Water, Mulch & Fertilizer
Roses do best with uniform soil moisture throughout the growing season. The general rule of thumb suggests that one inch of water be applied per week during the growing season. The amount and frequency of application will depend on soil type. Sandy soils will need more frequent irrigation than heavier clay soils. Hot temperatures would call for more frequent irrigation, also. The use of soaker hoses in rose beds is highly encouraged. Water can be delivered in adequate amounts while keeping the foliage dry, preventing disease.
The use of mulch around roses to help retain soil moisture is a practice that is highly encouraged. Mulch will also help keep soils cool and help retard weed growth. Materials such as wood chips, straw, or dry grass clippings make good mulches. More decorative materials such as shredded hardwood bark or cocoa bean hulls could also be used. Mulches should be applied about 2-3 inches deep and replaced as needed. Because organic mulches tend to bind up nitrogen as they decompose, additional fertilizer may be needed to prevent nutrient deficiencies. Leave an un-mulched area about 6″ in radius around the plant.
In order to maintain strong, healthy roses, it is important to establish an annual fertility program. Fertilization schedules vary depending on the types of roses being grown. For species roses, a spring application of general-purpose fertilizer is usually adequate for the season. General-purpose fertilizers such as 10-10-10 or 12-12-12 are used at about one-half to one cup per plant. Spread the fertilizer in a band starting six inches from the crown of the plant, going out to about 18 inches. Work it in lightly and water.
All other roses benefit from a second application about June 15 or at the end of the spring bloom period. For continuous-flowering or repeat-blooming roses, a third application in mid-July is suggested. No fertilizer should be applied after August 15 so as not to encourage soft, succulent growth that could be easily winter-damaged. Roses can be fall fertilized after the plants have gone dormant. Applying fertilizer at this time will not encourage growth but will be available as the plants start to grow in the spring. Also by using a fertilizer high in potassium winter hardiness tends to be increased.
Another fertilizer option is to use a timed or controlled release fertilizer (osmocote fertilizer pictured at right). These are dry, encapsulated fertilizers that release their nutrients slowly over the season, completing their work in 4, 6, or 8 months depending on the formulation. Nutrient release is dependent on the soil moisture and temperature. These materials are generally applied in May, using about 1/2 cup per plant. Several forms are commercially available.
A thriving garden is a testament to the effort of the gardener, and knowing what to do with and for the plants in it is part of that effort. Roses are an ornamental flower that have been popular worldwide for centuries. As a centerpiece for a garden, they add a touch of elegance, and investing properly into their care pays off.
Mulch is a catch-all term for any material spread over the surface of the soil around the base of a plant. It insulates the root system, helps retain water in the soil, prevents weeds from gaining a foothold and helps regulate the temperature of the soil itself. There are a multitude of mulch varieties available, so how do you choose what’s right for roses?
Organic Rose Mulch
The majority of available mulches are organic- they decompose, provide additional minerals for the soil and provide nutrients for the roses. As organic mulches decompose, they draw nitrogen in order to break down. This can draw the nitrogen from the soil, so it’s best to layer compost down first before adding organic mulches. Apply at least a 2″ (inch) layer of compost before spreading mulch in order to keep your roses healthy.
Grass clippings, straw, shredded or chipped bark and even newspaper can comprise organic mulch. For appearances, chipped bark mulch- usually native hardwood chips- is extremely attractive, but grass clippings or pine needles are a cheaper option. When using your own garden clippings, ensure that you’re not spreading any herbicide-treated or possibly diseased material around healthy roses.
Among organic mulches, grass is one of the fastest to decompose, but can become slimy and give off an odor which may contrast with the fragrance of your roses. Straw is more beneficial for vegetable gardens, and tend to attract insects which are necessary to a healthy crop, and may not be as suitable for ornamental plants. Newspaper is less attractive visually, but can be used without worrying about detrimental affects on roses. Shredded leaves have the benefit of boosting underground activity, such as with earth worms to aerate the soil, and are free for those with deciduous trees.
A benefit of organic mulch is the fact that it decomposes. While you will have to layer on fresh mulch every year, the decomposing mulch becomes the next layer of compost. Mircoorganisms in the soil break down the available material, lowering the soil level and providing ample room for the next layer of mulch. Doing this imitates the natural structure of a forest by allowing natural debris to become the compost for the next year’s growth.
Inorganic mulch does not decompose; this is usually a layer of small rocks, pebbles or even gravel. While it doesn’t move about as organic mulch could during a particularly windy time of year, it can absorb sunlight and heat the root zone of your plants. Inorganic mulches are best for northern climates. They do not create more work when it comes to fertilizing; simply sprinkle the fertilizer over the gravel, rake it around the base of the rosebushes and water it well. This allows the water to dissolve the fertilizer and drain through the gravel to reach the root system.
When selecting your mulch, consider how often you may be adding plants to your flower bed and keep your climate in mind. Smaller, swiftly decomposing mulch is not as easy to rake aside as bark, and inorganic mulch may be smothering for gardens in southern climates. Look around at gardens in your area and observe what tends to be most commonly used. Mulch is absolutely necessary for a thriving garden, so do a little research, observe your roses and enjoy the results of healthy root systems and weed-restrictive layering!
Mulch is the answer. Once you have found and planted own-root roses that will thrive in your area, don’t worry about fertilizing them. Rather than applying fertilizer, I recommend applying a lot of mulch and plan on watering during dry spells. But, since mulch keeps the soil moist, the more mulch you apply, the less supplemental water your roses will need.
I would not believe this if I had not seen it in my own yard. Mulching with organic material that breaks down over time feeds your plants more gently and gradually improves the health of your soil – rather than spurring green growth in sudden bursts.
When we first had a yard in which to garden, we used fish emulsion, rotted horse manure and other natural fertilizers on our flowerbeds. These fertilizers spurred our plants to grow with extra enthusiasm. But soon we redirected our energy to mulching very generously with leaves we collected every fall.
I noticed that once we stopped fertilizing and started mulching more, we saw less frenzied green growth in the spring, but we also saw fewer aphids. I believe the more moderate growth attracts fewer pests, because it is not quite as unnaturally juicy and enticing to bugs.
Mulching with leaves is ideal because they’re easy to get, but you can also use pine bark. If you’re buying pine bark mulch, get bark that is ground into the smallest, softest pieces you can find. Roses prefer slightly acid soil, so pine needles or coffee grounds are OK, too. Leave cedar or hardwood mulch alone – in my experience, it doesn’t break down quickly enough to enrich the soil.
Where to get leaves
In my town, every fall, folks rake the leaves off their lawns, bag them up and set them on the curb for pickup. My husband and I note their location, and after it gets dark, we drive up, leap out like a two-person Chinese fire drill, load the bags into the car and speed away into the night. We feel like we’re getting something for nothing.
Leaf mulch is free, feeds your plants at a steady, constant rate as the earthworms and bacteria turn it into soft dirt, and it also looks good as it breaks down. Mulch that rots slowly sits on top of the soil instead of becoming humus ASAP, which is what you want. Plus, slowly decaying mulch bleaches out and looks terrible.
What kind of leaves to use
Get the mulch that will break down the fastest. You want whatever organic matter you are mulching with to break down into the soil sooner rather than later. I prefer soft leaves such as hackberry or maple leaves to tougher leaves such as magnolia.
When to apply mulch
Mulch your roses whenever you have the mulch and the time. You can spread leaves over the flowerbeds as soon as you get them, or you can go according to the book and wait until the first hard frost forces the plants into dormancy. I’ve tried mulching both before and after the first hard frost, and I’ve never noticed that much difference.
How much mulch to apply
Apply as much mulch as you can haul without throwing your back out. You can mulch trees too deeply, but you can’t do that with roses, so pile on as much as you can get. Soft vegetable matter will compact quickly as it breaks down anyway.
Because I prefer own-root roses, I get most of my roses by mail. Here are my favorite sources, all locally owned businesses:
- Antique Rose Emporium: antiqueroseemporium.com
- Heirloom Garden Roses: heirloomroses.com
- I also have visited and bought a rose from Petals From the Past, near Birmingham, Ala. They do sell online through their website, petalsfromthepast.com. The folks who work here know all about roses, and it has an awesome selection of old, tough roses.
To read about roses
- theheritagerosesgroup.org: Worldwide aficionados of old (and therefore likely to be disease-resistant) roses. Links to articles and newsletters.
- texasroserustlers.com: Texas fans of tough old rose varieties. Lots of good links.
- ph-rose-gardens.com: This fellow’s Central Texas rose garden is no longer open, but his super-informative website lives on. The page titled “Confessions of a Rose Rustler” is hilarious.
From State-by-State Gardening June 2014. Photos courtesy of Karen Stokes.
Posted June 2014 Karah Stokes, Ph.D., has gardened for 15 years, and her blog, The Lazy Organic Rose Gardener, shares what she has learned from growing roses organically. She teaches college writing and literature.
The Two-Layered Mulch Approach For Feeding Roses.
Nothing like a pile of rotting compost!!
Photo/Illustration: Paul Zimmerman RosesNothing like a pile of rotting compost!!
Photo/Illustration: Paul Zimmerman Roses
Most all of us mulch our roses. We do so to keep weeds down, help save water and simply because it looks good. But did you know mulch, when properly applied, can also be an integral part of your rose feeing program? And if not properly applied can actually hinder your rose feeding program? More on how it can hinder later but let’s start with how it helps.
How it helps feed your roses relates back to a previous post we did on Preparing A New Rose Bed. In that post we talked about building a living soil profile through the use of compost, mycorrhizae and other beneficial micro-organisms in the soil. The approach is called “Pro-Biotics”. This is nothing more than increasing your rose’s inherent health through the pro-active use of organics. In other words a complete and balanced natural approach. The post talked about preparing a new rose bed to get everything started off right. But how do we maintain that living soil year in and year out?
In that previous post we mentioned a forest floor is one of the richest soil environments in the world and we want to duplicate that in our garden. It’s rich because every Autumn all the leaves fall and over the next year rot into the soil and become compost. The following Autumn fresh leaves fall and then they also become compost in the ground. This process simply repeats itself year in and year out. And that’s what we want in our gardens.
This is where the two layered mulch approach comes in. And it does nothing more that replicate what Mother Nature has been doing for the forest floor for millions of years.
It starts with two things. A layer of compost and a layer of fresh mulch on top of that. To understand why you need to know one simple fact.
Fresh mulch needs nitrogen to break down. It pulls nitrogen from the air and from the soil beneath it. Therefore if you put fresh mulch on bare ground it actually pulls it from the soil thereby robbing your plants of much needed nitrogen. You get the same thing if you remove all the old mulch first (and we’ve all heard to do this) and then put fresh mulch down on the bare ground.
However once the mulch is broken down the reverse happens. It begins to emit nitrogen down into the soil and into the air.
That is why the first layer should always be compost. It is your nitrogen emitting layer. It emits nitrogen in two directions. First to the ground and secondly into the fresh layer of mulch you put on top of it thereby helping it break down. This means your fresh mulch is no longer taking nitrogen from your plants as it breaks down.
This is also why you should never, ever remove the old mulch because over the season as it breaks down it becomes your nitrogen emitting (compost) layer and the following year fresh mulch can simply go down on top of it. That fresh layer of mulch rots over the season, becomes the “compost” layer and the following year fresh mulch goes right over it. We just keep repeating the process year in and year out. And that is how we duplicate the forest floor. Once you get the process “cooking” you should never have to add additional compost again. Just put fresh mulch over the old mulch. It just keeps feeding your soil and thereby your roses. Now you are being Pro-Biotic.
By now you’ve probably figured out why using mulch improperly actually hinders your rose feeding program. Fresh mulch on bare ground or raking out the old composted mulch steals nitrogen from your plants and does not feed the soil and maintain that living soil we want.
One last thing. Some of you may be thinking if you keep adding fresh mulch your soil level will get higher and higher ever year. No. Not if you have properly created and maintained that living soil profile we talked about in the previous post. It will simply disappear in the soil as all those micro-organisms do their job.
Still not convinced? Think of those majestic redwood trees that are 2000 years old. If every year the soil in the forest where they live got higher and higher they’d be pretty short by now!
Knock Out® Roses
Knock Out® roses are the hottest plants to hit the market in years. Gardeners love these colorful shrub roses because they bloom profusely with minimal care. The original Knock Out® Rose was introduced in 2000 and has since become the most widely sold rose in North America, according to the Conrad-Pyle Company.
Knock Out® roses can be grown throughout Florida and will bloom practically yearround in most of the state. They are drought tolerant, self cleaning, and resistant to black spot and powdery mildew. Since they require little maintenance, they are ideal for gardeners who enjoy roses but who aren’t interested in the upkeep required to grow hybrid tea roses. The only drawbacks of Knock Out® roses are that they don’t have a strong fragrance and they don’t last long as cut flowers.
The Knock Out ® family of roses was started by rose breeder Bill Radler when he crossed seedlings of ‘Carefree Beauty’ with ‘Razzle Dazzle’ to create the original Knock Out® rose. The family now includes varieties that range from blush to vibrant red, and even yellow:
Both the original Knock Out® and the Rainbow Knock Out® roses were named All-America Rose Selections (2000 and 2007).
Grafted and non-grafted plants are available, and both should perform well.
Planting and Care
Like all roses, Knock Out® roses need to be planted where they will receive at least six to eight hours of sun each day. It also helps to have a site with good air movement and well-drained soil that falls between pH 6.0 and pH 6.5.
Knock Out® roses generally grow three to five feet tall and equally as wide, but some sources say they can reach eight feet tall if not pruned, so be sure to space them appropriately.
After planting, water them regularly until they get established. Also apply a three-inch layer of mulch to help retain moisture in the soil, pulling the mulch back from the stem of the plants.
These roses are winter hardy to USDA zone 5 and also have good heat and humidity tolerance that allows them to grow through zone 9.
For more information on Knock Out® roses, contact your county Extension office.