Weekly Express-News Article
By Calvin R. Finch, PhD, SAWS Water Resources Director, and Horticulturist
Saturday, October 20, 2007
“When is Citrus Ripe?”

            Are you looking for a way to determine when the citrus on your patio or in the garden is ripe?  Consider this strategy. 

            The prime harvest month of citrus in San Antonio is December and most citrus changes color when it is ripe.  That being said, there is fruit than can be harvested right now and some of it is not completely orange or yellow.

            The advantage of harvesting fruit before December is that if your tree is full of satsumas, lemons, limes, tangerines, and/or grapefruit, you can be overwhelmed with fruit at that time.  Better to spread out the harvest October to December.

            If the tree is loaded, consider picking one or two every week to determine if you can use it.  Select a large fruit and one with some color change.  Quite often what you will find in a satsuma, lemon or lime is that some of the fruit is suitable.  If the sample fruit is sweet enough for fresh eating you can pick more fruit as you need it.  If it is still not as sweet as you like it, use the sample fruit for cooking or drink flavoring and wait at least another week before you do any wholesale harvesting.  As we progress towards December, the fruit will become sweeter in most cases.

            Although we brag about the drought tolerance of citrus, fruit quality is better if the plant is not water stressed.  Citrus in containers is especially vulnerable.  Irrigate when the soil is dry to one inch.  Add enough water that it seeps out the drainage hole or containers.  Add at least ten gallons to a small tree in the ground.  Fifty gallons is not too much for a large citrus tree in the ground.

            For those of you who do not have citrus trees or want more, autumn is a good time to plant citrus in our gardens or even in containers on the patio.

            Citrus makes a good patio plant because many varieties grow well in containers.  Meyer lemons, Mexican lime, and satsumas make especially good container plants.  Grow them in half whiskey barrels with seven to nine one inch drainage holes drilled in the bottom.  Fill the container with a high quality potting soil or a mix of one third washed sand and two thirds well finished compost. 

            In the garden, grapefruit and Changsha tangerine can also be added to the list.

            Enrich the potting soil with two cups of Osmocote or other long release fertilizer especially made for containers.  In containers citrus is naturally dwarfed due to the limited soil reservoir available for root growth.  The plants in whiskey barrels generally grow to about four feet tall.

            Citrus, whether in the ground, or in a container are desirable because they make a beautiful plant, have fragrant blooms, and produce high quality fruit. 

            Citrus are also quite drought-tolerant, and although they attract some pests, they are tough enough to survive well in the San Antonio area.

            Cold sensitively is an important issue, but not limiting enough to cause someone to reject citrus for their garden.  The most cold hardy plants are the Changsha tangerine and the satsuma.  They tolerate cold to the mid 20’s for short periods.  All citrus can survive temperatures lower than the upper 20’s if they are covered with a cloth material and plastic.  Never drape plastic on the plant without having the cloth insulating the plant.  A plastic tent works well, however, as long as there is a layer of air between the foliage and the plastic.  The plastic tent must be opened when the sun rises to avoid heat build-up.  Add a heat source such as a string of holiday lights or a mechanic’s light on very cold nights.

            For more information on citrus varieties, citrus culture, and cold protection, visit www.plantanswers.com