as temperatures cool from the summer heat. In Las Vegas this is towards the end of September through the middle of November.

            All the fig varieties grow well in the Mojave Desert if the soil is improved at the time of planting, they get enough water and it is delivered at the right time.