Pictures #1 and #2 are of two different miniature rose bushes with purplish-pink spots. Picture #2 also shows some brown crispy edges on some leaves on the right side of the bush. I am not sure what is causing these issues. Our winter has been extremely mild, no freezes, and only .29 of an inch of rain for the month of January. Daytime temps have been between the mid 50's and high 70's. Nighttime temps are mostly between the mid 40's and low 60's and only dropped in the high 30's 3 times this month. December was pretty much the same except for we had 2.49 inches of rain that month. I do supplement a good soaking if there hasn't been any rain for 2 weeks being careful not to wet the leaves.
This is the first year I have grown Heuchera. I planted 3 Plum Pudding and 4 Caramel. The Plum Pudding (No picture included) doesn't seem to be growing at all? And occasionally gets some brown crispy leaves. I supplement water for it the same as I do the roses, but because they are small (About 5 inches in diameter and 2-3 inches tall) I don't give them as much water. I water when the soil is dry about 1 1/2 inches down. They get mostly morning sun with a little sun in the afternoon because there are no leaves on the trees yet to shield them from the afternoon sun. Does Plum Pudding prefer more sun or less?
1 or 2 of my Heuchera Caramel are getting dark spots on the leaves, but they appear to be growing much better than the Plum Pudding. Picture #3 is a pic of 1 Caramel. Picture #4 is a close up of the dark spots on one of its leaves. What would be causing these spots and how do I stop them from developing further?
Rose Spots, Stunted Heuchera, & Heuchera w/ dark spots
Hello, judging from your pictures it looks like you have a couple of problems: 1. It appears both plants are infected with root rot. You have a lot of dead leaves and bark mulch surrounding the plants which is keeping the soil too moist for these plants. Also, there are a lot of dead leaves around both plants which is spreading the disease (and more) into the plants. Leaf margins are drying up from the outside in and are showing red and black spots...typical symptoms of the disease. Also, there might be some chemical damage (possibly from a pre-emergent herbicide) (picture # 2...leaf chloross (discoloration showing all veins indicates this possibility). However, root rot will also show this type of symptom as well as spider mites.
2. Spider Mites: It appears they are attacking the miniature rose. Because miniature roses are a small plant and grow close to the ground (which is where spider mites thrive in dry, warm locations), they attack smaller, greener, plants first. The feed by sucking the chlorophyll from leaves, therefore you will see lightening or discoloration on the leaf surface.
Spider Mites are a common pest in any garden are fairly easy to control with mineral oil applied on a cool day several times during the year.
Root Rot is much more difficult and almost impossible to correct. Once a plant is infected, they are pretty much gone. They may live for several years, but will eventually die. The best defense against this disease is to plant in a well drained area, keep the soil free of mulch, bark, leaves, or any other ground cover so it can breath and evaporate a lot of its' moisture, and diseases already present in the the bark, leaves, or any part of the mulch you use will not infect the healthy plant. There are several fungicides on the market to protect plants from this disease but are very expensive.
lily_tree_guy, thank you for replying. You said, "It appears both plants are infected with root rot." Do you mean both miniature rose plants, or the roses AND the Heuchera Caramel? The roses and the Heuchera are not in the same flower bed. They are on opposite side of the yard (Heuchera shaded under an oak tree and roses are by the patio in full sun).
I do have 2 more miniature roses in pots on the patio about 25 feet away from the ones pictures above. They have been growing great and have nice, dark green foliage, and many buds and blooms. All of my roses were treated with Bayer 3-In-1 Insect, Disease & Mite Control about 3 weeks ago. In the flower bed next to the 2 roses pictures above, I have another miniature rose which was the first to show those purplish spots about a month ago. At the time, the other 2 (pictured above) showed no signs) and that was when I decided to use the Bayer 3-In-1 on all of them. The original rose bush that showed the spots looks just fine now - no purplish spots or dying leaves. It wasn't until 4-5 days ago that I noticed these other 2 rose bushes developed these spots.
The soil where these roses are planted was very sandy, so before planting I amended with Black Kow Composted Manure and Soil Conditioner. It drains very well and as I mentioned before I don't water but once every 2 weeks if we've had no rain. Of course, I always check the soil prior to watering to make sure they need water. I am not sure why they would have root rot because they are definitely not sitting in water or sitting in water logged soil, but in good draining soil instead. I guess I can dig one up and check the roots today to see what they look like, take a picture, and post it back here for you to look at.
Thanks for helping!
The first thing that came to mind when you said purplish-pink spots was Anthracnose fungus. As warm and wet as the weather has been in your area this winter, I would not rule this one out. Most sites say there is no "cure" for Anthracnose, just control and prevention. The first steps to prevention are to remove all fallen leaves from around the plants and remove any affected leaves and canes(the canes will show purple to black spots if affected) from the plant. Never water the plants from the top which soaks the leaves and allows fungus a place to grow. Also, prune the plants with an eye to good air circulation. You have recently treated with Bayer Select, check the label to see if it includes a fungicide....if not, apply a fungicide that includes black spot in the things it treats...that will slow down the further spread.
"Anthracnose, caused by the fungus Sphaceloma rosarum, results in leaf spots. When first formed, spots are red or sometimes brown to purple. Later the centers turn gray or white and have a dark red margin. Fruiting bodies may appear in the middle of the spot, and the lesion may fall out creating a shot-hole symptom." (from the link below)
themoonhowl, reading through the links you provided, as well as looking at pictures of roses with Anthracnose, it sure sounds like this is what my roses possibly have. The Bayer 3-In-1 product I applied to the roses does say "This product will effectively control Anthracnose" on the label so that is a good thing :-) As of the moment, 2 of my 3 mini rose bushes look much better with darker green leaves, and new growth. The 3rd one took a hit by my 2 Chihuahua/Yorkie pups who decided to do battle with the mole that decided to tunnel in the vicinity. It is recovering...but slowly.The nasty cold and wet few weeks we've had here sure isn't helping, I'm sure.
As for the Heuchera Caramel, I the removed any leaves with spots and then sprayed the rest with Daconil. So far no new spots have appeared on the leaves. And for the Plum Pudding, I relocated the 2 that was receiving the most sun to shadier locations and they seem to like their new homes. The 3rd one, I left in its original spot because it was the one that put on the most growth since planting and had the best color. Didn't want to disturb it. No brown crispy leaves on any of them lately, so that's good. Also, I relocated 2 of the Caramels that was receiving the most shade to locations with more morning sun w/ filtered sun in the hottest part of the day and late afternoon sun. They seem to be doing much better and the leaves are much prettier because the colors are really coming out more. Also, I think in the shade the leaves were staying wetter longer after rain which helped promote the leaf spots.
The rainy season is upon us so I hope everything survives ok. I'll keep an eye out on them. Thanks for your help :-)
You are most welcome. Sounds like you are getting things back on track. Good to hear that you are seeing an improvement.