Thursday, April 19, 2018
Home and Garden

Dr. Hort: This could be year for oranges

This could be the year for oranges

Q: Have an orange tree, 4 years old. In the first year, I had a couple of blooms, but they fell off and no oranges. In the second year, the tree had many blooms, but they left and no fruit. In the fourth year, the tree was filled with blooms but they withered. Small brown buds were all that was left. I have been fertilizing four times a year with orange-tree fertilizer from Walmart. The tree has grown between double and triple. Do I give up? Dave Liehr

A: It is quite all right for your citrus to not fruit the first few years, as the energy goes to growth instead of fruit as you have seen. Fertilize in January, May and October. Be sure to water evenly before and after fruit set and continue irrigating twice per week until the rains come. After fruit set in February to March, we commonly experience our driest weather, so fruit drop can be an issue. This just could be the year!

Treat powdery mildew at first sight

Q: The leaves on my squash and zucchini plants are looking bad. They have yellow spots and then turn black and dry up. This all happened before a recent cold snap. I have fertilized with Miracle-Gro and with a little 6-6-6 when planted back in mid November. Could it be bugs? I recently dusted with Seven. Brian Bendis, Tampa

A: The problem on your squash is a fungus called powdery mildew which will kill your plant from the oldest leaves to the new. As with all plant parasitic fungi, free water is needed for the spores (microscopic seeds) to germinate so, any way to reduce water on the leaves is the first strategy. Grow plants in full sun, don't water overhead, use a drip system and space plants so leaf overlap is avoided. Managing the disease requires a keen eye. Powdery mildew starts as small white dots. As soon as the first dot is noticed your spray program begins (in your case, remove all diseased leaves, pronto). Use a mix of 2 tablespoons of baking soda plus 2 tablespoons of horticultural oil, spraying every millimeter of the plant, every four to five days. Milk mixed from 10 to 50 percent with water sprayed every four to five days is equally effective. (It is not totally understood just how milk works, but university research documents its promise as a fungicide). Both sprays work best as a preventive measure, so make sure any diseased leaves are removed before starting your spray program.

Cold winter weather results in clivia blooms

Q: My clivia is turning yellow. It was making plenty of pups or babies, so I gave my daughter a few. Hers are blooming every year, while mine only bloomed once in three years and now the leaves are turning yellow. Hers are in indirect sunlight under a tree. Mine get morning sun and evening shade. She only gives hers banana skins then neglects. I try to care for mine. Banana skins and water when it needs it. What is happening? My clivia is in a pot. Should I take it (them) out of the pot? If so, when is a good time to do this? Do I just feed regular bulb fertilizer as this seems to be the only kind of fertilizer that is sold in my neighborhood nursery. Jacqueline Durand

A: The secret to making clivias, Clivia miniata, and others bloom is hours of chilling during the winter months. They need four to five weeks of night temperatures below 55, but above freezing to guarantee March and April blooms. Another key to success is to keep the pot dry from Halloween through winter, and begin watering and fertilizing when the chilling hours have been met to produce spring blooms. They are happiest in broken shade, never full sun, a north face is quite accommodating. The yellowing leaves on your plants could be due to too much water or freezing temperatures. Set up an extra refrigerator and put your plant to bed there every evening and take it out for breakfast for four weeks, then begin to water and fertilize, and about eight weeks later, flowers! As the pups reach eight leaves or more, they are also blooming size which will make for a full pot of blooms, so leave the pot intact. A balanced soluble fertilizer, such as 20-20-20, mixed half strength to label directions and applied once per month from post-bloom until September is suggested. Never use soluble fertilizers that have more nitrogen (the first number) than anything else, 16-4-8 for example, or the plant will grow and multiply, but not bloom.