I was prowling around my roses last weekend, enjoying the first tiny buds beginning to unfurl on my north-facing pink Simplicity roses in the front yard and checking on the progress of a couple of transplanted rose bushes in the backyard.
Although I didn't see any aphids on the roses yet, they're bound to arrive, and will soon be coating the soft, new rose growth. Aphids almost perfectly match the color of the fresh rose foliage, in shades of green and red, feeding cheek-to-jowl along the choice buds.
You can take the do-nothing approach with aphids or choose attacks with rising levels of intensity and cost. Aphids on roses are annoying, but not life-threatening to the plants or the flowers. You can also let nature take its course. Aphids provide meals for ladybugs and other insects. The famous Bakersfield heat will also knock back your aphids on roses in a few weeks and the problem will be forgotten.
A blast from the hose
The lowest level of intensity would be to wash off the aphids with a blast of water from your hose. This is a mild attack and fairly effective, although some of the aphids may walk back to your plants. Squash the fallen aphids on the ground. (I would advise being careful with that first use of the hose in the spring, as black widows may establish a home in your hose over the winter. I turned on my hose a few weeks ago to water my newly planted strawberries and, whoosh, out came a black widow who was gingerly trying to pick her way out of the strawberry patch to safety.)
Insecticidal soap sprays are available at nurseries and home improvement stores in spray bottles.
You may also create your own soap spray concentrate by combining 1 tablespoon of liquid dish soap and 1 cup of vegetable oil. Do not apply this concentrate to your plants! You will burn them!
When you are ready to spray, shake up your soap and oil concentrate. Then, mix 1 teaspoon of the concentrate with 1 cup of water in a spray bottle. Apply the spray to the aphids.
In the past I've made up a bucket of suds and used paper towels to do a two-handed slopping of aphids off the plants. You can't leave soap on leaves, however, because you can burn them. Wash off with plain water.
Probably the most effective, if you want a complete knock down, would be a fertilizer with a systemic pesticide to kill plant-sucking insects. Many nurseries carry the Bayer All-in-One concentrate that fertilizes, controls pests and mildew; other brands are also available. This is not a spray, but rather is mixed with water and applied to the soil. The plants absorb the chemical through the roots.
Roses will benefit from fertilizing to produce great flowers and strong new growth of canes and leaflets in the coming weeks. Fertilize now and you'll see the effects in about six weeks.
It is easy to buy rose food that has the right blend of nitrogen (for green leaves), phosphorus (for roots and flowers) and potassium (overall plant growth), but any flower food will do. You can choose between slow-release pellets of fertilizer, dry granules or liquid fertilizer. Slow-release may be applied less frequently than granules or liquid fertilizer. Whichever fertilizer you choose, follow application directions exactly. Too much fertilizer is wasteful and can lead to burned plants and runoff. Apply fertilizer to moist soil and water it in after application.
Green Thumb meeting
The Bakersfield Green Thumb Garden Club will meet at 9 a.m. today at the Church of the Brethren, corner of Palm and A streets. Coffee and socializing begins at 9 a.m. At 9:30 a.m. Dale Edwards of Old River Sod will give a talk on "Growing Healthy Grass." The plant of the month speaker is Judy Domingos on bonsai. Following the meeting is a garden tour at the home of Eva and Gordon Nipp. The garden club's meetings are open to the public.