Food-Gardening Lessons From A Wartime Victory Garden

Articles

Tag: Grubs

How Do I Manage Codling Moths on Fruit Trees?

 

“I have a Liberty apple tree and a peach tree within 20 ft of each other and every year fruit tries to grow but what I believe is the coddling moth destroy it all. Do you have an effective solution?  Sprays have not helped.” Question from Ilene of West Greenwich, Rhode Island

Answer: It is likely that you are dealing with European apple codling moths (Cydia pomonella) and Asian peach moths (Grapholita molesta). Both exist in Rhode Island, look similar, and cause comparable damage, but one prefers peaches, and the other chooses apples. Here are three suggestions for overcoming these pests in your home orchard.

Know Your Pests

European apple codling moths (Cydia pomonella) are 1 cm, greyish brown, and have curved antennae. Their wings fold into a tent-like shape.

The codling moth is small and mottled with greyish-brown. Its wings fold in a tent-like manner, and it reaches about 1 cm in length. You will see them most often in the orchard from late May to mid-July. (Click here to learn more.) The Asian peach moth is smaller, mottled, gray, and measures about 1/4 inch (5 mm). The wings have mottled light and dark banding and also fold in a tent-like manner.  The first adults of the season appear from mid- to late-May. Subsequent generations appear from June through to mid-July. (Click here for more information.)

Keep Orchards and Trees Clean

In fall, remove all spoiled, fallen fruits that may harbor moths, bag them, and dispose of them away from your orchard. Look for the codling moth’s brownish moth pupae in winter, which can be found in protected spots near where apples are stored and in tree bark. The moths emerge in mid-spring ready to attack fruits.

I also recommend cleaning and disposing of all fallen fruit-tree leaves to reduce the prevalence of any potential fungal diseases that overwinter on dried foliage.

Time Your Spraying

Time your spraying with precision to stop these pests. A good time to first spray trees is in spring a week after they have dropped all of their petals. This should help tackle the first wave of both codling moths and Asian peach moths. The second time to spray is when the fruits are developing. Codling moths lay single white eggs on the fruits and leaves. These can be manually removed from fruits. Never spray trees when they are in flower. Otherwise, you will be killing all the essential pollinators, while not harming the moths.

I recommend two sprays for these pests: Codling moth virus and horticultural oil are approved for organic gardening, and will stop your apple moths, but frequent applications are needed. Organic insecticides with the beneficial bacterium Spinosad work well against both moths, but these sprays can only be applied several times in a season, so read the product instructions.

Use Sticky Traps

There are pheromone traps designed to just trap and kill these two pests. Set them up by mid to late May just before the first round of moths start flying. These should really help lower your populations and save you some fruit.

I hope that these tips help!

Happy gardening,

Jessie Keith

Black Gold Horticulturist

Do Grubs Hurt Plant Roots?

Do Grubs Hurt Plant Roots?

“Do grub worms hurt roots? I have a lot in one of my containers.” Question from Jody of Live Oak, Florida

Answer: Yes they do. I’ll fully answer your question in two parts. First, I’ll address grub problems in the garden as a whole, and then I’ll address the grubs in your pots.

Grub Root Damage

Grubs are the larvae of many types of beetles. Most grubs feed on plant roots from fall to spring or summer, until they emerge from the soil as adult beetles. But, grubs aren’t always a problem. Under normal circumstances, you will not see the impact of a low to moderate grub population on large, healthy plants or lawns. They become a real threat when populations are high. This happens when fast-generating, destructive garden beetles, such as Japanese beetles, are not managed properly and populations soar. At this point management is essential. There are several steps you can take to manage destructive beetle grubs, and these are detailed in our Q&A blog titled, “How Do You Manage Japanese Beetles?” (click on the link to view).

Managing Grubs in Containers

Pots are small spaces, so a large number of beetle grubs will harm any plants within. Here are three easy ways to get rid of the grubs:

  1. “Grub” them out, and either smash them or place them in a pail of water until they drown. It is so fast and easy to do it this way if it doesn’t gross you out.
  2. Apply milky spore to your pots. This natural grub killer that just targets Japanese beetle grubs and is approved for organic gardening.
  3. Remove the potting soil from the pot, bag the soil in plastic, and wait several weeks before adding it to garden beds as an amendment. By this time the grubs should be dead. Add new mix to your pot for a grub-free start. (Click here to see our many potting soils.)

I hope that these tips help.

Happy container gardening!

Jessie Keith

Black Gold Horticulturist