Hi Lucas,

Some roses are more susceptible to black spot than others. There are anti-fungal sprays that someone else will surely be able to suggest -- I don't spray my roses, because I do not mind a little bit of black spot, and I dislike working with toxic chemicals.

In addition to spraying, you can examine whether or not you are giving the roses their preferred growing environment, which would affect the health of their immune systems. Do they get plenty of sun? Do you water them regularly, so that the soil stays cool and damp to the touch (not dry enough that water pools on top of the soil when you water it the next time)? Or do they have too much water, so that the soil is always wet, and waterlogged? Often people try to keep miniature roses indoors, which can be hard on them, as they do not get enough light.

Hopefully someone who knows more about miniature roses will chime in here. My guess is that the grower you got them from used anti-fungal sprays, so that they would look great in the store. Those sprays probably wore off, which is why you are seeing black spot now.

Lucas,

Minis are extremely susceptible to black spot, probably more so than any other class of roses.

There are organic sprays and non-organic sprays. I find the non-organics far more effective in CONTROLLING black spot. I use the Bayer fungicide in the blue bottle which gives me excellent CONTROL. Serenade, an organic control made by Bayer is a possible option for you.

I capitalized CONTROL because you never cure black spot, you control it. Growing roses in a hot and humid climate is where black spot thrives.

Moses

Hey Lucas,

I'm in the spray camp, so here's the chemical suggestion...

You need a contact and a systemic fungicide. For a large garden I would suggest four to five systemics and a contact, but this isn't the case with you. For you I would suggest the Bayer three in one or the Ortho products. Both can be found in your local big box store easily enough and they are okay as far as being effective. You may also look into improving your growing conditions and also check to see that you don't have spider mites. Miniatures are famous for suffering from them.

Adrian.

Adrian has a great suggestion there; spider mites can thrive in minis. They can be kept in check with cold water spraying during spells of hot, dry weather. No need to worry about using a 2nd product for them.

My favorite "mini" is a monster called Sweet Chariot. It is short but here it can spread to four feet across!