After the May/June spring flush of rose blooms, the general rule of thumb for rose care is to prune significantly and to fertilize well during about the first two weeks of August. Did you do this? If so, then there are only a few more key rose care tasks.

From early September, it is four to six weeks to the last Rose Shows and six to eight weeks to the end of Fall Flush rose blooms in the garden. To promote beautiful blooms and healthy rose plants, the upcoming key rose care tasks are:

1) Water. When they are blooming and growing, ensure that roses are watered long and deep once per week (by slow, steady, long rainfall or by hand with the garden hose). For roses in pots or young, one- to two-year old rosebushes that do not have deep roots, water more often. If it is very hot and the ground is dry, water more often.

By mid-October, rosebushes will need less water. But if it is dry, water once every couple or three weeks.

2) Fertilize as desired during about the first two to three weeks in September, then stop. I will probably spray Miracle Grow the first and third weeks in September. Exhibitor friends will apply organic meal mix (e.g., Mills Magic Mix or hand-mixed) and alfalfa tea.

Water well before spraying liquid inorganics. Several years ago I sprayed liquid fertilizer on six-foot Baronne Prevost and formerly upright canes bent nearly to the ground; salt from the liquid fertilizer had drained water out of the bush. I watered hard late that afternoon and the bush quickly recovered. So water the day or morning before spraying liquid fertilizer.

Further, STOP fertilizing by mid- to late-September, so the plant will wind down production of new growth. Rosebushes need to go dormant for winter.

3) Trim lightly on canes and branches as needed through mid- to late-September. Then stop, because pruning encourages new growth and the rosebush needs to stop growing, shut down, and go dormant for winter. Stop deadheading spent blooms by the start of October, so the rosebush will set hips, which aids in going dormant.

4) Spray against fungus and insect pests till there is a hard frost. Every two weeks, I spray a mixture of systemic and contact fungicide mixed with a tiny amount of systemic insecticide Merit, with imidacloprid. For a systemic, I alternate funginex (Ortho® RosePride® Disease Control Concentrate with triforine) with Immunox (with myclobutanil). For a contact fungicide, I often use Dithane M-45 (with mancozeb), but sometimes use Daconil (with chlorothalonil, only spraying when the temperature is under 80 degrees F or it damages leaves). Friends spray the systemic fungicide, Banner Maxx (with propiconazole), alternating spraying it every two weeks with the mesosystemic Compass (with trifloxystrobin). You can stop spraying after the first hard frost, which will probably take place in October or November.

In addition, to prepare to winterize your roses, you may want to stock up on mulch. I will probably buy one to two bags of mini pine bark nuggets, to be applied in late November. Check supplies of lime-sulfur. I buy Bonide Oil & Lime Sulfur spray concentrate, that I will spray in late January or early February, in heavy dormant strength, to kill scale, spider mite eggs, and fungus spores of blackspot, etc. (Note: It’s unclear to the casual observer how Bonide prepares the combination, but if you try to mix oil and lime sulfur on your own, they do not mix. If you purchase separate products, spray them at least two weeks apart.)

Finally, depending on the wild animal population in your neighborhood, you may need to install or refresh fencing. The number of rabbits in Montgomery County MD seems to have exploded(!), such that rabbits now eat mini roses and chew ground growth from larger roses. We bought 36-inch chicken wire, cut it in half to 18 inches with tin snips, cut a length, and wrap it to form cylindrical wire cages (say 12- to 18-inch diameter). We drop the cage over those mini roses in danger, digging the wire in about one inch at the bottom.

Special Note on Fighting Rose Midge: As is well known, midge are small black gnats that lay eggs in rose flower and leaf buds, that develop into tiny larvae that eat flower and leaf buds. A few gardens have no midge. But some gardens will suffer a severe infestation and will see very few rose blooms. Other gardens have many blooms and just a touch of midge here and there. The key sign is that tips on the rosebush are not green, but look crisp and burned. Break or clip those small branches off.

From several generations over the summer, the last generation of rose midge over-winters in the ground in a cocoon. Years ago, people spread Diazinon on the ground, but it killed beneficial insects as well as midge, and it was banned by environmental authorities. Lately, people get some relief by spraying Merit – on the bush and on the ground as a soil drench. Recently, a Consulting Rosarian friend has recommended Bayer Advanced Complete Insect Killer. Active ingredients are imidacloprid and B-Cyfluthrin. A 40-oz container of concentrated liquid costs about $15.00 and should be mixed as 1 tablespoon per gallon of water. Spray rose bushes and the surrounding soil. Spray in the early morning or in the evening to protect bees (which fly more freely during the day). Repeat in two weeks. At his own large garden, our friend found midge problems completely solved with only two to three applications.

Finally, if you have any questions about autumn rose care, feel free to contact a Consulting Rosarian. (Click on "Consulting Rosarians" on this web-site, for a list with phone numbers and emails.) The Consulting Rosarians in Washington, northern Virginia and suburban Maryland know the local weather and soil conditions and they will be glad to help you. It is free to telephone a CR and ask them a question.

In addition, the reader is encouraged to read The Capital Rose, the award-winning bimonthly membership newsletter published jointly by the Potomac Rose Society and The Arlington Rose Foundation. It describes current rose care problems and how to solve them, among other topics. Click on “Upcoming Events” on this web-site, to see our calendar, come to a meeting, and hear that month’s speaker. Click on “Join the Potomac Rose Society,” for a membership form to join the Potomac Rose Society. We welcome new members and would be glad to talk roses with you!

In conclusion, if you have any questions about spring care, please contact a Consulting Rosarian. (Click on "Consulting Rosarians" on this web-site, for a list with phone numbers and emails.) The Consulting Rosarians in Washington, northern Virginia and suburban Maryland know the local weather and soil conditions and they will be glad to help you.

In addition, the reader is encouraged to look at The Capital Rose, the award-winning bimonthly membership newsletter published jointly by the Potomac Rose Society and The Arlington Rose Foundation. It describes current rose care problems and how to solve them, among other topics. Further information on membership in the Potomac Rose Society can be found on this website.

Kathy George, PRS Secretary