Math isn’t always fun! Here is Euclid explaining math in Raphael’s The School of Athens. Credit: Creative Commons.
There are a lot of things gardeners need to know to cultivate a beautiful landscape. Between plant zones, scientific names, soil chemistry, and pest identification, being a gardener takes curiosity and willingness to learn new things. Unfortunately, one topic that needs to be well understood, especially when it comes to applying pesticides and fertilizers, is a subject that many cringe when they hear it – mathematics!
Some of the most common mathematical concepts to have a good grasp on for gardening include area, converting decimals to percentages and vice versa, estimating volume and converting units, and determining how much fertilizer to be applied based on your fertilizer grade.
Here’s a couple tips to help you gardeners out with math.
Area
Most often, we need to know the square footage of our gardens. Rectangles are straightforward, you multiply length (in feet) by width (in feet) to get feet squared. Since most yards are not rectangles, we sometimes need to use other shapes to best calculate the area, such as circles and/or triangles. The area (A) of a circle is , where “π” is 3.14 and “r” is the radius (half of the diameter or the distance from the center to the edge). Remember that the little raised 2 means you multiply the radius by itself twice, not by two.
Most of the time, square feet is the best area unit to use. But just in case you need to know, one acre equals 43,560 square feet. So, if you find your lawn is 10,000 square feet, that means you have 0.23 of an acre (10,000/43,560).
Get your calculator’s out! Credit: iStockphoto.
Percent Conversions
This one may be better understood by most, but this becomes important later when we determine fertilizer needed or doing volume conversions. Basically, any percent can be divided by 100 to convert it to a decimal that can be used easily in other calculations. For example, 15% is the same as 0.15 (15/100). The easy way to remember is that 100% is the same as one, and 50% is the same as 0.5.
Volume Estimation and Conversions
Determining volume is required when figuring out how much mulch is needed for a garden bed or soil required for a raised bed. Converting one unit to another is especially important when determining how much pesticide product is needed to prepare a mixture.
For mulch and soil, the cubic feet (cf) or cubic yards (cy) are needed to figure out how many bags or truckloads will be needed. Most bulk products are sold by the cubic yard. Since we are dealing with volume, we need three measurements, the length, width, and depth. If we want to add three inches of mulch to a 500 square foot garden, we multiply the 500 by 0.25 feet (3”/12” equals 0.25 inches) to get 125 cubic feet. That is about 62 bags of mulch from the hardware store, which are often sold in 2 cubic foot bags. If we divide 125 cubic feet by 27 (three feet in a yard so 3’ x 3’ x 3’ = 27) we now have the answer in cubic yards and find that we need about 4.5 cubic yards of mulch. One cubic yard is roughly a half of a full-size pickup truck bed.
When it comes to converting liquid volume units to help with pesticide mixtures, fortunately we have the internet to help. However, it is a good idea to at least be familiar with converting ounces to gallons and vice versa. Since 128 ounces equals 1 gallon, to go from gallons to ounces you multiply by 128. For example, 0.5 gallons equals 64 ounces (0.5 x 128). To go from ounces to gallons, we just divide by 128. For example, 192 ounces equals 1.5 gallons (192/128).
Applying the proper amount of fertilizer keeps your landscape healthier and protects local waterbodies. Credit: UF/IFAS.
Calculating Fertilizer Needed
Okay, bear with me, as we are about to do some hard math and piece together several of the above concepts. First of all, most fertilizer rates are provided by extension resources and given in terms of pounds of a particular nutrient for a set area, usually 1,000 square feet. For example, when using slow-release fertilizer a homeowner should apply no more than one pound of nitrogen for every 1,000 square feet of lawn. To figure out how much actual fertilizer to apply to meet the recommendation, we will need 1) the recommended rate, 2) the size of the lawn, and 3) the fertilizer grade on the product (the three numbers that represent the percent N, P, and K). Our rate is one pound nitrogen per 1,000 square feet. The size of our lawn is 50 feet by 30 feet, so 1,500 square feet. We are going to use a 16-0-8 fertilizer. Now, here is the hard part! To figure out how much of our 16% nitrogen fertilizer will provide one pound of nitrogen, we need to convert 16% to a decimal (16/100 = 0.16) and then divide the amount of fertilizer we need by that number – 1 pound/0.16 – to find that 6.25 pounds of our fertilizer product are required for each 1,000 square feet. Since we have 1,500 square feet, we need to multiply our answer by 1.5, which gives us a total of 9.4 pounds.
Math is hard and there are usually many methods to get the same solution. When using pesticides and fertilizers in the home landscape, it’s important to make sure we’re using the right amount of materials to minimize the chance of harming ourself, our plants, and the local environment. If you need help, or would like someone to check your work, contact your local extension office.
Summer should be the time to relax and enjoy the fruit of all the hard work performed in the landscape over the previous winter and spring. However, there are still some essential tasks that need to be completed during the summer. Perform them in short energy bursts early in the morning or late in the evening.
1. Aerate Your Lawn
If your yard is starting to look weak and thin, even with fertilizing and proper moisture, it may need aeration. Aeration, which is creating channels into your lawn, allows water and nutrients to reach the deep roots of your grass more efficiently.
To test if you need to aerate your lawn, shovel up a patch of grass to a depth of at least four inches. If the layer of thatch is a half-inch thick or higher, your yard would benefit from aeration. There are self-drive aeration machines and tractor-pulled devices you can rent to make quick work of large areas. For smaller areas, simply punching multiple holes with a pitchfork will do the job.
2. Fertilize
Commercial landscape fertilizer applicators must obtain state certification.
Turf grass often displays a yellow color during the mid-summer rainy seasons due to the heavy rains flushing nitrogen away from plant roots. If your lawn is looking sad and yellow, chelated iron can often give a temporary green-up. Iron is not a replacement for nitrogen, but it can work well during our summer rainy season.
If you soil test revealed a potassium or magnesium deficiency, summer is a good time to make the last corrective application. Potassium (K) is an essential macronutrient. Fertilizer bags typically show the percentage of potassium in a product as the third number displayed on the front of the bag (e.g., the “8” in 16-2-8). Potassium acts as a “vitamin” for turf grass, increasing root strength, disease resistance and cold hardiness.
Magnesium (Mg), also a macronutrient, is essential for the production of chlorophyll, necessary for photosynthesis, and also plays a part in the movement of carbohydrates from leaves to other parts of the plant.
3. Don’t Mow Too Short
It’s a natural inclination to want to mow your grass as short as you can, so you have the longest time until you have to mow it again. However, giving your grass a buzz cut every time you mow can hurt your lawn over time.
While some turf grasses can be mowed relatively short, like Bermudas and some Zoysias, most grass types shouldn’t be cut shorter than two-and-one-half to four inches high. Mowing shorter than that can damage the growth point and leave it susceptible to disease and pest infestation. It can also dehydrate the grass and lead to long term damage.
5. Water Infrequently but Deeply
One common mistake made by many is watering too often and too shallow. When only given frequent shallow waterings, grass will begin to grow their roots upwards to take advantage of the small amounts of water, which makes weak and unhealthy. The grass becomes even more dependent on water and very susceptible to disease and insect attack.
Try watering only once or twice a week, but for a considerably longer time so that the water can penetrate deeper into the soil and encourage downward roots. Ideally, each irrigation zone is calibrated to determine the length of time it take to deliver ½ – ¾ inch. Then set the system to run every 3-4 days for that number of minutes. While checking the irrigation delivery system, make sure the rain shut-off device is working and set to the same ½ – ¾ inch.
6. Prevent Mosquitoes
Summer rains on a nearly daily basis lead to lots of standing water. In less than one inch of water, hundreds of mosquitoes can hatch 3 -5 days later. Not only are these blood-sucking pests annoying, but they can also transmit dangerous diseases like West Nile and Zika Virus. Even without disease, their bites are painful and irritating.
To prevent mosquitoes, make sure no standing water is allowed to remain in your yard, either in low points or in empty containers like flower pots or wheelbarrows. Any amount of stagnant water is the perfect breeding ground for mosquitoes. Take a walk around the yard, dumping out water and disturbing the oak and magnolia leaves that are acting a collection cup. Treat birdbaths and water features with floating “donuts” specifically designed to kill mosquito eggs.
While getting tasks done in quick morning trips to the yard, make sure to keep hydrated. Heat exhaustion can happen fast.
Dr. Bryan Unruh with robotic mower. Credit: UF/IFAS
With gas prices increasing, there are practical ways to reduce gasoline use in your own backyard.
There are electric, battery, solar powered and robotic (autonomous) lawnmowers. Do you remember the non-motorized reel mower? Or, you could use sheep. But, for the time being, most people have gasoline powered mowers. There are costs involved with mowing, including the cost of gas or diesel fuel.
Be smart as to where you grow grass. Use grass where it serves a purpose. Concentrate your efforts in growing grass where it will grow. It’s normal for lawns to decline in close proximity to large trees. As a lawn gives way to tree competition, do something else in that area. Use mulch under trees or plant shade tolerant plants.
Fertilize smart. Lawns need fertilizer. But, too much fertilizer, particularly too much nitrogen, results in excessive grass growth that requires more mowing.
Many homeowners overdo it with too much nitrogen and too little potassium. Fertilizers with the correct ratios of nitrogen to potassium will produce the right balance of shoot to root growth. Choose a fertilizer such as 15-0-15 or some similar analysis with some slow release nitrogen. Fertilize to produce adequate growth and the correct color. If your lawn is a healthy green and you’re mowing, mowing, mowing… why add more fertilizer?
Centipedegrass and bahiagrass will grow best with fewer problems when fertilized sparingly. This would be one or two light applications of fertilizer per year, or none at all if these grasses are performing well. St. Augustinegrass and zoysiagrass might get by on one spring application; however, it’s more common to apply a second time during summer.
Never apply more than the recommended amount of fertilizer per application. You can always split the total amount into two or more applications, which will produce more even growth and minimize sudden growth spurts.
Though it’s a popular practice, reconsider overseeding your lawn with ryegrass this fall. Weigh the desire to have a green lawn through winter with the extra time and costs (gas, fertilizer, water and pesticides) involved with maintaining it.
Finally, keep your gas-powered lawnmower in good working condition. It can make a difference in how efficiently it operates. Make sure the equipment is clean. Change the oil if needed. Replace or clean the air filter and spark plug. Keep lawnmower blades sharp. Basically, follow the owner’s manual for routine maintenance.
Implementing these ideas can help conserve fuel and result in a healthier lawn.
2022 has been a good tomato growing year for many Panhandle gardeners, myself included. It would have been difficult to have better climatic conditions to aid a terrific tomato harvest. After enduring a late frost just before Easter, the Panhandle then experienced two mild months in April and May that combined with nearly a month of dry weather during fruit development to deliver an excellent fruit set season with minimal disease and insect pressure. However, despite the favorable growing conditions, I have talked with several gardeners that once again struggled to yield a good crop of fresh garden tomatoes. Why is that? With the Panhandle tomato home gardening season nearing its conclusion, now is a perfect time to revisit 3 of the most common mistakes that prevent an excellent harvest!
Not Starting Early – Since Memorial Day, the rain and heat have really ramped up. These hot, wet conditions are perfect for developing tomato plant problems like fungal and bacterial diseases, not to mention the fact that tomato plants will stop setting fruit once nighttime temperatures rise above 75 F. While spraying fungicides preventatively can certainly help decrease disease incidence, the absolute best thing a gardener can do is try to get ahead of the disease-bringing heat and humidity by starting plants early when more favorable growing conditions prevail. So, what is early? I try to have tomato transplants in the ground by March 15 or soon after*. If you plan to grow plants from seed, they should be started indoors mid-January for planting outdoors in mid-March. Most tomato varieties take between 60 and 80 days to mature after planting, so a mid-March planting date normally yields harvestable tomatoes by the middle of May, comfortably beating the June disease deadline. *Planting early means protecting plants from occasional late frosts. Be prepared!
Not Scouting Your Plants – Pest and disease problems are a lot easier to manage if caught early and the best way to do that is to spend time with your plants. If you scout (just walking by and giving plants a short inspection) daily, you’ll learn what tomato plants and the beneficial insects that hang around all the time are supposed to look like an and be able to spot abnormalities and bad bugs when they occur. While tomato diseases and pest outbreaks can certainly cause a lot of damage in a short amount of time, they don’t reach disastrous levels immediately – be vigilant and catch them early!
Not Fertilizing and Watering Correctly – It takes a lot of energy for a tomato plant to grow a nice, bushy plant AND yield an abundance of America’s favorite vegetable (or fruit, depending on who you ask). To produce that necessary energy, gardeners must ensure plants receive adequate nutrition and water. Here’s my general prescription. At planting, apply a general purpose, slow-release fertilizer according to the label rate (for example, Osmocote, Harrell’s, or similar) and gypsum (a calcium supplement that helps prevent blossom end rot) at one pound per hundred square feet of garden. Then, supplement later in the season with a quick-release general purpose fertilizer sufficient to drive growth and fruit development. Watering is more of an ongoing concern. For the first couple of weeks of the tomato plant’s life, you can get by with watering once a day or every other day. As the plants get larger and the days get hotter however, watering twice daily is often needed to prevent wilting down in the heat of the day. Allowing tomato plants to wilt, even for a little while, is an excellent way to encourage blossom end rot and a subpar harvest!
When tomato season rolls around in 2023, remember to start early, scout often, and water and fertilize correctly. Follow those few tips and you’ll be well on your way to a great harvest in 2023! For more information about growing tomatoes or any other horticultural or agricultural topic, contact us at the UF/IFAS Calhoun County Extension Office at 850-674-8323 or email d.leonard@ufl.edu. Happy Gardening!
For many people in the Panhandle, gardening season begins when the weather warms in spring and nurseries start setting out tomato transplants. While I understand the allure of the yummy summer veggies and spring/early summer are the most traditional times to garden, cultivating a winter garden in the Panhandle unlocks many tasty options. Among these cool-season garden veggies is a classic southern staple that is among the easiest and most rewarding of all vegetables to grow, sweet onions!
‘Texas Super Sweet’ Onions almost ready for harvest in a Calhoun County garden. Photo courtesy of Joe Leonard.
Sweet onions are very popular in the culinary world for their mild flavor and soft texture and are among the most widely grown group of onions across the world, but the most famous of them, Vidalia’s, hail from Georgia! Despite its fame, the “Vidalia” onion is actually nothing more than a trademarked name for a specific variety of sweet onion that was bred in Texas (‘Yellow Granex’ and its derivatives), grown in a 20-county region in South Georgia with excellent onion-growing soil, and made famous by excellent marketing from the Vidalia Onion Committee. While they can’t be called Vidalias legally, you can absolutely grow your very own Vidalia type sweet onions at home here in the Florida Panhandle!
Sweet Onions are most easily grown at home if purchased in the fall as “sets”. Sets are small bulbs that have been started, harvested, dried to prevent rotting during storage, and shipped to garden centers ready to be “set” out in home gardens. Sweet onions may also be grown from seed but take much longer and have a lower success rate. When browsing onion set varieties for purchase at garden centers or in seed catalogues, make sure to purchase a short-day “Granex” type like “Texas Super Sweet” or similar. It is critical to remember that sweet onions are classified by how many hours of daylength they require to produce bulbs. The three classifications are Short, Mid, and Long-Day. Since sweet onions require cool weather to develop properly, Floridians must grow short-day varieties to compensate for decreased daylight hours in the winter. In the less hot Northern states, long-day sweet onions are grown in the summer, where they’ll be able to soak up 15-16 hours of daylight. Therefore, for best results in the Panhandle, select ONLY short-day onion varieties.
‘Texas Super Sweet’ Onions that have been harvested and are ready for use! Photo courtesy of Daniel Leonard.
Once you’ve selected your onion sets in the fall, they can be planted in the garden anytime from early October to mid-December. Individual bulbs should be planted about an inch deep in well-drained garden soil with high organic matter content (mushroom compost, composted manure, or other rich organic matter works) and spaced 4-6” between plants and about a foot between rows. Onions in general, and sweet onions in particular, are heavy feeders and require ample nutrition to meet their potential! To meet these fertility needs, I apply a slow-release fertilizer like Osmocote or a Harrell’s product at planting and supplement that with either a quick release granular or liquid fertilizer monthly during the bulb enlargement phase. Sweet onions also have a shallow root system and require frequent watering to develop properly and avoid splits, doubles, and small bulbs. Don’t let your onion bed dry out!
Finally, sweet onions planted in late fall/early winter are normally ready to harvest in April and May. However, rather than relying on a calendar, begin harvesting your onions when the tops start to turn yellow and fall over, this indicates maturity. After harvesting, allow your onions to “cure” with tops and roots still attached for a couple of weeks outside in a shaded, protected area. Once they’ve had an opportunity to “cure”, remove tops and roots and store the cured bulbs in a cool, dry place (a dark pantry in an air-conditioned room or the refrigerator crisper drawer work fine) and use at your convenience!
While they can’t be called Vidalias, sweet onions grown at home are oh so rewarding and very tasty! Provided they are planted in quality soil, receive plenty of water and fertilizer, and are harvested/stored correctly, sweet onions will provide a delicious, home-grown culinary treat throughout the year! For more information about growing onions in the home garden or any other horticultural/agricultural topic, contact us at the UF/IFAS Calhoun County Extension Office. Happy Gardening!
Yes, that’s right! We made it through the hottest part of the year and we are looking ahead to fall just around the corner! I am excited to be discussing September and what we can do to prepare for fall in the garden. As the nighttime temperatures start to cool down, we are given many more options.
For annual color plantings in September, try Ageratum, Celosia, Zinnias, and Wax Begonia to add fall color to your landscape. Bulbs will also add color, texture, and pattern to a bed. If you have some extra space, a variety of elephant ears could really accent a bed or you could always go with the classic calla, narcissus or zephyr lily. Popular vegetables to plant in North Florida in September are broccoli, carrot, cabbage, and collards. See Vegetable Gardening in Florida This is also the time of year to establish strawberry plants. Some great herbs to get started are Mexican tarragon, mint, rosemary, and basil.
Image Credit: Matthew Orwat UF/IFAS Extension Washington County
There are many things that can be done in your lawn during September. Monitoring your lawn for its health and potential insect pests is important this time of year. Common insects to scout for are fall armyworms, chinch bugs, mole crickets, and sod webworms. The last fertilizer application should be done by the middle to end of September. Make sure you choose a fertilizer with little to no phosphorus unless a soil test shows differently. To maintain a healthy lawn, avoid weed and feed products and only apply herbicides in areas with high infestations of weeds. Weed and feed products are not recommended because the timing of when to fertilize and the timing of the weed killer is not always the same. The best management practice is to use a separate treatment for weeds and when possible spot treat weeds.
If you already have bulbs in your landscape from previous growing seasons, this is the time to divide and replant those that are big. You can also add organic matter to new planting areas. Continue working on your vegetable plants and prepare them for either transplants for a fast start, or plants seeds for more variety. Throughout your landscape, it is important that plants are getting the right amount of water as we go in and out of wet and dry weather this time of year.
October will be here before we know it in just a couple of weeks. Look out for the next article to come. We will be getting into the cooler nights and more options for planting vegetables and herbs!
