Seasonal Rose Care
by Corinne Clifton, Master Rosarian
FALL
In September the rain often returns and this may mean either a return to the spray program or stepping up the pace to keep the roses as disease-free as possible going into winter.
The last application of synthetic fertilizer should have been applied in August. If you are using liquid fertilizers you may continue until the end of the month since they are very short-acting.
Late September is a great time to begin to put down some type of top dressing for the soil. I like to use either steer or chicken manure but a soil building compost would also be appropriate. Fall rains help to break these products down and carry the nutrients down. The idea is to keep your soil microbes, the various fungi and bacteria, happy and well-fed. They, in turn, will be ready to break down the fertilizer in the spring so that when conditions are right, the rose roots will be able to absorb the nutrients.
September is a little early to apply lime but it is a good idea to begin to shop around for it and stockpile it. Remember that the soils in this area are not deficient in magnesium but are lacking in sufficient calcium. So when shopping for lime make sure it contains more calcium than magnesium. A 50 lb bag will lime about 500 square feet.
September is also a good time to evaluate the performance of the roses in your garden. Take a hard look at each one. Is it planted in the correct place? Does it bloom enough? Is it a disease magnet?
If you are like me and your garden has reached maximum capacity, if you want to introduce new roses, something has to come out.
In October, roses are slowing down although on the coast they may not ever stop blooming depending on how much sunshine and warmth your garden receives. Modern roses do not go dormant in mild climates so it is up to the rosarian to create an artificial dormancy.
Rose hips are beginning to develop and for those adventurous enough to try, the hips may be harvested and the seeds planted to produce new roses.
It is time to stop applying any fertilizer that has nitrogen but an application of a 1-10-10 fertilizer (if you can find one) may be applied.
October is a great time to put down the first application of lime. I like to break down my lime application in two parts-the first in October or November and the second in February or March. Lime needs rain to work and if 2026 is anything like 2025, the spring application will not be effective. Remember to apply a lime with more calcium than magnesium and a 50 lb bag will cover about 500 square feet.
I stop deadheading my roses in late October. This prevents the rose from putting out a lot of new growth. Make sure to clean leaves and debris from around roses. Downy-diseased leaves can leave spores on the ground and those spores remain active for a number of years. This is also a good time to clean up the weeds and apply a pre-emergent herbicide such as Preen or Casoron. Do not compost leaves or debris. You could spread disease spores.
Prune off overgrowth on climbing roses and make sure canes are secured. A coastal wind storm can break off canes and topple insecure climber structures.
Apply some type of mulch. It not only provides nutrients but adds and insulating layer to the soil
Fall is an excellent time to do a little additional work in the garden to enhance soil fertility and boost soil microbes.
In our climate we are lucky that soil rarely freezes so we are able to do some things in fall that other gardeners can only do in spring when soil warms up. This is not the time to apply fertilizer. The goal is to enhance soil not boost growth in roses.
When looking at soil fertility there are several things to take into account. The soil pH is of primary importance.
While a discussion of soil pH can be rather complicated, the easiest way to think of it is that it is the measurement of hydrogen ions present in the soil. The more hydrogen ions the more acidic the soil. So let's discuss a basic chemical equation, H2O-more commonly known as water. For us an average annual rainfall can vary between 70-140 inches. That's a lot of hydrogen ions since for every molecule of water there are two hydrogen ions for every one of oxygen.
Soil pH is not a once and done treatment, especially with our rate of rainfall. So in early October I like to put out between 1/2 and 1 cup of lime per rose bush. Now if you have had a soil test done and the results indicate a surplus of either calcium or magnesium that determines which type of lime to apply, either calcitic or dolomite. I try to apply one kind of every other year. That way I don't have a build up of either.
The other two things I like to add are 1/3 cup azomite or rock dust if you can find it and 1/4 cup biochar. An addition of some type of manure to compost really adds a finishing touch.
WINTER
Most modern roses have been bred to withstand a Zone 6 winter which is much colder than what we in the coastal area of the Pacific Northwest experience.
Our challenges are not to get our roses to survive the cold but to get them through the winter without drowning or being desiccated by winter winds.
During the month of November observe your rose garden and make sure that the ground drains quickly following one of our rainy storms.
Make sure to dead head any remaining blooms so that they don't become one mushy mess of petals. A good cleaning up of the leaves is also a good idea. Although there seems to be some debate on whether the fungal spores cling to the downed leaves. It is better to err on the side of caution. After all, in this part of the world, disease pressure in the garden is always going to trump insect pressure.
The ground usually remains warm enough to begin transplanting or continue planting. It is warm enough to allow the roots to continue to grow or to become established in the case of a new planting or transplant.
A side dressing of compost is an excellent idea as the compost has a tendency to buffer our naturally acidic soil and to provide for a very gradual release of nutrients in the spring when the ground warms up. An application of azomite and worm castings would also be appreciated by those roses which work so hard during the spring and summer providing much joy and beauty.
Keep up with the weeding or you will regret it in spring when there is so much to do in the garden.
November is a great time to reflect back on this year's rose growing and assess what worked and what didn't.
It is also a good time to take a hard look at your roses and decide on which ones are going to make the cut. With the amount of effort and time devoted to growing roses, there is no pint in growing something which brings you no pleasure.
If a rose has been languishing try to assess what might have made the situation better. Does it need a better location, more sun perhaps. Sometimes just moving a rose makes all the difference in performance.
Start planning for new roses. Rose catalogs should begin to show up in mail boxes and some nline stores open in the fall for late winter delivery. Dig holes and prepare soil beore it turns to muck.
Clean fallen rose leaves and if you have dealt with any rose diseases, dispose of leaves by burning or in trash. Do not compost. Compost piles do not get hot enough to destroy disease spores on the coast.
Top tall roses to prevent them from rocking in the wind and check ties on climbers to prevent wind damage.
During the winter months, weed control is a priority. When you allow weeds to go to seed you create a lovely seed band. It will take years to get a handle on it. Areas of gardens are covered by what looks like a green carpet. Whatever weed control method you choose, it looks like it is going to take some persistence to get rid of them.
The second application of lime should have been applied and the third will go down in a couple of weeks. Then thoughts will turn to soil amending.
Of course in the middle of all of this, prunng needs to be accomplished.
Although some gardners approach rose pruning with trepidation, keep some simple principles in mind.
Start at the bottom, not the top. Cut away all dead, dying and diseased canes. Then take a good look at the center and remove all crossing canes. Open the center of the rose bush as much as possible. Good air circulation aids in disease and spider mite control. Lastly rid the bush of all spindly canes smaller than a pencil in diameter. These weak canes will do nothing for the bush.
If you have shrubs you can choose to do nothing. Lightly prune to a certain height or hand prune to remvoe most old wood.
The Southwest Oregon Rose Club offers opportunities for the public to learn rose pruning at several locations in January, February and March. Please contact us for further information.
In January and February we need to start pest control and apply a dormant spray. If the roses still have leaves take them off as they may have fungus spores lurking on them or insect eggs that are so small you can't even see them. If they are allowed to stay on the plant, they will wake up just as the roses do and the problems begin.
Cleanliness is most important right now. Make sure all leaves that have blown off or fallen off are picked up and removed also. It is not a good idea to compost them so either burn or throw in the garbage.
A dormant spray can be used. The dormant spray is a mix of horticultural oil and either copper or lime sulfur. Recently I have heard that copper is best for us to use. The mixture that is recommended is 6 tablespoons horticultural oil and 4 tablespoons liquid copper to a gallon of water. I seriously recommend that you use hot or very warm water so the mixture mixes evenly and the sprayer does not clog up. Cover the canes with the spray until they are dripping and also spray around the bud union and ground where they are growing. The copper will kill the disease microbes and the oil will smother and kill any remaining insects and their overwintering eggs. The fungus spores of blackspot, mildew and anthracnose are all eliminated with the copper and the oil suffocates aphids, spider mites, scale, sawfly and thrips.
Do not use if the buds are open and over a 1/2 inch long. The oil will burn them and delay new growth.
Most roses should be pruned by the end of February. On the south coast we usually experience the coldest weather of the winter in February so there is not going to be much, if any growth on roses. You want the pruning finished by the end of February so that in March you can start applying soil amendments and fertilizing if using organic fertilizers. As you finish pruning this is an ideal time to apply alfalfa meal to the roses. A one or two cup application is enough. if you can not find alfalfa meal, you can also buy alfalfa pellets used in animal feed. The rain will break it down and the earthworms in the warming soil will carry it down into the soil.
In February most garden centers will have new roses and this is an ideal time to plant them. There is plenty of time to allow for the root systems to develp before the leaves appear in spring.
Maintain weed control. This is critical if you want to control nasty weeds such as hairy bittercress, henbit or creeping Charlie. All can be invasive on the coast and this is where an ounce of prevention can prevent a lifetime of weeds. This is also the time to begin the slug and snail control.
Some of the soil amendments to consider are manures, azomite, biochar and worm castings. These can be applied in the late winter - early spring:
Alfalfa Meal (2--6-2 to 2.5-0.5-2.5) well balanced, slow release; Blood Meal (13-0-0) rapidly available nitrogen; Bone Meal (3-2-0.5) rapidly available phosphorous, increases pH slightly; Compost, balanced slow release, contains calcium, magnesium; Cottonseed Meal (8-2-2) rapidly available nitrogen; Epsom salts (0-0-0) excellent source of magnesium sulfate; Fish Meal (10-4-4) rapidly available nitrogen: Kelp Meal (1-0.2-2) slow release of potassium and micronutrients plus growth stimulators; Manure cow(2-1-2.5) good source of sulfur, calcium and micronutrients. Compost; Manure horse (2-1-2.5) good source of sulfur, calcium and micronutrients. Compost; Manure chicken (4-3-1) good source of nitrogen. Compost. Plants requiree 17 different chemical elements to be healthy. Most of these elements are already in the soil or the air and don't need to be applied regularly. These 17 elements are broken down into four general groups-the essential elements, the primary or macronutrients, the secondary nutrients and the micronutrients or trace elements. the elements essential to all forms of lie, carbon, hydrogen and oxygen are derived primarily from air and water. The three primary nutrients are nitrogen, phosphorous and potassium, the most common fertilizer ingredients. I use fir or hemlock chips for mulch every two to three years to control weeds.
A soil test would be good at this time. It is important to determine pH and nutrient levels before planting new roses. A pH of 6.5-7.0 is needed for the nitrogen, phophorous, potassium and trace minerals to work.
SPRING
The daffodils are blooming! Pussy willows and alder are bursting with catkins. Songbirds are busy setting up home. Gird thy loins! Spring is here!
Pruning should be finished by now and at least one addition of organics made. When weather permits, it would be a good idea to begin a regular spray program. March weather can be tricky-warmer than 60 degree days and cool nights-a perfect recipe for powdery mildew. And if the rainy weather continues, the ideal conditions for downy mildew to make its appearance.
If any of you have been troubled by powdery mildew in the past-whether it be on roses or vegetables-and you have a computer, check out the information on using common household hydrogen peroxide for powdery mildew control. The newest biofungicides making their way to the professional grower ar almost all hydrogen peroxide based. Researchers have discovered that the application of hydrogen peroxide literally causes the fungal spores to explode. March is also the month when rose bush grooming begins. The dedicated rose grower begins to look closely at the bush and removes all of the growth in the bush's center. This keeps the bush opened up so more sunlight can penetrate the interior. It cuts down on the areas which are prone to disease and insect infestation. It also results in the remaining growth becoming much stronger.
If your new growth is 1 inch or longer and you have true leaves appearing, it is time to put down your first application of fertlizer. With the amount of rainfall we have had there is no nitrogen left in the soil. Organics take time to work so March is a good time to get it down and worked into the soil. But even if we rose growers prefer organic fertilizers, a very small application of a synthetic fertilizer such as 10-10-10 at the beginning of spring is very beneficial in high rainfall areas.
Use the link at top of the page to access the Fertilizing page of suggestions for rose care.
Use the link at top of the page to access the Disease Control page of suggestion for disease control and prevention.
If you have any questions about the material on the site or joining the Southwest Oregon Rose Society please contact Ed and Mary Anne Kreutzer by phone: 541 572-3426 or email: ednmarykreutzer@gmail.com. Alternate contact would be:
Corinne Clifton by phone: 541 347-1135 or email: rose.editor@hotmail.com
If questions or comments on the web site please phone Linda Gilliland at 541 260-2748 email: llgcpr@yahoo.com
SUMMER
tHE MOST IMPORTANT THING TO DO FOR SUMMER ROSE CARE ON THE SOUTHERN OREGON COAST IS WATERING. However, while this is the most important chore the gardener can do, it is also the one which is impossible to impart, especiallly for the novice gardener.
There are too many variables to consider. Is your soil sandy or composed of clay? How much organic matter have you used in garden beds? What kind? How much sunlight are roses getting? How windy is the location? Are plants established or newly planted?
So let's take each of these variables one by one:
Sol composition: If soil is sandy water moves through rapidly. The addition of organic matter, especially animal manures, compost, wood chips is of paramount importance. The entire bed should be amended not just the holes where roses are planted. If soil is clay, the addition of organic matter is just as important because this is the only way to allow clay to drain. However, it is even more important not to just amend the planting holes. Rain and water are always looking for the easiest path. A hole dug in clay provides such a place for water to linger. Add copious amounts of organic matter and you have just turned your planting hole into a swimming pool for the rose.
Sunlight: roses need at least six hours of sun a day. They would really prefer eight. That does not mean they will not grow with less but canes will be much more spindly and bloom will be sparse. Roses receiving fewer than six hours of sun will not need as much water as ones receiving eight. However, roses are not xeriscape plants. They require (at minimum) 1-2 inches of water per week. This translates to 4.5 to 5 gallons of water per rose per week. Newly planted roses will require more water than established roses (ones which have been grown for three years or more). If watering
by hose, count to 20 while watering each rose to reach desired water amount.
Wind is very drying. The windier the location, the more water the roses will need. As wind moves across the leaves, it pulls the moisture from the plant and that moisture must be replaced.
Mulch is very important. It allows soil to retain moisture and cuts down on weed production. Too much mulch is not good so try to keep the mulch layer at betwenn 1-2 inches. As it breaks down it can be replaced. And remember to keep mulch away from the base of the canes.
Keep roses deadheaded in summer to allow for more than one flush of bloom. cut above a five-leaflet.
Fertilizer may be applied after the first bloom and monthly up to September.
Fungal diseases such as downey mildew, rust and powdery mildew can be a problem. Fungal diseases can be treated but not eradicated. Insects are rarely a problem other than the occasional aphid or thrips outbreak. A consulting rosarian may assist with these problems.