Yay for Yarrow

Yay for Yarrow

Gardeners delight in finding a versatile and resilient landscape plant, especially one that is easily shared. Unfortunately, when a plant checks off those characteristics, it usually finds itself on the invasive species list (see IFAS Assessment). Well, in the case of yarrow (Achillea millefolium), we get a tough plant that is easily propagated, has attractive blooms and foliage, attracts butterflies, and is considered native! As I’ll discuss below, it doesn’t come totally flawless.

Yarrow, in the Asteraceae family, is a great addition to the landscape.

Yarrow is considered a cosmopolitan species. It is found across the entire northern hemisphere and there has been a lot of mixing of native and introduced plants, causing much confusion amongst botanists. It is currently considered a single, though complicated, species. Much of the mixing is due to its history with man, being carried along all sorts of expeditions, even the mythical character Achilles, where the plants genus name comes from. The species name comes from the finely divided leaves – like a thousand leaves. It is in the daisy and sunflower family, called the Asteraceae, or composite family, due to the flower heads being composed of many individual flowers.

The cluster of flowers over the feathery leaved foliage is what makes yarrow stand out. The classic yarrow is white-flowered, but breeders have developed many cultivars in an array of colors, including red (‘Rosea’ or ‘Paprika’), pink (‘Cerise Queen’), purple (‘New Vintage Rose’), and yellow (‘Gold’ or ‘Lemon’). Yarrow is also great for its drought tolerance and has few pests or diseases that bother it. It is even reported to be deer resistant! It can be propagated by seed and is easily divided.

Yarrow ‘Paprika’ is a commonly found yarrow cultivar. Source: Timeh87, Creative Commons license.

The common yarrow shows off beautiful white blooms over the feathery foliage. Credit: Rachel Mathes, UF/IFAS.

With all these great attributes comes one potential problem – it is considered toxic to dogs, cats, and horses. Yarrow contains a toxic alkaloid, called achilleine, that can poison some mammals. So, if you have an adventurous pet that likes to chew on random plants, then you may want to skip adding yarrow to your landscape. Achilleine is the same compound that has led it to be used by humans for centuries as a blood clotting agent. Achilles was said to have carried yarrow to the battlefield in Troy for his soldiers and the plant has been known as herba militaris and soldier’s woundwort. Of course, always consult a doctor for medical advice!

While not a good choice around Fido, yarrow can be a great plant for Florida gardeners. For more information on growing yarrow, see this Ask IFAS publication and this profile from Evergreen State University. You can also contact your local county extension agent for additional information on gardening and more.

Save the Rainy Day

Save the Rainy Day

Food Grade Barrel converted to rain barrel

Rain Barrel made from food grade container.

A great way to save money on your water bill and reduce the amount of water withdrawn from the aquifer is to use a rain barrel.  The water savings from using stored rainwater rather than municipal or well water can be substantial over a period of time.  A rain barrel may not provide all the water needed to sustain all your plants, but it can certainly benefit some houseplants or even an entire vegetable garden. If you currently have a standard irrigation system, you may be able to turn off the sprinkler zones that are in flower beds and use stored rainwater instead.

Typically, the rain barrel is connected to the gutter downspout of the house.  For a general calculation, you can collect about a half-gallon of water per square foot of roof area during a 1 inch rainfall.  A typical ½ inch rainfall event will fill a 50-55 gallon barrel.  Multiple rain barrels can be linked together with PVC or flexible hose to increase storage capabilities.  However, with a screen modification on the lid, the rain barrel can be located anywhere in order to collect open rain fall.  It will take a lot longer to fill, but may be more practical if the area you want to water is a good distance from the house.

Now is the time to prepare for the long, hot season to come.  If you want to learn more, please join the Walton County Environmental Department and UF/IFAS at the Walton County Extension office on Monday, March 7, 2022 for an educational lecture on stormwater and demonstration on how to build a rain barrel.  The first 20 participants may also sign up to build a take-home rain barrel.  The program begins at 1:00 pm and is free to the public. Those interested in assembling a ready-to-go rain barrel will need to pay $35.  Custom assembly will begin at 3:30 p.m.  Please contact the Walton County Extension office to register.  850-892-8172.

Fruit Thieves: Roof Rats

Fruit Thieves: Roof Rats

We often think of plant pests to be only insects.  However, plant pests can also be fungal and bacterial diseases, weeds, and even rodents.  That’s right, rodents, like squirrels, mice, and rats!  One particularly annoying rodent pest of the garden is the roof rat (Rattus rattus, a.k.a. citrus rat, fruit rat, black rat, or gray rat).  Roof rats are native to southern Asia.  This is the same species that was responsible for carrying the bubonic plague around the world.  Roof rats are the most detrimental rodent pest to fruit crops in the state of Florida.  In addition to fruit crops, they feed on stored animal and human food.  Roof rats live in attics, soffits, walls, and outbuildings.  They also chew through wires, pipes, and walls.  Roof rats damage some fruit crops (like citrus and melons) by first creating a half dollar sized hole, then they hollow out the fruit.  In crops without a rind or peel, like peaches and tomatoes, they just eat large chunks.

Roof rat damage to tangerines.

Roof rat damage to tangerines. Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County

Adult roof rats are 12-14 inches long with tails longer than their body length.  In Florida they have been identified in three color phases: black back with gray belly; gray back with light gray belly; and brownish gray back with a white or cream colored belly.  Other than fruit damage, evidence of infestation includes 1/4-1/2 inch long droppings and rub marks left along travel trails.  Roof rats will travel up to 150 yards from their den for food and water.  They breed year-round and have litters of 5-8 pups with a gestation period of only 21 to 23 days.

An adult roof rat.

An adult roof rat. Photo Credit: Alabama Cooperative Extension System

A well-thought-out integrated pest management strategy is needed to control and potentially prevent roof rats on your property.  Integrated pest management is a strategy consisting of multiple tactics to control a pest.  These tactics include scouting (looking for evidence of the pest population); prevention; trapping and exclusion; biological control such as predators; and rodenticides and repellants.

  • Prevention – Roof rats are good climbers and swimmers.  It is important that fruit trees are planted away from the house, fences, and outbuildings.  Make sure to prune fruit trees away from these structures if they can’t be removed or transplanted to another location.  Also prune branches from touching the ground to help prevent rats from using trees for cover.  Sheet metal (18-24 inches wide) can be loosely wrapped around the tree trunk to keep rats out of the tree.
  • Trapping – Rat traps can be placed in several strategic locations.  Traps (triggers facing down) can be attached to the trunks of trees.  Traps can also be attached to the stringer boards on a fence.  Make sure that traps are only set from dusk to dawn to avoid killing non-target species like birds and squirrels.  Leave traps in place for at least a week before moving them because roof rats are cautious of new objects.
  • Rodenticides & Repellants – Poisons should only be used after all other control methods are exhausted.  Most products are very toxic to humans, pets, and wildlife.  If used outdoors, poison baits must be placed in tamper-resistant bait stations.
  • Biological Control – Rat snakes and king snakes are good natural predators for roof rats.  If you have more open spaces you may consider building a barn owl house.  Barn owls and hawks are also natural predators.  You may also consider getting a farm cat to help control the population.  Cats will kill juvenile rats, but have trouble catching adult rats.

Hopefully you will never have to encounter roof rats or other rodents invading your yard and house.  However, if they do come around more information is available in the publication “Pests in and Around the Southern Home“.

Prevent Pests Later With Dormant Treatments Now

Prevent Pests Later With Dormant Treatments Now

Citrus red mite leaf damage, red mites may overwinter, but are susceptible to control by dormant oil. Image UF / IFAS HS-806

During cold winter weather, one doesn’t often think about spraying fruit trees and ornamental shrubs for spring insects and diseases. It’s just not on the radar, but it turns out that January and February are the best time to apply dormant sprays to combat insect and disease issues. Many ask, “What are dormant sprays”?

Dormant sprays act on insects or disease pathogens differently. Many insects overwinter on trees and shrubs, either as eggs or immobilized in a protective shell (scale insects).  Horticultural oils applied during cool dormant conditions work by smothering the eggs of some insect species or encapsulated scale insects. Since they cannot breathe, they die.

On the other hand, dormant sprays containing copper or sulfur actually kill latent fungal spores that are ready to infect the moment weather warms. They also burn tender young plant tissue, so can only be used when the plant is not actively growing. These preventative sprays can delay disease incidence in early spring and allow for reduction or elimination of regular fungicide applications. The old adage “an ounce of prevention is worth a pound of cure” surely applies to these situations.

Phomopsis leaf and stem symptoms. Credit: N. Flor, UF/IFAS

Phomopsis leaf and stem symptoms. Dormant fungicide sprays may lessen the severity of this disease. 
Credit: N. Flor, UF/IFAS

There are several products on the market for dormant applications.

Dormant oil is a type of horticultural oil, made of refined petroleum products, for application on trees or shrubs when the trees are not actively growing. It has been in use for over 100 years. They are effective in the suppression of scale insects and mites. Care must be used to not apply them when daytime temperatures are above 75 degrees or night temperatures below 28 degrees. Other horticultural oils exist that may be applied during the growing season to control soft-bodied insects, but not during extremely hot weather. Many different brands exist, some are certified organic. They can be purchased at most garden centers, but the best selection is usually found at your independent nursery or farm store.

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Cottony Cushion Scale, often controlled by Dormant Horticultural Oil. Image Credit, Matthew Orwat, UF / IFAS Extension

Dormant fungicides can be classified into two groups. Those that contain copper and those that contain sulfur. The most common preventative remedy for fungal disease had been lime-sulfur. It is no longer available in small home garden quantities due to shipping container restrictions, it can be purchased online in larger quantities for use in Florida. When applied to dormant plants, lime sulfur actually works by sanitizing the stem, killing all fungal spores. It cannot be used during the growing season since it burns leafy tissue. Caution must be taken when mixing and loading since, being an acidic product, can burn the skin. Wear chemical resistant gloves when applying (bought at your local hardware store for $4.00-$10.00), safety goggles and follow all label directions carefully since it is caustic and labeled DANGER. Also, never apply lime-sulfur within one month of horticultural oil applications. It should be applied in early to mid February, avoiding hard freezes for the 24 hours around application time. Sulfur based fungicide sprays may also be used instead of Lime-Sulfur as a dormant application.

Dormant copper sprays are effective on both bacterial and fungal pathogens and used primarily on fruit crops for the suppression of many fruit diseases including fire blight, bacterial leaf spot, powdery mildew, downey mildew and anthracnose. There are several different brands of copper fungicide preparations on the market, most nurseries and garden supply centers will have some in stock. Always read the label for proper personal protective equipment and dosage rates, to avoid copper buildup in the soil over time.

For more information, contact your local extension agent or consult these extension publications from: Disease Management Strategies, Florida Blueberry Disease Guide and Pest Control Using Horticultural Oils .

This article was originally published on January 2016, and has been modified to reflect current information.

More Gardening Tips for February & March

More Gardening Tips for February & March

Are you “chomping at the bit” to get started gardening this year, but not sure what you can do at this point? Well, good news, there’s plenty of things that can be done whether landscaping or vegetable gardening is your passion.

new potatoes

“New” potatoes grown in Florida. Photo Credit: C. Hutchinson, UF/IFAS

Temperatures can drop significantly in the Panhandle this month, and with short notice. If you want to enhance your flower beds, be sure to use annual bedding plants that can withstand the chill. Dianthus, pansy, viola and dusty miller are some good suggestions to plant. It’s a good time to plant bulbs too. Dahlias, crinum and agapanthus are good choices this time of year. Be sure to provide adequate mulch and water during this cold weather month. There are plenty of trees and shrubs that are beginning to bloom this time of year also. If you’re like me, your allergies will tell you this too. Red maple and star magnolia, just to name a couple, will soon be in bloom.

As for vegetable gardening, the potato is a good choice for Florida gardens. As Americans, we consume approximately 125 pounds per person a year. Potato farming is done commercially in Florida, but mostly with “new” potatoes. These are the small, rounded immature potatoes that have a thin skin and are perfect for low country boils.

It’s February, so it’s Irish potato planting season. The planting season for this cultivar for the Panhandle is from February 1st to mid-March. Sweet potatoes can be planted beginning in late March through June. A hundred pounds of seed potatoes should yield approximately ten bushels. Buy healthy certified seed potatoes from a garden center. Avoid using table stock potatoes. Often, table stock will not sprout successfully. Store bought potatoes are often treated with sprout inhibitors too. This treatment can cause development issues if used as seed potatoes.

Raised beds, at least 6”, are the best way to grow potatoes. Be sure to fertilize the bed soil mixture and fertilize again down furrows when planting. Irish potatoes require copious amounts of fertilizer. For fertilizer, use a general, complete formulation like 10-10-10. Before planting, be sure to dust the seed potatoes with a fungicide to reduce the chance of decay. Plant seed potatoes 3” in depth, at 12” apart and allow for 36” row spacing.

Please take these gardening tips into consideration this month and the next. Spring is just around the corner. Happy gardening! For more information please contact your local county extension office.

Supporting information for this article can be found in the UF/IFAS EDIS Publications, “ Florida Vegetable Gardening Guide” by Sydney Park Brown, Danielle Treadwell, J. M. Stephens, and Susan Webb : http://edis.ifas.ufl.edu/pdffiles/VH/VH02100.pdf and “Growing Potatoes in the Florida Home Garden”, by Christian T. Christensen, Joel Reyes-Cabrera, Libby R. Rens, Jeffrey E. Pack, Lincoln Zotarelli,Chad Hutchinson, Wendy J. Dahl, Doug Gergela, and James M. White: http://edis.ifas.ufl.edu/pdffiles/HS/HS18300.pdf

Supporting information can also be found on the UF/IFAS website under “Florida Gardening Calendar” by Sydney Park Brown: http://solutionsforyourlife.ufl.edu/lawn_and_garden/calendar/pdfs/February_North.pdf