Are these beautiful rose bushes salvageable?

Question

My 8 English heritage rose bushes all have black spot leaf fungus w all leaves falling off for three yrs now.. Spraying hasnt worked & theyre nearly dead. Would it be worthwhile to transplant them to a new site?

Answer 1

The spores of black spot float around in the air and when it rains or is windy, they are forced to the ground. If they land on soil or fallen leaves, they soon die but if they land on a rose leaf then they start their life cycle by pushing their roots below the surface of the leaf. Pockets of fungus can reside on the canes as well as leaves. If you spray the canes with a dormant horticultural oil with sulfur overwintering spores can be mostly eliminated.
Like all fungi the weather has something to do with this disease. Fungi like damp and humid conditions to grow well. This has lead to the myth that overhead watering causes BS. It isn't just watering the leaves it is keeping them wet when the other conditions are right to grow the spores. Midday heat (72 - 85) and wet leaves for long periods (6-7 hours) that have spores present provide excellent growth conditions.

Roses should never be placed where there is no air circulation if you have humid conditions. The best is if they get very early morning sun directly so they dry the dew off before they warm up.
Remove all dead leaves beneath the roses and the top layer of mulch to eliminate spores near roses. Dust the ground with 2 pounds of cornmeal for every 100 square feet along with fresh mulch. Water well to activate the fungus killing properties. (There is a cheap, nonfood grade available at some garden centers.)

Try spraying with dormant oil before the leaves start and continue with a rotation of sprays after the leaves start.
Spray weekly for a month and then just once a month after alternating your sprays.

Cornell spray-
Do not substitute vegetable oil spray for the summer weight agricultural oil, it doesn't emulsify in suspension when water is added. SunSpray brand contains a sticker so no soap is necessary, with other oils you may need a few drops of dishwashing liquid. Another tip I have learned is to spray this in the evening, around or just after supper time. Do not spray this in the hottest part of the day.
2 T Horticultural Oil (Sunspray or Volk Oil)
4 tsp of baking soda or potassium bicarbonate
Optional additions to basic spray mix
1 T of fish oil/seaweed emulsion
3-5 drops of Superthrive (plant vitamins)
Add to 1 gallon of water and spray leaf surfaces LIGHTLY, not to dripping. Spray canes as well as leaves.

Neem oil is a fungicide and miticide.

Milk diluted to 20% is another spray that has shown promise in greenhouse trials for the control of fungus.

Commercial organic fungicides premixed & ready to spray
Bonide makes 141 sulfur dust, Lilly Miller Sulfur Dust,
Cooke's wettable, Safer Garden Fungicide, & Microthiol Special Sulfur.

Rosemania spray chart
http://www.rosemania.com/

Mycorrhizal inoculant may be of use.
http://www.tandjenterprises.com/protocol_for_roses.htm

Answer 2

you can transplant. The blackspot is caused by watering the leaves when watering the plant.

I would suggest transplanting in the fall, but what you can do now:

cut all the affected leaves off and throw away. do not let any stay on the ground. Then give your roses a product by Bayer (the asprin maker) that is called 3-in-1 for roses. This will help keep the black spot from coming back (fungii), protect against aphids (and other insects), and give essential nutrients to your roses.

I don't consider myself a master of roses. But, I have had nothing but success with this product. Here in Oregon black spot is prevalent, so it can be tedious, but this product helps a great deal.

So, water your roses at the base, not the foliage.
Use Bayer 3-in-1 for roses
Cut off the leaves with black spot (and continue to do so in the future)

Good luck

P.S. another little tip on roses. After the blooms are done and are starting to look dead....Pull the bloom off and the rose will force out more blooms.