Pests on Rose Buds
Question from John:
What is the best organic method to get did of the little white flies on the buds of my rose bushes.
Yhank you, regards John
Answer from Pat:
If you truly have “white flies” on your roses, your roses are growing in too much shade and should be in full sun. Plants growing in appropriate light and properly cared for will never suffer from greenhouse white fly. (Greenhouse white flies are flying insects that get on foliage of plants such as tomatoes, not on rose buds. Giant white flies get on plants with tropical foliage, such as hibiscus and make white filaments and lay eggs in circles under leaves.)
More likely, you are actually talking about aphids on your rose buds, which are usually green but can look whitish if they are being attacked by beneficials (which is good.) Wash the aphids off with water. Never spray with chemicals. Within the next week, purchase lady bugs at your local nursery. Place the container on the top rack in your refrigerator to chill them for a few hours to lower their metabolism. Meanwhile, sprinkle your entire garden, getting foliage wet. At dusk release the ladybugs in 1/2 teaspoon amounts down low on plants including your roses. They will gradually walk up plants and lay eggs. If you have not sprayed with chemicals your aphid problem will be gone. If not gone in a week or two, repeat the process.
Be sure to provide some moisture and a fountain or some flat pans of water for the lady bugs and other beneficials. Get rid of ants by placing a layer of dry Wormgold earthworm castings on top of the soil surrounding your rose bushes. They cannot cross it without dying. (Ants bring aphids.)
Whenever you see aphids, repeat the system.
Ladybugs work! Also try a root drench (water-in) with an organic liquid kelp. We have found that using double the recommended use (4TBLS per Gal instead of two with “Jong’s Grow Better” brand Sea-Kelp)makes the whiteflies go away for a few weeks. Also, spray your leaves with a worm-castings spray (worm-tea). There are enzymes in worm castings that little bugs do not enjoy.
Goodluck!
Thanks for comment. Worm-castings contain chitinase, an enzyme that attacks chitin. The exoskeletons of insects are made of chitin, which explains why this works. I wonder if worm-casting tea would kill rose slugs, also? Some folks suggest mixing in a little molasses to make the spray stick. It also feeds beneficial fungi and increases microorganisms that benefit plants.
One of my rose bushes, New Zealand, has lots of beautiful pink buds this year but they are not opening. Is this a disease or a pest like mites?
Sounds as if your rose is suffering from “balling” which can be caused by botrytis blight or thrips or wrong climate. Some varieties are more prone to balling than others, so if other roses in your garden are doing fine, yank that one out. If your rose is not appropriate for your climate zone it could be it has too many petals to open up if you live near the coast. Next winter pull it out, fix the soil and plant an All America Award-winning rose from the last 20 years or so reputed to grow well and be easy anywhere in the USA. Many are wonderful! Look for one that is reputed to be disease-resistant, floriferous and trouble-free in your climate zone, which you have not shared with me. Also consult with your local members of the Rose Society and they can tell you if thrips are a problem this year or if botrytis has been a problem. Spread ladybugs at the first sign of thrips, also put earthworm castings on the ground over the roots of the rose. Check the drainage before planting next winter. Also ask the Rose Society to recommend a good, easy pink rose for you. Always yank out trouble makers and replace with the best varieties you can find. Never pick out a rose just because it’s pretty and you like it in the nursery. Always do your homework and know what you’re getting!