Are there ants in your plants?
Although ants do not, by themselves, eat or disfigure plants in any way, they create problems through their sap-sucking insect agents.
In hot, dry weather, ants come out of the ground looking for moisture and food. One of their favorite sources of food is the undigested plant sap or honeydew excreted by sucking insects such as aphids, scales, whiteflies, and mealybugs. If the leaves of your plants are shiny and sticky, this is a sure sign that one or more of these insects is present.
Ants are mightily industrious in procuring their honeydew repast. They will transport sap-sucking insects or their eggs from the ground to a plant or from one plant to another.
Ants deposit their insect underlings where they will be happiest, which is typically on recently emerged, succulent plant parts; the sucking insects produce abundant honeydew in their new homes – to the delight of their ant overseers.
If you have roses, you will notice that aphids – sometimes called ant cows – are most numerous on the terminal leaves, buds, and stems or young shoots. Aphids may find and infest roses or other plants on their own, although the presence of ants on a plant is nearly always proof positive that aphids – or other sucking insects – are about.
When you see ants going up the trunks of certain trees or up the stems of particular shrubs, you can be virtually certain that you will encounter specific insect pests. In the Valley, ant trails on citrus trees lead to whiteflies or cottony cushion scales, ant trails on abutilon (Chinese lantern) lead to black scales; ant trails on banana trees or giant birds of paradise lead to brown scales; ant trails on Modesto ash trees terminate in colonies of wooly blue aphids.
To discourage ants from climbing onto plants, prune tips of low branches before they touch the ground. Tanglefoot or other sticky substances, available at nurseries, can be slathered on tree trunks or stems to prevent ant progress up into your woody plants. Since some barks are sensitive to Tanglefoot, apply it to tree wraps made of cardboard or old silk stockings to be tied around trunks 8 to 10 inches off the ground.
Soil kept slightly moist – that is, soil not allowed to go bone dry between waterings – will also discourage ants from leaving its confines.
Long term, the best way of keeping ants out of your plants is to grow a diversity of flowering trees, shrubs and perennials to attract birds and beneficial insects that prey on sucking insects. With no sucking insects to herd around, ants will cease to take an interest in your plants.
To keep beneficial insects – green lacewings, ladybugs, parasitic wasps and hoverflies – in your garden, you should assemble a collection of plants that provide sources of nectar and pollen year round. In other words, make sure that several different plants are flowering at any given time of the year.
Sages are attractive to both beneficial insects and hummingbirds and stay in bloom practically all the time. The sages would qualify, in my opinion, as the salvation of the Valley gardener, and not only because of their medicinal properties, for which they were given the botanical name “Salvia,” which means safe, well or sound in Latin.
In my own garden, there are four sages that seem to be in bloom at all times. Salvia chiapensis, a low mounding shrub with pink flowers; Salvia bicolor, with navy blue petals and silvery green calyces; Salvia guaranitica, whose violet-purple petals resemble the gaping jaws of a dragon; Salvia “Waverly,” with long wands of white flowers tinged with magenta.
To find these and other exotic salvias, contact Worldwide Exotics in Lakeview Terrace at (818) 890-1915.
Besides the mint family, which includes not only the sages but rosemary, thyme, lavender and yerba buena as well, the daisy family (coreopsis, cosmos, Shasta and Michelmas daisy), the carrot family (parsley, fennel, dill, cilantro), and the verbena family (verbena, caryopteris, aloysia, lantana) are all famous for attracting beneficial insects.
If you create a garden that includes three or four species from each of these plant families, you will control garden insect pests without having to resort to insect sprays or poison granules, and ants will disappear from your plant for good.
Are there ants in your plants?