Q: Can you identify a plant I have seen growing in a local landscape? It started blooming near the end of March, and it’s still putting on an eye-catching flower display. The flower heads are round and borne on tall slender stalks and the individual flowers are blue.
A: The name most commonly used for this landscape perennial is agapanthus. It is also known as lily of the Nile, African blue lily and African lily. Agapanthus was introduced to this country from South Africa in the 17th century. Its name is derived from Greek and translates roughly as “flower of love.”
Agapanthus bears large, round heads of blue flowers on tall, stout stems. While most varieties have blue flowers, which range in shades of light blue to an intense dark blue, varieties with white flowers are also available. Agapanthus is also available in standard and dwarf varieties.
The evergreen leaves of the standard varieties are long and strap-shaped and look like large amaryllis leaves. Flowers are borne on stems that can be 3 feet tall or taller. The dwarf varieties are about half the size of the standard varieties.
Agapanthus is an underutilized perennial in local landscapes. While it is typically grown in beds, it may be grown in large containers. Agapanthus needs a well-drained soil with high organic matter. During periods of dry weather conditions in the summer, be prepared to give agapanthus ample water. During the winter, give it just enough to keep the soil from becoming very dry.
When aapanthus is grown in containers, it should be provided a dilute liquid fertilizer feeding every two weeks during the spring and summer growing season. When it’s grown in a bed, you should fertilize it in the spring, then in early summer and again in the fall.
Q: I am concerned about so many of the standby insecticides that I have used over the years being taken off the market. The stores seemed to be filled with ones I have never heard of or read about. Are they as good as the ones before?
A: The only thing that is constant is change. Several years ago, many of our more popular insecticides, such as Lindane, Dursban and Diazinon, were removed from the marketplace. They are being replaced with products from Bayer, Ortho, Spectracide and several other companies and are being sold as general-use or all-purpose type sprays.
Many of the current generation of general-use sprays contain a class of insecticides known as pyrethroids. These chemicals are known for their ability to control insects at low rates. The marketplace is full of new pyrethroids with names like cyfluthrin, permethrin, esfenvalerate and tralomethrin. They are found under various trade names. They work quite well for the pests for which they are labeled.
Q: My newly transplanted landscape trees have turned yellow and some have died. This has been a rather low rainfall spring, and I have been watering every day. When we dug up the dead trees, they were sitting in a pool of water and I could smell a rotten odor. I was told to add organic matter to the planting hole and water the trees daily when I bought them, but now I wonder if I over did it. What happened?
A: Too much TLC is harmful to plants, especially in heavy clay soils. To be more precise, too much TLC when it is misdirected is harmful to plants. And the most common misdirection is watering either too little or too much.
Many of our gumbo clay soils do not drain well. The texture of these soils is so fine that the water will not drain well when excessive amounts occur either through irrigation or heavy rainfall. Adding organic matter to the fill soil in the planting hole is like planting in a bath tub with a clogged drain. In this case, the bath tub (the planting hole) fills up with water, does not drain adequately, and plant roots are damaged or killed because of lack of oxygen. It is recommended the original soil dug from the planting hole be used as fill soil after placement of the root ball in the hole.
Dealing with our gumbo clay soils can be extremely frustrating. If you have soils of this nature, you need to modify your watering schedule. Depending on the time of year trees are planted, you may have to water deeply two or three times a week for the first few weeks after transplanting depending on rainfall.
Thereafter, once a week is generally enough to get new landscape trees through the first growing season. There should be little need to water any newly transplanted landscape tree daily unless you planted them in an extremely sandy soil. We do have sandy soils in a few areas in our county, but this is a rare commodity in these parts.
So adjust your watering schedule to your soil type and soil moisture conditions. Watering schedules should be based on your ongoing soil conditions, not on a set schedule. Just as people need to drink water when thirsty, new transplants should be watered when soil moisture level is low.