Japanese Beetle Summer Battle Report 2019

If your landscape is free from Japanese beetle chewing, then you've won the plant lottery, at least for the time being. These voracious eaters of scores of many of our favorite landscape plants, fruits and vegetables and well-watered grass roots are on the move in more neighborhoods of metro Denver and locales north and south. To track their spread in our state and arrival in your yard, please contact Dr. Frank Krell at the Denver Museum of Nature and Science. Follow the reporting instructions here. 

Japanese beetles arrived in New Jersey (from Japan) in 1916 and didn't make it to Colorado for almost one hundred years. I've been battling Japanese beetles in our landscape for over seven years, it seems longer. 

Managing Japanese beetles and their offspring white grubs (next year's generation) is very doable and might ease your frustration of seeing your favorite plants chewed or defoliated. 

Hand picking, or flicking adult beetles into a soapy death bath is easy and provides immediate satisfaction. Use an old can or plastic bucket and drain the contents and toss every few days, they get stinky. Chickens, ducks and goats will gladly munch on Japanese beetles for an all day snack - they can't reach tall plants on their own, however. Some birds like grackles and starlings are reported to eat JBs, but I've never seen them in the act in my yard. 

4000+ Drowned Dead Japanese Beetles (2 days worth)

The best time to flick is morning or evening when they are docile on plants as they wait for the heat of the day to engage in their sole mission of chewing and scre (you know).

There are several over the counter products to mix and spray on adult beetles, but timing is very important so bees and other valuable pollinators are protected. First, read the product label, mix correctly and use with caution and care. 

Dr. Whitney Cranshaw's fact sheet on Japanese Beetles is a helpful resource on the many products available, their chemical names, trade names and other information about using on food crops and comments about pollinators. Click here. Print a copy, circle what your time frame and pocket book will allow. Some products can be pricey and most of them need to be sprayed every few days or so. 

Right now is the optimum time to put down a product in lawns to kill the eggs and white grubs (next year's beetles). Don't wait much longer. Only one product is needed per summer. Again, read all the package instructions, refer to the fact sheet for all the available products. Two products are very low to no impact to beneficial insects, people, pets, etc. Beneficial nematodes (mix and spray) and grubGONE! (granular application with spreader). Both products should be available locally at reputable independent garden centers or online.

There is long-term good news on the Japanese beetle battle. Dr. Cranshaw and the Colorado Department of Agriculture are responsible for bringing biocontrols that specifically attack adult beetles and or white grubs to Denver, Boulder and Pueblo. I wrote about the three controls last summer in a Denver Post article, read here. Efforts are continuing this summer for additional releases and testing to see if any of the controls are getting established, stay tuned! 

Additional Resources:

Japanese Beetle Management in Colorado - My Dedicated Japanese Beetle Website 

Plants - From Resistance to Extensive Feeding   

Japanese Beetle Fact Sheet 5.601 - Dr. Whitney Cranshaw

My Next Japanese Beetle Class at Denver Botanic Gardens, August 10, 2019. My last JB class of the year, look for the class again next winter and spring at Denver Botanic Gardens.   

Hot, Rainy and Windy, it must be July

"What a diff'erence a day makes" - a treasured song title which describes the last couple of days of weather in Colorado (there goes my obsession with weather-themed blogs again). From scorching 101 on Friday, July 19 to a pleasant-normal 85 the next day ... what a difference.

According to Wikipedia "What a Diff'erence a Day Made" was written in 1934 by Maria Grever, a Mexican songwriter. Translated that same year by American Stanley Adams, many artists started recording and singing this song in public, and with good reason. It's a wonderful song and an expression we use often for story telling and events. It could be the theme song for gardening in Colorado (at least the sun and the flower lyrics for sure)!

I could sit here watching YouTube videos of this song for hours. Why don't you pick the version you like best from the links below. 

Dina Washington (won a Grammy for Best Rhythm and Blues in 1959 for this recording)

Aiysha

Aretha Franklin

Rod Stewart

Cher (this will take you back ... way back)

Bobby Darin

Dean Martin 

En Vogue

There are many, many more versions and artists to view and listen, but a warning, you won't get your garden chores finished if you keep clicking! 

Hot, Dry and Windy, it must be July

One thing gardeners in Colorado can count on is not counting on the weather to provide ideal spring conditions to get the garden planted on time and tomatoes off to a good start. Our tomatoes got their good start in mid-June, no BLTs in sight until August. No worries, it will be well worth the wait.

Now it's July, the weather is typical July conditions in Colorado - hot, dry and often windy - a hot wind. I hate the wind.

Buckle up, or better yet, unbuckle to allow more air flow, the heat will be on and turned up the next few days. Sunday looks cooler, back to the 80s (if they're right).

My garden plans include the following, perhaps yours are similar:

Complete most outdoor chores early in the day. This includes walking Ferris around the park before 7:00 am. He doesn't like the heat, he's Irish by heritage and would be happy with 24/7, 365 cold and snow conditions.

I hand water containers and the newly seeded areas twice a day (at least). We're on our third sowing of basil. Several batches have already been harvested, processed with olive oil, labeled and frozen. Tomato sauces this winter will have the added benefit of almost fresh, homegrown basil. Thinking of a cold winter right now ain't so bad.

Tips on watering. If you're too busy to water in the morning, try watering in the cool of evening (there won't be much cool the next couple of days, so just pretend). When watered thoroughly (until water comes out of the bottom) containers will be nice and hydrated through the night and hot next day. 

If your containers are located on hot surfaces or near walls, make time before you're off to work in the morning to give them a quick, thorough shower of water. Yes, overhead watering, which is the opposite of the normal recommendation to water at the base of plants. 

Overhead watering is a great way to prevent or fight off spider mites which love many plants growing in hot conditions. A good dose of water easily splashes spider mites off of foliage and in these oven-like temperatures, your plants will be dry before you arrive at work. Do this every morning if you can. 

Consider moving your sunniest hanging baskets to a location with half-day sun until temperatures cool down a bit.  

Don't freak when you see plants wilt mid-day, that's their response to the heat, if they are still nodding later in the evening, check to see if they need watering - thumb down two-four inches. Or use a handy (free) screw driver near the plant. If it goes down fairly easily, then the rooting zone is probably moist, if you're pushing it down, then she's dry!  If in doubt, purchase a ten dollar indoor plant meter and poke it down like the screw driver. Water deeply, yet infrequently, about every 3-4 days depending on how fast your soil drains. 

Lawn watering - I use the soak and cycle method two times a week through most of the summer. That means the zones run through twice. I added an extra day this week with the hot temperatures. The system goes off at 5:00 am, 20 minutes each zone. Also, the grass is kept on the high side for three reasons. Taller grass keeps turf roots cooler, weeds aren't happy (they like short), and the female Japanese beetles don't like tall grass to lay their eggs. 

If you're seeing dry spots in the lawn, check your sprinkler heads. They may be broken or slightly askew. Also check to see that they aren't spraying the sidewalk or street. I'm seeing a lot of that this summer, what a waste! 

Other morning or evening chores:

Renew mulch around plantings to keep soil roots cooler, and weeds out. I'm not a fan of landscape fabric which long term doesn't improve the soil like organic mulches, they may compromise plant health and weeds get in, through or on top anyway.  

Shade new plantings and growing vegetables if you can. I've invested in shade cloth to use for hail and sun protection. It's sold in independent garden centers, some sell it bulk in rolls. It's not that expensive and will last for years if stored away at the end of the season. Tomatoes are especially adversely affected by 92+ temperatures. Fruiting stops or dry up which mean less fruit. Leaf roll is common and watch out for blossom end rot on the first fruits. 

No need to remind you to keep hydrated (your pets too), even while you're indoors watching The Open. Time for my water refill now. Stay cool out there fellow gardeners!!

Shade Cloth over Tomato

Japanese Beetle Plan for 2019

The following is revised from 2018. Not much has changed except the beetles emerged later this summer, most likely due to spring and early summer storms. Time will tell if they catch up in numbers, spread to new areas along the Front Range or hang around longer in the fall.

The Summer 4-Step Plan of Action-  

First, as difficult as it may seem - wrap your head around the fact that Japanese beetle management is ongoing from first sighting on your favorite plant (s) to sometime in the fall when their numbers wane. There is no one fix all/kill all application for adult beetles and their egg-larvae offspring (both stages can be treated). Well there is one fix all but that would require moving to Alaska or the Caribbean. 

Second, determine if and how you'll remove or manage the adult beetles all summer as they keep coming and coming and coming - just like the mail.

Third, determine if and how you'll treat your turf where they lay their eggs - you know, the next generation - 2020 beetles. 

Four, act on your plan.

The good news for determining two through four is that Dr. Whitney Cranshaw, Colorado State University entomologist extraordinaire has written a very informative and helpful fact sheet on the Japanese beetle. Find it HERE.

I suggest printing the document and reading it carefully. Pay attention to the Japanese beetle life cycle (one year) and understand that effective management involves dealing with both adult beetles and their offspring (larvae, also called white grubs). Adult beetles feed on foliage, flowers and fruit while their offspring - white grubs feed on grass roots. Both stages damage plants and roots.

Dr. Cranshaw includes excellent management recommendations for both life stages. Circle the ones that make the most sense to you based on your time and pocketbook. Some products are pricey if you choose to use them regularly all summer into fall.

Dr. Cranshaw has helped us tremendously with control details on the fact sheet by listing common names for products, trade names, persistence tips, whether the product is okay for use on food crops and the ever important pollinator hazard information.

Action - You may opt to do nothing - no management. Trust me, you'll incessantly complain about the out of control J. beetles to anyone who comes within ear shot. Eventually they will ask you to please stop whining and suggest that move. Maybe they will pack your bags.

The most rewarding and immediate control method is to flick adults into soapy water in the morning or evening when they are sluggish and easy to flick. Keeping the numbers down actually reduces more beetles from joining the eating party on your plants. What attracts them to the plants is the plant oils released by beetle chewing (called aggregation feeding), so less beetle chewing means less beetle visits. The research on Japanese beetles says that it is fine to squish or pinch adults on the spot. Their smushed parts do not attract more beetles to the area - it's the chewed plant oils that put out the welcome sign.

I know retired people who flick beetles on their infested plants twice a day. I don't think they are available for hire. If they were, their business card might read something like this - 
 

Japanese Beetle Removal - The Number One Firm in Flicking

"We flick so you don't have to"

 

For additional information you're welcome to view my website on Japanese beetle management in Colorado. In one place you'll find many more research-based fact sheets, plant lists and more. 

Click - Japanese Beetle Management Colorado

Inexpensive bridal tulle from fabric store over basil plants growing in Smart Pot to prevent JB eating - works great!

 

July Seeding - Fall Vegetables 2019

The third or fall season of vegetable planting is here and it's mid-summer!

We generally consider early spring (March if using cold frames) to the middle of May the first planting season with cool crops. The second season with warm season crops is mid-May to early summer. The third or fall season includes both warm and cool season and starts in July or later, depending on crop maturity before the fall frost.

We typically use mid-October as the first frost or freeze date, so focus on crops that will mature in about sixty days to be on the safe side. The seed packet will list days to harvest. 

Check the chart below for plants that can be seeded now through August and into early September. The list includes several other cool season vegetables and their best window for seeding and planting, some are perennials vegetables.

Tuck in seeds wherever there is room in the landscape or vegetable area. Try the shady side of taller crops like tomatoes or corn. This location keeps the plants cooler late in the day.

Cool season vegetables and herbs that can be seeded right now in early to mid July include beets, Brussels sprouts, cabbage, cauliflower, cilantro, Swiss chard, collards, bunching onions, parsley, peas.

Warm season vegetables and herbs that can be seeded right now include basil, bush beans, slicing cucumber, okra, New Zealand spinach, summer squash.

DIRECT SEED COOL SEASON VEGETABLES OUTSIDE before first fall frost   Use of cold frames or tunnels allow season extending

 

CROP – COOL SEASON	Days to Emerge	Days to Maturity	FALL SEED BASED ON MID-OCTOBER FREEZE
Arugula (herb) Eruca sativa	7-14 days	30-45 days	Mid-Aug
Arugula – wild or heirloom Diplotaxis tenuifolia	7-14 days	30-45 days	Mid-Aug
Asparagus Asparagus officinalis	14-21 days soak seeds prior	Perennial	Spring Plant
Artichoke – Imperial Star Cynara scolymus	10-15 days	85-100 days	Spring Plant
Beets Beta vulgaris	5-21 days	60-65 or sooner for leaves	Mid-July
Broccoli Brassica oleracea	7-14 days	45-75 variety differences	Mid-July
Broccoli Raab Brassica rapa	4-14 days	35-45 days	End-July
Brussels Sprouts Brassica oleracea Gemmifera group	5-10 days	80-110 days	Early-Mid July
Cabbage Brassica oleracea var capitita	7-12 days	60-80 days	Mid-July
Cabbage (Napa or Chinese) Brassica rapa var pekinensis	10-15 days	50-55 days	Mid-July
Cardoon Cynara cardunculus	10-15 days	100 days	Spring Plant
Carrots Daucus carota var sativus	10-25 days	65-75 days	Direct seed every 3 weeks until August 15
Cauliflower Brassica oleracea var botrytis	8-10 days	50-80 days variety differences	Mid-July
Celeriac Apium graveonlens	14-25 days	95 days	Spring Plant
Celery Apium graveonlens	14-25 days	80 days	Spring Plant
Cilantro (herb) Coriandrum sativum	10-20 days	50-55 days	Mid-July, likes cool weather
Chard-Swiss Beta vulgaris	5-10 days	25 days – baby leaves 50 days –  bunch	Spring-Summer-Early Fall
Chicory Cichorium intybus	14-21 days	65-70 days	Late July, prefers cool weather, moist soil
Chives Onion (herb) Allium schoenoprasum	10-15 days	Perennial	Spring-Summer, Early Fall
Chives Garlic (herb) Allium tuberosum	10-15 days	Perennial	Spring-Summer, Early Fall
Claytonia Claytonia perfoliata	7-14 days	40 days	Late August. Known as winter purslane, likes cool weather and soil
Collards Brassica oleracea	10-15 days	50-60 days	Mid-July
Cress Lepidium sativum	5-15 days	20-30 days	Early fall
Endive Cichorium endivia	7-10 days	60-70 days 35 days – baby leaves	Late summer, needs cool soil and temperatures
Escarole Cichorium endivia	7-10 days	45-60 days	Late summer, needs cool soil and temperatures
Fennel (herb) Foeniculum vulgare	14-21 days	90 days for bulbs, less for foliage	Mid-July
Garlic Allium sativum	10 days for warm fall	9 months for fall planted	From Mid-Sept to Mid-Oct
Greens – Baby varies	5-10 days	25-30	Seed through early fall
Horseradish Armoracia rusticana		Perennial	Harvest roots in late fall
Kale Brassica oleracea	5-10 days	50-55 days	Early August
Kale Greens Brassica oleracea	5-10 days	25-30 days or 7-14 days for micro -greens	Every two weeks until first fall frost
Kohlrabi Brassica oleracea (gongylodes group)	10-14 days	55 days	Mid-August
Leek Allium ampeloprasum (porrum group)	7-14 days	40 days for baby leeks, 84-100 for full size	Mid-August for baby leeks, okay to harvest after a couple of frosts
Lettuce Loose- Leaf Latuca sativa	5-10 days	21-68 days many varieties	Every three weeks until early fall, seed in afternoon shade of other plants
Lettuce Cos or Romaine Latuca sativa	5-10 days	50-70 days	Every three weeks until early fall, seed in afternoon shade of other plants
Lettuce Crisphead or Iceberg (tight leaves) Latuca sativa	5-10 days	75 days	Every three weeks until early fall, seed in afternoon shade of other plants
Lettuce Butterhead or Bibb (loose leaves) Latuca sativa	5-10 days	65 days	Every three weeks until early fall, seed in afternoon shade of other plants
Mâche Valerianella locusta	10-20 days	45-60 days	Late-August, afternoon shade
Mizuna Brassica rapa var. Japonica	4-7 days	35-45 days 21 days baby leaves	Late-August, afternoon shade
Mustard Greens Brassica juncea	7-10 days	50 days 21 for baby leaves	Late summer
Onion Seeds Allium cepa	7-15 days	70-150 days per onion day length	Spring Plant
Onion Bulbs or Sets Allium cepa	7-15 days	100 days or 3-4 weeks for green onions	August to Fall
Onion Bunching (Scallion) Allium fistulosum	10-15 days	60-65 days	Mid-July
Onion Egyptian Allium cepa var. proliferum	10-14 days	Perennial	Spring Plant
Orach Atriplex hortensis	7-14 days	35 days	Late August. Like a warm-season spinach, tolerates heat, nice annual ornamental too
Microgreens INDOORS	4-7 days	10-21 days, harvest days vary per seed types	Many seeds to choose from, seed in shallow trays all year, esp. in winter
Pak choi or Bok choy Brassica rapa (Chinensis group)	5-10 days	30-50 days	Late July to mid-September
Parsley (herb) Petroselinum crispum	14-28 days	60-75 days	Mid-July, Soak seeds prior to seeding, prefers afternoon shade
Parsnips Pastinaca sativa	10-25 days	85-120 days	Harvest in fall after frosts for sweet flavor
Peas – shell, snap, snow Pisum sativum	5-10 days	50-65 days	Mid-July, soak seeds prior to sowing
Potato Tubers Solanum tuberosum	10-15 days	90-120	Spring Plant
Radicchio Cichorium intybus	7-10 days	60-90 days	Late summer, needs cool soil and temperatures
Radish Raphanus sativus	5-10 days	20-30 days	Late summer until first fall frost
Radish - Daikon Raphanus sativus	5-10 days	60 days	Harvest any size in late fall before ground freezes
Rhubarb Crowns Rheum rhabarbarum		Perennial	Spring Plant. Grow one full year before harvest
Rhubarb Seeds Rheum rhabarbarum	7-14 days	Perennial	Spring Plant Soak seeds before planting. Grow one full year before harvest
Rutabaga Brassica napus	4-7 days	90-100 days	Spring Plant
Shallots Allium cepa var. aggregatum	10-15 days	100 days	Zone 5 or warmer fall or spring plant, Zone 4 or colder spring plant
Spinach - Common Spinacia oleracea	6-10 days	30-45 days	Use bolt resistant varieties during heat of summer, cold hardy types can overwinter
Tatsoi Brassica rapa var. narinosa	5-10 days	21 days baby leaves, 45 full leaves	Sow up to three weeks before first fall frost
Turnip Brassica rapa	5-10 days	40-75 days	Sow late summer before first fall frost

 

Many thanks to the following companies for reference - Botanical Interests Inc., Johnny’s Selected Seeds, Renee’s Garden, John Scheepers Seeds, Park Seed, Pinetree Garden Seeds, Colorado State University, Cornell University