It's time to begin a spray program for the growing season! Now that your plants are coming out of dormancy and even pushing out some leaves, its time to unmound the plants and start the preventative spray program. Unmounding the plants after the danger of frost has passed, which is around April 15 in NC, will allow the base of the plant to put out new canes. Be careful when unmounding because, if you’re lucky, the plants have already started to push out new canes under that pile of mulch. Don’t break them off when pulling the mulch away from the plant.
In the southeast United States, due to high humidity, the most important plant protectants that you can use for roses are fungicides. Fungicides come in many different forms, formulations, and modes of action.
Systemic fungicides – soak into the plant tissue and sometimes travel throughout the plant to help fight blackspot, powdery mildew, or downy mildew. These fungicides can be applied as a spray solution or in a soil drench or granular application. There are fertilizer products that include systemic fungicides as well.
Contact fungicides – applied directly to the plant surfaces where they destroy fungal spores on contact. They are always applied foliarly and they come in many different forms. Most of the “natural” fungicides on the market are contact fungicides.
Application – whichever method or product you choose, follow the label strictly to ensure correct and effective application. When spraying, the product has to be applied to the bottom of the leaf as well as the rest of the plant. Fungal spores attach to all parts of the plant, especially the forgotten underside of the leaves. Apply the fungicide to the entire rose bush to the point of a light drip, paying special attention to the underside of the leaves.
**We have found that the best way to protect roses from the onset of fungal diseases is to combine a contact fungicide with a systemic fungicide. This can be done by combining both products in the same spray application. As always, carefully read the label of any chemical that you use and apply it per label instructions.
The Witherspoon Spray Recipe Kit includes Captan and Thiomyl which are contact and systemic fungicides respectively. Preventive fungicide application is extremely important to have beautiful and healthy rose bushes with leaves from the ground up, which means apply before your garden becomes infected.
When leaves begin to shrivel up and holes appear in buds, we know there is an insect feasting on the rose bush. Aphids, thrips and various types of chewing worms are the main pests to watch out for on roses. Please keep in mind that with any pest control program the idea is to work with nature to keep a balance, NOT to eradicate every living creature in your garden!
Systemic insecticides – absorbed into the plant tissue and delivered to the insect as it eats the plant tissue. These insecticides can be applied with fertilizer, in a soil drench, or applied foliarly.
Contact insecticides – eliminate insects on contact, usually applied as sprays to the leaves and blooms of the plants. If insects are present during the time of application or if they ingest leaves that have been sprayed, they will be affected. Natural or Organic – like all plant protectants there are many products that are listed as organic or natural. Neem oil and pyrethrins are two main natural insect controls. As with all products read the label carefully to see what insects these products control.
Common Rose Pests Include:
Aphids - develop huge colonies that suck the juices out the stems and buds. The damage that they impart is limited and they are relatively easy to control. Most systemic or contact control products including natural insecticidal soap will lower the aphid population. In most cases it takes repeated applications at 5-7 day intervals to get them off of your bushes completely.
Thrips - are tiny insects that live inside your rose buds and suck the water out of the base of the petal leaving brown spots on your blooms. Systemic insecticides do not help with thrips control because the tissue of the rose leaf is different from that of a petal and the flowers do not absorb the product systemically. Use a contact product that is labeled for thrips and spray it into the bloom getting it all the way down to the base of the bloom whenever possible.
Beneficial insects are a crucial part of maintaining ecological balance in your garden. They will eat many of the pest insects and naturally keep the populations from growing out of control. When you apply broad spectrum insecticides to your garden, you may be killing beneficial insect along with the pest insects and you are risking even greater populations of pest insects in the near future. Broad spectrum insecticides will also quickly get rid of any butterflies or bees that you may want in your garden. We strongly recommend limited use of broad spectrum insecticides. If you must use them, smart application will help. Only apply them early in the morning and to parts of the plant where the infestation is the greatest, possibly with a small spray bottle. Targeting small areas to spray, rather than blanketing the plant and garden with strong insecticides is a good way to save the beneficial insects
Rose Gardens Need a Little Spring Cleaning Too!