Rosie's Corner Articles - 2020

April 28, 2020

ACK!  What are those flying bugs/beetles eating my roses? 

Hoplia Beetle

Ah, yes.  It is spring and time for the annual Hoplia Beetle invasion.  They tend to be particularly bad in the central valley of California (unlucky us!).  After waiting months for the first blooms of spring, it is disheartening to see a Hoplia Beetle infestation destroying your beautiful blooms.  They love light colored roses and this year, for the first time, I am also getting them on my Iris!  How dare they! 

What can you do about them?  Plant only dark colored roses?  What is the fun in that?  I have learned, over the years, to not be squeamish about hand picking them off and squishing them. I do wear leather gloves when I do that.  I am not that brave…yet!  You can also carry a bucket of soapy water and shake the bloom over the bucket.  They will fall into the water and drown.  You can also cut the bloom (with them inside) and destroy it. 

The Hoplia Beetle starts out as a grub underneath the soil.  They complete their development in early spring and the adult crawls out from the soil and flies to gardens where they like to feast on roses (mine and perhaps yours) and other flowers.  They mate and fly away to where the female lays her eggs in areas of undisturbed vegetation.  The cycle lasts about six weeks from March/April to May/June.  Thank goodness, there is only one generation per year. 

Here is a link to more information about Hoplia Beetles.  http://ipm.ucanr.edu/PMG/PESTNOTES/pn7499.html

Types of Roses

Sometimes when I ask someone if they know that there are different types of roses, they respond, “Sure!  There are red, white, yellow and pink ones.”  Granted, those colors exist, along with a few others, and there are even striped and bicolored roses.  However, generally, when talking about roses, they tend to fall into the following; wild or species roses, heirloom roses and modern roses.  

Wild or species roses tend to have single flowers.  A single flower refers to a rose flower of five petals.  They go back in history about 70 million years ago.  Images of wild roses are even found in the pyramids in Egypt!  They were/are considered valuable for their medicinal properties and have been used in medicines, cooking, etc., for thousands of years.

An heirloom rose is defined by some, as any rose that belonged to a class of old roses, which existed before the introduction of the first Modern Rose, ‘La France,’ in 1867.  For others, an heirloom rose is one that is over 100 years old.  There are different names for an old or antique rose, such as a heritage or historic rose.  Within heirloom roses are different groups of roses such as albas, gallicas, damask, moss, china, tea, bourbon roses, hybrid perpetuals, etc.  A lot of people think that antique roses only bloom once in the spring.  Actually, it depends upon the rose.  I grow several old/antique roses that bloom more than once during the season, have a great scent and are very disease resistant. 

Hybrid Tea roses were the first of the modern types of roses.  They were the result of crossing tea roses with hybrid perpetuals.  This happened in 1867 and the result was ‘La France.’  As with antique or heirloom roses, there are several different groups of modern roses; hybrid teas, polyanthas, grandifloras, floribundas, miniatures, English, shrub roses, etc. 

So, why is any of this important to know for growing roses in my yard?  Certain types of roses do better with certain types of climates, soil conditions, have better disease resistance, require different amounts of sun, can be grown in a pot (for those of you who don’t have a yard), fragrance (or lack thereof) etc.  We will be exploring this more in the future. 

Vick’s Caprice

The rose picture up at the top of this section (and below) is an old rose called Vick’s Caprice.  James Vick is the breeder who found/bred this rose.  The photos were taken in my yard of one of Vick’s blooms.  Isn’t he a charmer? 

He is a hybrid perpetual rose and does great with the soil and climate conditions here in the central valley.  He had to have at least 100 buds on him this spring.  He gets to be about 3—4 feet wide and 3—4 feet tall.   I find him to be disease resistant (but not resistant to the dreaded Hoplia Beetles).  They also tend to love Vick as much as I.   He will bloom off and on, all summer long but his heaviest bloom is in the spring.  I just love his subtle stripes and dashes of colors. 

Who was the Vick in Vick’s Caprice?

James Vick (1818-1882) was a well-known seed merchant who dominated the floral industry in New York.  He was born in England and he and his family emigrated to the United States when Vick was 12.  When Vick lived in England, one of his childhood friends was Charles Dickens and they remained good friends throughout their lives. 

Vick started working at age 12 learning the printing trade.  When he was 16, he and his family moved to Rochester, New York.  Vick had acquired skills as a printer and writer.  He was always interested in horticulture and bought and edited The Genesee Farmer in 1855.  He later owned part of a workers’ journal and helped to found Frederick Douglass’s North Star. 

About this time, James started growing and importing seeds from Europe.  He established a seed house and mail order catalogue. He was one of the first people to publish a seed catalogue which had a circulation of over 250,000.  He also started a horticultural magazine.  The seed catalogue continued after his death and was run by his sons until it was sold to the Burpee Seed Company in the early 20^th century. 

Vick was one of the most successful US horticultural seed merchants, writers and merchandisers of his day.  There are still streets in Rochester named where his growing fields for his seed business were located (Vick Park A and Vick Park B).    The name for the rose, Vick’s Caprice, came from one of his readers of his seed catalogue.  He had a contest to name the rose and the name, Caprice, was chosen. 

Vick’s Caprice is considered to be a sport of the rose, Archiduchesse Elisabeth d’Autriche.  What is a sport you ask?  A sport is a genetic mutation that changes the characteristics of the plant.  In this case the “Mom” Elisabeth does not have stripes and spots but her “son” Vick’s Caprice does.  Occasionally, I will find that Vick’s Caprice will revert back to his “Mom” and have no stripes or spots on his flowers.  That is not uncommon for roses that are sports.  There is nothing wrong with the flowers or plants when this happens.  Just part of its nature from time to time. 

Until next time…

“We can complain because rose bushes have thorns, or rejoice because thorn bushes have roses.” –Abraham Lincoln

5/27/2020

Help!  My roses have measles! 

Nope.  Not measles (thank goodness!).  It is probably a fungal disease. 

We have had late rains this year, so roses that are susceptible to fungal diseases may have them.  Other years, when the weather is dry, your roses may not suffer from them.  There are several types of fungal diseases.  For the most part, I usually see them in early spring and by the time the weather warms up, they are gone.  I don’t worry about them too much.  I pick off the leaves and buds that are infected and dispose them. 

There are lots of different types of fungal diseases.  This month, I will discuss two common ones for roses.  

Black Spot

Black Spot

Black spot looks just like its name implies.  Brown to black spots on the leaves.  The edges of the spots are feathery and diffuse into the green tissue of the leaf.  The leaves or parts of the leaves may turn yellow and fall off the plant. 

Solution?  There are varieties of roses that are less susceptible to black spot.  You may want to explore planting those.  For us, in the Fresno area, this disease is not much of a problem other than in early spring.  I know it will be gone in a matter of weeks.  I only get it on a couple of my roses, and I choose not to spray for it.  I just pick off the infected leaves (they will grow back).  Here is more information from the UC Davis integrated pest management web page. 

Black Spot Information

Botrytis

Botrytis Blight--see the spots on the petals and the brown edges?

Botrytis will often appear on the petals of a rose.  Especially after a rain, light colored roses may end up with red spots that will remind you of measles (for those of us who remember what measles look like).  Also, the petals can start to turn gray, brown or tan (sometimes with fine gray spores) and won’t open.  The petals, with small pink to purple spots are called ghost spotting.  Sometimes the spots can have clear centers. 

The gray, brown or tan marks on the petals are called botrytis blight.  It can be hard, after waiting all winter for your beautiful roses to bloom, to have a late spring shower and suddenly, the buds won’t open or your roses (especially the light-colored ones) are covered in spots.  What can you do?  Not much.  I cut off the infected parts and wait for new growth and blooms to appear.  Make sure your roses are not crowded and are able to have air circulating around them to discourage fungal diseases.  Don’t leave rose debris around your roses as that can also harbor fungal diseases.  The UC Davis integrated pest management page has more information. 

Botrytis Blight Information

Breeder Highlights—Ralph Moore

Did you know that the “Grandfather of the miniature rose” lived in Visalia and had his rose nursery there?  His name was Ralph Moore and he owned the Sequoia Nursery which he started in 1937.  Ralph was born on January 14, 1907. He died on September 14, 2009.  In addition to roses, Ralph also bred Crape Myrtles that would do well in hot dry summer areas; Sequoia Red, Sequoia White, Sequoia Pink, Sequoia Lavender and Sequoia Near-Blue. 

Ralph has according to the website, “Help Me Find…” bred or found 517 different roses.  In reality he had over 50,000 rose crosses that he did yearly.  He would only keep just a small number of roses that he thought were viable from all of those crosses.  One of his quotes was, “Make a good plant first.  You can always hang a pretty flower on it later.”  This is one of many reasons why I have Ralph Moore bred roses in my garden.  They do extremely well in our weather (his roses are always in bloom during our hot summers) and they are extremely healthy and disease resistant. 

Ralph was taught by his grandfather how to take cuttings and propagate them.  He discovered that by crossing small roses with large climbers, he was getting offspring that were miniatures.  He also propagated his roses on their own root rather than grafting them.  He was the first to introduce moss roses in miniature and shrub form.  He introduced the first striped miniature rose.  He was one of the first to breed ground cover roses that are so popular today.  I could go on and on.  The Huntington Botanic Garden honored him as one of the great rosarians of this age. 

On May 29, 2004, the Visalia Parks and Recreation Foundation dedicated the Ralph Moore Rose Garden, filled with a collection of his miniature and shrub roses. The garden is open daily for those who wish to see the work of the “Father of the Miniature Rose.”

Rose Classification:  Miniature Roses

Miniature roses are the same as their bigger cousins other than size.  However, most are grown (here in the US) on their own roots and are not grafted.  They have the same requirements regarding sunlight, watering, fertilizing, etc., as their cousins but on a somewhat smaller scale.  For example, you would not feed a small one-foot miniature rose the same amount of fertilizer as a large 12-foot climbing rose. 

Miniature roses come as shrub roses, climbers, etc.  They are great for tucking into corners, planting in flowerboxes or pots.  They are quite hardy and not difficult to grow.  I have several that I have “saved from death” at the grocery store, and planted them in my yard.  They do extremely well.  One of my favorites (I do have several), is a Ralph Moore rose called Peppermint Parfait.  It is a stripey rose and is continuously in bloom.  It is very disease resistant and makes me smile every time I look at it.   It does wonderfully in a large (20-24 inch) pot as it will get two to three feet tall and wide.  It also does well with our summer heat. 

Peppermint Parfait

6/29/20--Soil

Shall we talk about some of the basics that roses need in order to grow and thrive?  Let’s talk about soil.  This may sound like a science class, but soil is important to growing roses and other plants in your garden. 

Soil

A good soil is made up of four major components;

• Inorganic materials (about 45% by volume) such as sand, silt, clay, etc.
• Organic materials (about 5%), i.e., the living and dead organisms of the soil
• Air (about 25%)
• Water (about 25%)

Inorganic Materials

The amount, or proportions of sand, silt and clay in the soil determines its texture.  The proportions are important.  How do you find out how much of each is in your soil?  Your soil can be tested.  The results can then be plotted on a graph called the soil triangle.  The triangle may look scary but it is not.  When you know what the numbers are (of sand, silt and clay) from your soil test, they can be plotted on the graph and it will show you what type of soil you have.  You can then amend your soil, (if necessary) in order to have the best soil possible for growing roses and other plants. 

USDA Soil Triangle

So, let’s talk about each of the components. 

Sand

Sand is a very large particle and forms large pores in the soil that allows for good drainage and space for roots to grow.  The drainage of water allows air (oxygen) to penetrate the soil. 

Silt

Silt is a medium size particle and is formed as sand is broken down into clay.  It is the most important source of available water in the soil.  Sandy soil allows water to drain too quickly for the plants to use.  Clay soil holds onto water too tightly for the plants to use.  It is therefore important to have silt in the soil, so water can be taken up by the roots, as needed. 

Clay

Clay is a very small particle that has a crystalline lattice form.  This causes the clay particles to have a net negative charge.  (Goodness, Rosie!  Where are you going with all of this?)  This charge plays an important role in the soil’s ability to hold nutrients. 

Loam

When the proportions of the sand, silt and clay all contribute to the soil’s properties, it is called loam.  The ideal soil texture for roses is 40% sand, 40% silt and 20% clay. 

So why is this important? 

Sandy soils require more frequent watering and fertilizing because the water flows through so quickly, the nutrients are rapidly leached from the soil.  Clay soils tend to have extremely poor drainage, but require less fertilizing and watering.  Loam soils have the best properties with both good water retention and drainage while also retaining nutrients. 

So, how do you improve your soil?

Get it tested.  Find out what kind of soil you have and what you need for optimum growing conditions.  There are several companies where you can purchase a soil testing kit on the internet or you may be able to get one at your local garden center.  After you test your soil, you can always contact your Master Gardener program or local extension for a recommendation on how to correct your soil, if necessary.  Many soil tests will also let you know what you need to add to your soil to get it up to the ideal. 

Organic Material in the Soil

Living and dead organisms make up the organic material in the soil.  They are crucial to giving your soil fertility.  Decomposing organic material breaks down in the soil and creates humus.  (No, not the stuff you eat on pita bread.  That is hummus.  We are talking humus). 

Humic acid plays several important roses in the soil.  It helps to break down the inorganic materials into nutrients available to the plant.  This happens about 20 times faster in the soil if there is humic acid available.  This is the natural replenishment cycle for minerals (nutrients) in the soil. 

Humic acid and clay particles create the Cation Exchange Capacity (CEC) of the soil.  The CEC of the soil is a measure of how well it can hold positive ions or cations.  This is important because many of the nutrients needed by roses (or plants in general) require these positive ions in order to be absorbed by the plant. 

Humic acid also plays a role in the soil aggregate formation process (peds).  This is critical in the formation of good soil structure.  Humus and organic material increase the soil’s ability to hold water.  The available water is higher in soils with high levels of organic materials. 

Living organisms such as worms, insects, microbes, fungi, algae, mammals, etc., till the soil as they move through it.  They help to bring down the organic material to lower soil levels and mix up the soil’s components.  They also break down the organic matter into nutrients the plants can use (mineralization) and create soil aggregates (those peds we mentioned above) which improve the overall soil structure.  This increases the water holding capacity in sandy soil and can lower a soil’s pH.

pH

What is pH and why is it important?  pH is a figure that expresses if something is acidic (less than 7 on the pH scale), neutral (7) or alkaline (greater than 7 on the pH scale). 

Soil pH affects the nutrient availability for a plant.  It must be at certain levels for plants to survive and thrive.  Roses like an environment that is 6.0—6.5 on the pH scale.  If your soil is too acidic, there are things you can do to raise it (if necessary).  If your soil is too alkaline, you can add certain things to lower the pH.    Again, consult your local extension or Master Gardener as to what can be done if your soil tests too alkaline or too acidic.  Your soil test results may also suggest what to add to your soil to make it ideal for growing roses (and other plants). 

Air

Most of the air your roses need comes through their leaves.  However, roses cannot grow in water saturated soil.  Air is needed for those living organisms in the soil and the plant roots to survive.  Those living organisms mentioned above help to break up the soil to create the air and nutrients necessary for roots (and therefore your roses) to grow.

Water

Did you know that plants consist of 50% to 90% water?  Roses use water in photosynthesis (the process where they make food).  Water is also used to cool their leaves in a process called transpiration.  It is used to transport nutrients and carbohydrates throughout the plant. 

Too much water in the soil can be harmful to your roses.  There is a saying that “Roses don’t like wet feet.”  So good drainage is important as is water retention. 

A balanced soil structure allows the water to pass through the soil at a rate that allows nutrients to be taken up by the roots of the plants.  You can actually test the drainage of your soil.  Here is a fact sheet from UC Davis on how to do this.  Again, I would recommend that you do this so you can further add to your knowledge of the soil in your garden and how to create the optimum conditions for growing your roses.  

UC Davis Soil Drainage Test

OK, enough with the science lesson for today.  I want your roses to thrive and having good soil for them is important.  But Rosie, I don’t have a garden.  I love roses.  How can I grow them?  Ah, a preview of things to come.  You can grow roses in pots!  I have for many, many years.  They do just fine and look beautiful on a balcony or patio. 

6-29-20  Did you know?  

Did you know that June is National Rose Month and June 12th is National Red Rose Day?  

Ascot Rose

This rose is called Ascot.  It was bred by Hans Jurgen Evers in 2001.  It was introduced into commerce in 2007 by Tantau roses.  The rose is a beautiful hybrid tea rose.  It is one of the few red roses that I grow.  This one is just a baby rose that is grown on its own root.  The plant is about a year old or so.  This was the first bloom that it ever produced.  However, in checking on the rose this morning, it has more buds and soon, more flowers to come!    

6-29-20  Until next time…

”Just like the rose holds her beauty among the thorns—we can gather our strength from the most unlikely places.”  Christine Evangelou  

Water

Did you know that plants consist of 50% to 90% water?  Water to a plant is critical.  Roses use water for

• Photosynthesis (how the rose internally makes food for it to survive),
• Transpiration—the process of evaporation of water from the plant,
• Transporting nutrients and carbohydrates throughout the plant,
• Making the cells of the plant stiff (no droopy plants, please!).

Remember last month when I wrote about soil?  The types of soil are important to the uptake of water to your roses.  Water drainage (how fast the water goes through the soil) and water holding capacity (how much the water stays in the soil, so it is available to the plant as necessary), are vital to keeping your rose plants alive and well.  Soil that drains rapidly (such as sandy soil), does not allow the plant to absorb the water it needs.  OK, so, if I flood the plant and keep it constantly wet, will that be better?  Nope!  Too much water can actually drown the plant.  Roses in particular, as the saying goes, “don’t like wet feet!” 

Last month, I spoke of air space between the soil particles.  In sandy soil, water flows too fast through it, leaving too much air.  The plant doesn’t get a chance to draw up the water and nutrients it needs to thrive.  In clay soil, the water drains too slowly, not leaving enough air space between the soil particles for the plant to be able to draw up nutrients so it can grow. 

If you recall from school, plants do something called photosynthesis.  That is where the plant takes up the sunlight, carbon dioxide from the air and water to produce carbohydrates (the food the plant uses to live) and gives off oxygen (the stuff we breathe).  The process where the plant produces the carbohydrates through photosynthesis, and then converts them into energy, so the plant can grow, is called respiration.  The roots of plants need air for respiration.  That is why having water saturated soil (too much clay soil) isn’t good.  The plants can’t get the air they need for respiration. 

Good drainage is important so water can percolate through the soil with the deep watering roses need.  A balanced soil (see last month’s article) is important as it allows the water to pass through the soil at a rate slow enough to permit nutrients to be taken up by the plant’s roots.  This is one of the reasons to get your soil tested, so you know what type of soil you have.

Other factors to take into consideration in addition to soil type when watering your roses, include temperature and surrounding plants.  One to two inches of water a week (4—5 gallons) may be all that is needed.  Too much water can promote root rot.  Water deeply and infrequently to encourage deep root growth and minimize leaf wetness (which can cause fungal diseases).   

You can use soaker hoses or drip for your roses.  Water can then be delivered in adequate amounts while keeping the foliage dry, preventing fungal diseases. If your roses are on drip, it is then easy to figure out how many gallons of water they are getting by the size of the drip emitter.  If your roses are on a sprinkler system, early morning watering is best.  That way the sun can dry any moisture on the leaves to again, discourage fungal diseases. 

Use a good mulch.  It will help to retain water in your soil and keep your roses roots cooler in summer and warmer in winter.  This will also help to retard weed growth.  No one likes to pull weeds around a thorny rose bush.  Materials such as wood chips, straw or dry grass clippings make good mulches.  Shredded hardwood bark can also be used.  Eventually, these organic mulch materials will break down and help to improve your soil. 

Mulch should be applied about three to four inches deep and replaced as needed.  You can place the mulch in about an 18-inch radius around your rose bush, but leave an un-mulched area in a six-inch radius from the center of the rose. 

Here is a soil percolation test from UC Davis that you can do at home. 

UC Davis Home Soil Percolation Test

Until Next Time...

“I don’t know whether nice people tend to grow roses or growing roses makes people nice.” – Roland A. Browne

9/27/2020

Let’s Talk Fertilizers (and that is not a lot of bull!)

Today, we are going to get into the nitty gritty about fertilizers. 

First of all, what is a fertilizer? 

“A fertilizer is any material containing at least one of the essential elements for plant growth that is added to the soil for the purpose of supplementing the plant nutrient supply.”

So, what are the nutrients that roses need? 

There are sixteen basic elements (actually, there are more but we won't get into that today) that are required for plant growth.  The main ones are carbon (44%), hydrogen (6%) and oxygen (45%).  These nutrients are obtained from the air (carbon dioxide) and from water. These main elements make up 99.8% of the components necessary for plant growth.  The remaining macronutrients and micronutrients are obtained from the soil. 

What are the macronutrients and what do they do? 

They are;

• Nitrogen (N) about 2%--stimulates growth, strong canes, good blooms and rich dark foliage,
• Phosphorus (P) about 0.5%--stimulates root growth and big blooms,
• Potassium (K) about 1%--promotes root growth, vigor and bloom color
• Calcium (Ca) about 0.6%--promotes stability, early growth and bloom color
• Sulfur (S) about 0.4—supplies material for amino acids and proteins needed for plant health and lowers the Ph of the soil, and
• Magnesium (Mg) about 0.3%--promotes chlorophyll formation to produce greener foliage and disease resistance.

OK, so I am at the store and looking at the various fertilizers on the shelf.  What do those letters and numbers mean on the bag? 

The main letters you will see on a bag of fertilizer are N (Nitrogen), P (Phosphorus) and K (Potassium).  The numbers represent the percentage of nutrient compared to filler ingredients in the product.  A 10-10-10 fertilizer contains 10% of each nutrient, e.g., nitrogen, phosphorus and potassium.  A 10-pound bag of fertilizer labeled 5-10-5, would contain 5% nitrogen, 10% phosphorus and 5% potassium.  The remaining 80% could be comprised of other nutrients and fillers. 

An easier way to remember what each of the main nutrients (the N, P and K), does for your roses or any other plant, is easy.  The N (Nitrogen) is for the above portions of the plant (canes, growth, foliage).  The P (Phosphorus) is for the below portions of the plant (root growth, etc.).  The K (Potassium) is for “all around” growth (root growth, vigor and bloom color).  So, think above, below and all around.  It is a good way to remember what those letters and numbers on the fertilizer bag, bottle or package represent. 

Plants also need micronutrients.  These are just a very small amount of the nutrients that your roses need.  They are;

• Manganese—aids in chlorophyll formation and helps in photosynthesis,
• Zinc—stimulates stem growth and bud formation,
• Boron—stimulates flower formation and pollination,
• Copper—stimulates stem development,
• Iron—aids in chlorophyll formation,
• Molybdenum—stimulates plant growth and vigor, and
• Chlorine—involved with photosynthesis in the opening and closing of the stomata, which are the pores in leaves that enable plants to take in and release gases, e.g., carbon dioxide, oxygen, etc.

OK, so how do I assure that I give my roses what they need? 

Again (you have heard me say this over and over), get your soil tested to find out what type you have and what nutrients are or aren’t there.  You can supplement your roses with fertilizers and amendments, such as compost.  Fertilizer is not one of the things where a little bit is good, therefore more is better.  Over fertilizing can have detrimental effects on your plants. 

Does it make a difference what type of fertilizer you buy?  Do your plants care if the fertilizer is organic or not? 

Surprisingly, no.  Plants use nutrients in their ionic forms, so it does not matter where the source the nutrient originated.  Now, that being said, is there a reason to use organic fertilizers?  Yes! 

Synthetic fertilizers are made up from the chemical sources listed on the label.  These tend to be faster acting than organic fertilizers and may be a good choice in aiding plants in severe distress from nutrient deficiencies.  However, all chemical fertilizers are comprised of salts.  Salt interferes with the ability of the plant to obtain water.  Heavy applications of chemical fertilizers will cause leaf burn similar to not watering a plant during hot weather. 

The one cardinal rule about applying fertilizer (especially chemical fertilizers) is NEVER APPLY FERTILIZER TO DRY SOIL!  Water your roses before and after an application of chemical fertilizer.  The existing salt level in the soil can contribute to the burning effects of adding chemical fertilizers. 

Organic fertilizers come from once living organisms.  They are low in nutrient content and are slow release.  They require biological action from the soil organisms to release the nutrients.  This feeds the soil which helps to keep your soil healthy.  A healthy soil is able to hold air, nutrients and water.  Examples of organic fertilizers are manures, fish emulsion, alfalfa meal, compost and cottonseed meal.  These fertilizers release their nutrients slowly.  They are broken down by bacteria in the soil, providing nutrients as they decompose. 

You will also see on the bag of fertilizer the words “complete” or “incomplete.”  What does that mean? 

It really is pretty simple.  Complete fertilizers contain all three major nutrients, Nitrogen (N), Phosphorus (P) and Potassium (K), such as a 10-10-10.  An incomplete fertilizer lacks one or more major nutrients, such as a 0-20-20. 

Help!  The bag also says “general-purpose” or “all purpose.”  What does that mean? 

A general-purpose fertilizer contains equal amount of each major nutrient or a slightly higher percentage of nitrogen than phosphorus and potassium.  These are intended to meet most general plant requirements throughout the growing season. 

Rosie, I also see on the shelf, special-purpose fertilizers.  What are those? 

Those specialized fertilizers are formulated for specific plants and their needs.  They have a particular combination of nitrogen, phosphorus and potassium for specific plants or garden situations.  You may see fertilizers that are specifically for roses or ones for citrus trees, other flowers, lawns, etc. 

What is a slow-release fertilizer? 

Plants can take up nutrients continuously.  Slow-release fertilizers contain one or more of the essential nutrients for plants.  These elements are released or made available for plant use over an extended period of time.  It will usually say that on the label, e.g., three months, six months, nine months, etc.  These synthetic fertilizers are usually in a granular form and are meant to be sprinkled into the soil or worked around the plants.  Again, after applying one of these fertilizers, the plants should be watered immediately before and after fertilizing to avoid burning the plants. 

There are bottles of fertilizers.  What are those? 

Liquid fertilizers are water-soluble powders or liquid concentrates that are mixed with water to make a fertilizer solution.  These fertilizers generally last one to two weeks, so you would need to reapply them often.  You have to make sure they are properly diluted so you reduce the chance of burning the plants, especially the leaves.  This is particularly true in In warm weather.  I have known people to spray their rose leaves with fish emulsion during hot weather which caused their leaves to burn and fall off!  These fertilizers can provide a boost to plants and properly diluted can be great for starting plants.  If you choose to use them, read and follow the label instructions.  Again, do not use in warmer/hot weather or you can risk burning the leaves of your plant. 

How about manure? 

Manure can be used to increase the fertility of the soil.  It is important to use well aged manure.  “Fresh” manure can damage plant tissue and kill seedlings.  It is too “hot.”  Make sure you use manure that has been processed or composted.  Do not use any manure from dogs, cats or other meat-eating animals!  There is a risk of parasites or disease organisms that can be transmitted to humans!

What is compost and is it good for my plants/roses?

According to the Environmental Protection Agency (EPA), “Compost is organic material that can be added to soil to help plants grow.”  This organic matter has been decomposed in a process called composting.  It recycles various organic materials otherwise regarded as waste products and produces a soil conditioner.  It is very rich in nutrients that plants need.  Compost will feed the soil and fertilizer will feed the plants.  Compost and organic fertilizers can work together.  The compost will store the fertilizer nutrients until they are needed by the plants.  Compost also provides many of the micronutrients that the roses need.  

How about those products that have fertilizer and insecticide and/or fungicide in them? 

Ah, you may think, this will make my life easier if I use this product.  Personally, I don’t use them.  They tend to be expensive.  The fertilizer in them is not as good as buying a specialized fertilizer for roses.  People in the central valley rarely get fungal diseases, so why spray for something we don’t get?  You may have one type of bug on your roses but that may not be the one targeted in the spray. 

I follow the Integrated Pest Management principles put out by the University of California, Davis, if I have pests.  I follow the recommendations by UC Davis or by the American Rose Society for fertilizing my roses.  Next month, we will get into those recommendations as to when to fertilize your roses. 

Until next month…

“True friendship is like a rose.  We don’t realize its beauty until it fades.”

--Anonymous