The Good,
the Bad
and the Ugly of Mulch

October and November tend to be one of our peak seasons for mulching.  Here in the east we tend to have very loose and open planting schemes with the sorts of compact and mounded plants that sell well because they look nice in containers.  As a result, most gardeners take it for granted that mulch is a basic requirement of having a nice garden. Using mulch is actually trickier than it seems and not necessarily your best option.  

The Good

At first glance, mulch does look pretty good, especially when the alternative is a lot of scraggly weeds between your plants.  It suppresses (but never prevents) weed germination and growth, holds in moisture, builds organic matter, adds nutrients and moderates soil temperature.  What’s not to like about it?

The Bad

Mulch, especially when poorly applied, can actually do more harm than good.  When applied too heavily or piled against stems and trunks it can hold too much moisture against your plants, causing trees to grow roots that girdle the base of the trunk that can eventually strangle the tree.  Heavy mulch against trunks and stems also creates a breeding ground for root rot and fungus.  Smaller herbaceous perennial plants are particularly likely to really struggle or fail under the weight and extra moisture of a thick layer of mulch.  Even large trees can be seriously damaged, stunted and eventually killed if mulch is piled against their trunks year after year.  Thick mulch also creates a great environment for slugs and voles.  Last but not least, applying mulch every year can be expensive!

The Ugly

Plants die. If not replaced, they leave gaps in your plantings that are open to more weeds popping up.  A smooth, brown mulched area without weeds doesn’t look particularly great either.  Individual plants surrounded by a sea of mulch do not look natural or invite interaction in the same way that beautiful natural areas do. If you are actively trying to move towards a more natural look, many of our desirable natives that are normally useful for filling in planting gaps can not perform their very important function of self seeding and filling in empty spots.   

A Better Way

Plants make the very best mulch!  If you make sure that you have plantings that cover every gap in your garden, you won’t need mulch at all. Plants function for the earth in  somewhat the same way that our own skin does for us.  Bare earth, even when covered with mulch, is sort of like an open cut. The weeds that pop up on bare earth (or mulched areas) are very much like our own ability to form scabs until our skin can heal and become whole again.  If you plant densely to prevent open spaces, you are preventing those open “cuts” that will be scabbed over with weeds.  If you choose native species to prevent bare spots in your plantings, it is far healthier for the local ecosystem and more beautiful to look at.  Some of the plants you choose can even be self seeders like Aquilegia canadenis, Viola sororia or Lobelia cardinalis.  If you don’t have heavy mulch down, these self seeders will quickly fill in planting gaps and hold the space for you until you replace them with something else.  Properly chosen dense plantings also support the local ecosystem, especially if the plantings are 70% or more native species.  When done well, dense plantings can create inviting natural spaces.  Cates Creek Park in Hillsborough has a beautiful example of a layered and densely planted garden where weeds have a hard time getting started and mulch is not needed.  For examples from all sorts of locally native habitats, Blomquist Garden of Native Plants at Duke Gardens or The North Carolina Botanical Garden are great places to go to learn and get inspired.  There are also excellent books on the subject of growing plantings that don’t require mulch, are beautiful and help support local pollinators and birds.  Read on for a book review of Planting in a Post Wild World.  

Unless you have a first year garden where the plants haven’t had an opportunity to fill in yet, mulch should never be the dominant visual.  If you have a first year garden, the mulch should only be laid down very thinly at one inch in depth or preferably less.  Leaves from your own yard are the very best mulch.  They are healthier for your soil and your local ecosystem.  They break down more easily than shredded hardwood mulch providing nutrients, micronutrients and organic matter quickly for your hungry plants. If you use your own leaves, they are free. If you don’t have a good supply on your own property, you can often get them from your local municipality for free as well.  Because they break down easily, they are also less likely to smother your herbaceous plants.  

So to sum it all up, mulch has its uses for plant nutrition, soil building and keeping weeds at bay, but plants do a much better job with all three, look much nicer, and support more wildlife.  For a gallery of photos showing where mulch has gone wrong and where plants act well as mulch, see the article Why Many American Gardens are Full of Mulch by Radovan Hajek on the USPerennials.com blog. 

— Mary Beth

PLANT FOCUS: The Mighty Oak
(Quercus spp.)

The mighty Oak (Quercus spp.) is well named, not just for its adult size but also because it is a ruler among keystone species, supporting more life forms than any other North American tree genus. It is a host tree to 488 species of butterflies and moths in our area, not to mention all of the other insects, birds, reptiles, amphibians and mammals it supports.  Check out these links to see some of the fun and beautiful caterpillars, moths and butterflies that rely on Oak trees; Spun glass slug, Clymene moth, Giant leopard moth, and the stunning Red spotted admiral. If you want to dive deeper, go to the oak page on the native plant finder offered by the National Wildlife Federation.   

If you have the space and are looking for some shade in your yard, consider planting a grouping of three to five very young oak saplings roughly 5-10 feet apart.  If the thought of 5 oak trees together feels like too much, you might try a mix of oak and understory trees like dogwood, redbud or persimmon. If trees are planted closely together as tiny saplings, their roots will interlace as they grow, keeping them firmly anchored in the ground and the competition between them will make a thicker tree canopy above.  They will also support more wildlife. I suggest using tiny saplings because they will be healthier, grow faster and live longer than trees that are planted when they are larger.  Planting trees is always an investment in the future and it is one that grows more quickly than you might think even if you start small.  

If you already have one or more oak trees in your yard, don’t take them for granted!  Check out this link from The California Oak Mortality Task Force about basic care.  Call an arborist who is dedicated to preserving trees like Leaf and Limb or Eno River Arboriculture if you have any questions.  They have a wealth of knowledge and can really help you understand whether or not a tree is safe.  They can also catch problems early so that you don’t have to lose a tree.  Both companies focus on tree preservation and health rather than removal. They will only recommend removal if there is a serious problem with your tree and may be able to save your trees by recommending proper care.  Once a tree starts showing signs of stress, it is often too late so having an arborist check out your trees at least once every 5 years is a good plan.  

While you are planting, you might consider planting Christmas Fern (Polysticum acrosticoides) as a living ground cover around your new tree installation or under existing trees.  Christmas fern provides winter cover and nest building materials for songbirds.  It is great for erosion control.  It is very resistant to deer, and it is evergreen.  If you decide to install these lovely ferns under larger trees, dig with care so that you don’t damage any tree roots.  Christmas fern loves partial to heavy shade.  It prefers well drained loam, sandy or even shallow rocky soil and is drought tolerant, making it an excellent choice for tough to plant shady areas in your yard.  

— MaryBeth

Book:
Planting in a Post Wild World by Thomas Rainer and Claudia West

Planting in a Post Wild World by Thomas Rainer and Claudia West is a beautiful guide to growing layered gardens that look gorgeous at all times of the year.  Rainer and West explain how to create designs and choose plants based on the existing soils, climate and topography of an area.  They go into great detail about how to decide the overarching theme of a design, how to choose and layer the plants, and how to establish a planting.  Once established, the resulting naturalistic, layered designs allow the plants themselves to be part of the design process over time as they settle in and find their space in the planting.  The established garden does not need traditional maintenance chores of weeding, pruning, watering and fertilizing on a seasonal schedule.  Rather, the garden simply needs management; filling in gaps, removing invasive species and thinning as needed to maintain the overall intention of the garden.  Management takes less time and materials than maintenance does once a planting is established and the results can be stunning.  

Not only is the book filled with detailed instructions on how and why to design for a naturalistic layered look, it is also loaded with beautiful example photos.  I highly recommend this read!  Check it out from your local library or order it through your local independent bookstore.  

— MaryBeth

November To-Do list

November is the month our planting zone (8)  has its first frost of the season! You may be able to fit in one more round of loose leaf lettuce if you practice some season extension. Keep an eye on the weather. Finish up your harvests, store your crops, and save your seeds! 

• If you haven’t already, plant garlic, shallots, walking onions, and potato onions.

• Continue the harvests of your fall crops. Some such as parsnips, peas, Brussels sprouts, and kale actually have enhanced flavor after a frost. You can also use a cold frame or put up a low tunnel to extend the season.

• Make a note of any particular productive or unsatisfactory varieties of vegetables that you planted this year. Such information can be very useful when planning next year’s garden.

• Leave seed heads on asters, sunflowers, and cosmos for birds to eat.

• Drain the hoses and empty the bird baths before a hard frost.

• Potted perennials can be buried in an empty part of the vegetable garden or surrounded with a thick layer of straw to get them through the winter.

• Collect soil samples now for testing to prepare for next year’s fertilization of the lawn, vegetable garden, shrub border, and flower beds. Submit separate samples for distinct areas used to grow different types of plants and where growing conditions are different for the same plants. A shady lawn area on a slope should be a different sample than a sunny lawn area. Our NC Agricultural Extension Agency does soil testing for free until Dec.  From Dec. 1 to March 31 there is a $4 per sample fee. 

• If you haven’t already, get your new spring-flowering bulbs planted now.

• Early in the month, keep an eye on the weather and harvest any remaining summer produce like beans, eggplants, peppers, and tomatoes before a hard frost rolls in. You can also dig up sweet potatoes at this time if you haven’t already. 

• If you plan to apply shredded hardwood mulch, wait until after the first frost and keep the depth of mulch to 2” or less.  Even better, use leaves from your own yard.

• If you haven’t already, order seed catalogs now for January planting. For variety, consider companies that specialize in open-pollinated and heirloom varieties. 

• Cover broccoli and cauliflower on frosty nights.

• Start digging up winter carrots as soon as they are big enough.

Resting Acorn

Beneath the broad old oak,
an acorn rests—
small, round, and sure of nothing
but the soil beneath it.

Above, branches whisper
in the slow language of wind,
and sunlight filters down
like a promise kept.

In time, the acorn listens—
and roots begin to dream.

— Shannon

Happy Gardening!