March 30, 2004 > What's Eating Your Roses?
What's Eating Your Roses?
Every spring, my 40-plus rose bushes apparently send out personalized invitations to every bug within miles:
Come one, come all!
Breakfast, lunch, dinner and snacks
Baby buds for entrèe's.
Green, yellow, pink and black aphids send an advance crew to scan the goodies. In no time at all, assorted in-laws, 13th cousins and various hangers-on appear. In and out go a thousand needle-like proboscises...Slurp! Out goes plant sap...Slurp! The aphids apparently pause just long enough to have 100 offspring per aphid. Aphids are mostly female. Their children have children with a week. You will see them all clustered around your rose buds and leaflets. A feeding frenzy is taking place. The result, a weakened plant with distorted leaves. Sap is the life-blood of plants. It carries nutrition to plant parts. When sap disappears, plants go on starvation rations.
Joining aphids at mealtime are the whiteflies. You'll see leaves covered with 1/8-inch white flecks with transparent wings. The flecks are sucking plant sap with straw-like beaks. Each and every female whitefly can have about 300 children within a month. Massive whitefly feeding also results in distorted leaves and a sad plant. Disturb the plant and the whiteflies scoot into the air. But they return.
Included in the rush-hour feeding traffic are some leafhoppers. These don't usually arrive in hordes, and they are pretty. Wedge-shaped leafhoppers come in full dress brilliance of reds, yellows, blues, orange, black, stripes and splashes. A 1/2-inch leafhopper can sit there, bold as brass, sucking sap from my Double Delight, and I'll still admire it. Leafhoppers hop, run sidewise, and can even fly. Damage isn't really severe if you have just a few. A lot of them equal yellow and white leaf speckling, plus possible brown curled leaf edges and tips.
As if roses haven't suffered enough, there are spider mites too. If you have never seen a spider mite, it's because you haven't looked through a magnifying glass. Spider mites are 1/60-inch long. That's about the size of a salt grain. Sometimes they're black, but they can be red, orange, yellow and varying shades of green.
Spider mites multiply like crazy. One today leads to one zillion tomorrow. Spider mite damage shows up as a pale yellowish leaf mottling. With severe infestations, you may see very fine webbing on the leaves.
Then there are thrips. There is no singular "thrip," which should give you some idea of how fast they reproduce. Thrips are 1/8-inch to 1/5-inch black, brown or yellow specks that can fly. Thrips hide near the base of petals. They, too, suck plant sap. Buds turn brown, petals stick together. If the bud opens, petals have brown edges. Blossoms may never unfold to full size.
People keep asking me what to do about aphids, whiteflies, leafhoppers, spider mites and thrips. I'm not a fan of pesticides, and prefer not to use them in my garden. What bothers pest insects also decimates bees and other beneficial insects, butterfly caterpillars, and birds that feed on all kinds of bugs. However, if the sap-feeding horde gets overmuch, you can buy a systemic insecticide at any garden store or section. Basically, systemics travel through the plant, and when the insects feed on the poisoned sap, they die.
There are also contact sprays, many less toxic. But contact sprays only kill what they land on. Since many insects feed on leaf undersides and plant nooks and crannies, the spray seldom reaches all and must be repeated regularly. Try to remove the ladybugs first. I am a big ladybug fan. They eat lots of aphids, etc.
What do I do to keep infestations in control? First, of course, I keep my roses as healthy as possible with regular fertilizer and water. When aphids, etc., start their spring feeding, I just hose them off regularly. This keeps the numbers down, either because a few drown, or after a while, they get the not-so-subtle hint to leave.
But, enough of the tough stuff; here is a reminder that roses are the flower of love. In the Victorian language of flowers, different rose types and colors are assigned to different birthdays. A white rosebud is the flower for July 6, and means "a heart ignorant of love." A red rosebud is the birthday flower for July 7, and it means "you are young and beautiful." The damask rose is the birthday flower for August 12, and signifies "bashful love." In general, roses signify bliss, elegance, beauty, fragrance, joy, life, pleasure, prayer, pride, secrecy, a star, the sun, wisdom and woman.
Note: THE GARDENER'S PERPETUAL ALMANACK, a book of days, by Martin Hoyles, Thames and Hudson publishers, 1997 is the best, and probably the most available, for days of varying flowers including some roses. Look for it at Amazon.com, Alibris.com, or Abe Books.com