Straw: thank you for clearing this out. This picture is from the pot with Double Delight. I wasn't worry much because I see tons of buds ( she always blooms, but this time I see twice more buds forming ). The corn is under the mulch I moved it for the picture.

I get whole corn from the mill to crack for my chickens. I didn't know corn is good for roses. what does it do and how should I apply? Thanks Straw!

Alana: It depends on your soil & climate and the rootstock. Anna is in CA with alkaline soil and tap-water, thus acidic corn (pH 4) helps to LOWER her alkaline tap water. But I won't recommend acidic corn for someone with acidic clay.

Also Le Nia Rias (centifolia) once-bloomer is a real pain to grow, and a real-pain to dig up. I haven't have the time to kill that one: it suckers every where, despite my rock-hard clay. I tried to dig up one sucker, and gave up, the root is too deep. I simply chop the suckers off with a clipper, and hope that after brutal zone 5a winter, I'll have time to kill. It sends suckers 4 feet away, right inside my peonies, and more suckers on my lawn. Le Nia Rias is very invasive, don't recommend that.

I did test mixing alkaline clay with cracked corn, and topped a few roses with that .. I pH-tested the combo (it's slightly acidic, barely pinkish in red-cabbage juice). Stephen Big Purple (next to limestone patio) loved that stuff, Double-Delight (prefer alkaline) exploded in 7 buds for 3rd-flush, with minor blackspots due to lowering of pH. But Pink Peace grafted-on-Dr.Huey (prefer alkaline) came down with blackspots from lowering pH.

Yes, cracked corn is full of nutrients & trace elements, but its acidic pH will make leaves thinner and prone to blackspots if the soil is neutral to acidic. However, acidic & moldy corn is beneficial for wimpy own-roots that can't do acid-phosphatase (secrete acid to utilize phosphorus from soil).

When corn is fully composted & neutral pH, then it's safer for neutral to acidic soil. With my alkaline clay pH near 8, I put fresh cracked-corn in the planting hole with zero problems, since my clay buffers the acidity of corn.

An excerpt from below link on how mold on corn can help plants with nutrients-uptake:

http://sciweb.nybg.org/science2/hcol/mycorrhizae.asp.html

What Benefits do Mycorrhizal Fungi Offer to Plants?

Fungi are heterotropic organisms, and must absorb their food. Fungi also have the ability to easily absorb elements such a phosphorus and nitrogen which are essential for life. Plants are autotropic, producing their food in the form of carbohydrates through the process of photosynthesis. However, plants often have difficulty obtaining and absorbing many of the essential nutrients needed for life, specifically nitrogen and phosphorus.

Thanks for all the info Straw! I think I do have neutral to acidic clay, so it would not work for me. I think it was a 7 or so the last time I checked. I can't remember exactly. Thanks for everything Straw. You are so full of great helpful information. I think you said you had a degree in science or something..Thanks for letting me know about Le Nia Rias too.

Alana: Thanks for the kind words .. yes, my B.S. is in Computer Science, minor in Chemistry. I took all the science classes: microbiology, biochemistry, organic chemistry, inorganic chemistry. I worked as a C-programmer before I became a stay-home Mom.

I learn best from new-posters, such as Anna who posted honest pics. of her roses, that's how I first learned about boron deficiency and how boron is essential for blooming. Another poster (Grace) informed me of her soil test too high in calcium, too low in potassium which resulted in slender stems, balling, and blackspots. And Khalid's using wood-ash with zero blackspots on his 100+ roses.

There's another lady who posted how she applied iron sulfate, and her roses came down with blackspot. At first I thought it was iron, but after I did my thread on anti-fungal agents, iron was on the list of anti-fungal agents. Recently my village shut down of their 5-wells, due to high-radium .. they stated that they can't fix it, due to that well's high-iron content.

The years which I used my tap-water: very little blackspots. My disasters of inducing rust via gypsum (calcium sulfate) in 2014, then recently blackspot via gypsum .. I'm convinced that lowering the pH via sulfate, or anything caustic to roots will result in fungal diseases.