Home gardeners are busy harvesting their crops until the summer garden pests move in! To talk to an expert, I called up UK Extension Entomologist Dr. Jonathan Larson to see what information he could provide to keep these summer pests under control.
A popular summer pest in the Kentucky garden is the Japanese beetle. Japanese beetles are easily recognized by their attractive, shiny emerald-green and copper color. They are about 7/16 of an inch long, and if you look closely, you’ll see patches of white hair on their sides.
The beetles have sharp, chewing mouth parts that allow them to grind up tender leaf tissue between the veins, leaving the leaves skeletonized and lacy. But they don’t stop at leaves. They will shred flowers – you’ve probably seen them buried into the blooms on your roses – and even eat fruit. They attack and feed on more than 300 different plant species. Their favorites include linden, roses, grapes, blackberries and peaches.
So how do you protect your garden from Japanese beetles? First, if you’re in the process of planning or planting your landscape, consider including species and cultivars they don’t like to eat. Examples of those are most oaks, hollies, tulip trees and silver maples.
For those of us whose landscapes are mature and planting more trees isn’t feasible, one of the best methods is to simply pick off and kill beetles when you see them on your plants. Beetles will be strongly attracted to a plant that is already damaged by beetles. The more damage, the more beetles, resulting in more damage and more beetles. It’s a vicious cycle. If you walk through your garden in the evening and remove beetles by hand, you’ll cut back on the number of beetles that show up the next day. Pick them off and plop them in a bucket of soapy water.
There are insecticides available that can help kill or repel beetles, but always follow the label instructions carefully and beware of treating any plant that is blooming. Organic options, which offer a three to four days of protection, include Neem oil, pyola and BtG (Bt for beetles). Synthetic options, which offer protection for one to three weeks, include bifenthryn, carbaryl, cyfluthrin and lamda-cyhalothrin.
Another common summer garden pest is the squash vine borer. The squash vine borer is a key pest of squash, gourds, and pumpkins in Kentucky. Symptoms appear in mid-summer when a long runner or an entire plant wilts suddenly. Infested vines usually die beyond the point of attack. Sawdust-like frass near the base of the plant is the best evidence of squash vine borer activity. Careful examination will uncover yellow-brown excrement pushed out through holes in the side of the stem at the point of wilting. If the stem is split open, one to several borers are usually present. The caterpillars reach a length of 1 inch and has a brown head and a cream-colored body.
Monitor plants weekly from mid-June through August for initial signs of the borer’s frass at entrance holes in the stems. Very early signs of larval feeding indicate that other eggs will be hatching soon.
Home gardeners may have some success with deworming the vines. At the first signs of the sawdust-like frass, vines are slit lengthwise near where the damage is found and the borers removed. The stems should be immediately covered with earth. Sanitation is also important. After harvest is complete, vines should be removed from the garden and composted to prevent the remaining borers from completing larval development.
Gardeners should also be concerned with ticks that can harm the body. To hear the full interview with Dr. Larson, make sure to check out Episode 9 on Summer Garden Pests from the Sunshine Gardening Podcast!
We appreciate Dr. Jonathan Larson being our guest on the show! If you would like to learn more about insects, Dr. Larson also has his very own podcast called Arthro-Pod. To hear more about what is covered on the Arthro-Pod, click here: http://arthro-pod.blogspot.com/.
As always, gardeners keep on digging into gardening and remember to add a little sunshine!
Kristin G. Hildabrand, Warren County Extension Agent for Horticulture
Home gardeners have finally gotten warm-season vegetable crops planted in their home vegetable gardens. Now, you may wonder, “What should I do next?” Today on episode 7 of the Sunshine Gardening Podcast, I am sharing 4 secrets on how to keep your garden looking attractive to finish strong for the month of May! Stay with me for more details right here on the Sunshine Gardening Podcast!
#1- Use Companion Planting Strategies.
Gardeners have planted several warm-season vegetables in the garden this month! They may have planted a nice mixture of tomatoes, peppers, eggplant, cucumbers, squash, and sweet corn. Alongside these vegetables, gardeners should consider planting culinary herbs since they serve as a great companion plant. Companion planting is defined as planting two or more crops near each other crops in the vegetable garden to gain benefits for the home gardener. It has been shown to maximize vegetable yields, improve pest management, increase nutrient uptake, and enhance pollination with some crops.
Planting herbs around vegetables invite beneficial organisms to the garden. Herbs like basil, cilantro, dill, and parsley attract beneficial insects to feed and find shelter to support various stages of predatory and parasitic insects. Lady beetles, lacewings, praying mantids, and spiders are among those organisms that are attracted to aromatic culinary herbs. Not only are companion plantings good for attracting beneficial insects, they also draw in native pollinators. Some examples of culinary herbs to make room for in the garden are basil and oregano. Basil is a good herb for planting around tomatoes and provides shelter for a number of beneficial insects such as lady beetles and lacewings. Oregano is the pizza herb to use for seasoning pizza dishes at home.
Another plant that comes to mind with companion planting is marigolds. Several gardeners plant this warm season flower every year in their garden to protect vegetables from harmful insects. Research has shown that the roots of marigolds produce biochemical that are poisonous to minute worm-like organisms that can cause damage to plants.
To discover other possibilities of companion plants to use in the home vegetable garden, make sure to see the show notes. I have included a table that lists crops that do well when planted next to each other in the home vegetable garden.
|Corn||Beans, Cucumbers, English Pea, Irish Potato, |
|Cucumber||Beans, Cabbage, Corn, English Pea, Radish, Sunflowers|
|Eggplant||Basil, Beans, Catnip, Lemon Grass, Marigold|
|Okra||Peppers, Squash, Sweet Potatoes|
|Pepper||Basil, Clover, Marjoram, Tomato|
|Squash||Nasturtium, Corn, Marigold|
|Sweet Potato||Okra, Peppers, Sunflowers|
|Tomato||Asparagus, Basil, Carrot, Cucumber, |
Marigold, Onions, Parsley, Rosemary
Source: ATTRA publication on
Companion Planting & Botanical Pesticides: Concepts & Resources
#2- Provide vegetable plants with water after being planted.
It is important to provide plants with water after being planted in the ground. Carry out watering routines in the morning between the hours of 6am and 10am. This time frame allows plants plenty of time to dry off during the day. Avoid splashing the foliage with water to reduce foliar diseases.
While it may be expensive, drip irrigation is a convenient way to provide consistent soil moisture to plants. Water is targeted at the base of the plant which is then absorbed by the root system.
Here are critical times to water common vegetable crops in the home garden.
- Cucumber- flowering and fruit development
- Eggplant- uniform supply from flowering through harvest
- Melon- fruit set and early development
- Pepper- uniform supply from flowering through harvest
- Summer squash- bud development, flowering, and fruit development
- Sweet Corn- silking, tasseling, and ear development
- Tomato- uniform supply from flowering through harvest
#3- Apply fresh organic mulch.
Mulch can offer several benefits to the home gardener! It helps conserve soil moisture by creating a barrier between the soil and the air, controls weeds by blocking the sunlight, and is aesthetically pleasing and attractive to the garden.
Apply 2 to 4 inches of fresh mulch around plants to help conserve soil moisture and reduce weeds. If you desire an organic mulch, layers of newspaper or straw are good mulches to consider. These mulches will return nutrients into the ground after they have decomposed. Another option would be inorganic mulch like black plastic. This type of mulch will reduce weeds and encourage earlier planting for crops by 2 weeks.
#4- Side-dress vegetables at the correct time.
In order for vegetables to produce lush, continuous growth throughout the season, they require a uniform supply of nutrients. Gardeners should side-dress vegetable transplants at the correct time and at the recommended rate to give them an extra supply of nutrients needed for continuous growth throughout the season.
Here are the recommended times for side-dressing common vegetables in the home garden.
- Cucumber- apply 1 week after blossoming begins and Eggplant- after first fruit set
- Peppers- after first fruit set
- Squash- additional nitrogen might reduce yield or lower quality
- Sweet corn- when plants are 12 inches tall
- Tomatoes- apply 1 to 2 weeks before first picking and same amount 2 weeks after first picking
I hope that you found this information helpful today. If you would like additional information on other gardening tasks to perform this month, make sure to see the show notes on the blog at Warren County Agriculture to find the May Gardening Checklist that I have created. It lists other activities to do in and around the home garden. To view this checklist, visit me on the blog at Warren County Agriculture, https://warrencountyagriculture.com/. Feel free to leave any questions that you might have or make any additional comments on the blog.
As always, make sure to tune in with me for more gardening information each week right here on the Sunshine Gardening Podcast! Each week, I plan to share seasonal gardening tips and tricks to help gardeners reach their gardening goals and to help the sun shine a little brighter over their Kentucky garden. To stay up to date on all the latest episodes, hit the subscribe button wherever you get your podcasts.
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Gardeners keep digging into gardening and remember to add a little sunshine!
Home Vegetable Gardening in Kentucky, ID-128- http://www2.ca.uky.edu/agcomm/pubs/id/id128/id128.pdf