Iridescent gold and shiny emerald green, this critter may look beautiful in the sun, but it can easily do a lot of damage to your garden. The Japanese beetle is an invasive species with a giant appetite.
Currently, the insect is still in its larval stage in the soil. If you dig into the ground, you might see the telltale C-shaped grubs, waiting to mature and become full beetles. When they emerge, they'll be hungry, and your garden is the closest salad bar.
With some preventative treatment now, you can do your plants a favor and help avoid full-on beetlemania.
Inoculate with nematodes
The best method to control these invasive beetles is with microscopic organisms called parasitic nematodes. These are available to purchase locally or through the mail.
The nematodes will arrive in a sponge that you then ring out into a bucket of water. From there, grab a hose end sprayer and spray the nematode-rich water into the areas where grubs live and where adult beetles were feeding last year.
Aim to spray around rose bushes, grape vines, raspberries and basil. The nematodes will then parasitize the Japanese beetle grubs in the soil, and fewer will grow into adult beetles.
Spray with Bt
Another method is a new form of Bacillus thuringiensis, or Bt, that is used on cabbage worms, called "Galleria." It is purported to work on both Japanese beetle grubs and adults.
Take care using any Bt, though, as it kills all types of lepidoptera caterpillars in the butterfly family, including swallowtails and other beneficial pollinators.
Set traps
This next Japanese beetle remedy can be polarizing: beetle traps. Many gardeners have sworn off traps, because they seem to attract more beetles to your yard than they repel or catch. Still, they can be used effectively, with the right placement and coordination.
You may have seen them in lawns and gardens over the years and wondered what they were. Beetle traps are available in garden centers and usually have a yellow top and a green collection bag and hang on a hook that you place in the ground.
These lures contain scents that the beetles find enticing (think, flowers) and usually an attractant like pheromones.
The hope is the beetles will be drawn to the trap, get curious about what’s inside, then fall in.
In order to benefit from this method, assess your yard size. If you've got a fairly large lawn, place the beetle traps a couple hundred feet away from your garden. This way, the Japanese beetles are hitting the traps before they hit your garden.
And height placement is key, too. The cruising altitude of a Japanese beetle is less than a foot off the ground. Aim to hang the traps there.
Conversely, if you are covering a small area, invite your neighbors to join you in combating the beetle invasion and have them set up traps, as well. That way, the beetles won’t all descend on your yard and garden. More traps can help catch more beetles before they decimate your plants and flowers (and your neighbors', too).
And if you prefer a free approach, the tried-and-true hand-picking method works just fine. Once the adults come out in a few weeks, you can start hand-picking the beetles to lessen their numbers.
Growing lentils in Vermont
Q: I wish to grow lentils to harvest, not sprouts to eat. Where can I find information? - Ellen, in New Haven
A: Lentils are a cool-season legume that can grow in Vermont and prefer cool temperatures and dry conditions.
Plant them at the same times as other legumes like peas in spring. They take a long time to mature and are ready to harvest in August or September.
If you want to give them a try next year, some seed companies carry them, like Victory Seeds and Annie's Heirloom Seeds.
How to tell if your compost is nutrient-rich
Q: Suggestions on how to routinely nutritionally test our various in-content mature compost piles? We love to “ shop” for the best pile for the needs of our crops but would like to test quickly for more specificity on nutrients. - Scout, Someday Farm, East Dorset
A: A lot of the state land grant university labs will test soil samples from compost piles. Unfortunately, the University of Vermont no longer does, but the University of Maine does.
You can send out samples as you would a regular soil test, and they will give you the analysis of the nutrient levels of your compost pile.
Knowing the nutrient details can let you know if certain compost piles are better for certain crops than others.
Lilac tree needs an energy boost
Q: I thought I was looking at big buds forming on my lilacs, but as it turns out they are the seed pods from last year’s flowers. After a closer inspection, I did see a few new flower buds forming, but not that many. Did last year’s big blooms tucker them out for this year? - Patricia, in Cornwall
A: If the lilac has leafed out already but not produced blooms, then just let it be. But if you don't see any new leaves, then a drastic pruning is likely the remedy here.
Cut the lilac back to a couple of feet off the ground to stimulate some new growth. You should start to see new growth from the ground and other branches.
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