Fertilizers Are Easy

Rob Trawick
Extension Horticulturist
Jackson County

Understanding the numbers on a bag of fertilizer helps you apply the right amount and ratio of fertilizer your yard and garden need. Fertilizers come in different strengths and blends, with the three numbers on the bags showing the percentage by weight of the three major nutrients.
Bag of Fertilizer showing the percentage of the three major components: Photo Credits: Image Courtesy of Fertilizer101.org

The first number of the left-to-right sequence always is the percentage of nitrogen (N). The second is the percentage of phosphorus (P) as expressed in phosphate, which is not pure phosphorus. The third number is the percentage of potassium (K) as expressed in the oxide called K20 equivalent.

Recommended amounts of nitrogen, phosphorus and potassium are almost always given as these equivalents rather than the true elements. The higher the number, the stronger that nutrient is in the fertilizer, so you can apply more of a weaker fertilizer to get the amount of nutrient needed or less of a stronger fertilizer. For example, about 7 pounds of cow manure can substitute for 1 pound of 8-8-8. Just look at the analysis on the bag. Blended fertilizers have more than one nutrient, such as 0-20-20 or 8-24-24. A complete fertilizer is one that has some of all three nutrients, like 8-24-24.

Muriate of potash is 0-0-60, and triple super phosphate is 0-46-0. Some nitrogen sources are ammonium nitrate 33-0-0, ammonium sulfate 20-0-0 or urea 46-0-0.
Other fertilizer materials are potassium sulfate (0-0-50), DAP (18-46-0), IBDU (31-0-0), SCU (32-0-0), UF (38-0-0), bone meal (2-20-0) or cottonseed meal (6-3-2). These materials are considered slow- or controlled-release fertilizers

Dividing 100 by the percentage of the nutrient in the fertilizer gives the
pounds of the fertilizer needed to supply 1 pound of that nutrient. For example, with a bag of 8-8-8 fertilizer if you divide 100 by 8 you’ll get 12.5, which is the number of pounds that will supply a pound each of nitrogen, phosphate and potassium oxide.
The nutrient numbers on the bag also are ratios to one another.  8-8-8 is a 1-1-1 ratio, while 5-10-15 is a 1-2-3 ratio. Different crops and soils may need different ratios.
A vegetable garden of average fertility may use a 1-1-1 ratio, a 1-2-1 ratio or a 1-3-3 ratio for sweet potatoes, peas and beans. Lawns generally like a 3-1-2 ratio, but centipede grass fertilizers are often a 1-0-1 ratio.

The best way to determine the nutrient needs of your grass, garden or crop is to have the soil scientifically tested. Your county agent can tell you how to take a representative sample to send to the University of Florida’s Soil Testing Lab. Kits and instructions can be found at your county extension office. Test results and fertilizer recommendations matched to the crop to be grown will be returned to the grower.


Busy Bees

Beth Bolles
County Agent
Escanbia County

Consider yourself lucky this year if your landscape is found to be a suitable spot for one of our solitary bees.  Late winter and spring are the times when these beneficial bees begin their development, causing interest and concern for many homeowners.

Female bee excavates a tunnel in the soil. Photo Credits: North Carolina Cooperative Extension Service

The majority of bee species do not produce a colony. The solitary bees include leafcutter bees, digger bees, sweat bees, and mining bees. These bees use existing holes, excavate nests in rotten wood and plant stems, or dig burrows in the ground to rear their young.

The mining bees or adrenids are often seen in areas of landscapes that have little ground vegetation and loose soil.  After mating, the female bee will excavate a very small tunnel in the ground that has several small cells attached to it.  The bee collects pollen and nectar to add to the cell and then lays a single egg in each cell. The emerging larvae feed on the nectar and pollen until it changes to an adult bee in the fall. There is only one generation a year.  Although these solitary bees individually produce small nests, sometimes many will nest in close proximity to each other.

Solitary bees are not aggressive and stings are quite mild. Most solitary bees can be closely observed and will elicit no defensive behaviors. Perhaps the most common stings that occur are when the sweat bee, which is attracted to moisture, stings when swatted. Males of some solitary bees, which can not sting, will sometimes make aggressive-looking bluffing flights when defending a territory.

Like the most famous honey bee, solitary bees play a beneficial role in the pollination of plants.  Their activity in the spring is short-lived and no management is necessary.

Color in the Garden

David W. Marshall
Agriculture and Natural Resources
Program Leader
Leon County Extension

The months of March and April are months of change in the garden. Winter is ending and spring beginning. In the beginning of March freezes are still possible. By April, though, the probability of a freeze, though not impossible, is much more unlikely. It’s very important to know what to plant and when to plant it. If you wish to plant flowers for color in early March you should plant those that can withstand a freeze should it occur. By April, though, especially mid-April, you shouldn’t plant any more cool-season flowers. It will be time to think about the summer that will soon be here. So heat-tolerance will be the main consideration.

Sweet alyssum is one of those flowers you can plant in early March, because alyssum, being a cool-season annual, will be okay if we get a late freeze. Normally alyssum fades out in late spring as the temperatures begin to soar. But this particular one, Snow Princess, takes the heat pretty well. In fact, in this planting, at the UF-IFAS North Florida Research & Education Center in Quincy, Snow Princess lived through last summer. This photo was taken in the fall. So this plant should be on your “to plant” list now. Plant in full sun. Photo Credits: David W. Marshall

Verbena is another plant that can be planted in early March, as it, too, will tolerate the cool weather. Yet it will live into summer when the heat will probably take it out. It stays low-growing and creates a thick bed of color. The purples, pinks, and reds of verbena would be a good contrast to the alyssum shown in the last photo. Photo Credits: David W. Marshall

Vista Bubblegum Supertunia is yet another bedding plant for early spring. It is indeed a super petunia! If you didn’t plant it in the fall, delay no more and get some planted soon so that you can enjoy its flowers all spring. Petunias are cool season annuals. So most petunias fade out when the summer heat and rains begin. Vista Bubblegum has been known to survive the summer in our demonstration gardens and then start blooming again in the fall. Plant in full sun. Photo Credits: David W. Marshall

Another flower you can plant in fall or early spring is the snapdragon. Snaps will begin flowering a little later in the spring and go all the way to summer. Sometimes they will even hang on into the summer. Plant them now, in full sun, and you won’t have to worry about late freezes damaging them. They are plenty hardy! Photo Credits: David W. Marshall

Once we’re into April, it’s best to start thinking about summer heat when selecting flowers as June is only eight weeks away. The trailing torenias, as shown in this photo at the base of the variegated shell ginger plant, have been our best summer annual in the demonstration garden at the UF-IFAS Leon County Extension Center. The planting just gets thicker and thicker, wider and wider, and the blooming is non-stop until the first hard freeze next November or December. Make sure you select one of the trailing torenias, though, such as Summer Wave, Catalina, or the Moon series. The trailing torenias are much more vigorous growers than the upright Clown torenias… not that the Clowns are bad plants either. It’s just that even someone with a brown thumb can grow the trailing torenias. Half a day of full sun, in the morning, is preferable. But they will tolerate full sun all day, too. The hot afternoon sun just causes the plants to look a little faded. Photo Credits: David W. Marshall

The narrow-leafed zinnia (Zinnia angustifolia or Z. linearis) is another very heat-tolerant summer annual that can be started in April. Just give it full sun and well-drained soil. It’s a good complimentary planting to the trailing torenias, which you can see in the background in this photo. Photo Credits: David W. Marshall

Need some easy color in a spot? Then consider the many varieties of coleus. There are many that will even take the full sun, such as in this photo in Medellin, Colombia, the city of eternal spring. So plant some coleus in April, sun or shade, and create your own eternal spring in your garden, as the coleus will last until the following winter. The only downside to coleus is that they do require a good bit of water during the very hot weather. Photo Credits: David W. Marshall

Sunpatiens are the new super impatiens. They’re really a type of New Guinea impatiens, but much tougher than the New Guinea impatiens of the past. We’ve grown them the last several years in the demonstration garden and they have held up very well. This photo was taken in the fall. Yes, they will take full sun, but they probably do best where they get a little shade, too, for part of the day. They come in various flower colors and some have dark leaves, while there are others with variegated leaves. It’s another good plant to start in April.

If you plant any of the eight plants I’ve mentioned in this column, I would appreciate if you would drop me an email and tell me. Write me at marshalld@leoncountyfl.gov Photo Credits: David W. Marshall

Mowing Magic

Theresa Friday
Horticulture Agent
Santa Rosa County Extension

A healthy, good-looking lawn isn’t the result of magic.  It’s from using proper cultural techniques and mowing is perhaps the gardener’s most important chore. Done properly, mowing can increase the thickness of the lawn and make it more resistant to weeds.  Done improperly, mowing can produce long-term damage to the turf.

Cutting height and frequency are the most critical components of proper mowing.
Turfgrass undergoes physiological stress with each mowing, particularly if too much leaf blade is removed.  A rule of thumb is to never remove more than the top 1/3 of the foliage in any one cut. When the turf grows back out about 50 percent, then it’s time to mow –even if it’s not yet Saturday morning.

Recommended mowing heights for St. Augustine are 2 ½ to 4 inches. However, only the dwarf varieties of St. Augustine, such as ‘Seville,’ ‘Jade,’ ‘Palmetto,’ and ‘Delmar’ should be mowed at less than 3 inches.  Centipede is best cut 2 to 3 inches.

A sharp mower blade produces a cleaner cut with less stress on the grass. Sharpening a common rotary mower blade is not a big problem and should be done often.
Rotary sharpening stones that fit on a hand drill are available. They can sharpen a blade or ‘bring out the edge’ without removing the blade from the mower housing. These, however, will just do light-duty sharpening and will not allow for balancing the blade to reduce vibration.

The best way to sharpen a rotary mower blade is to take off the blade and sharpen with a grinder or metal file. When grinding, use eye or face protection and watch out for your loose clothing and sparks.

Before working on the mower, always disconnect the spark plug wire. Tilt the mower body to reach the blade, and watch for leaking gas and oil. Chock the blade with a piece of wood so that it can’t spin. Remove the blade’s fastening bolt with a wrench or socket. Note the top side and bottom of the blade. Installation is the reverse procedure.

When sharpening the two cutting end surfaces, maintain the cutting surface angle at an angle of about 40 degrees. Thinner will be too knife-like and weak; it won’t hold up. Thicker angles will be blunter and will not cut as cleanly. As you sharpen, move the blade back and forth with light pressure. Avoid overheating the steel and losing the metal’s temper (hardness).

After sharpening, always check the blade’s balance using an inexpensive, cone balancer. A nail in a wall or stud can do in a pinch. If the blade leans more to one end, take more metal off of that end’s cutting surface to balance it. A balanced blade will vibrate less and cause less engine wear.

Never try to straighten a badly bent blade. Never try to use a cracked blade. If the blade is damaged or the cutting surfaces worn too thin, replace the blade.
Choose the correct blade type and length for the mower housing and type of mowing you do. Mulching blades have more bends and greater cutting surface than do standard blades. Mulching blades are designed to circulate the clippings and cut them several times. On most lawns, grass clippings should be returned to help recycle nutrients to the soil.

After sharpening, always check the blade’s balance using an inexpensive, cone balancer. A nail in a wall or stud can do in a pinch.