Rose

Pull off the old mulch and lay down a fresh 3-inch layer of pine straw, leaves, pine bark, or wood chips, keeping the area right at the stem clear. Come fall, add extra mulch over the roots for winter protection. Mulch conserves moisture and suppresses weeds, but replacing it rather than topping it up is what matters for disease: the old layer holds the fungal spores that washed down out of last year's foliage, and clearing it out early removes that inoculum before the new leaves are up.

Fertilize when the plant first leafs out with a rose fertilizer or a slow-release tree and shrub fertilizer at label rate, then feed again after each flush of bloom. Through the heat of midsummer cut the amount in half but keep feeding once blooms appear. Apply to damp soil under the leaves, keep it off the canes, and water it in thoroughly. Composted manure works as a top dressing and adds organic matter along with the nutrients. Stop feeding six weeks before your area's earliest frost date. A repeat-blooming rose spends itself on every flush and rebuilds for the next one, so the feeding tracks the bloom cycle rather than the calendar. Stopping six weeks before frost matters because late nitrogen pushes soft new growth that will not harden off in time and dies back over winter.

Give a light feed in spring before growth begins, and stop by midsummer. On decent soil a rugosa often needs nothing at all - this is a shrub that tolerates poor, sandy, salt-washed ground. Rugosa is adapted to nutrient-poor maritime soils, and a plant still growing vigorously late in the fall is the one most likely to suffer winter dieback.

Walk the edge of the planting and cut or pull the suckers coming up outside the bounds you want, taking as much rhizome as you can while the soil is moist. One cut does not stop it - expect to cut repeatedly through the growing season, and to keep at it for several years. Rugosa spreads by underground rhizomes as well as seed and forms dense thickets that crowd out everything around them, which is exactly why it escaped cultivation in the first place.

Watch the canes and cut when the buds swell and break, not on a calendar date. On repeat-blooming roses like hybrid teas and floribundas, keep only three to five of the healthiest, most vigorous canes and shorten them to 15 to 18 inches, removing anything thinner than a pencil and any canes that cross. Cut a quarter inch above an outward-facing bud, angling the cut at the same angle as the bud. Old garden roses want a gentler hand: take only the oldest unproductive stems and never more than a third of the bush. Once-blooming roses and their climbers are the exception, prune those right after they flower instead. Bud break tells you the plant has come through winter and shows you which wood is actually alive, so you are cutting to living buds rather than guessing in the cold. Once-blooming roses set their flowers on the previous year's wood, so a spring cut removes the very buds that were going to bloom.

In early spring, while the shrub is still dormant and you can see its structure, cut about a third of the oldest, thickest canes right down to the soil line and head back the remaining stems to control size. Work before growth begins - that moment arrives anywhere from March in the south of its range to May in the far north, so watch the plant, not the calendar. A rugosa needs this only every few years, not annually. Rugosas flower on new wood and rebloom from June to September, so removing the oldest canes pushes vigorous young shoots that carry both the bloom and the hip crop, and it opens the dense canopy so leaves dry faster after rain.

Begin spraying at bud break, when leaves are first unfolding, using chlorothalonil, myclobutanil, or a copper fungicide. Repeat every seven to 14 days until wet weather subsides. Alternate between at least two different active ingredients rather than leaning on one. Water at the base with a soaker or drip hose instead of overhead, and space plants for airflow. Diplocarpon rosae overwinters in fallen rose leaf litter and in infected canes, and wind or splashing rain carries its spores onto the tender new leaves exactly as they emerge. That first flush of wet-weather infection is what produces the spores that defoliate the plant later in the season, so a spray after lesions appear is already behind the fungus.

Check the shrub daily while beetles are active and knock them into a bucket of soapy water. Morning and evening are easiest, when the beetles are cool and sluggish. Do not hang a beetle trap anywhere near the rose. A rugosa is in flower more or less continuously from late spring to frost, so the plant is full of foraging bees for the whole window when adult beetles are feeding - there is almost no moment when a spray would not hit pollinators.

Walk your roses through the growing season looking for abnormally red new shoots, thickened stems, rapidly elongating growth with shortened spaces between leaves, a mass of soft flexible thorns, and witches'-broom clustering. There is no chemical cure. Bag the foliage before you dig so the mites do not scatter on the wind, then remove the entire plant including every root so it cannot resprout. Do not compost it or throw it on a brush pile. Remove any wild multiflora rose within 100 yards, and wait until all the diseased roots are out before replanting a rose in that spot. The virus is carried by microscopic eriophyid mites that blow in on the wind and feed on tender new growth, and it goes systemic through the whole plant including the roots. That is why pruning out the symptoms does nothing and why leftover roots that resprout keep the infection alive on your site.

Check the blooms and foliage early in the morning while temperatures are still cool and the beetles are sluggish. Shake or pick them into a bucket of soapy water and dispose of them. Repeat daily through the flight period, since new beetles keep arriving. Beetles cannot fly well when they are cold, so the same insect that is untouchable at midday drops straight off the cane at dawn. Handpicking also spares the bees working the open flowers, which a blanket spray would not.

Watch for reddened, thickened shoots, a witches-broom cluster of soft flexible thorns, distorted leaves, and aborted flowers. If you find it, uproot the entire shrub promptly - roots included - and then check every other rose nearby. Remove any wild multiflora rose in the vicinity. The virus is spread by wind-borne eriophyid mites and lives systemically in the roots, so cutting out the affected cane leaves the infection in the plant, and an infected shrub becomes the source that infects everything downwind.

If you see black spot, rust, or powdery mildew, pick off and remove the infected leaves, water at the base rather than overhead, and prune to open the shrub to air movement. Rugosas are nearly indestructible shrubs, so the leaf spots that do appear are usually a symptom of a crowded, slow-drying canopy rather than a problem needing chemistry - the fix is airflow and sanitation.

At the first sign of the white powdery coating on leaves or stems, spray weekly until conditions turn unfavorable. Sulfur, myclobutanil, propiconazole, thiophanate-methyl, or neem oil are all options, as is baking soda mixed with horticultural oil. Give the plant good air circulation and full sun rather than a shady, crowded spot. In a wet spring and summer you may not need to treat at all until the drier weather of late summer, so scout before you spray. Powdery mildew infects when temperatures are mild, around 70 to 80F, and humidity is high at night but low during the day. It is worst in shade and during cooler spells. Unlike black spot, a film of water on the leaf actually inhibits this fungus, which is why a rainy spring can suppress it and the drier stretch of late summer is often when it arrives. Weather and the first lesion set the trigger, not the month.

Gather the hips once they are red and ripe but still firm - the window runs from late summer through winter, and many growers pick after the first frost, when the flesh has sweetened. Leave the deadheading off if you want a crop, since a spent flower is what becomes a hip. Rugosa sets unusually large, meaty hips that hold well on the shrub into winter, and ripeness is what makes them sweet enough to be worth processing.

After the season winds down, rake up and remove every fallen rose leaf under the plants along with the old mulch, and cut out canes with visible black spot lesions or canker, taking the cut 6 to 8 inches below the infection and only when the canes are dry. Do not compost any of it. In windy sites, shorten long canes to about 3 feet so winter wind cannot whip and loosen the plant. The black spot fungus does not overwinter in the soil, it overwinters in the fallen leaves and in the infected canes still standing on the plant. Every leaf you leave under the bush is next spring's spore source landing on next spring's new growth.