Pruning Hydrangeas

Pruning Hydrangeas

We grow many types of hydrangeas in North Florida. In order to prune your hydrangeas at the correct time of year, you need to identify which types you have in your garden.

Bigleaf hydrangea (Hydrangea macrophylla)
Bigleaf hydrangea (Hydrangea macrophylla) comes in mophead and lacecap flower forms. They bloom on old wood, so prune in summer after blooming is finished. Repeat bloomers, such as ‘Endless Summer’ bloom on both old wood from the previous year and on the current season’s wood. You can prune after the first bloom and still get a bloom later in the season.

Hydrangea macrophylla. Photo by Beth Bolles,
UF IFAS Extension Escambia County

Oakleaf hydrangea (Hydrangea quercifolia)
A native hydrangea that blooms on old wood, so prune after flowering. This type requires little pruning, only
to maintain size and shape.

Oakleaf hydrangea. Photo by Beth Bolles,
UF IFAS Extension Escambia County

Panicle hydrangea (Hydrangea paniculata)
These shrubs bloom on new wood, so prune in winter or early spring before new growth emerges. ‘Limelight’ and ‘Pee Gee’, are examples of this type. Plants only require pruning to shape or thin out the shrub.

Limelight hydrangea. Photo by Beth Bolles,
UF IFAS Extension Escambia County

Here are some additional pruning tips for your hydrangeas.

For all types, check for winter-damaged wood in early spring. Remove all dead branches before buds start to open.
Some plants need rejuvenation pruning. Old wood may die back or be less productive, so in early spring remove very old stems at the base. This stimulates new growth.
Deadheading flowers (cutting off spent blooms at a set of leaves) can happen as needed.

Select and Plant Trees for Florida’s High Wind Climate

Select and Plant Trees for Florida’s High Wind Climate

Many future problems can be avoided by paying attention to tree selection, planting and maintenance in Florida’s high wind climate. We may think of tropical storms causing tree damage but our typical summer thunderstorms can produce winds in excess of 50 miles per hour with downbursts reaching over 100 mph. 

There is no way to protect trees from all storm damage. Trees are not adapted to worst-case storms, such as Hurricanes Michael or Ian, only to our average wind climate.

It’s wise to take time to select and correctly plant the right trees for North Florida.

Past hurricanes have taught us that large growing trees planted too close to curbs, sidewalks or buildings blow over easily because they don’t have adequate room to develop a sound root system. It’s best to either plant these trees farther away, plant trees that may stay small, or increase the size of space allocated for tree root growth.

Research and storms have taught us that tree roots need large soil spaces for strong, stable growth. The more rooting space trees have, the less likely they are to fail. Strong root growth is essential for tree stability and health. Large maturing trees need at least 30 feet by 30 feet (900 ft. sq.) of rooting space. Many construction practices such as paving over roots, raising and lowering soil grade, and soil compaction from equipment result in root injury for existing trees, making them less durable and less stable.

Magnolia Tree in the Landscape. Photo courtesy Stephen Greer

Studies have also shown that trees growing in groups better survive high winds compared to individual trees. A group was defined as five or more trees growing within ten feet of another tree, but not in a row.

A short list of large maturing, storm resistant trees to consider include live oak, sand live oak, bald cypress, pond cypress, black gum and magnolia.

Do some homework and take a look at tree species that have done well in your area. If you don’t want or need a large tree in your yard, there are many small and medium sized wind-resistant trees from which to choose, like Crape Myrtle and Vitex. Many palms are wind resistant too, particularly the cabbage palm.

Having success with trees in the landscape involves starting with healthy, well-developed trees. Plant the right tree in the right place. Follow good planting procedures, including not planting trees too deep and providing adequate root space to allow for strong, healthy root growth. Practice correct maintenance techniques, which includes learning how to prune to produce a structurally sound tree. Finally, consider if it is time to be proactive and have large over-mature, declining trees removed and replaced before the next storm.

The following UF/IFAS Extension link, Trees and Hurricanes, includes the most current recommendations on tree selection, planting and pruning. https://hort.ifas.ufl.edu/treesandhurricanes/wind_and_trees.shtml

Fall color in the Panhandle

Fall color in the Panhandle

Perpetual Question

Do any of the leaves change color down here in the fall?  The most common answer is that there is none here in the land of evergreens.  The prevalence of oaks (Quercus spp.) and pines (Pinus spp.) see to that.  There is hope. Deciduous trees put on a show as the need for photosynthesis reduces. Chlorophyll production stops replaced with anthocyanins and carotenoids.  As they take over, the beautiful display we all love begins. Several tree species thrive in the panhandle and have great autumn foliage. Once you know which, you’ll see a color pallet that would make DaVinci himself drool.   

Tree for all seasons

Sweet gum (Liquidambar styraciflua) is a larger tree growing upwards of 75 feet tall with a 50 foot spread.  The canopy has an early conical shape which evolves into an oval as the tree ages. This tree is excellent for local parks and to provide shade in your front yard.  Red tinged flowers produced in spring combined with multi-shaded leaves provide interest throughout the year.  However, autumn this tree comes into its own. As the days shorten and cool these leaves begin their journey to the ground by taking on shades of yellow, orange, red, or burgundy.   

IFAS photograph Heather Kalaman

Panhandle Delight

A unique tree growing primarily in the Panhandle, the Florida maple (Acer floridanum) puts on an excellent autumn show.  At that time of year, the leaves will change to a muted yellow or orange color.  Reaching 60 feet high and 30 wide this oval canopied tree is ideal for shade or along streets.  Fall is the only time you will see color changes from this tree, but in summer you’ll be treated to that classic maple leaf shape.

IFAS Photograph

An Oddity of a Tree

The bald cypress (Taxodium distichum) is a tree rife with oddity.  Growing at times as high as 80 feet with a roughly 35 foot spread these trees excel in your lawn. Be wary as when grown in wet environments they develop “knees” thought to help aerate roots in standing water. Ball shaped cones are the primary reproductive organs of this tree. For the purposes of this article, we’ll focus on the color changing needles.  When winter is nigh, they change from pale green to an eye catching yellow or rusty copper. One of the few deciduous conifers, the needles will fall off revealing peeled bark for winter interest.

IFAS Photograph Kathy Warner

To Sum it Up

These are but a few of the trees in north Florida known to change color in the autumn. The list is not overly exhaustive, but there are several in this category.  For more information on landscape trees, see this Ask IFAS document, or contact your local extension agent for additional information on this and any topic regarding your gardens and more.

Math for the Home Gardener

Math for the Home Gardener

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 Tasks

Summer Tasks

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

Gardener fertilizing yard
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.