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belcantocanto

I'm a newbie - help / advice please!

belcantocanto
14 years ago

Hello,

I am new to gardening and this fall planted 4 knockout rose bushes (backyard) as a hedge and some flower carpet roses (front yard). They both get great sun, however because of the humid weather and rain, they have developed pretty bad black spot and some brown and curling leaves. I've lost a lot of leaves.

I tried a baking soda/dr. bronners, neem oil spray but that really didn't help much. I just don't know what to do to help these roses.

Will they bounce back by themselves once the weather is less humid? Will leaves grow back? I've started feeding them once a month with Rose Tone (I think Sept will be their last feeding until spring)

What can I do to cure them and bring them back? They were looking so lovely. Your advice is MOST appreciated. Thank you!

--Jen

Comments (7)

  • Kimmsr
    14 years ago

    What is the soil these roses are planted in like? the brown, curling leaves can be an indication the plants are unable to move sufficient moisture and if your soil is too wet that can happen, just as it can happen in a too dry soil.

  • wesley_butterflies
    14 years ago

    Welcome :

    Sept. ends fertilizing
    Neem is more pesticide it does have fungus born disease control features to some effectivness under light conditions
    Backing soda dish soap mix what happens when you apply it is it elevates the PH on the leaves and midlews and fungus find an uncoftable home to grow on but it doesnt last very long at keeping a leaf PH changing

    Compliments to you on your rose choises and the home work you already did too
    carpet rose is about as easy growing as they get it will boast a very dencly packed foilage and is very winter hardy as well disease tollerant Yes it will grow new leaves its a real hardy rose I have two and I did just two days ago end of season leaf cleaned em it took 45 minutes on 2 different days ( they get bigger than that too )
    I dont have any knock outs but I see enough of em to know there as disease tolerant as the carpet rose

    how to PREVENT mildew born and fungus born diseases has been done by many in differant manners

    Example I have no idea what Dr Brooners is as I use Serinade to combat these diseases as well K-neem and the backing soda dish soap idea ( yes this idea is more myth then fact I find it ineffective at best )
    someone else might use dramatic K in place of serenade there both organic products I am told that dramatic K is not as harsh this disicion is up to you

    Theyll tell you not to water leaves. the day after it'll rain watering the roots of a carpet isnt that easy I use gloves and lift with one hand and water with the other any rose plant needs good ventilation Go figure huh I just got done saying dencely packed leaves too

    dont take this the wrong way as it is I only apply the following growing technics to my caprpet roses only ( I dont have any knock outs here ) and only MY CARPET roses grow this way

    I fertilize them from march till early sept and water em one maybe two times a week if needed during that time I bend stalks for the shape I want it to grow in. I dead head off about 4 realy nice small tree shaped flowering canes per month I will use serinade on them at the same time as my other roses I donot pluck trim or otherwise remove any leaves exept those that got dead headed untill the last fertilizing week Sept this task takes a long time to do 45 minutes a day on 2 different days and maybe one more time befor winter

    Yep a self tested carpet is in fact disease tolerant

    I am including a link for you for extra guidance on rose growing and disease information As you read it do enjoy the humorus side of Bob

    http://www.rose-roses.com/problems/fungi.html#rosewilt


  • diane_nj 6b/7a
    14 years ago

    Jen, when you sat "this fall" do you mean this year or last year (2008)? Plants bought late in the season may not have been treated well.

    Knock Out roses don't like their foliage to be sprayed with a fungicide. Now, many people have noted that while they are resistant to blackspot, they can get one of the other fungal, leaf spot, diseases (anthracnose, mostly). Mature plants are usually the most resistant. I would leave the Knock Outs be. Humid weather shouldn't bother them, but we on the east coast have had a strange growing season this year, and even the most resistant plants have been challenged.

    In addition to soil moisture problems (do check) brown, curling, leaves could be spider mites. Check for webbing and what looks like small grains of pepper on the leaves. A good squirt of water can help control spider mites.

    Check the drainage.

    The carpet roses (which "Flower Carpet", there are many; the name will be "Flower Carpet something", like "Flower Carpet Coral" or "Flower Carpet Red") vary widely in their disease resistance. Depending on the variety, these might need more aggressive treatment for disease. Since this is the Organic Rose Growing forum, I won't recommend any synthetic fungicides here. You can send an e-mail or post over in the Roses Forum for more options.

    Dr. Bronners is an organic soap.

  • Kimmsr
    14 years ago

    What is the soil these are planted in like? Some people constantly "fertilize" their roses because they are not planted in a good, healthy soil which will provide all the nutrients any plant would need to grow strong and healthy and be better able to resist plant diseases. Serenade, has a small quantity of "Bacillus subtilis", a very common bacteria, as the active ingrediant which does provide some kind of assistance in disease prevention. Neem Oil products also provide some antibacterial properties.

    Many people will tell you that you should never, ever wet your plants leaves, but these same leaves get wet when it rains, and it is known that hosing plant leaves can rinse some disease pathogens off those leaves. The problem is not getting the leaves wet it is letting them stay wet for a prolonged time, as you have seen from the rainy, humid weather you have had and if that is what you are experiencing now there may not be much you can do except wait it out since anything you spray on the plants leaves now would be washed off before it had a chance to work.

    I have found that a good, healthy soil that grows strong and healthy plants that are better able to withstand plant diseases and then an occassional spray of either 1 teaspoon of baking soda mixed in 1 quart of water, or a 50/50 mix of fat free milk and water, sprayed every 5 to 7 days will help with any Black Spot that does appear.

    Here is a link that might be useful: Bacillus subtilis

  • wesley_butterflies
    14 years ago

    Thanks for the idea of Doc bonners Diane it does look like a nice idea should I need a bath ( LOL ) and heck sence I use dawn to do dishes and use it on this BS battle too I am willing to try it out and yes if it does the job Ill pass it along
    Thanks on the Knock Out information I dont grow any but do see many. In a nut shell them carpet roses or what ever one will call them fall in the Ground Cover of hybrids go figure huh I get em in pink and lt.red and then I find em in muave geeesh

    A concern to fertilizing: a general rule of thumb is YES people do feed there soil which in turn makes said soil strong and healthy for roses to grow better and they tend to do this on a monthly basis. The rose will do more work for you but you will need to feed it and I promise you that the rose will reward you for feeding the soil There are a few organic fertilizers to choose from I used Rose Tone this season my results for the 2 carpets and the 3 minis I have Rose Tone did a pretty good job. Rose Tone sadly fell short of good performace on other types of roses I have.

    Prior to the one who wishes to comment on soil strenth and health. Last weekend when I airated my carpet beds I came across some pesky ole worms to the tune of perhaps 600 per plant as it was in the spring I didn't see so many and I sure didnt buy any to put in to the soil. Might I be doing something wrong ?


  • serenasyh
    14 years ago

    Kimmsr, you need to chill when it comes to fertilizing... All healthy soil is actually fertilized-- it is fertilized with compost, added minerals for those soils that lack the necessary nutrients that their soil tests indicate, manure, all that is "fertilizer". Your advice is beginning to drive everyone berserk because it is so contradictory. To say that compost, added manure and added minerals is not fertilizer is a bunch of malarkey. Soil balancing in all practicality is "fertilizing" the soil because you are adding stuff to the soil for PH levels and required nutrients. To deprive a soil from manure and compost mixes certainly doesn't help the soil become healthy either. It does the opposite. Soil always has to be replenished in one way or the other.

    There is nothing wrong either with adding compost teas and fish fertilizer. Hybrid Teas love this stuff and it's all organic too. In addition, it breaks down and nourishes the soil in the same way. For hybrid tea growers, compost tea and fish fertilizer gives us the huge beautiful blooms and increases the amount of rebloom. Sea Tea is especially useful for transplant shock and for emergency measures when a rose is disease stressed. Had it not been almost October, yes, feeding is important if one's rose has been overtaken with blackspot-- it helps the rose quicken the output of new leaves and new growth without hurting the rose by too much growth that artificial fertilizers can induce.

    Here is my 1st year climbing America. Again, to me a healthy rose is vigor, growth and big blooms.

    But don't worry Belcanto. If your roses were very healthy up until just a few weeks ago they will still make it. They've got enough "reserves" to pull through.

  • sammy zone 7 Tulsa
    14 years ago

    I have 11 Knock Out roses in my collection of about 200. I would either spray or not spray. I quit spraying about 4 years ago, and have made quite a few discoveries about my roses.

    If they get spots, I think it is difficult to tell whether it is one of many different diseases. We had rain for a record number of days this Sept., and many of my roses are spotted. I will not spray them, they will drop the leaves and grow clean ones.

    I cannot help you with carpet rose since I mainly grow tea, china, and some disease resistant shrubs.

    You know, the sprays prevent BS, but do not kill it. I think one might, (Mancozeb) but they prevent BS on the leaves. More than likely the new leaves will be clean whether or not you spray. My Knock Outs seldom get BS or anything else.

    Sammy

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