Great Plants for Your Garden

Looking for ideas for new garden plants?  Many organizations highlight special plants each year.  The Perennial Plant Association’s pick for 2018 is Allium ‘Millenium’.  This ornamental onion is heralded as a butterfly magnet.  It grows best in full sun and produces a clump of upright glossy deep green leaves that reach 10-15 inches tall in spring.  By midsummer, it with have two to three flower stalks each sporting a 2-inch sphere of rose-purple florets.  Flowers can last as long as four weeks and then can be picked and dried holding on to a blush of their rose-purple color.  Allium ‘Millenium’ has no serious insect or disease problems, plus deer and rabbits usually avoid this great perennial.  What’s not to like!

Allium ‘Millenium’ in full bloom. Photo credit: Perennial Plant Association

The Delaware Nursery and Landscape Association (DNLA) picks a woody plant and an herbaceous plant each year.  The 2018 picks are marginal wood fern (Dryopteris marginalis) and common pawpaw (Asimina triloba); both native to the region.  The DNLA selects plants that are typically underused or unknown and are particularly well suited to thrive in Delaware. The marginal wood fern forms tidy clumps and can be easily identified by the spores along the outermost edges of the fronds.  Leathery leaves are evergreen and twice compound resulting in a lacy texture.  Leaves are blue-green on the upper surface with a light green underside and reach a height of 18 to 30 inches. Marginal wood fern requires good drainage and grows best in shade or partial sun.  It tolerates dry shade and like all ferns is deer tolerant. It is extremely cold hardy, but may need a protected location to keep the evergreen fronds looking good. Stands of marginal wood fern provide valuable habitat to small wildlife.  The dramatic feathery foliage makes marginal wood fern a great accent for a shade garden or in the right conditions, a lush, verdant groundcover.

Common pawpaw is a small to medium sized tree or large multi-stemmed shrub (10-40 feet tall).  It is native to the eastern United States, but has an exotic feel due to large, tropical-looking foliage. Pawpaw is the northernmost member of a primarily tropical family (Annonaceae; Custard Apple Family). Thick, bright-green leaves turn yellow-green for interesting fall color.  Purple, six-petaled flowers are borne singly in leaf axils in early spring before leaves emerge.  They are not particularly showy, but reward the keen observer as a harbinger of spring. Fruit are large, cylindrical and edible. They have a soft texture and flavor often described as strawberry banana-like. Fruit are not commercially available because they bruise easily and do not withstand shipping. Therefore, if you want to taste pawpaw, you need to grow one. Pawpaws make an excellent grove-forming understory tree. They provide food for birds, butterflies and small mammals and give an exotic touch to a native garden.

Paw paw in full yellow fall color. Photo credit: R. Darke

Interesting maroon flowers of the pawpaw tree. Photo credit: R. Darke

Delicate fronds of the marginal wood fern. Photo credit: R. Darke

The Native Plant Center at WestChester Community College in New York has its picks as well.  Blackhaw viburnum (Viburnum prunifolium) is the native woody plant of the year and Eastern bluestar (Amsonia tabernaemontana) is the native perennial of the year.  Blackhaw viburnum is a large shrub, reaching 12 to 14 feet at maturity.  Large, creamy white flower clusters are born above the foliage in late spring to early summer.  These are followed by pinkish-red berries that turn blue-black as they mature.  Flowers provide nectar for pollinators and a host of beneficial insects and fruit provides food for birds and small mammals.  Fruit is edible by people and can be made into preserves.

Eastern bluestar has multiple seasons of interest.  Powder blue five-stared flowers are born in clusters in spring, providing nectar for pollinators.  Bright green, shrubby foliage is makes a great background for other summer-bloomers.  Then in the fall, the leaves turn golden yellow.  Amsonia hubrictii (Arizona bluestar) is another bluestar with even more dramatic fall foliage color. This perennial is a member of the dogbane family and has a milky sap that makes it unpalatable to deer, rabbits and groundhogs.

Bluestar blooming along I95 at the gateway to Delaware from Pennsylvania.

If you want to learn more about horticulture in Delaware, visit my blog (http://sites.udel.edu/suebarton/)  and follow my instagram (sbartonhort).

Spring: Around the Corner?

It is hard to believe, but spring really is around the corner.  Soon many landscape companies will whip into action providing lawn and landscape services for all those homeowners anxious to get their yards and gardens in shape for the coming season.  It is hard for homeowners to assess whom to hire to manage their lawns and gardens.  Recently, I heard from a landscaper who was frustrated upon hearing a competitor tell her customer there was no need to test the soil before applying fertilizer.  That is just wrong.  A soil test is always a first step in proper lawn and landscape management.  Everything starts with good soil.  Plants will not grow properly unless they get water, nutrients and support from the soil.

Testing the soil will tell you the pH; whether the soil is acidic (low pH), neutral, or alkaline (high pH).  Lawns grow best at a soil pH or 6.0 – 6.5.  Some plants, like blueberries, camellias, azaleas and rhododendrons like the soil to be somewhat acidic, about 5.5.  Other plants, like boxwood, lilac, deutzia and weigelia like a neutral to slightly alkaline soil, about 7.0-7.5.  The only way to know what pH you are starting with is to take a soil test.  Once you know your soil’s pH, you can lower it by adding sulfur or raise it by adding lime.  You can also keep the soil at its current pH and select the plants that will thrive in those conditions.  But, if you plan to have a lawn, you wil need to make sure the soil pH is 6.0 to 6.5.  At that pH, nutrients the lawn needs are available, they are not present in toxic quantities, and microorganisms necessary to maintain healthy soil structure will thrive.

Testing the soil will also tell you quantities of phosporus, potassium, calcium, magnesium and sulphur present in your soil.  If you want to know about micronutrients, you can request a special test.  But, micronutrients are always present in soil and only become a problem for plant growth if the pH is too low (manganese toxicity) or too high (iron unavailable to plants).  Phosphorus is a nutrient we worry about in Delaware streams, rivers and bays.  Phosphorus adheres to the soil, so erosion will carry soil, and with it phosphorus, to bodies of water.  Plant debris, such as leaves, grass clippings, yard waste etc., contains phosphorus as well, so rains that carry those materials into the water will cause phosphorus pollution.  It is against the nutrient management law in Delaware to add phosphorus to soils already high in phosphorus on sites greater than 10 acres.  Sites smaller than 10 acres do not require a nutrient management plan, so it is not against the law, but it is certainly a bad idea, environmentally.

No one should be applying fertilizer without taking a soil test first.  The University of Delaware has a soil testing service (http://extension.udel.edu/dstp/) or you can use a private soil testing lab. Get off to a good start this spring, and test your soil before adding fertilzer!

If you want to learn more about horticulture in Delaware, follow my instagram (sbartonhort).

The proper way to take a soil test is to take 10 samples from the area you want to test and mix them in a bucket. Then pull the sample from that mixed bucket of soil. Tracy Wootten and Carrie Murphy, Extension Agents in Sussex and New Castle counties, respectively, are demonstrating that process.

Once the samples are mixed in the bucket, fill the plastic bag that comes with your soil testing kit with soil.

Use a soil core to pull a plug of soil out of the ground.

Kate Murray of the soil testing lab starts the analysis process on a soil sample.

Here are the tools you will need to take a soil sample.

 

What should you do for your lawn in the spring?

I received the following question last week through the Cooperative Extension “Ask the Expert” system.  It illustrates how confusing the lawn care industry is to homeowners trying to do the right thing on their lawns:

I have a turf-based lawn. I intend to weed and feed in early March. I know that my lawn needs a pre-emergent to control Bermuda/crabgrass. However, there are also other weeds, e.g., clover and other varieties. What weed control do you recommend and when should it be applied?

First, forget about “weed and feed” products.  They do not make sense for your lawn.  Apply most of the fertilizer your lawn needs in the fall and if anything, only apply ½ lb of nitrogen/ 1000 square feet (that equals 5 lbs of a 10-10-10 fertilizer, which is 10% nitrogen) in the spring.  Apply that small amount of fertilizer in March and no later than April 15.  Apply weed control later in the spring; so bundling those two products will not work.

This person wants to use a preemergent to control unwanted grasses.  That is great for crabgrass.  As an annual grass, it must germinate each year, so if you can prevent its emergence with an herbicide you can reduce the crabgrass in your lawn later in the season.  We recommend applying crabgrass preemergent products when forsythia is blooming, usually April, after you have applied spring fertilizer.  The other grass mentioned is bermudagrass—a perennial grass that cannot be controlled with a preemergent herbicide.  Bermudagrass is a warm season grass, so it will not start growing until late spring.  It cannot be controlled with a preemergent since its roots are alive and ready to burst into action with warm soil temperatures.  It cannot really be controlled with a selective herbicide either since there is very little difference between bermudagrass and the desirable grass in your lawn—except you like one and dislike the other.  For bermudagrass, we recommend spot treatment with a systemic herbicide that is non-selective (like glyphosate).

They also mention clover and other weeds.  Clover is not an annual, so a preemergent herbicide will not control it.  Instead, use a broadleaf herbicide specific for clover control (MCPP will work) once the clover is green and growing, but still young and susceptible to chemical control.  When you use selective herbicides, you must know which weed you are controlling.  For example 2,4-D products will control dandelions but not clover.

The best strategy for controlling weeds and maintaining a healthy lawn is to promote healthy turfgrass growth.  Fertilize modestly, if at all, in the spring.  Cut your grass at the appropriate height and frequency.  Don’t remove more than one-third of the leaf blade at any single mowing.  So, if you have a fescue lawn and you want to maintain it at a height of 3 inches, cut the grass when it reaches 4 ½ inches removing 1 ½ inches (one-third of the leaf blade).  By following these guidelines, your grass is able to catch light and photosynthesize, producing its own food for healthy growth.  Always use a sharp mower blade.  Control weeds when they are young so they do not take over.  Finally, apply most or all of the fertilizer required by your lawn in the fall (between late August and mid-October).

If you want to learn all about managing a healthy lawn, visit the Delaware Livable Lawns website.  Learn how you can make your lawn livable.  https://www.delawarelivablelawns.org/

If you want to learn more about horticulture in Delaware, follow my Instagram (sbartonhort).

Clean, healthy turfgrass at a sod farm in southern Delaware. Buy healthy turf and keep it healthy with proper care to avoid the need for weed control.

UD Students Explore Brazil

In January, I led a UD study abroad program in Brazil.  I took fourteen students and a TA to the Amazon for a week and then to Rio de Janeiro for the remaining two and a half weeks of January.  It was a great opportunity to learn about environmental issues in Brazil and the wonderful gardens of Roberto Burle Marx and other great Brazilian landscape architects.  The fourteen students came from all over the University, but several were landscape architecture and wildlife conservation majors from the College of Agriculture and Natural Resources.  Most of the remaining students were environmental studies majors or science majors with concern for the environment.

Our first stop at Uacari Lodge was in the Mamiraua Reserve about one hour via motor boat from the town of Tefe on the Amazon River (or Solimoes at that location).  The Reserve showed students a wonderful community model.  Two naturalists, as well as local guides and support employees who rotated from the communities within the reserve staffed the floating lodge.  Ecotourism dollars from the lodge provided employment for local community members and proceeds were used to buy items like a new motor so the community boat could reach a city hospital more quickly in emergencies.  Students loved seeing plants and animals of the Amazon, especially, pink river dolphins (botos) and caiman swimming near our lodge.  We discussed the importance of saving the Amazon ecosystem and all the valuable plants and animals that reside there, but also how important it is to allow native peoples to make a living and prosper.

In Rio de Janeiro, we had the opportunity to visit several gardens designed by Roberto Burle Marx, including his home or sitio, which includes acres of spectacular tropical plantings and several fascinating buildings reconstructed on site.  Burle Marx is the landscape architect credited with beginning the native plant movement in landscape architecture.  He spent several teenage years in Germany and became enamored with the tropical plants he found in hothouses in the 30’s.  When he returned to Brazil, he realized those plants were Brazilian native species and began to create colorful mosaic landscape designs with those tropical plants.

Burle Marx used those native plants, not in naturalistic designs, but in painterly sweeps that create artwork on the landscape.  We visited Tacaruna just north of Petropolis.  This garden includes broad sweeps of colorful plants (the flowing “female” side of the landscape) and a checkerboard of different grass species (the orderly “male” side of the landscape). The roof garden on the Brazilian Re-Insurance Institute (Instituto de Resseguros do Brasil “IRB”) was recently renovated by BurleMarx, Escritorio de Paisagismo, the landscape firm  owned by Burle Marx and his partner Haruyoshi Ono, now run by Isabela Ono.  Burle Marx brought gardens to the tops of buildings long before it became fashionable throughout the world.

We also visited Inhotim, a public garden featuring modern art in galleries and landscape settings.  Art from many of the Brazilian artists (Helio Oiticica, Clido Meireles, Vik Muniz and more) students researched for a study abroad presentation was displayed throughout the garden.  Students said “It was fun to see “my” artist’s work in a garden setting”.

Penisula is a development in Barra da Tijuca built on highly disturbed land surrouding an inland lake.  It was designed by Fernando Chacel and includes three important zones – mangrove swamps to cleanse the water provide biodiversity; restinga zone to protect the mangroves; and the park zone providing spaces for people to enjoy. This reconstruction was made possible through Brazilian laws requiring re-establishment of mangroves around bodies of water prior to development.

Students also enjoyed the wonderful people and culture of Brazil.  If you want to learn more about this program, visit the student blog  (http://sites.udel.edu/explorebrazil/).  For more information about Study Abroad programs at UD, visit http://www1.udel.edu/global/studyabroad/.

If you want to learn more about horticulture in Delaware, follow my instagram (sbartonhort)

Floating lodge in Mamiraua Reserve on the Amazon.

Restinga planting between mangrove swamp and park at Peninsula development.

Students learning about the turtle rescue project from a local guide.

Relaxing on the boat after a forest excursion.

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Student, Cate Medlock, sketching in Roberto Burle Marx’s garden.

The roof garden on the Brazilian Re-Insurance Institute (Instituto de Resseguros do Brasil “IRB”) was recently renovated by BurleMarx, Escritorio de Paisagismo.

Students exploring the rooftop garden.

Sweeps of colorful annuals at Burle Marx designed, Tacaruna.

The checkerboard pattern is made with two different species of grass.

Students sketching a cool outdoor sculpture at Inhotim.

Delaware Attacks Ecological Extinction

The current extinction rate is possibly 100 times great than normal and humans are definitely responsible. So what are we doing about it? Stephanie Hansen, a Delaware State Senator got the state senate to convene a task force to address this issue in Delaware.  The Task Force began in July with a presentation from UD’s Doug Tallamy, author of Bringing Nature Home and The Living Landscape, both books that address the loss of species diversity and possible solutions. The Task Force submitted recommendations to the Governor, President Pro Tempore of the Senate and Speaker of the House on December 1, 2017. There were 19 members representing a wide variety of stakeholders including state senators and representatives, County administrators, DNREC, DDA, Delaware Association of Realtors, DE Farm Bureau, Chamber of Commerce, Home Builders Association and a number of environmental organizations on the Task Force. I represented the Delaware Nursery and Landscape Association.

The Task Force findings include seven major areas:

  1. Education – The public has an important role in the prevention of extinction of local species and education is key to understanding.
  2. Incentivize Private Landowners – Incentives taking the form of money, public recognition and ease of permitting encourage the removal of invasive species and their replacement with native species as well as the replacement of non-native species with native species.
  3. Government Leads by Example – Government facilities should be landscaped and managed with native species.
  4. Legislation Affecting Development – Policy changes may be necessary at the state and local level.
  5. Funding Open Space Program at Statutory Level – The Open Space Program provides opportunities to stem the loss of native species.
  6. Legislation to Prohibit the Sale of Invasive Species – The sale of invasive species is an important factor contributing to the loss of native species in Delaware.
  7. Deer Management – The proliferation of deer is an important factor contributing to the loss of native species in Delaware.

Education is by far the highest priority, with 22 individual recommendations including developing curricula for school children; promoting demonstration gardens; providing public presentation; encouraging landscape contractors to remove, manage and control invasive plants and replant with native species; and promoting the Delaware Livable Lawns Program.

There are recommendations to create incentives for reducing lawn area and replacing it with native plants.  Pollinator and other insect habitat gardens are encouraged.

All Delaware state facilities should set the example by reducing lawn and replacing it with native or pollinator plants and revising land management practices to be more pollinator friendly. DelDOT should take the opportunity for roadside right of way to provide habitat and reduce mowing.

A significant recommendation is to make the sale of invasive plants illegal in Delaware with an appropriate phase-out period, Invasive plants are defined as those on the Delaware Invasive Species Council plant list, which must be reviewed and amended.

The final recommendation is the formation of a Delaware Native Species Commission by the General Assembly to implement the 78 recommendations of the Task Force and report back to the General Assembly.

While there is a long way to go before implementation, this is good news for Delawareans and especially the nursery and landscape industry.  By moving away from mowed lawn, we create opportunities for the nursery and landscape professionals. Anyone can ride on the back of a lawn mower, but skilled professionals will be required to plant and manage landscapes. Industry members have called for a “leveling of the playing field” for a while now when it comes to a few key invasive plants still bought and sold in the trade. Once they are illegal to sell, we will be in step with other Northeastern states who are reducing the introduction of these plants that destroy natural areas. I hope Delaware’s legislature takes the Task Force recommendations seriously and starts the implementation process to save Delaware’s remaining wildlife and all the ecosystem services it provides to us, like clean water, clean air, wildlife habitat and much-needed human engagement in the landscape.

Callery pears are one of the species that might be banned from sale in Delaware. This tree has choked our roadsides and while it has attractive white flowers, it supports no native insects and chokes out important native species like serviceberry and black gum that should be populating Delaware’s forest edges.

New Park for Newark?

I recently had a meeting with Tom Zaleski and Joe Spadafino to talk about meadow management in Newark parks.  They are doing a great job of allowing some areas to become meadows and even letting a few park areas, where appropriate, return to forest.  During the meeting, I found out about an exciting new proposed park.  The site of the Rodney dorm complex is slated to be sold to the City of Newark, if a referendum passes next April.  If you live in the City of Newark, you will have an opportunity to vote on this referendum.

The plans included tearing down the existing Rodney dormitories.  Then as early as 2019, construction will start on a new park.  The park includes a large pond designed to handle significant storm water from several Newark neighborhoods with flooding problems.  It will also have a fishing pier and observation deck.  Wetlands will be planted along pond edges and a rain garden handles water at the northeast end of the park. Several floating wetlands are included to help with water quality.  I am excited to see the floating wetlands used in a pond.  I have seen them proposed on projects, but never implemented.  When Gary Smith included small floating wetlands in a project at the New England Wildflower Center, a female duck took up residence on one island and comes back every year to raise a new brood—so fun for staff and visitors to watch!

The proposed park will include some lawn areas but it will also include woodlands and meadows.  There are plans to naturalize bulbs in the meadow and provide a walking trail through the meadow to a natural play area with seating and small pavilions.  The play area will encourage creative play.  It will not be your typical playground with swings and a sliding board.  There is even an outdoor classroom with amphitheater seating in another section of the park.

Parking areas will be available for cars and bikes and there are plenty of trails providing access throughout. This is just the type of resource Newark needs to get kids outdoors and allow everyone to interact with natural areas and planned garden spaces.

Most importantly, get out and vote next April, so you can have a say in the resources available to you in Newark.

Interpretive panels

Fishing pier