Hi Ingrid: Last year I had very little blooms at 100 degrees drought ... I kept watering with my tap water at pH 8, didn't get much blooms, but giant Austin octopus canes.

This year it's hot and dry, but I pruned Austins really short early spring when we had rain, and kept putting citric acid or vinegar when I water Radio Times, it's blooming steady, no break in flushes, and stay compact below my knees.

Khalid in the English Roses Forum showed pics of his roses loaded with blooms, and dark-green leaves at 113 F, or 45 Celsius ... much hotter than my present 95 F (35 Celsius). His secret? He put gypsum in the planting hole, and regularly apply gypsum and superphosphate, plus his tap water is neutral.

I tested soluble gypsum powder (calcium sulfate) bought from Kelp4Less, 5 lbs. for $8. That stuff is slightly acidic so it dissolved well in water. The 6 roses I bought from Roses Unlimited summer sale did nothing, until I put soluble gypsum ... they broke out in new growth, 4 of them grew buds. Nahema did nothing after last winter, zero growth, finally put forth a new growth plus bud. King Arthur roses was all yellowish & pale, now dark-green with soluble gypsum.

The sulfate in calcium sulfate promotes new growth, and green up foliage. The calcium part is to maximize water uptake ... works just as well as alfalfa meal (high in calcium). Epsom salt (magnesium sulfate) has the sulfate part to promote new growth, but the magnesium part is useless in clay (already high in magnesium). Epsom salt was very hard to dissolve in water when I tested it, made 2 roses in pot more yellowish.

Calcium sulfate (gypsum) works better, both in promoting new growth, and help plants to retain water during high heat. I got my 1st bloom from Angel Face, bought end of June from Roses Unlimited, thanks to soluble gypsum, see below ... no JB on that one either:

Ooooh, pretty roses, and I'm thrilled to hear of soluble gypsum because I'm on a huge viticulture kick at the moment :) My few vines are babies and still potted and I've already picked out an appellation name, lol. If you are a geology geek, let me know! I have rock questions.

My roses, unfortunately, all attract JBs. Not at first, but by this time of year they are all messed up. The best I can say is that Weeping China Doll still looks nice from a distance because of the sheer quantity of bloom. Or maybe they don't finish munching on her? They have a feast in my yard (acreage), unfortunately. They tear up Maman Cochet and many others in the bud stage, even. They do seem to like the pale ones when they first arrive, if that helps.

Wait, I have a pale rose blooming -- My Wild Irish Rose -- and she's not very bad at all. She's a scentless single and not close to most of my other roses. She's on the edge of a very woodlandy, snakey spot. I would be thrilled if something is eating them! The JBs are eating other things nearby in more sun and less groundcover, definitely.

I haven't had thrips in a while. Something must like eating them here or something, because I used to and I never sprayed for thrips. I don't spray for most things, and then it's a little bit of spinosad on a very few plants. My pale Austins were the worst for thrips.

I have never noticed a Japanese beetle on my Starry Night single white rose...I don't know if this is the rose or the location, right up against the house. My container rose, Jubilee Celebration, has never had one, either, to my knowledge. My daughter goes out with a bowl of soapy water every day to knock those buggers to their death, so we are watching the bushes closely.

Ragged Robin (Gloire des Rosomanes) - second summer in my garden - no blackspot, thrips or aphids. My only no-spray rose.

It's a pity you can't have it, Strawberryhill. According to HMF it's USDA zone 7 through 10. Lovely rose. Wonderful colour. Very robust if it survived my awful ministrations (I moved it half a dozen times already).

Those who get really heavy infestations claim that sooner or later the JBs will get to ALL the roses, though they seem to like starting with the lighter ones and then graduate to the darker ones.

Kate

Thank you, Kate, Vicky, Wintercat, and Meredith for the info.

Hi Meredith: I love your sense of humor! Per your question if I'm a geology geek ... sort of, since I hang out in the Soil Forum, plus my B.S. is in Computer Science, minor in Chemistry. I grew up on a 5-acres farm in Michigan so my interest extends beyond roses to soil and gardening. I welcome your "rock questions" ... I'm sure I learn something too.

This year, The Generous Gardner is a JB magnet, but Windermere (not that dissimilar in color/fragrance) is virtually free of JB's. It's interesting though, from reading your posts strawberry, that Windermere is under the porch overhang and thus gets less direct rain (and I haven't watered it with hose), while TGG gets rained on quite a bit. But Windermere has been blooming better this year.
The weather here has been terrible. It's either torrential downpours or blistering-surface-of-the-sun 90-95 degree solar blasts. I feel so bad for my poor flowers. Windermere is finally blooming again, but poor TGG's blooms barely last a day with the JB offensive.

At peak I find them on all roses, through the years Ive grown hundreds of different roses and many classes, I cannot say I found a JB that wouldnt munch on all of them. I stopped buying any repeating or modern roses years ago, becuase it wasnt worth the pain and aggrevation to grow roses (wide mix of Austins, HTs, Floribundas, even some knockouts)

So ANYTHING in bloom at this time attracts them first, then ANY new growth attracts them second.

Since I mostly have zero blooms left, this leaves my mid summer vigorous growers as the ones hit the most, they particular seem to like the new growth on my centifolias the best, but will chew on anything.

At peak I would have near 100k JBs in my yard, I learned long time ago not to bother combating them, I grow Once bloomers now , then pray and hope they are done thier flushes before JBs arrive in any #s.

I see JBs on almost all plants, even supposedly ones they do not like, (cosmos and nigella, even annual poppies for goodness sake)

This year first JB was seen on 6/18 in my yard (typical year is around 7/4) this just means less flowers. Early blooming is best (late spring) and anything you can eek out later august (asters and assorted fall bloomers)

Maybe there is a peak difference between chicago area and northeast new england? But peak here pretty much means your done for a month or so, I started growing daylilies instead. JBs eat those too, but only when they are open, since they last a day, makes a big difference.

Celeste who probably had the biggest rose collection in the northeast on this forum, has scaled back her roses as well, she is also starting to add more and more daylilies in her yard.

Silverkelt

Just curious, but do any of you grow Four O'Clocks to control the Japanese Beetles?

I have read how the white sap is poisonous to the beetles, was curious if anyone had any practical knowledge.

I tried growing four o clocks one year as a filler in a entire bed of about 25 austins or so..

It did nothing.. they even chomped on some of its leaves.

However, it was rather pretty, but its not a perreniel here. I might have to sow some more of it now that you bring it up !

At one time, pelargonium (pot geranium) was promoted as a JB killer. Thing is, though, JBs much prefer eating roses. They are attracted to rose scent and the big splashes of color.. And if you have thousands of JBs in the yard, it makes no difference if a few of them make themselves dizzy by nibbling a four o'clock.

Color is a primary factor in attracting both JBs and thrips. Red and orange get fewer customers than light pink and white. 'Quietness' seems exceptional in being resistant to thrips although it should be an ideal target, being blush white with lots of petals.

Hi Silverkelt: My sympathies and best wishes regarding JB. My soil is alkaline-rock-hard clay. Grass roots are very deep, less chance for grubs to dwell. I used to live in Connecticut with acidic and fluffly soil. My Mom's lawn in acidic Michigan is thin and mossy.

Some info. from eHow: "Some plants, instead of repelling pests, actually attract and then kill them. Larkspur and four-o-clocks, for instance, both attract Japanese beetles but also contain substances toxic to them... Garden plants that repel Japanese beetles include tansy, rue, garlic and catnip."

One info. from Purdue Extension: "Small plants such as roses can be protected by covering them with cheesecloth or other fine netting (less than one quarter inch"

I tried the above approach with a cluster of ripe peaches .. didn't work, since I used the netting of a lemon bag, holes were too big. More info. from link below:

"The beetles can be killed by causing them to drop into a container of soapy water. With the container opening under the beetle, poke at the beetle. It will readily fall into the container and die. This may be easier to do early in the morning when temperatures are lower because the insects are more sluggish. "

"For preventative treatments of grubs in the lawn, apply products containing imidacloprid or halofenozide before eggs hatch (late July-early August). Curative grub treatments are applied in August after egg hatch."

Here is a link that might be useful: Purdue Extension on JB

Using Strawberries info:

"Some info. from eHow: "Some plants, instead of repelling pests, actually attract and then kill them. Larkspur and four-o-clocks, for instance, both attract Japanese beetles but also contain substances toxic to them... "

I wonder if planting the Four O'Clocks some where one had no roses if it would attract them there instead? (they come in white and pink too)

Just curious since thank goodness we do not have those bugs!

This has been the same discussion for over a decade on here. I have tried, rejected and retried items dozens of times. When you are surronded by hundreds of acres of woods (as most who live in rural maine are) spraying your little patch of yard isnt all that effective) I too for years did the soap can, but frankly after one weekend where my family and friends helped me pick over 10k JBs and I finally relized its impossible to really put a dent in them, Ive given up. There are members here that DO spray and they were pretty much forced away from the Forums at that time. Weve had some back and forth battles here, with sadly knowledge people have left becuase of it.

There is nothing you can do except spray with heavily toxic substances every 2-3 days to keep a rose garden in bloom. I fail to see where putting cheesecloth down would help, you couldnt see anything under them!

I choose not to spray (other then remove infastations early in the season (red asian beetles and rose slugs, pre flower forming invasive, and 1-2 applications is enough to knock them out) so I have forgone repeating roses. I think its the best choice all around.

I still have a couple and every once in awhile will get a small fall rose flush.

When I first started (more north from here and a decade and half ago) growing roses, the season wasnt as bad, you could basically pick the JBS off, but now, it is worse, I can tell, you cannot keep up on a rose garden without spraying, especially if you have roses in any numbers

Hi Silverkelt: I feel your frustration, I wonder if everyone has a Japanese beetle-trap, would that decrease the overall population of JB? I put a trap on the tree in our 1st year of JB, no-work way of having hundreds in a bag. The next year tremendous decrease of JB. There's a farmer who reported putting traps on trees just to catch JB to feed his chickens.

My neighbor put JB trap on his peach tree last year. He got peaches to eat, I did not set a trap on my peach tree ... I didn't have much to eat. This year, a tremendous decrease in JB, not sure if it's from my neighbor's traps. JB hatch from the grubs buried in our lawn here.

I'm going to buy traps just for the tremendous satisfaction of crushing tons of them. The traps saved my tree that year ... there were hundreds of them feasting on that tree.

Assorted JB damage pictures, its actually past peak now, these were taken early today, before they were really active.

THEY love coneflowers.. well they like most flowers. but Coneflowers are right behind roses..

{{gwi:295826}}

On Ghiseline..

{{gwi:295827}}

Rober El Diable.. about 25% of my roses look like this below.

{{gwi:295828}}

A few early in the morning, there #s go up 100 fold during the mid morning to mid afternoon then tail back down at night.

{{gwi:295829}}

I'm so sorry, Silverkelt ... My heart goes out to you. It's a sad sight. My sister in CT has it good: no dandelions on her lawn, no JB either. She lives in the suburb near Hartford.

Info. below: "As they devour your landscape they start laying batches of eggs. Usually 20 to 60 eggs total per female beetle."

I checked on whether traps should be used, here's the best answer I found: "Without a doubt these traps attract a lot of beetles, but some research indicates that they attract more beetles to the area of the trap. That means that plants in the path of the trap might suffer more damage...If you use traps place them near the edge of the property and well away from plants that are damaged by Japanese Beetles."

I'm going to set traps far way from my roses.

Here is a link that might be useful: How to get rid of Japanese Beetles

I hope that someone is still reading this thread. I have a very special (to me) Hybrid Tea Rose that is destroyed by Japanese Beetles. Has anyone tried under-planting roses with Catmint (Catnip)? Does it keep the JPs away?

Vivien: Catmint doesn't keep the JPs away, at least in my garden. I have just as much JP damage to the roses interspersed with catmint as to those that aren't.

Too bad! Thank you so much for your reply.

No more repeat bloomers for me. JB arrived last year heard about them on hear for years. Its ruined my garden. NOT sure if its worth all the work now...

The JB ruined my first bloom on my Hybrid Tea, but now, in second bloom, the roses are free of those monsters. I'm in Ontario, close to Niagara Falls, and am re-assessing my desire for roses. I have only three because we recently moved and I had to start over. I find that I am healing more slowly as I get older and I wonder how much flower value there is for the work, the thorns, and the beetles. I need to keep my Peaudouce because my mother gave it to me (it was called Sunnybrook because it was sold as the hospital fundraiser back in the '90's, and was the name of our farm and business). And because it is SO beautiful. Also Red Corsair, a climbing rose that blooms for ages, has nice hips, and was not bothered by Japanese beetles. But the Jasmina (also no JB and so pretty, but blooms for a short time only) will probably be replaced by Clematis.