Landscape  Q & A

Landscape Q & A

On August 12, 2021, our panel answered questions on a wide variety of landscape topics. Maybe you are asking the same questions, so read on!

Ideas on choosing plants

What are some perennials that can be planted this late in the summer but will still bloom through the cooler months into fall?

Duranta erecta ‘Sapphire Showers’ or ‘Gold Mound’, firespike, Senna bicapsularis, shrimp plant, lion’s ear

Where can native plants be obtained?

Dune sunflower, Helianthus debilis. Photo credit: Mary Salinas UF/IFAS Extension.

Gardening Solutions: Florida Native Plants  – see link to FANN: https://gardeningsolutions.ifas.ufl.edu/plants/ornamentals/native-plants.html

What are some evergreen groundcover options for our area?

Mondo grass, Japanese plum yew, shore juniper, ajuga, ferns such as autumn fern.

What are some ideas for partial morning sun butterfly attracting tall flowers to plant now?

Milkweed, salt and pepper plant, swamp sunflower, dune sunflower, ironweed, porterweed, and salt bush.

I’m interested in moving away from a monoculture lawn. What are some suggestions for alternatives?

Perennial peanut, powderpuff mimosa, and frogfruit.

We are new to Florida and have questions about everything in our landscape.

Florida-Friendly-Landscaping TM Program and FFL Web Apps: https://ffl.ifas.ufl.edu/

https://ffl.ifas.ufl.edu/resources/apps/

UF IFAS Gardening Solutions: https://gardeningsolutions.ifas.ufl.edu/

What are some of the top trends in landscaping today?

Houseplants, edible gardens, native plants, food forests, attracting wildlife, container gardening, and zoysiagrass lawns

Edibles

Artwork broccoli is a variety that produces small heads. Photo credit: Mary Salinas UF/IFAS Extension.

What vegetables are suitable for fall/winter gardening?

Cool Season Vegetables: https://gardeningsolutions.ifas.ufl.edu/plants/edibles/vegetables/cool-season-vegetables.html

North Florida Gardening Calendar: https://edis.ifas.ufl.edu/publication/EP451%20%20%20

Florida Vegetable Gardening Guide: https://edis.ifas.ufl.edu/publication/vh021

How can I add herbs to my landscape?

Herbs in the Florida Garden: https://gardeningsolutions.ifas.ufl.edu/plants/edibles/vegetables/herbs.html

My figs are green and hard. When do they ripen?

Why Won’t My Figs Ripen: https://www.lsuagcenter.com/profiles/rbogren/articles/page1597952870939

What is best soil for raised bed vegetable gardens?

Gardening in Raised Beds: https://edis.ifas.ufl.edu/publication/EP472

And there are always questions about weeds

How can I eradicate cogongrass?

Chamber bitter is a troublesome warm season weed in our region. Photo credit: Brantlee Spakes Richter, University of Florida, Bugwood.org

Cogongrass: https://edis.ifas.ufl.edu/publication/WG202

Is it okay to use cardboard for weed control?

The Cardboard Controversy: https://gardenprofessors.com/the-cardboard-controversy/

What is the best way to control weeds in grass and landscape beds?

Weed Management Guide for Florida Lawns: https://edis.ifas.ufl.edu/publication/EP141

Improving Weed Control in Landscape Planting Beds: https://edis.ifas.ufl.edu/pdf/EP/EP52300.pdf

Landscape practices

Can ground water be brackish and stunt plants?

Reclaimed Water Use in the Landscape: https://edis.ifas.ufl.edu/publication/ss545

How can I prevent erosion from rainwater runoff? 

Stormwater Runoff Control – NRCS: https://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/water/?cid=nrcs144p2_027171

Rain Gardens: https://gardeningsolutions.ifas.ufl.edu/design/types-of-gardens/rain-gardens.html

And https://gardeningsolutions.ifas.ufl.edu/pdf/articles/rain-garden-manual-hillsborough.pdf

What is the best time of the year to propagate flowering trees in zone 8B?

Landscape Plant Propagation Information Page – UF/IFAS Env. Hort: https://hort.ifas.ufl.edu/database/lppi/

Which type of mulch works best on slopes greater than 3 percent?

Landscape Mulches: How Quickly do they Settle?: https://edis.ifas.ufl.edu/publication/FR052

When should bulbs be fertilized?

Bulbs and More – UI Extension: https://web.extension.illinois.edu/bulbs/planting.cfm

Should I cut the spent blooms of agapanthus?

Agapanthus, extending the bloom time: https://gardeningsolutions.ifas.ufl.edu/plants/ornamentals/agapanthus.html

http://blogs.ifas.ufl.edu/wakullaco/2020/10/07/extending-bloom-time/

Plant questions

Monarch caterpillar munching on our native sandhill milkweed, Asclepias humistrata. Photo credit: Mary Salinas, UF IFAS Extension.

I planted native milkweed and have many monarch caterpillars. Should I protect them or leave them in nature?

It’s best to leave them in place. Featured Creatures: Monarch Butterfly: https://edis.ifas.ufl.edu/pdf/IN/IN780/IN780-Dxyup8sjiv.pdf

How does Vinca (periwinkle) do in direct sun? Will it make it through one of our panhandle summers? Can I plant in late August?

Periwinkles  and  No more fail with Cora series: https://gardeningsolutions.ifas.ufl.edu/plants/ornamentals/periwinkles.html#:~:text=Plant%20your%20periwinkles%20where%20they,rot%20if%20irrigated%20too%20frequently.

Insect and disease pests

What to do if you get termites in your raised bed?

The Facts About Termites and Mulch: https://edis.ifas.ufl.edu/publication/IN651

How to combat fungus?

Guidelines for ID and Management of Plant Disease Problems: https://edis.ifas.ufl.edu/publication/mg442

Are there preventative measures to prevent diseases when the humidity is very high and it is hot?

Fungi in Your Landscape by Maxine Hunter: http://blogs.ifas.ufl.edu/marionco/2020/01/16/fungi-in-your-landscape/

 

If you missed an episode, check out our playlist on YouTube https://www.youtube.com/watch?v=bp0HfdEkIQw&list=PLhgoAzWbtRXImdFE8Jdt0jsAOd-XldNCd

 

Soil Compaction in the Landscape

Soil Compaction in the Landscape

One big goal of establishing a home lawn and landscape is to enjoy an attractive setting for family and friends, while also helping manage healthy soils and plants.  Soil compaction at these sites can cause multiple problems for quality plants establishment and growth.  Soil is an incredibly important resource creating the foundation for plants and water absorption.

Photo courtesy: Stephen Greer, UF IFAS

Soils are composed of many different things, including minerals.  In Florida, these minerals often include sand of differing sizes and clay in the northern area of the counties in the panhandle of Florida. Soil is also composed of organic matter, nutrients, microorganisms and others.  When soil compacts, the air spaces between the sand or clay are compressed, reducing the space between the mineral particles.  This can occur anytime during the landscape and lawn construction phase or during long term maintenance of the area with equipment that could include tractors, mowers, and trucks.

What can be done to reduce soil compaction?  There are steps that can be taken to help reduce this serious situation.  Make a plan on how to best approach a given land area with the equipment needed to accomplish the landscape of your dreams.  Where should heavy equipment travel and how much impact they will have to the soils, trees, and other plants already existing and others to be planted?  At times heavy plywood may be needed to distribute the tire weight load over a larger area, reducing soil compaction by a tire directly on the soil.  Once the big equipment use is complete, look at ways to reduce the areas that were compacted.  Incorporating organic matter such as compost, pine bark, mulch, and others by tilling the soil and mixing it with the existing soil can help.  Anytime the soil provides improved air space, root will better grow and penetrate larger areas of the soil and plants will be healthier.

Even light foot traffic over the same area over and over will slowly compact soils.  Take a look at golf course at the end of cart paths or during a tournament with people walking over the same areas.  The grass is damaged from the leaves at the surface to the roots below.  Plugging these areas or possibly tilling and reestablishing these sites to reduce the compacted soils may be necessary.

Photo courtesy: Stephen Greer, UF IFAS

Water absorption is another area to plan for, as heavy rains do occur in Florida.  Having landscapes and lawns that are properly managed allow increased water infiltration into the soil is critically important.  Water runoff from the site is reduced or at least slowed to allow the nutrient from fertilizers used for the plant to have more time to be absorbed into the soil and taken up by the plants.  This reduces the opportunity for nitrogen, phosphorus, and other nutrients to enter water areas such as ponds, creeks, lagoons, rivers and bays.  Even if you are miles from an open water source, movement of water runoff can enter ditches and work their way to these open water areas, ultimately impacting drinking water, wildlife, and unwanted aquatic plant growth.

Plan ahead and talk with experts that can help with developing a plan.  Contact your local Extension office for assistance!

 

Soil has Many Names, Just Not the “D-word”

Soil has Many Names, Just Not the “D-word”

For all my years in the classroom, I never let students say the “d-word” when discussing soil science.  In some instances, we had a “d-word” swear collection jar of a quarter when you used the term and even today, I hesitate from spelling the word out in text due to feedback from all those I have corrected.  In case you still need a clue on the “d-word”, it ends in irt.

As a horticulturist for 46 years, I have read, heard, and been told many secrets to growing good plants.  I still hold firm that without proper knowledge of how soil works, most of what we do is by chance.  Soil is a living entity comprised of parent material (sand, silt, and clay), air, water, organic matter (OM), and microorganisms.  It is this last item which makes our soils come to life.  If you have pets, then you know they need shelter, warmth, air, water, and food.  From this point forward think of soil microorganisms as the pets in your soil.  If you take care of them, they will take care of your plants.

Sandy Soil

Sandy soil without any organic matter at the Wakulla County Extension office.

There is a huge difference in habitat from a sandy soil to a healthy soil with a good percentage of OM (5% – 10%).  In one gram of healthy soil (the weight of one standard paper clip), you can have bacteria (100,000,000 to 1,000,000,000), actinomycetes (10,000,000 to 100,000,000), fungi (100,000 to 1,000,000), protozoa (10,000 to 100,000), algae (10,000 to 100,000), and nematodes (10 to 100) (1).  A teaspoon of healthy soil can contain over four billion organisms (2).  These microorganisms are part of the soil food web and they form a relationship between soil and your plants.  They help convert nutrients to useable forms and assist with other plant functions.

The question becomes how to take care of your soil pets.  For years we have performed practices that compromise these populations.  Growing up we put all of our grass clippings in the weekly trash.  We know now how valuable those clippings are and to leave them be.  Two practices still common today though are tilling and raking leaves.

OM Soil

Master Gardener Volunteer vegetable bed with organic matter added.

Tilling has a limited purpose.  If I place a layer of organic matter on top of the ground, then tilling incorporates the OM which feeds my pets.  Excess tilling of soil introduces large amounts of oxygen which accelerates the breakdown of OM thus reducing our pet populations over time.  Another adverse result from tilling is disturbing the soil structure (how the parent materials are arranged) which can reduce pore spaces thus limiting water percolation and root growth.  There is a reason agriculture has adapted no-till practices.

Raking leaves (supposedly the sign of a well-kept yard) is removing large amounts of OM.  Do you ever wonder why trees in a forest thrive?  All of their leaves fall to the ground and are recycled by the microorganisms.  Each of those leaves contains macronutrients (carbon, hydrogen, oxygen, nitrogen, phosphorus, potassium, calcium, sulfur, and magnesium) and micronutrients (boron, copper, chlorine, iron, manganese, molybdenum, nickel, and zinc) which are necessary for plant growth.  You would be hard pressed to find all those nutrients in one fertilizer bag.  So recycle (compost) your leaves versus having them removed from the property.

We are in our off season and tasks such as improving soil health should be considered now for soils to be ready in spring.  Remember a little organic matter at a time and never work wet soils.  As your OM levels build over the years, remember to change your watering and fertilizing schedules as the soil will be better adapted at holding water and nutrients.  Soil tests are still recommended before fertilizing.

If you would like more tips on improving your soil, contact me or your local county horticulture extension agents.  For a more in depth look at caring for your soils, read The Importance of Soil Health in Residential Landscapes by Sally Scalera MS, Dr. A.J. Reisinger and Dr. Mark Lusk (https://edis.ifas.ufl.edu/ss664).

  1. Chapter 2: Soils, Water, and Plant Nutrients.  Texas Master Gardener Training Manual.
  2. The Importance of Soil Health in Residential Landscapes. 2019.
Using a Buckwheat Cover Crop in Raised Bed Gardens

Using a Buckwheat Cover Crop in Raised Bed Gardens

2020 has not been the most pleasant year in many ways.  However, one positive experience I’ve had in my raised bed vegetable garden has been the use of a cover crop, Buckwheat (Fagopyrum esculentum)! Use of cover crops, a catch-all term for many species of plants used to “cover” field soil during fallow periods, became popular in agriculture over the last century as a method to protect and build soil in response to the massive wind erosion and cropland degradation event of the 1930s, the Dust Bowl.  While wind erosion isn’t a big issue in raised bed gardens, cover crops, like Buckwheat, offer many other services to gardeners:

Buckwheat in flower behind summer squash. Photo courtesy of Daniel Leonard.

  • Covers, like Buckwheat, provide valuable weed control by shading out the competition.  Even after termination (the cutting down or otherwise killing of the cover crop plants and letting them decompose back into the soil as a mulch), Buckwheat continues to keep weeds away, like pinestraw in your landscape.
  • Cover crops also build soil. This summer, I noticed that my raised beds didn’t “sink” as much as normal.  In fact, I actually gained a little nutrient-rich organic matter!  By having the Buckwheat shade the soil and then compost back into it, I mostly avoided the phenomena that causes soils high in organic matter, particularly ones exposed to the sun, to disappear over time due to breakdown by microorganisms.
  • Many cover crops are awesome attractors of pollinators and beneficial insects. At any given time while my Buckwheat cover was flowering, I could spot several wasp species, various bees, flies, moths, true bugs, and even a butterfly or two hovering around the tiny white flowers sipping nectar.
  • Covers are a lot prettier than bare soil and weeds! Where I would normally just have either exposed black compost or a healthy weed population to gaze upon, Buckwheat provided a quick bright green color blast that then became covered with non-stop white flowers. I’ll take that over bare soil any day.

Buckwheat cover before termination (left) and after (right) interplanted with Eggplant. Photo courtesy Daniel Leonard, UF/IFAS Calhoun County Extension.

Now that I’ve convinced you of Buckwheat’s raised bed cover crop merits, let’s talk technical and learn how and when to grow it.  Buckwheat seed is easily found and can be bought in nearly any quantity.  I bought a one-pound bag online from Johnny’s Selected Seeds for my raised beds, but you can also purchase larger sizes up to 50 lb bags if you have a large area to cover.  Buckwheat seed germinates quickly as soon as nights are warmer than 50 degrees F and can be cropped continuously until frost strikes in the fall.   A general seeding rate of 2 or 3 lbs/1000 square feet (enough to cover about thirty 4’x8’ raised beds, it goes a long way!) will generate a thick cover.  Simply extrapolate this out to 50-80 lbs/acre for larger garden sites.  I scattered seeds over the top of my beds at the above rate and covered lightly with garden soil and obtained good results.  Unlike other cover crops (I’m looking at you Crimson Clover) Buckwheat is very tolerant of imperfect planting depths.  If you plant a little deep, it will generally still come up.  A bonus, no additional fertilizer is required to grow a Buckwheat cover in the garden, the leftover nutrients from the previous vegetable crop will normally be sufficient!

Buckwheat “mulch” after termination. Photo courtesy of Daniel Leonard, UF/IFAS Calhoun County Extension.

Past the usual cover crop benefits, the thing that makes Buckwheat stand out among its peers as a garden cover is its extremely rapid growth and short life span.  From seed sowing to termination, a Buckwheat cover is only in the garden for 4-8 weeks, depending on what you want to use it for.  After four weeks, you’ll have a quick, thick cover and subsequent mulch once terminated.  After eight weeks or so, you’ll realize the plant’s full flowering and beneficial/pollinator insect attracting potential.  This lends great flexibility as to when it can be planted.  Have your winter greens quit on you but you’re not quite ready to set out tomatoes?  Plant a quick Buckwheat cover!  Yellow squash wilting in the heat of summer but it’s not quite time yet for the fall garden?  Plant a Buckwheat cover and tend it the rest of the summer!  Followed spacing guidelines and only planted three Eggplant transplants in a 4’x8’ raised bed and have lots of open space for weeds to grow until the Eggplant fills in?  Plant a Buckwheat cover and terminate before it begins to compete with the Eggplant!

If a soil building, weed suppressing, beneficial insect attracting, gorgeous cover crop for those fallow garden spots sounds like something you might like, plant a little Buckwheat!  For more information on Buckwheat, cover crops, or any other gardening topic, contact your local UF/IFAS County Extension Office.  Happy Gardening!

Clean Up for the Fall Vegetable Garden

Clean Up for the Fall Vegetable Garden

A common question for gardeners at the end of the season is if one should till the soil or use no till practices.  Opinions vary regarding this question, even among Extension Agents.  However old crops harbor insects, both good and bad.  This phenomenon was noticed on some recently cut back tomato plants.  The intention was to cut the leftover spring garden tomatoes back to encourage fall production.  Instead, a host plant for mealybugs was provided.

Whitefly larvae on a tomato plant.

Mealybugs on a tomato plant. Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County

Mealybugs are soft-bodied insects that possess a covering of flocculent, white, waxy filaments.  They are about 1/8 inch in length and usually pinkish or yellowish in color.  Mealybugs have piercing-sucking mouthparts which they use to siphon fluids from the leaves, stems, and sometimes roots of many ornamental and vegetable plants.  Mealybug damage produces discolored, wilted, and deformed leaves.

One very common example of an insect pest likely to claim residence in your garden’s crop residue, are squash bugs. They like to overwinter on squash, cucumber, and other cucurbit crop residue.  If you choose to not till your garden and leave a portion of last seasons crop in your garden, then you should consider applying an insecticide to your spent crop at the end of the season.  A product containing a pyrethrin or pyrethroid as an active ingredient would be a good broad spectrum insecticide to control any pest that may reside on plant residue.  More information on pyrethrins and pyrehtroids can be found at the EPA webpage: Pyrethrins and Pyrethroids.  If you choose to apply an insecticide, it is important that you follow the information on the label regarding pollinator protection.  Another option is to plant a trap crop on the edge of your garden to help attract pest insects away from your desired crops.  More information on trap crops can be found in the EDIS PublicationIntercropping, Pest Management and Crop Diversity.

An adult squash bug on a zucchini leaf.

An adult squash bug on a zucchini leaf. Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County

So the answer to the till or no till question is…it depends.  It is really up to the gardener.  Yes, the residue from crops will add nutrients and organic matter to your soil, but it could also increase pest pressure in your garden.  If you don’t plan to remove crop residue and don’t plan to till, then keep an eye out for what could be hiding in your garden.