Get those citrus plants back in shape

I love to grow citrus, especially Meyer lemon and Owari satsuma mandarin. The fresh fruits arrive every winter and the sweet scent of blossoms fill the air in the summer. But this past year, I have fallen down on the job when it comes to keeping them healthy and productive.

Here is what I am doing to get them back in shape. Citrus boot camp:

FEED >> Citrus are heavy feeders and require a constant supply of nutrients. I am giving each plant a good dose of blood meal this month. Then, I will reapply every eight weeks until the plants bulk up with fresh green leaves and strong new shoots. Blood meal is high in nitrogen and iron, nutrients that citrus love. There are also many brands of citrus fertilizers available and all are good. The most common fertilizer problem with citrus is not enough iron.

REPOT >> Citrus in containers need to be repotted every couple of years. The rule of thumb is to bump up into the next size pot. If a plant is in a five-gallon pot, bump up to a sevengallon pot. I always use a top-quality soil that has good drainage.

WATER >> Citrus trees growing outdoors and under the eaves of the house need to be checked to make sure the ground is nice and moist, especially during the winter. Citrus do not like to dry out. Containerized plants in the greenhouse also need frequent attention to watering. Curling leaves, yellowing and dropping leaves often indicate watering problems.

SPRAY >> Two major pests make growing citrus a challenge: spider mites and scale. This challenge is best solved by spraying plants monthly, especially from spring through fall, with an oil-based spray before the pests take hold. I use Organicide.

If the citrus tree is already infected with these pests, it is best to trim back heavily infected leaves and branches. Using a sponge, wash the leaves and branches with soap and water.

If scale is a problem, be sure to scratch them off, especially along branches. Get on a regular spray routine after cleaning the plant.

PRUNE >> Pruning to shape is one step to keeping a citrus healthy. Another necessary task is to keep thick clusters of flowers from matting together. This invites fungus, especially in cool greenhouse settings. Thinning is necessary after fruit set. Thin fruits when they become the size of marbles. This will assure a few very nice fat fruits, instead of a bunch of tiny ones.

BE PATIENT >> When it comes to rejuvenating neglected citrus, patience rules. It takes some time for neglected plants to heal. Repotting, feeding and pruning now will result in fresh new growth when the days warm up and become longer. New leaves and fresh shoots is the reward when healing a neglected citrus. But it takes some time.

Terry Kramer is the retired site manager for the Humboldt Botanical Garden and a trained horticulturist and journalist. She has been writing a garden column for the Times-Standard since 1982. She currently runs a gardening consulting business. Contact her at 707-8342661 or terrykramer90@gmail.com.