This document printed from the University
of Illinois Extension Coles County Yard and Garden at http://www.extension.uiuc.edu/coles/
Japanese Beetles and Flower Container Design Tips
June 13, 2009
If Japanese beetles weren't so destructive, they'd be pretty. Shiny bronze-green adults are about 3/8 in. long. Larvae are 1-1/4-in.-long, C-shaped white grubs.
DAMAGE — Adults feed on most plants, boring into flowers or fruit and skeletonizing leaves. Grubs eat grass roots, causing spongy, off-color patches in lawns.
CONTROL — If you see just a few, pick them from plants in early morning or late evening when they're less active. A big infestation may need a general-purpose pesticide, but be sure it's safe for the plant. Don't use traps — they just attract more beetles.
To control the grubs, try bacterial milky spore disease or parasitic nematodes (Heterorhabditis), which you can find at stores. Both are watered into the lawn in early June, which means RIGHT NOW. Further helpful online articles:
For beautiful containers, choose three types of plants: Tall spikes, lush fillers, and long trailers. No matter what size or shape your pot, this no-fail formula is sure to produce results!
Be sure to choose plants which have similar light and water needs. Also, since containers dry out faster than plants in the ground, consider adding a moisture retention medium to the potting soil. I had a lot of old florist foam sitting around, so I cut it up into ½ inch cubes with an old bread knife. I mix several handsful into the pots, and it really does seem to cut down on the watering schedule. There are water-retaining polymer crystals for sale which perform the same function. Some potting soils already have them included.
Make sure you purchase plants of proportional mature size. Pay attention to the size information on the tag so you don't choose plants which will soon outgrow the pot or overpower the other plants.
AIM HIGH — The first type of plant that you'll need is a spike -- any plant that adds height to your container. The following plants make great spikes: Agave, amaranth, Bamboo, Bougainvillea, Cabbage tree (Cordyline indivisa), Canna, Colocasia, Common boxwood (Buxus sempervirens), Cycad, Dracena, Elephant Ear (Alocasia esculenta), Feather reed grass (Calamagrostis x acutiflora), Hibiscus, New Zealand flax (Phormium tenax), Palm Lily (Cordyline), Princess Flower (Tibouchina urvilleana), Purple Fountain grass (Pennisetum setaceum 'Rubrum'), Sweet Bay (Laurus nobilis), Tufted fescue (Festuca amethystina).
MIDDLE MAGIC — Fillers are shorter than the spike and taller than the trailers and are vital to the container's success. Fillers can play any role you'd like: Supporting actor to the star spike, or show-stopping diva. For a supporting role, make sure you choose fillers that have colors that complement the spike and don't compete with it.
If you want the diva, then look for lush, bold flowers like yellow begonias, or brightly colored or variegated foliage. The most successful fillers have mounding or bushy habits, like lantana, impatiens or blue fescue.
THE TRAILERS — Last, but certainly not least, are the trailers. These low-growers spill over the edge of the container and run along the sides. They help create a visual bridge between your pot and the rest of the planting. Trailers you might choose are: Swedish ivy, Alternanthera dentate, Alyssum, Asarina (Chickabiddy), Bidens, Brachycome (Swan River Daisy), Calibrachoa (Million bells), Cobea (Cup and Saucer Vine), Creeping Zinnia (Sanvitalia), Eccremocarpus (Glory Flower), Helichrysum petiolare (Licorice plant), Iberis (Annual Candytuft), Ipomea batatas (Sweet Potato Vine), Ivy geranium (Perlargonium peltatum), Laurentia Lotus berthelotii (Parrot's beak), Lobelia, Nasturtium, Plectranthus argentatus (Silver plectranthus), Scaevola (Fan Flower), Thunbergia alata (Black-eyed Susan vine), Verbena, Vinca, Wave Petunias.
With trailers, aim to keep it simple. Choose just one or two types of plants for the most impact. Plant the trailers right at the edge of your container. They can go all the way around the pot, or just spill over in one or two particular spots. By the middle of summer, don't worry if you have to cut back a trailer that's taking over the container.
The last step is to fix yourself a cold glass of iced tea and admire your artistry from the vantage point of your favorite lounge chair.
Upcoming gardening events:
TODAY Saturday, June 13, 10 am, 316 Briar Lane, Mattoon
Come for a free guided tour of Master Gardener Phyllis Schultz's beautiful gardens. This is a great opportunity to see how plants look in a home setting.
Phyllis' gardens show you how you can have it all on an urban lot. Something is almost always in bloom in this garden. Using a variety of grasses, evergreens, flowering shrubs, perennials and bulbs, with some annuals for color, make this possible. A berm, lily beds, patio area, shaded bench area and a tropical style bed with a banana tree give lots of variety for the plantings.
And while you're in garden-viewing mode, stop by the Master Gardener's Idea Garden by the emergency room entrance of SBLHC to see all the lovely flowers in bloom. It's worth a trip!
Sunday, June 14 at the 5 Mile House, Charleston Susan Humphreys will give two interesting talks: 1:00 - Frontier Plant Pharmacy, 2:00 - Heirloom Veggies for Today's Gardens. To get there, take Route 130 south from Charleston High School to the corner of the Westfield Road. 5 Mile House is one of the oldest structures in Coles County, ca.1840, serving as a stage coach stop and a blacksmith shop, among other functions. Go to the website http://www.fivemilehouse.org/ to see photos and learn about other Sunday programs going on this summer.
If you have any horticulture questions, call the U of I Extension office 345-7034. Volunteer Master Gardeners are in the office on: Monday—2 to 4 p.m.; Wednesday and Friday—9-11 a.m.
This column is based on information and materials at the University of Illinois Extension office, located at 707 Windsor Road, Suite A., Charleston, 61920; phone 345-7034; or web site: www.extension.uiuc.edu/coles/
