The Phoenix / May 2024
May in the rose garden
by Bobbie Reed, Master Roasarian
Observe
April brought us beautiful flowers — not just roses — and an early onset of rose season.
Despite our worries, and a few dips into the thirties, there were no freezes to damage early blooms. Depending on when and how hard you pruned and the vagaries of your microclimate you could be seeing a few roses or a whole gardenful. In our little patch of Gwinnett County, some of our earliest bloomers have already passed their first peak bloom – and given our seasonal shade, we may not see as much of them again later this year. The deer continue to decimate the tasty buds, or we would have had even more. Spring is always my favorite season!
Section 1 / 9
Water
January and March were really wet this year, while February ran a little dry. April is running just below normal through the 27th. We’ve averaged 3.36 inches of rain for the month so far. Atlanta and Jonesboro were notably wet, more than 1.5 inches above normal rainfall. We set a new record for one day’s rainfall on the 2nd, with 2.66 inches of rain in Atlanta. Overall, we’re still almost 10 inches or 67% ahead for the year. The big lakes are near full-pool levels.
Our excess rainfall is credited to the strong El Niño we’ve been experiencing. But that’s coming to a close, and the National Weather Service now predicts a La Niña, bringing lower than normal rainfall, by late summer or fall. We can also expect warmer than normal temperatures in the next few months.
Warm temperatures speed up evaporation from the soil and dry out our roses, so we’ll need to be more attentive to how much rain we receive and how much water we need to supplement for our roses. Watering duties put a crimp in other garden chores. But rose bushes need lots of water to make food available to our roses, to protect them from chemical burn as we spray, and to make the most glorious, fragrant, long-lasting blooms. When you have less than one inch of rainfall per week IN YOUR GARDEN, you need to water, using a drip irrigation system or watering by hand for most efficient watering. If you have a special rose occasion coming up, try to water every day or two for the week beforehand. For “normal” rose needs, plan to water every two or three days unless you receive sufficient local rainfall. Regular watering adds “substance” (starch) to the blooms, making them look better and last longer. Roses in pots will need more frequent watering than roses in the ground.
This rose: Coral Beauty
This rose: Jadis
Section 2 / 9
Feed
Our roses are blooming, but we need to give them food for the energy they need all through the summer growing season. You may accomplish that with a single long-term fertilizer like nine-month Osmocote, by monthly applications of a balanced granular fertilizer like 16-4-8, by using a water-soluble fertilizer like Miracle-Gro or Peter’s 20-20-20 every two weeks or fish emulsion, or by providing an organic fertilizer like Mill’s Magic Rose Mix or Purely Organic. Many dedicated rose growers use a combination throughout the season as time and money permit. Adjust your fertilizer regimen based on the results of a recent soil test. Your roses need to eat to make beautiful blooms. That applies to roses in pots, too.
This rose: Yesterday
Section 3 / 9
Spray
I’m finding more blackspot than I would have expected this time of year. You may also have some anthracnose spotting, but it is managed the same way. We will need to spray weekly with a good fungicide, preferably alternating chemicals to ensure that the fungi don’t develop resistance to them. Combine a systemic fungicide with a contact fungicide in a single spray tank, to get more bang for your buck and time. Many rosarians use mancozeb or manzate (contact fungicides) every time they spray, in combination with systemic fungicides like Banner Maxx, Cleary’s 3336, or Compass (you’ll need to rotate the systemic fungicides among those with different Modes of Action – see the Tri State Rose Society of Chattanooga for more detailed information). It’s tempting just to rotate fungicides by brand, but BannerMaxx, Funginex, Immunox, Eagle, Rubigan, and Systhane all attack fungi in the same way, and are therefore more likely to cause problems from fungi that are resistant to your spray.
Watch out in your garden for aphids, which like to suck on tender new shoots and leave shiny honeydew on the leaves below, and thrips, which leave ugly brown damage on rose petals this time of year. My favorite control for aphids is to squish them between my fingers, but you can also use a strong spray of water to wash them off or an insecticidal soap to kill them. Control thrips by misting just the buds every two or three days with spinosad (Conserve), imidacloprid (Merit), or acephate (Orthene) – these last two will be more toxic to bees and other beneficial insects. Minimize the use of insecticides throughout the season, however, and be careful when you spray to save beneficial insects and to delay the onset of spider mites in your garden.
A less toxic way to reduce thrips damage is to lure them away from your rose blooms. One technique is to take a BLUE plastic cup, paint it with sticky STP oil treatment, and invert it on a stake in your garden. When it’s covered with dead bugs or when the rains wash off the coating, replace it with a freshly coated cup. Bugs, it turns out, are very color-specific: YELLOW cups will attract white flies.
If you are reading this article later in May or in June, you will be noticing Japanese beetles, shiny coppery and green critters that lounge and munch on our roses this time of year. I heartily recommend that you NOT try to spray them away with insecticides, which are both toxic and inefficient. You would be killing beneficials, encouraging the population of spider mites, and attacking only a small portion of the thousands (millions?) of them in your neighborhood that day; the rest will keep reproducing madly and invading your garden in waves from day to day. A better alternative is to walk your garden while beetles are in town early each morning with a cup of soapy water (no insecticide needed). As you find the remnants of the previous night’s orgy, tap the hung-over beetles into your cup; they will be unable to fly out of the soapy water. Meanwhile, be sure to cut roses as soon as the sepals reflex and the bloom starts to show color, and bring them into the house. The roses will open in a vase, and their color and fragrance will not be available to attract beetles to your garden. There, you’ve had a nice morning stroll to commune with your roses, without the stress of spraying. Doesn’t that feel better?
This Rose: Rosa Rugosa-Alba
This rose: Bon Bon + Sydney the Whippet
Section 4 / 9
Deadhead
If there are fresh blooms on your roses, soon there will be spent flowers, which the bush will continue to nurture as they turn into rose hips. To speed your next cycle of bloom, start removing blooms as they fade. Snap the spent bloom off below the bloom, trim neatly just above the highest five-leaflet leaf, or cut anywhere in between. Remember to remove any plant debris from your garden to reduce pest activity. If you are interested in creating new roses by hybridizing, leave the spent bloom on the plant as it develops into a rose hip, containing the seeds for new rose varieties. The Rose Hybridizers Association website has tips for getting you started.
This rose: American Maid
Section 5 / 9
Prune
Continue “thumb-pruning” in your garden, pinching off secondary buds and the growth associated with them, so you can have a single strong stem emerging from your canes at any one level. Continue to “disbud” your bushes to produce bigger blooms or better-shaped sprays. Keep pinching out the center bud in a spray – that one usually blooms before (and below) the others; removing it early allows the rest of the spray to bloom all at once, and gives a more shapely arrangement of flowers on the end of the stem. A sidebud (that small bud growing beside the main one) can also be removed, allowing more energy to go into the one perfect bloom you want.
This rose: Brass Band
Section 6 / 9
Mulch
Make sure your mulch is ready for summer. Clean up any debris which could harbor insects or disease, and refresh as needed to leave a three-inch layer of wood chips or a four-to-six inch layer of pine straw to conserve soil moisture and keep your roses’ feet cool as hot weather arrives. Some folks like to use colored wood chips; while the color is purely a matter of aesthetics, I prefer natural chips.
This rose: Elizabeth
Section 7 / 9
Plant
If you have new roses in pots, you can plant them now, or hold them in the pot for planting later in the year. You will need to upgrade the size of the pot your rose came in, to help it through the summer heat. Your rose can survive in a three-gallon or larger pot for a long time, as long as you water, feed, and monitor its pH regularly. If you decide to leave your plant in a pot, you’ll need to water it every day or two. But most roses are happier when they can get out of the pot, spread their toes, and play with their friends. When you plant, give them a big hole with lots of soil amendments like coarse sand or expanded shale in addition to our native clay, and lots of organic material. Composted manure will please them longer than peat. Adjust the soil pH to 6.5-6.8. Once your bush is planted, cover the soil with mulch, and remember to water frequently through this first summer. Frequent watering of any rose is likely to lower the pH, so keep track of changes.
This rose: True Love
Section 8 / 9
Learn
With even the most conscientious care, roses can develop fungal diseases like blackspot and powdery mildew. In cool weather like we had this spring, blackspot can develop up to thirty days after an infecting event – blackspot spores (they’re everywhere!) soaking in water standing on roses leaves for at least six to eight hours. In our garden, we always have leaves through the winter, we certainly had plenty of rain, and we did not start to spray fungicides until April. We should not be surprised that blackspot has set in on our roses. Next year, we need to begin spraying fungicides regularly much earlier, at least by the end of February, no matter how that might interfere with our pruning schedule. Weeds, weeds, weeds. A weed is described by the optimistic as “a plant out of place”. Maybe we think of them as natural ground cover under desirable plants. Some see a parasitic pest, sucking food and water intended for better plants, or just an ugly addition to the garden. For me… well, I just grit my teeth whenever I walk past, but rarely do I have the time or the equipment to tackle them as I scurry by on my way from one task to another. Do we really need to do anything about them? In addition to their co-opting fertilizer and water directed to the rose bush, weeds may smother the intended plant. They can be horribly invasive – have you seen all the privet in bloom this month (achoo!), crowding out native species? Some may be attractive (violets), but cleavers, dandelions, and pokeweed are just a nuisance. I refuse to spray herbicides on weeds – too much risk of spray drift that could hurt the roses – although painting them with Round-Up seems reasonable. This year we are seeing one of the worst weed situations – trees! When a bird eats the seeds of said tree, or a squirrel buries nuts for the future, too often the seed sprouts and grows. And if it grows under your rose bush without being removed promptly, it can grow into an enormous tree, shading the desired plant and eventually out-competing and out-growing the rose. I can think of a couple of oak trees we pass around Lawrenceville that we have watched as they displaced the roses we had admired. This year, we are having the problem among our azaleas, after noticing but not removing the sprouts a couple of years ago. The privet is now over ten feet tall, and it will be much harder to remove this year than it would have been two years ago. So it is time to get out a saw, some Round-Up, and a paintbrush to do some remedial weed removal. Next time, we pull.
This rose: Sweet Chariot
Section 9 / 9
Enjoy
Walking around a rose garden in full bloom is always an inspiration, and the fragrances are incredible. For even more inspiration, I hope you attend a rose show this year, at the Atlanta Botanical Garden on May 11-12, or in Fayetteville on May 18-19. A rose show is always an education in the diversity of roses and rose growers. Some rosarians prefer low-maintenance roses, others want exhibition-style roses at any needed level of effort, and many of us fall somewhere in between. It can also be an opportunity to verify nursery catalog claims against the reality of growing various rose cultivars here in the South. You can add roses to your wish-list at a show, and find help in growing the kinds of roses you prefer. If you missed the show, be sure to continue taking photos of your roses as you visit your garden. You don’t need a fancy camera (most of us are using cellphones these days). After you take a photo of each bloom, take a photo of the name tag so you will remember their names. Every rose prefers to be called by name. Enjoy your roses this spring!
