Download Sat-B7 Creating Meadows and Grass Ecologies Cool

Sat-B7 Creating Meadows and Grass Ecologies
The response to last years Meadows by Design lecture was overwhelmingly positive, and many
people wrote asking for more information on the nuts and bolts of planting and maintaining
meadows and grass ecologies. This session will provide just that, presenting case studies of
projects large and small and showing a variety of grass gardens from start to finish, including site
preparation, plant selection, installation, and maintenance.
LEARNING OBJECTIVES
• Learn step by step how to design and create meadows and grass ecologies
• Review how climate, soil, and site considerations impact design
• Learn recommended practices and understand special problems and unique situations
Cool-Season Grasses
•
Cool-season grasses grow when temperatures are cool. They generally
look their best in fall, winter, and spring in temperate areas. Many do not
grow in hot summer, and can look raggedy in the dog days of summer.
Many cool season grasses are summer dormant.
•
Examples: Koeleria, some fescues.
Warm-Season Grasses
•
Warm-season grasses grow when temperatures are warm. They’re
typically dormant in cool weather. Many warm-season grasses have
beautiful fall and winter color.
•
Examples: Panicum, Bouteloua, Andropogon
Tropical Grasslands
•
Tropical grasslands have wet & dry seasons. Winter is the dry season in
Florida.
•
Examples: Hawaii, southern Florida
Monsoonal Climates
•
Monsoonal climates are often characterized by cold dry winters and hot
dry summers that are interrupted by infrequent but often severe
thunderstorms.
•
Examples: Tucson, Albuquerque, and parts of West Texas
Mediterranean Grasslands
•
Mediterranean grasslands are a twist on the traditional warm-season/coolseason paradigm. These climates are more “wet-season/dry-season”.
Mediterranean grass ecologies are adapted to rainy cool winters and hot
dry summers. Many true Mediterranean grass ecologies can be a
summer fire hazard.
Two Often Overlooked Aspects of Designing with Grasses
•
Not all grasses are long-lived. Large-scale plantings should be long-lived!
Some grasses may be long-lived in one setting but not another
•
Many grasses require a period of cold dormancy in order to thrive—this is
known as vernalization. Failure to provide usually results in poor
performance.
Choosing the Right Plants is Critical
•
Know the plants, or find somebody who does
•
“Plant-driven design” means having plants solve your problems and
design challenges
•
The right plant in the right place
•
Bad horticulture makes for shitty art
Selecting Grasses: Questions to Ask
•
Is it short- or long-lived?
•
Is it cool-season or warm-season? (When does it actively grow?)
•
Does it run or does it clump?
•
Does it have showy flowers?
•
Does it spread readily from seed (naturalize)?
•
Is it native or well adapted to your region?
•
All Grasses Flower
•
Grass flowers come in many shapes, from slender spikes to fluffy cloudlike blooms
•
Different grasses bloom at different times
•
Cool-season grasses usually bloom in winter and spring
•
Warm-season grasses usually bloom in summer and fall
•
Not all grasses have showy flowers – many grasses have insignificant
flowers and maintain a neater appearance year-round. These make good
groundcover grasses.
•
Many showy-flowering grasses have seed heads that deteriorate and look
messy at some point in the season
Considering Grass Flowers
•
Most grass flowers provide two color effects
•
The first is the color of the inflorescence on emergence. Emergent colors
are often silver, white, green, and pink
•
The second is the color as the seedheads mature
•
Some grasses have long-lasting flowers. With others the flowering effects
are fleeting
•
Some flowering grasses shatter and clean themselves. Others need to be
cut back when they become unsightly
Get to Know Your Site
•
What type of soil?
•
What’s growing there now?
•
What used to be there?
•
What’s nearby?
•
How is the site affected by wind & weather?
•
What time of year is it?
Site Preparation
•
After plant selection, starting with a clean slate is often the most important
part of site preparation
•
The key to successful grass planting is to be as weed-free as possible
•
Many grasses will thrive without extensive soil preparation
•
Choosing grass varieties adapted to your site is always a better strategy
than trying to change your site
•
Weed Control
•
Many methods are available:
•
Herbicide
•
Mowing
•
Burning
•
Discing & plowing
•
Soil removal
•
Solarization
•
Animals
Dealing With Weeds
•
Weed competition is the primary cause of failure in the first growing
season
•
A typical weedy site can have up to 10,000 weed seeds per square meter
•
Annual grass weeds are important to control prior to seeding because of
the lack of selective herbicides
•
Broadleaf weeds are equally problematic, but can be controlled with
selective broadleaf herbicides
•
Successful Grow-Kill Cycles
•
Grow-kill cycles eliminate weeds and weed inoculum from the soil
•
Spray herbicides when weeds are actively growing, between irrigating
•
Water and fertilize to stimulate weeds to their optimum stage in order to be
killed. Older or established weed plantings may need to be cut back to
stimulate new growth and better absorb herbicide application
•
Wait to see what has been killed. Many herbicides require 7-10 days to
work
•
Repeat cycle as needed
•
Hard to kill noxious perennial weeds may need 3-4 grow-kill cycles to be
eliminated
•
Time of year affects growth cycle of weeds. Schedule grow-kill cycle to
coincide with active growth of your target weeds
Methods of Planting
•
Rooted pots or plugs
•
Divisions (bare root shoots, rhizomes, or stolons)
•
Seed
•
The time of year and weather will determine the success or failure of any
given method
•
Spacing
•
Spacing grasses is both art and science
•
Creeping grasses will fill in eventually – spacing is often determined by
budget (plants closer on center will fill in faster)
•
Clumping grasses can be spaced further apart if bulbs, perennials, and
annuals are being planted in between
•
Clumping grasses may be spaced closer on center at the top of a slope
where water drains away, and further apart at the bottom
•
Clumping grasses placed too close together can look crowded and result
in poor growth
•
Spacing can be affected by irrigation, as plants may be smaller on a dry
site
Tips for Successful Seeding
•
Start with clean fresh seed that is as weed-free as possible
•
Know your seed source
•
Do a germ test if possible
•
Work with a reputable seed producer
•
Plant at the right time of year for your crop
•
Try to save a small portion of the seed for reference
Planting Grasses from Seed
•
Hand broadcasting
•
Hydroseeding
•
Drilling
•
Impregnated mats
•
Native hay
•
Growing Grass from Seed: Things to Consider
•
Not all grasses or grass varieties can be grown from seed
•
Many seed mixes require specific windows of time to be successful
•
Not all components in a seed mix germinate at the same time or at the
same percentage,
•
Weather makes a difference
•
Because there are so many variables, it’s often best to work with
experienced consultants
Mulch Matters
•
Types of mulch:
•
Native hay
•
Paper fiber
•
Wood chips
•
Gravel
•
Agricultural byproducts (cocoa shells, grapeseed, etc)
It’s All About Establishment
•
The most important aspect of establishment is water management. Newly
planted grasses should not be allowed to dry out
•
New grass plantings can be overwatered, underwatered, or the seed can
blow away or be eaten. There are lots of ways to go wrong.
•
Deliver the Water Any Way You Want
•
Grasses can be irrigated by overhead or drip systems. There are pros and
cons to each style.
•
It can be problematic to deliver water up and over tall grasses, but drip
systems can be difficult to maintain
•
All irrigation systems can be damaged when grasses are cut back
Getting Grass to Grow
If you want grass to grow, give it water and fertilizer. Grasses love nitrogen!
•
Types of fertilizers:
•
Organic – these are usually low in nitrogen
•
Inorganic
•
Pellatized/Granular
•
Liquid
•
“Natural” nitrofiers – clovers & nitrogen fixers
•
Mycorrhizal associates
•
A good all-around formula for making grass grow is 16-6-8
Some Tips on Fertilization
•
Always water well after fertilizer applications
•
Fertilize till you see results—if grass doesn’t noticeably grow after
fertilization, increase frequency or up the percentage of nitrogen
•
Maintaining Grasses
•
In nature, grasses are burned, grazed, or both
•
In gardens, grasses must be cut back or burned in order to thrive
•
In many parts of the country, grass ecologies want to become forest.
Without intervention, they become dominated by “weedy woodies” and are
prone to failure.
•
Cutting Grasses Back
•
Methods:
•
Hand shears
•
Hedge pruners
•
Weed-eaters
•
Weed eaters with blades
•
Mowers
How to Cut Grasses Back
•
Always use sharp tools
•
Most grasses want to be cut back as close to the crown as is possible
•
However, some grasses resent being cut back too hard – it’s important to
know when this is the case
•
When to Cut Grasses Back
•
Fall, winter, and early spring are the best times for cutting back grasses—
it depends on the variety of grass
•
Many cool-season grasses are best cut back after flowering in late spring
or early summer
•
Many warm-season grasses can be cut back in early summer or late
summer and will grow back and sometimes even flower and look better
longer into the winter months
•
Warm-season grasses can be cut back after fall color, but you will
sacrifice winter interest
•
In mild climates, warm season grasses may start growing in late winter, so
cut back when new shoots emerge. This may be as early as late January
or early February in warmer climates
Burning as a Maintenance Tool
•
Always check local regulations
•
Architects should design with burning in mind
•
Many grass ecologies require burning to be truly successful
•
Burning at different times will manage different weed problems
Pests, Diseases, and Problems
•
Most grasses are relatively pest- and disease-free
•
The biggest problems are rabbits, gophers, ground squirrels, moles, and
voles
•
The most destructive diseases are root diseases caused by overwatering
•
Most foliar diseases (i.e., rust and powdery mildew) are usually seasonal
and cosmetic and will disappear with changing weather conditions
•
Poor growth is often the result of too much or too little water
FEATURED SPEAKER
John Greenlee
Known as the Grassman in horticultural circles, John Greenlee is an internationally known
horticulturist, landscape designer, and an advocate for sustainable lawns and meadows. He
specializes in the cultivation and study of grasses and grasslike plants. John Greenlee founded
Greenlee Nursery of California in 1985. The nursery is the oldest and largest specialty
ornamental grass nursery on the West Coast. His bestselling book, The Encyclopedia of
Ornamental Grasses (Rodale, 1992), is considered by many to be an indispensable reference. As
an expert in grass ecology and champion of sustainable design, Greenlee has made meadows
throughout the United States and all around the world, including the Getty Museum and the
Norton Smith Museum in Los Angeles, the San Diego Zoo, the savannas at Walt Disneys Animal
Kingdom in Florida, to private residencies in Morocco and Saudi Arabia. In October 2009 he
published his second book, The American Meadow Garden (Timber Press, 2009).