What I was wondering is it possible Rose Midge are attacking these two plants?

I can not find much info on Rose Midge and what states they may be in...

Hi Jim: When I googled, "rose bud turning black", the below link gave this answer, which confirmed my suspicion:

http://www.olyrose.org/pests.htm

"Roses fail to blossom or existing buds suddenly turn black and die. The foliage and the stem surrounding affected buds may also blacken and die. (Cause) Rose midge, a fly larva that is white and 1/12 inch long. The larvae feed in clusters at the bases of rosebuds. These will be hard to spot, look carefully at the bud base."

Mars asked me about rose midge before, which I detailed the answer in another thread. Mulch provides the optimal moisture for midge-germination. I had rose-midge on Golden Celebration early spring, since I made the soil fluffy in that area, perfect moisture for midge. Golden Celebration gave me 2 blooms in spring flush. Then I researched on midge, and FLOODED that area daily.

Midge can't germinate when it's too dry like CA, or too wet (flooding). They germinate when it's the right moisture, as in mulch. I also sprinkled gritty lime around Golden Celebration, now it has 15+ fat buds, and I get daily blooms.

Hi Jim: Forget to mention that calcium (in lime pellets, ground, or gritty lime at pH 9) is alkaline and helps to neutralize rain water (pH 5.6).

Calcium strengthen the cell-wall of plants, to prevent entry by insects such as aphids, midge, and thrips. Frederic Mistral rose is known as Mr.Thrips ... but thrips leave him alone after I spread gritty lime. My Fred's stems & flower petals are super-firm & thick.

I have Stephen's Big Purple, a rose that likes heat plus good vase life .... such rose needs a larger amount of calcium for firmness. It's next to my limestone patio, so I thought I don't need to spread gritty lime. WRONG !! It does nothing after the 1st flush (at least 10 long stem blooms). Sulfate of potash didn't help, nor Pennington tea, nor tons of rain. No new grow for weeks !!

I notice 2 leaves got black spots, so I spread gritty lime. BOOM !! It broke out in new shoots, lots of buds. Calcium is documented by studies to enhance absorption of nitrogen, phosphorus, potassium, and trace elements. So it helps plants to utilize fertilizers better.

Calcium is the second most important macronutrient for plants. It's essential for root growth. See this excerpt from eHow: "Plants with calcium deficiency may show signs of tip burn in young leaves. Fruits such as cherry and apple may show cracking in ripe fruits. Corn plants cannot develop healthy root tips and new leaves do not develop. In some cases, seeds may not develop or the plant may show stunted growth.

Solution: Calcium deficiency occurs more often in acidic soil. Gardeners can increase the calcium content of soil by adding dolomitic lime or gypsum." Read more : http://www.ehow.com/facts_7762437_calcium-plant-grow.html

Here is a link that might be useful: eHow on calcium requirement for plants

It was confirmed today we have Rose Midge...

Thanks for the info Strawbhill!

Found a pdf file from University of Kentucky Agricultural Station, Department of Chemistry on the effects of manganese, zinc, and copper on yeast to make alcohol. Yeast is a fungi. Their conclusion: "The use of manganese sulphate increased the yield of alcohol by 3%. But the use of zinc chloride resulted in the sugar NOT being fermented. And fermentation was DECREASED in copper vessel compared to glass vessel."

That paper confirms the other research, see below:
http://www.bioportfolio.com/resources/pmarticle/301868/Antifungal-Activity-And-Cytotoxicity-Of-Zinc-Calcium-Or-Copper-Alginate-Fibers.html

"... the fungal inhibitory rates were measured using the plate-count method following shake-flask test. Moreover, an inhibition-zone test and observation by scanning electron microscopy were carried out. The inhibitory rate of the calcium, copper, and zinc alginate fibers were, respectively, 49.1, 68.6, and 92.2 %. "

*** From Straw: I notice the same effects in my garden, the holes which were fixed with pine bark (used to break up my rock-hard clay) result in the most BS-prone roses. Frederic Mistral is always clean for the past 3 years, because I ran out of pine bark, and put decayed leaves in there. Pine bark is high in manganese, an element that encourages fungal growth. Pine bark is acidic at pH 4.5.

Here is a link that might be useful: Effects of manganese, copper, and zinc on yeast

This post was edited by Strawberryhill on Thu, Jul 10, 14 at 23:11

We do not get rust here nor much PM just mainly Blackspot and we get that fungal disease that looks like BS. (A?)

Thanks for the info Strawbhill...

Thank you, Jim, for the info. that you don't have rust nor powdery mildew, only black spots and anthracnose. I looked that up, here's an excerpt from below link:

"Anthracnose This fungal disease overwinters in the lesions of older rose canes. As wet conditions occur in spring and early fall, spores attack nearby canes and leaves. Symptoms appear as round, quarter-inch (six-mm), dark black, brown or purple spots on leaves. As these spots mature, they turn tan or light gray in color with dark red around the margin. The leaf tissue within these rings may separate from the underside of the leaf, leaving a tissue paper effect. Symptoms on stems and canes are raised brown or purple spots."

I don't have anthracnose, only black spots. I induced mildew one time when I used too much acid fertilizer high in nitrogen & salt ... that was 3 years ago. I didn't have rust in my 20+ years of growing roses, nor see any rust in the rose park for the past decades. But I induced rust last year on 4 roses by throwing gypsum (calcium sulfate) on top.

In that experiment, gypsum release of 21% calcium, and 17% sulfur was too fast, thus driving down potassium, which is essential for rust-prevention. I did many experiments to control black spots, the most effective I have seen is dusting leaves with corn meal, and putting cheap cracked corn in the planting hole.

Spreading A THIN LAYER of slow-release gritty-lime (pH 9) on top, to counter-act the rain (pH 5.6) works too, but I have to balance the calcium by watering with sulfate of potash. Too much trouble, so I prefer using cracked corn in the planting hole, for its antifungal agents of zinc & copper.

Here is a link that might be useful: Gardenguides to rose diseases